NCBI Conserved Domain Search

Third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule 1 (NCAM-1); member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions) through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain.

Pssm-ID: 143207 [Multi-domain] Cd Length: 95 Bit Score: 173.19 E-value: 1.16e-50

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  208 LPTIRIRQAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESG-NKYSFNEDGSEMTVLDVTKLDEGDYTCIAKNK 286
Cdd:cd05730     1 PPTIRARQSEVNATANLGQSVTLACDADGFPEPTMTWTKDGEPIESGeEKYSFNEDGSEMTILDVDKLDEAEYTCIAENK 80

                          90
                  ....*....|....*
gi 528501372  287 AGESEQELSLKVFVQ 301
Cdd:cd05730    81 AGEQEAEIHLKVFAK 95

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1); The members here are composed of the fourth Ig domain of Neural Cell Adhesion Molecule 1(NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM) and heterophilic (NCAM-non-NCAM) interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 143277 [Multi-domain] Cd Length: 97 Bit Score: 143.58 E-value: 2.59e-40

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  300 VQPKITYLESQTTTEMDEQVTLTCEATGDPTPTITWSFGTRVFTEGEQEQqkriyqaswtrpeqhkgpDGEVLVRSDARV 379
Cdd:cd05869     1 AKPKITYVENQTAMELEEQITLTCEASGDPIPSITWRTSTRNISSEEKTL------------------DGHIVVRSHARV 62

                          90       100       110
                  ....*....|....*....|....*....|....*
gi 528501372  380 SSLTLKYPQYTDAGQYLCTARNAIGETVQPVSLEV 414
Cdd:cd05869    63 SSLTLKYIQYTDAGEYLCTASNTIGQDSQSMYLEV 97

First immunoglobulin (Ig)-like domain of neural cell adhesion molecule (NCAM-1); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of neural cell adhesion molecule (NCAM-1). NCAM-1 plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-nonNCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves the Ig1, Ig2, and Ig3 domains. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409451 Cd Length: 97 Bit Score: 138.25 E-value: 2.12e-38

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   20 LQVDITPAHGEISVGESRFFLCEVIGGAK--EIDWFAPAGEKIEPGRPDISVIRNDETSSTLTIYNAKVDNAGTYRCVAS 97
Cdd:cd05865     1 LQVDIVPSQGEISVGESKFFLCQVAGEAKdkDISWFSPNGEKLTPNQQRISVVRNDDYSSTLTIYNANIDDAGIYKCVVS 80

                          90
                  ....*....|....*..
gi 528501372   98 SGDQ-DAEATVNLKIYQ 113
Cdd:cd05865    81 NEDEgESEATVNVKIFQ 97

First immunoglobulin (Ig)-like domain of neural cell adhesion molecule NCAM-1, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of neural cell adhesion molecule NCAM-1. NCAM-1 plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM) and heterophilic (NCAM-nonNCAM) interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves the Ig1, Ig2, and Ig3 domains. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. Also included in this group is NCAM-2 (also known as OCAM/mamFas II and RNCAM). NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409366 Cd Length: 95 Bit Score: 130.45 E-value: 1.18e-35

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   20 LQVDITPAHGEISVGESRFFLCEVIGGAKEIDWFAPAGEKIEPGRPDISVIRNDETSSTLTIYNAKVDNAGTYRCVASSG 99
Cdd:cd04977     1 LQVKIIPSYAEISVGESKFFLCKVSGDAKNINWVSPNGEKVLTKHGNLKVVNHGSVLSSLTIYNANINDAGIYKCVATNG 80

                          90
                  ....*....|....*
gi 528501372  100 -DQDAEATVNLKIYQ 113
Cdd:cd04977    81 kGTESEATVKLDIIQ 95

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1) and similar proteins; The members here are composed of the fourth immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. Also included in this group is NCAM-2 (also known as OCAM/mamFas II and RNCAM) NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE). One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 409395 [Multi-domain] Cd Length: 96 Bit Score: 130.34 E-value: 1.32e-35

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  300 VQPKITYLESQTTTEMDeQVTLTCEATGDPTPTITWSFGTRVFTEGEQEqqkriyqaswtrpeqhkgPDGEVLVRSDARV 379
Cdd:cd05732     1 VQPKITYLENQTAVELE-QITLTCEAEGDPIPEITWRRATRGISFEEGD------------------LDGRIVVRGHARV 61

                          90       100       110
                  ....*....|....*....|....*....|....*
gi 528501372  380 SSLTLKYPQYTDAGQYLCTARNAIGETVQPVSLEV 414
Cdd:cd05732    62 SSLTLKDVQLTDAGRYDCEASNRIGGDQQSMYLEV 96

First immunoglobulin (Ig)-like domain of neural cell adhesion molecule NCAM-2; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of neural cell adhesion molecule NCAM-2 (OCAM/mamFas II, RNCAM). NCAM-2 is organized similarly to NCAM-1, including five N-terminal Ig-like domains and two fibronectin type III domains. NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE), and may function like NCAM, as an adhesion molecule. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409452 Cd Length: 93 Bit Score: 95.89 E-value: 1.41e-23

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   20 LQVDITPAHGEISVGESRFFLCEVIGGAKEIDWFAPAGEKIePGRPDIsVIRNDETSSTLTIYNAKVDNAGTYRCVASSG 99
Cdd:cd05866     1 LQVSISLSKVELSVGESKFFTCTAIGEPESIDWYNPQGEKI-VSSQRV-VVQKEGVRSRLTIYNANIEDAGIYRCQATDA 78

                          90
                  ....*....|....*
gi 528501372  100 D-QDAEATVNLKIYQ 113
Cdd:cd05866    79 KgQTQEATVVLEIYQ 93

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 80.63 E-value: 3.23e-18

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  209 PTIRIRQAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNK-YSFNEDGSEMTVLDVTKLDEGDYTCIAKNKA 287
Cdd:cd20970     1 PVISTPQPSFTVTAREGENATFMCRAEGSPEPEISWTRNGNLIIEFNTrYIVRENGTTLTIRNIRRSDMGIYLCIASNGV 80

                          90
                  ....*....|..
gi 528501372  288 -GESEQELSLKV 298
Cdd:cd20970    81 pGSVEKRITLQV 92

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 76.53 E-value: 7.22e-17

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   212 RIRQAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSF--NEDGSEMTVLDVTKLDEGDYTCIAKNKAGE 289
Cdd:pfam07679    2 KFTQKPKDVEVQEGESARFTCTVTGTPDPEVSWFKDGQPLRSSDRFKVtyEGGTYTLTISNVQPDDSGKYTCVATNSAGE 81


                   ....*....
gi 528501372   290 SEQELSLKV 298
Cdd:pfam07679   82 AEASAELTV 90

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 2 (NCAM-2); The members here are composed of the fourth Ig domain of Neural Cell Adhesion Molecule NCAM-2 (also known as OCAM/mamFas II and RNCAM). NCAM-2 is organized similarly to NCAM, including five N-terminal Ig-like domains and two fibronectin type III domains. NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE), and may function like NCAM, as an adhesion molecule. One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 143278 [Multi-domain] Cd Length: 98 Bit Score: 65.38 E-value: 8.83e-13

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  300 VQPKITYLESQTTTEmDEQVTLTCEATGDPTPTITWSFGTR--VFTEGEqeqqkriyqaswtrpeqhKGPDGEVLVRSDA 377
Cdd:cd05870     1 VQPHIIQLKNETTVE-NGAATLSCKAEGEPIPEITWKRASDghTFSEGD------------------KSPDGRIEVKGQH 61

                          90       100
                  ....*....|....*....|....*..
gi 528501372  378 RVSSLTLKYPQYTDAGQYLCTARNAIG 404
Cdd:cd05870    62 GESSLHIKDVKLSDSGRYDCEAASRIG 88

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 64.97 E-value: 9.71e-13

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372    21 QVDITPAHGEISVGESRFFLCEVIG-GAKEIDWFAPaGEKIEPGrpDISVIRNDETSSTLTIYNAKVDNAGTYRCVASSG 99
Cdd:pfam07679    2 KFTQKPKDVEVQEGESARFTCTVTGtPDPEVSWFKD-GQPLRSS--DRFKVTYEGGTYTLTISNVQPDDSGKYTCVATNS 78

                           90
                   ....*....|..
gi 528501372   100 DQDAEATVNLKI 111
Cdd:pfam07679   79 AGEAEASAELTV 90

Fibronectin type 3 domain; One of three types of internal repeats found in the plasma protein fibronectin. Its tenth fibronectin type III repeat contains an RGD cell recognition sequence in a flexible loop between 2 strands. Approximately 2% of all animal proteins contain the FN3 repeat; including extracellular and intracellular proteins, membrane spanning cytokine receptors, growth hormone receptors, tyrosine phosphatase receptors, and adhesion molecules. FN3-like domains are also found in bacterial glycosyl hydrolases.

Pssm-ID: 238020 [Multi-domain] Cd Length: 93 Bit Score: 62.13 E-value: 1.07e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  513 PSAPSIGEVQPYSST-AQVLFEEPESTGGvPVLKYRAEWRAVGRGKWvQRVYEVKDGLSSVTVTGLKPETDYEVKMSAIN 591
Cdd:cd00063     1 PSPPTNLRVTDVTSTsVTLSWTPPEDDGG-PITGYVVEYREKGSGDW-KEVEVTPGSETSYTLTGLKPGTEYEFRVRAVN 78

                          90
                  ....*....|....*
gi 528501372  592 GKGEGDSSPSMVFKT 606
Cdd:cd00063    79 GGGESPPSESVTVTT 93

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 61.32 E-value: 1.42e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  209 PTIRIRQAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGSeMTVLDVTKLDEGDYTCIAKNKAG 288
Cdd:cd04969     1 PDFELNPVKKKILAAKGGDVIIECKPKASPKPTISWSKGTELLTNSSRICILPDGS-LKIKNVTKSDEGKYTCFAVNFFG 79

                          90
                  ....*....|
gi 528501372  289 ESEQELSLKV 298
Cdd:cd04969    80 KANSTGSLSV 89

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 61.36 E-value: 1.67e-11

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 528501372  225 GFSTLLACDPDGFPEPIVTWRRNNAPL--ESGNKYSFNEDGS-EMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd05744    15 GRLCRFDCKVSGLPTPDLFWQLNGKPVrpDSAHKMLVRENGRhSLIIEPVTKRDAGIYTCIARNRAGENSFNAELVV 91

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 59.50 E-value: 4.69e-11

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   302 PKITYLESQTTTEMDEQVTLTCEATGDPTPTITWSFGTRVFTEGEQEQQkriyqaswtrpeqhkgpdgevlvRSDARVSS 381
Cdd:pfam13927    2 PVITVSPSSVTVREGETVTLTCEATGSPPPTITWYKNGEPISSGSTRSR-----------------------SLSGSNST 58

                           90       100
                   ....*....|....*....|
gi 528501372   382 LTLKYPQYTDAGQYLCTARN 401
Cdd:pfam13927   59 LTISNVTRSDAGTYTCVASN 78

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 59.27 E-value: 5.38e-11

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 528501372  230 LACDPDGFPEPIVTWRRNNAPLESGNKYS--FNEDGSEMTVLDVTKLDEGDYTCIAKNKAGESEQ 292
Cdd:cd00096     3 LTCSASGNPPPTITWYKNGKPLPPSSRDSrrSELGNGTLTISNVTLEDSGTYTCVASNSAGGSAS 67

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 59.58 E-value: 6.06e-11

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 528501372   117 FTNVPSPQEFTEGDNAIIVCDVISSPPPTVLWKYKGAKIQFDKDVRFKTLSNNH-LQIRGIRKTDEGVYTC 186
Cdd:pfam07679    3 FTQKPKDVEVQEGESARFTCTVTGTPDPEVSWFKDGQPLRSSDRFKVTYEGGTYtLTISNVQPDDSGKYTC 73

Fibronectin type III domain;

Pssm-ID: 394996 [Multi-domain] Cd Length: 85 Bit Score: 58.58 E-value: 1.46e-10

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 528501372   626 NSLKVKWIKQDDGGSPITHYLVRYKAREDSEWKPEIRLPSGSEYVMLIGLDWDTEYDVFVVAENQQGKSKP 696
Cdd:pfam00041   14 TSLTVSWTPPPDGNGPITGYEVEYRPKNSGEPWNEITVPGTTTSVTLTGLKPGTEYEVRVQAVNGGGEGPP 84

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 58.29 E-value: 1.82e-10

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372    121 PSPQEFTEGDNAIIVCDVISSPPPTVLWKYKGAKIQFDKDvRFKTLSNN---HLQIRGIRKTDEGVYTCEgrIKARGEVD 197
Cdd:smart00410    1 PPSVTVKEGESVTLSCEASGSPPPEVTWYKQGGKLLAESG-RFSVSRSGstsTLTISNVTPEDSGTYTCA--ATNSSGSA 77


                    ....*...
gi 528501372    198 FRSIKVVV 205
Cdd:smart00410   78 SSGTTLTV 85

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 58.18 E-value: 1.93e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  214 RQAETNATADMGFSTLLACDPD-GFPEPIVTWRRNNAPLESGNKYSFNEDGSEMTVLDVTKLDEGDYTCIAKNKAGESEQ 292
Cdd:cd05724     1 RVEPSDTQVAVGEMAVLECSPPrGHPEPTVSWRKDGQPLNLDNERVRIVDDGNLLIAEARKSDEGTYKCVATNMVGERES 80


                  .
gi 528501372  293 E 293
Cdd:cd05724    81 R 81

Fibronectin type 3 domain; One of three types of internal repeats found in the plasma protein fibronectin. Its tenth fibronectin type III repeat contains an RGD cell recognition sequence in a flexible loop between 2 strands. Approximately 2% of all animal proteins contain the FN3 repeat; including extracellular and intracellular proteins, membrane spanning cytokine receptors, growth hormone receptors, tyrosine phosphatase receptors, and adhesion molecules. FN3-like domains are also found in bacterial glycosyl hydrolases.

Pssm-ID: 238020 [Multi-domain] Cd Length: 93 Bit Score: 58.28 E-value: 1.96e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  612 PSPPI-LEGTLQPKgNSLKVKWIKQDDGGSPITHYLVRYKAREDSEWKPEIRLPSGSEYVMLIGLDWDTEYDVFVVAENQ 690
Cdd:cd00063     1 PSPPTnLRVTDVTS-TSVTLSWTPPEDDGGPITGYVVEYREKGSGDWKEVEVTPGSETSYTLTGLKPGTEYEFRVRAVNG 79

                          90
                  ....*....|....
gi 528501372  691 QGKSKPGT-LTFRT 703
Cdd:cd00063    80 GGESPPSEsVTVTT 93

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 57.96 E-value: 2.17e-10

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 528501372   116 TFTNVPSPQEFTEGDNAIIVCDVISSPPPTVLWKYKGAKIQFDKDVRFKTLSNN-HLQIRGIRKTDEGVYTCE 187
Cdd:pfam13927    3 VITVSPSSVTVREGETVTLTCEATGSPPPTITWYKNGEPISSGSTRSRSLSGSNsTLTISNVTRSDAGTYTCV 75

Fibronectin type III domain;

Pssm-ID: 394996 [Multi-domain] Cd Length: 85 Bit Score: 57.81 E-value: 2.26e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   511 DVPSAPSIGEVQPYSstAQVLFEEPESTGGvPVLKYRAEWRAVGRGKWVQRvYEVKDGLSSVTVTGLKPETDYEVKMSAI 590
Cdd:pfam00041    1 SAPSNLTVTDVTSTS--LTVSWTPPPDGNG-PITGYEVEYRPKNSGEPWNE-ITVPGTTTSVTLTGLKPGTEYEVRVQAV 76


                   ....*....
gi 528501372   591 NGKGEGDSS 599
Cdd:pfam00041   77 NGGGEGPPS 85

First immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409387 Cd Length: 97 Bit Score: 57.87 E-value: 3.02e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  117 FTNVPSPQEFTEGDNAIIVCDVISSPPPTVLWKYKGAKIQFDKDVRFKTLSNNHLQIRGI-----RKTDEGVYTCEGRIK 191
Cdd:cd05722     4 FLSEPSDIVAMRGGPVVLNCSAESDPPPKIEWKKDGVLLNLVSDERRQQLPNGSLLITSVvhskhNKPDEGFYQCVAQNE 83

                          90
                  ....*....|....
gi 528501372  192 ARGEVDFRSIKVVV 205
Cdd:cd05722    84 SLGSIVSRTARVTV 97

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 57.13 E-value: 4.64e-10

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372    317 EQVTLTCEATGDPTPTITWSFGtrvftegeqeqqkriyqaswtrPEQHKGPDGEVLVRSDARVSSLTLKYPQYTDAGQYL 396
Cdd:smart00410   10 ESVTLSCEASGSPPPEVTWYKQ----------------------GGKLLAESGRFSVSRSGSTSTLTISNVTPEDSGTYT 67

                            90
                    ....*....|....*...
gi 528501372    397 CTARNAIGETVQPVSLEV 414
Cdd:smart00410   68 CAATNSSGSASSGTTLTV 85

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM and human neurofascin.

Pssm-ID: 409394 [Multi-domain] Cd Length: 83 Bit Score: 56.65 E-value: 5.54e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  217 ETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGnKYSFNEDGSEMTVLDVTKLDEGDYTCIAKNKAGESEQELSL 296
Cdd:cd05731     2 ESSTMVLRGGVLLLECIAEGLPTPDIRWIKLGGELPKG-RTKFENFNKTLKIENVSEADSGEYQCTASNTMGSARHTISV 80


                  ..
gi 528501372  297 KV 298
Cdd:cd05731    81 TV 82

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 56.42 E-value: 6.95e-10

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 528501372   209 PTIRIRQaeTNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGN--KYSFNEDGSEMTVLDVTKLDEGDYTCIAKN 285
Cdd:pfam13927    2 PVITVSP--SSVTVREGETVTLTCEATGSPPPTITWYKNGEPISSGStrSRSLSGSNSTLTISNVTRSDAGTYTCVASN 78

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 55.97 E-value: 1.11e-09

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 528501372  122 SPQEFT--EGDNAIIVCDVISSPPPTVLWkYKGAKIQFDKDVRFKTLSNNHLQIRGIRKTDEGVYTC 186
Cdd:cd20952     5 GPQNQTvaVGGTVVLNCQATGEPVPTISW-LKDGVPLLGKDERITTLENGSLQIKGAEKSDTGEYTC 70

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 55.59 E-value: 1.36e-09

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372     26 PAHGEISVGESRFFLCEVIGGAK-EIDWFAPAGEKIEPGrPDISVIRNDeTSSTLTIYNAKVDNAGTYRCVASSGDQDAE 104
Cdd:smart00410    1 PPSVTVKEGESVTLSCEASGSPPpEVTWYKQGGKLLAES-GRFSVSRSG-STSTLTISNVTPEDSGTYTCAATNSSGSAS 78


                    ....*..
gi 528501372    105 ATVNLKI 111
Cdd:smart00410   79 SGTTLTV 85

Fifth immunoglobulin (Ig) domain of contactin-1; The members here are composed of the fifth immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409438 Cd Length: 89 Bit Score: 55.78 E-value: 1.71e-09

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  209 PTIRIRQAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGSeMTVLDVTKLDEGDYTCIAKNKAG 288
Cdd:cd05852     1 PTFEFNPMKKKILAAKGGRVIIECKPKAAPKPKFSWSKGTELLVNNSRISIWDDGS-LEILNITKLDEGSYTCFAENNRG 79

                          90
                  ....*....|
gi 528501372  289 ESEQELSLKV 298
Cdd:cd05852    80 KANSTGVLSV 89

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 54.64 E-value: 2.23e-09

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 528501372  132 AIIVCDVISSPPPTVLWKYKGAKIQFDKDVRFKTLSNN-HLQIRGIRKTDEGVYTCEGRIKARGEV 196
Cdd:cd00096     1 VTLTCSASGNPPPTITWYKNGKPLPPSSRDSRRSELGNgTLTISNVTLEDSGTYTCVASNSAGGSA 66

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 55.09 E-value: 2.38e-09

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 528501372  121 PSPQEFTEGDNAIIVCDVISSPPPTVLWKYKGAKIqfdKDVRFKTLSNNHLQIRGIRKTDEGVYTCE-----GRIKARG 194
Cdd:cd05725     4 PQNQVVLVDDSAEFQCEVGGDPVPTVRWRKEDGEL---PKGRYEILDDHSLKIRKVTAGDMGSYTCVaenmvGKIEASA 79

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 54.82 E-value: 2.71e-09

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372    426 VYTWEGNPANISCEVLAHPSdVSITWLRDGFQLPnANTSNIKIHNTPSASYLEVNPESQSDFGNYNCTTSNEIGTESREF 505
Cdd:smart00410    4 VTVKEGESVTLSCEASGSPP-PEVTWYKQGGKLL-AESGRFSVSRSGSTSTLTISNVTPEDSGTYTCAATNSSGSASSGT 81

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 54.43 E-value: 3.82e-09

                            10        20        30        40        50        60        70
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372    232 CDPDGFPEPIVTWRRNNA-PLESGNKYSFNEDG--SEMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:smart00410   16 CEASGSPPPEVTWYKQGGkLLAESGRFSVSRSGstSTLTISNVTPEDSGTYTCAATNSSGSASSGTTLTV 85

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 53.87 E-value: 3.86e-09

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  319 VTLTCEATGDPTPTITWsfgtrvftegeqeqqkriyqaswTRPEQHKGPDGEVLVRSDARVSSLTLKYPQYTDAGQYLCT 398
Cdd:cd00096     1 VTLTCSASGNPPPTITW-----------------------YKNGKPLPPSSRDSRRSELGNGTLTISNVTLEDSGTYTCV 57

                          90
                  ....*....|
gi 528501372  399 ARNAIGETVQ 408
Cdd:cd00096    58 ASNSAGGSAS 67

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 53.65 E-value: 8.18e-09

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  117 FTNVPSPQEFTEGDNAIIVCDVISSPPPTVLWKYKGAKIQFD-KDVRFKTLSNNH-LQIRGIRKTDEGVYTCEGRIKArG 194
Cdd:cd05744     3 FLQAPGDLEVQEGRLCRFDCKVSGLPTPDLFWQLNGKPVRPDsAHKMLVRENGRHsLIIEPVTKRDAGIYTCIARNRA-G 81


                  ....
gi 528501372  195 EVDF 198
Cdd:cd05744    82 ENSF 85

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 53.42 E-value: 8.86e-09

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   298 VFVQPkityLESQTTTEmDEQVTLTCEATGDPTPTItwsfgtrvftegeqeqqkriyqaSWTRPEQHKGPDGEVLVRSDA 377
Cdd:pfam07679    2 KFTQK----PKDVEVQE-GESARFTCTVTGTPDPEV-----------------------SWFKDGQPLRSSDRFKVTYEG 53

                           90       100       110
                   ....*....|....*....|....*....|....*..
gi 528501372   378 RVSSLTLKYPQYTDAGQYLCTARNAIGETVQPVSLEV 414
Cdd:pfam07679   54 GTYTLTISNVQPDDSGKYTCVATNSAGEAEASAELTV 90

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains, five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409460 [Multi-domain] Cd Length: 83 Bit Score: 52.61 E-value: 1.49e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  216 AETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLeSGNKYSFNEDGSEMTVLDVTKLDEGDYTCIAKNKAGESEQELS 295
Cdd:cd05876     1 SSSSLVALRGQSLVLECIAEGLPTPTVKWLRPSGPL-PPDRVKYQNHNKTLQLLNVGESDDGEYVCLAENSLGSARHAYY 79


                  ...
gi 528501372  296 LKV 298
Cdd:cd05876    80 VTV 82

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 52.51 E-value: 1.93e-08

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 528501372  128 EGDNAIIVCDVISSPPPTVLWKYKGAKIQ-FDKDVRFKTlSNNHLQIRGIRKTDEGVYTCEGRIKARGEVDFRsIKVVV 205
Cdd:cd20970    16 EGENATFMCRAEGSPEPEISWTRNGNLIIeFNTRYIVRE-NGTTLTIRNIRRSDMGIYLCIASNGVPGSVEKR-ITLQV 92

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 51.62 E-value: 4.39e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  213 IRQAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGSeMTVLDVTKLDEGDYTCIAKNKAGESEQ 292
Cdd:cd20978     4 IQKPEKNVVVKGGQDVTLPCQVTGVPQPKITWLHNGKPLQGPMERATVEDGT-LTIINVQPEDTGYYGCVATNEIGDIYT 82


                  ....*.
gi 528501372  293 ELSLKV 298
Cdd:cd20978    83 ETLLHV 88

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 51.24 E-value: 5.78e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  304 ITYLESQTTTEMDEQVTLTCEATGDPTPTITWSFGTRVFTEgeqeqqkriyqaswtRPEQHKGPDGevlvrsdarvsSLT 383
Cdd:cd20978     4 IQKPEKNVVVKGGQDVTLPCQVTGVPQPKITWLHNGKPLQG---------------PMERATVEDG-----------TLT 57

                          90       100       110
                  ....*....|....*....|....*....|.
gi 528501372  384 LKYPQYTDAGQYLCTARNAIGETVQPVSLEV 414
Cdd:cd20978    58 IINVQPEDTGYYGCVATNEIGDIYTETLLHV 88

Second immunoglobulin (Ig)-like domain of a Follistatin-related protein 5, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in human Follistatin-related protein 5 (FSTL5) and a follistatin-like molecule encoded by the CNS-related Mahya gene. Mahya genes have been retained in certain Bilaterian branches during evolution. They are conserved in Hymenoptera and Deuterostomes, but are absent from other metazoan species such as fruit fly and nematode. Mahya proteins are secretory, with a follistatin-like domain (Kazal-type serine/threonine protease inhibitor domain and EF-hand calcium-binding domain), two Ig-like domains, and a novel C-terminal domain. Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Follistatin is a secreted, multidomain protein that binds activins with high affinity and antagonizes their signaling.

Pssm-ID: 409399 [Multi-domain] Cd Length: 93 Bit Score: 51.49 E-value: 5.90e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  209 PTIRIrQAETNATaDMGFSTLLACDPDGFPEPIVTWRRNNAPL--ESGNKYSFNEDGSEMTVLDVTKLDEGDYTCIAKNK 286
Cdd:cd05736     1 PVIRV-YPEFQAK-EPGVEASLRCHAEGIPLPRVQWLKNGMDInpKLSKQLTLIANGSELHISNVRYEDTGAYTCIAKNE 78

                          90
                  ....*....|....*
gi 528501372  287 AGESEQELSLkvFVQ 301
Cdd:cd05736    79 GGVDEDISSL--FVE 91

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 50.85 E-value: 8.33e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  307 LESQTTTEMDEQVTLTCEATGDPTPTITWSFgtrvftegeqeqqKRIYQASWTRPEQHKG-PDGEVLVRsdarvssltlk 385
Cdd:cd20969     8 KAQQVFVDEGHTVQFVCRADGDPPPAILWLS-------------PRKHLVSAKSNGRLTVfPDGTLEVR----------- 63

                          90       100
                  ....*....|....*....|....*....
gi 528501372  386 YPQYTDAGQYLCTARNAIGETVQPVSLEV 414
Cdd:cd20969    64 YAQVQDNGTYLCIAANAGGNDSMPAHLHV 92

immunoglobulin-like domain of telokin and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig) domain in telokin, the C-terminal domain of myosin light chain kinase which is identical to telokin, and similar proteins. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the telokin Ig domain lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409565 [Multi-domain] Cd Length: 88 Bit Score: 50.65 E-value: 1.03e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  214 RQAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGS---EMTVLDVTKLDEGDYTCIAKNKAGES 290
Cdd:cd20973     1 IQTLRDKEVVEGSAARFDCKVEGYPDPEVKWMKDDNPIVESRRFQIDQDEDglcSLIISDVCGDDSGKYTCKAVNSLGEA 80


                  ....*...
gi 528501372  291 EQELSLKV 298
Cdd:cd20973    81 TCSAELTV 88

C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin, and similar domains; member of the I-set IgSF domains; The members here are composed of the C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin and similar proteins, including Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. In humans these proteins are called Titin. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig-like domain of the Twitchin is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins (titin, telokin, and twitchin), the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D.

Pssm-ID: 409541 [Multi-domain] Cd Length: 89 Bit Score: 50.41 E-value: 1.07e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 528501372  116 TFTNVPSPQEFTEGDNAIIVCDVISSPPPTVLWKYKGAKIQFD--KDVRFKTLSNNhLQIRGIRKTDEGVYTC 186
Cdd:cd20949     1 TFTENAYVTTVKEGQSATILCEVKGEPQPNVTWHFNGQPISASvaDMSKYRILADG-LLINKVTQDDTGEYTC 72

Fourth immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the fourth immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted, and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143223 Cd Length: 69 Bit Score: 49.49 E-value: 1.36e-07

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 528501372  230 LACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGSeMTVLDVTKLDEGDYTCIAKNKAGESEQELSL 296
Cdd:cd05746     3 IPCSAQGDPEPTITWNKDGVQVTESGKFHISPEGY-LAIRDVGVADQGRYECVARNTIGYASVSMVL 68

Immunoglobulin (Ig)-like domain in neuregulins; The members here are composed of the immunoglobulin (Ig)-like domain in neuregulins (NRGs). NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. There are four members of the neuregulin gene family (NRG-1, NRG-2, NRG-3, and NRG-4). The NRG-1 protein, binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. The other NRGs proteins bind one or the other or both of these ErbBs. NRG-1 has multiple functions: in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors, while in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. Less is known of the functions of the other NRGs. NRG-2 and NRG-3 are expressed predominantly in the nervous system. NRG-2 is expressed by motor neurons and terminal Schwann cells, and is concentrated near synaptic sites and may be a signal that regulates synaptic differentiation. NRG-4 has been shown to direct pancreatic islet cell development towards the delta-cell lineage.

Pssm-ID: 409408 [Multi-domain] Cd Length: 92 Bit Score: 50.20 E-value: 1.41e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 528501372  430 EGNPANISCEVLAHPSDVSITWLRDGFQLPNANTSNIKIHNTPSASYLEVNPESQSDFGNYNCTTSNEIGTES 502
Cdd:cd05750    13 EGSKLVLKCEATSENPSPRYRWFKDGKELNRKRPKNIKIRNKKKNSELQINKAKLEDSGEYTCVVENILGKDT 85

Fibronectin type 3 domain; One of three types of internal repeat within the plasma protein, fibronectin. The tenth fibronectin type III repeat contains a RGD cell recognition sequence in a flexible loop between 2 strands. Type III modules are present in both extracellular and intracellular proteins.

Pssm-ID: 214495 [Multi-domain] Cd Length: 83 Bit Score: 49.92 E-value: 1.62e-07

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372    513 PSAPSIGEVQPYSST-AQVLFEEPESTGGV-PVLKYRAEWRAVGrGKWVQrvYEVKDGLSSVTVTGLKPETDYEVKMSAI 590
Cdd:smart00060    1 PSPPSNLRVTDVTSTsVTLSWEPPPDDGITgYIVGYRVEYREEG-SEWKE--VNVTPSSTSYTLTGLKPGTEYEFRVRAV 77


                    ....*.
gi 528501372    591 NGKGEG 596
Cdd:smart00060   78 NGAGEG 83

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 49.70 E-value: 1.73e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  309 SQTTTEMDEQVTLTCEATGDPTPTITWsfgtrvftegeqeqqkriyqaswtRPEQHKGPDGEVLVRSDarvSSLTLKYPQ 388
Cdd:cd05725     5 QNQVVLVDDSAEFQCEVGGDPVPTVRW------------------------RKEDGELPKGRYEILDD---HSLKIRKVT 57

                          90       100
                  ....*....|....*....|....*.
gi 528501372  389 YTDAGQYLCTARNAIGETVQPVSLEV 414
Cdd:cd05725    58 AGDMGSYTCVAENMVGKIEASATLTV 83

Immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain from the C-terminus of human titin x and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is gigantic; depending on isoform composition it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone and appears to function similar to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 143224 [Multi-domain] Cd Length: 92 Bit Score: 49.66 E-value: 2.33e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 528501372  221 TADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKY--SFNEDGSEMTVLDVTKLDEGDYTCIAKNKAGESEQELSL 296
Cdd:cd05747    14 TVSEGESARFSCDVDGEPAPTVTWMREGQIIVSSQRHqiTSTEYKSTFEISKVQMSDEGNYTVVVENSEGKQEAQFTL 91

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 49.56 E-value: 2.48e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  218 TNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLE-SGNKYSFNEDGSEMTVLDVTKLDEGDYTCIAKNKAGESEQELSL 296
Cdd:cd20976     9 KDLEAVEGQDFVAQCSARGKPVPRITWIRNAQPLQyAADRSTCEAGVGELHIQDVLPEDHGTYTCLAKNAAGQVSCSAWV 88


                  ..
gi 528501372  297 KV 298
Cdd:cd20976    89 TV 90

Immunoglobulin (Ig)-like domain of titin and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain found in titin-like proteins and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is a giant protein; depending on isoform composition, it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone. It appears to function similarly to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. Within the sarcomere, titin is also attached to or is associated with myosin binding protein C (MyBP-C). MyBP-C appears to contribute to the generation of passive tension by titin and like titin has repeated Ig-like and FN-III domains. Also included in this group are worm twitchin and insect projectin, thick filament proteins of invertebrate muscle which also have repeated Ig-like and FN-III domains.

Pssm-ID: 409406 [Multi-domain] Cd Length: 82 Bit Score: 49.13 E-value: 2.71e-07

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 528501372  236 GFPEPIVTWRRNNAPLESGNKYSF--NEDGSEMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd05748    18 GRPTPTVTWSKDGQPLKETGRVQIetTASSTSLVIKNAKRSDSGKYTLTLKNSAGEKSATINVKV 82

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 48.93 E-value: 2.91e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  219 NATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGnKYSFNEDGSeMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd05725     6 NQVVLVDDSAEFQCEVGGDPVPTVRWRKEDGELPKG-RYEILDDHS-LKIRKVTAGDMGSYTCVAENMVGKIEASATLTV 83

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 48.72 E-value: 3.96e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   418 PKILGS-VAVYTWEGNPANISCEVLAHPSdVSITWLRDGfqLPNANTSNIKIHNTPSASYLEVNPESQSDFGNYNCTTSN 496
Cdd:pfam13927    2 PVITVSpSSVTVREGETVTLTCEATGSPP-PTITWYKNG--EPISSGSTRSRSLSGSNSTLTISNVTRSDAGTYTCVASN 78

Second C-terminal immunoglobulin (Ig)-like domain of palladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of palladin. Palladin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to this family contain multiple Ig-like domains and function as scaffolds, modulating actin cytoskeleton. Palladin binds to alpha-actinin ezrin, vasodilator-stimulated phosphoprotein VASP, SPIN90 (also known as DIP or mDia interacting protein), and Src. Palladin also binds F-actin directly, via its Ig3 domain. Palladin is expressed as several alternatively spliced isoforms, having various combinations of Ig-like domains, in a cell-type-specific manner. It has been suggested that palladin's different Ig-like domains may be specialized for distinct functions. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409582 Cd Length: 91 Bit Score: 48.56 E-value: 4.92e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  215 QAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPL--ESGNKYSFNEDGSEMTVLD-VTKLDEGDYTCIAKNKAGESE 291
Cdd:cd20990     5 QAPGDLTVQEGKLCRMDCKVSGLPTPDLSWQLDGKPIrpDSAHKMLVRENGVHSLIIEpVTSRDAGIYTCIATNRAGQNS 84


                  ....*..
gi 528501372  292 QELSLKV 298
Cdd:cd20990    85 FNLELVV 91

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 48.26 E-value: 5.79e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  311 TTTEMDEQVTLTCEATGDPTPTITWsfgtrvFTEGEQE--QQKRIYQaswtrpeQHKGpdgevlvrsdarvsSLTLKYPQ 388
Cdd:cd20952     9 QTVAVGGTVVLNCQATGEPVPTISW------LKDGVPLlgKDERITT-------LENG--------------SLQIKGAE 61

                          90       100
                  ....*....|....*....|....*.
gi 528501372  389 YTDAGQYLCTARNAIGETVQPVSLEV 414
Cdd:cd20952    62 KSDTGEYTCVALNLSGEATWSAVLDV 87

C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin, and similar domains; member of the I-set IgSF domains; The members here are composed of the C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin and similar proteins, including Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. In humans these proteins are called Titin. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig-like domain of the Twitchin is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins (titin, telokin, and twitchin), the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D.

Pssm-ID: 409541 [Multi-domain] Cd Length: 89 Bit Score: 48.10 E-value: 6.61e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 528501372  225 GFSTLLACDPDGFPEPIVTWRRNNAPLESG----NKYSFNEDGseMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd20949    14 GQSATILCEVKGEPQPNVTWHFNGQPISASvadmSKYRILADG--LLINKVTQDDTGEYTCRAYQVNSIASDMQERTV 89

Immunoglobulin domain I1 of the titin I-band and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin domain I1 of the titin I-band and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig I1 domain of the titin I-band is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409543 [Multi-domain] Cd Length: 94 Bit Score: 48.19 E-value: 7.15e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 528501372  230 LACDPDGFPEPIVTWRRNNAPLES---GNKYSF-NEDG-SEMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd20951    20 LRVEVQGKPDPEVKWYKNGVPIDPssiPGKYKIeSEYGvHVLHIRRVTVEDSAVYSAVAKNIHGEASSSASVVV 93

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 47.88 E-value: 7.61e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 528501372  213 IRQAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGSEMTVLDVTKLDEGDYTCIAKNKAGE 289
Cdd:cd20952     2 ILQGPQNQTVAVGGTVVLNCQATGEPVPTISWLKDGVPLLGKDERITTLENGSLQIKGAEKSDTGEYTCVALNLSGE 78

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 47.19 E-value: 1.46e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   426 VYTWEGNPANISCEVLAHPSDVSITWLRDGFQLPNANTSNIKIHNTPSASyLEVNPESQSDFGNYNCTTSNEIGTESREF 505
Cdd:pfam00047    6 VTVLEGDSATLTCSASTGSPGPDVTWSKEGGTLIESLKVKHDNGRTTQSS-LLISNVTKEDAGTYTCVVNNPGGSATLST 84


                   ..
gi 528501372   506 IM 507
Cdd:pfam00047   85 SL 86

Fibronectin type 3 domain; One of three types of internal repeat within the plasma protein, fibronectin. The tenth fibronectin type III repeat contains a RGD cell recognition sequence in a flexible loop between 2 strands. Type III modules are present in both extracellular and intracellular proteins.

Pssm-ID: 214495 [Multi-domain] Cd Length: 83 Bit Score: 46.84 E-value: 1.80e-06

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372    612 PSPPILEGTLQPKGNSLKVKWI--KQDDGGSPITHYLVRYKaREDSEWKPEIRLPSGSEYVmLIGLDWDTEYDVFVVAEN 689
Cdd:smart00060    1 PSPPSNLRVTDVTSTSVTLSWEppPDDGITGYIVGYRVEYR-EEGSEWKEVNVTPSSTSYT-LTGLKPGTEYEFRVRAVN 78


                    ....*
gi 528501372    690 QQGKS 694
Cdd:smart00060   79 GAGEG 83

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 46.82 E-value: 1.93e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  218 TNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSFnEDGSemtvLDVTKL---DEGDYTCIAKNKAGESEQEL 294
Cdd:cd05728     7 SDTEADIGSSLRWECKASGNPRPAYRWLKNGQPLASENRIEV-EAGD----LRITKLslsDSGMYQCVAENKHGTIYASA 81


                  ....
gi 528501372  295 SLKV 298
Cdd:cd05728    82 ELAV 85

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 46.85 E-value: 1.97e-06

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 528501372  212 RIRQAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGSeMTVLDVTKLDEGDYTCIAKNKAG 288
Cdd:cd20968     1 KITRPPTNVTIIEGLKAVLPCTTMGNPKPSVSWIKGDDLIKENNRIAVLESGS-LRIHNVQKEDAGQYRCVAKNSLG 76

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 46.41 E-value: 2.86e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  209 PTIRirqAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGSeMTVLDVTK-LDEGDYTCIAKNKA 287
Cdd:cd20958     2 PFIR---PMGNLTAVAGQTLRLHCPVAGYPISSITWEKDGRRLPLNHRQRVFPNGT-LVIENVQRsSDEGEYTCTARNQQ 77

                          90
                  ....*....|..
gi 528501372  288 GES-EQELSLKV 298
Cdd:cd20958    78 GQSaSRSVFVKV 89

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 46.78 E-value: 2.98e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  302 PKITYLESQTTTEMDEQVTLTCEATGDPTPTITW-SFGTRVFTEGEQEQQKRIYQaswtrpeqhkgPDGEVLVRS--DAR 378
Cdd:cd07693     1 PRIVEHPSDLIVSKGDPATLNCKAEGRPTPTIQWlKNGQPLETDKDDPRSHRIVL-----------PSGSLFFLRvvHGR 69

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 528501372  379 VSSltlkypqyTDAGQYLCTARNAIGETV-QPVSLEV 414
Cdd:cd07693    70 KGR--------SDEGVYVCVAHNSLGEAVsRNASLEV 98

Third immunoglobulin (Ig) domain of contactin-1; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 143259 Cd Length: 88 Bit Score: 46.17 E-value: 3.90e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  209 PTIRIRQAETNATadMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSFNedGSEMTVLDVTKLDEGDYTCIAKNKAG 288
Cdd:cd05851     2 ADINVKFKDTYAL--KGQNVTLECFALGNPVPVIRWRKILEPMPATAEISMS--GAVLKIFNIQPEDEGTYECEAENIKG 77

                          90
                  ....*....|...
gi 528501372  289 ESEQElsLKVFVQ 301
Cdd:cd05851    78 KDKHQ--ARVYVQ 88

Immunoglobulin domain of human Synaptic Adhesion-Like Molecule 5 (SALM5) and similar proteins; member of the I-set of IgSF domains; This group contains the immunoglobulin domain of human Synaptic Adhesion-Like Molecule 5 (SALM5) and similar proteins. The SALM (for synaptic adhesion-like molecules; also known as Lrfn for leucine-rich repeat and fibronectin type III domain containing) family of adhesion molecules consists of five known members: SALM1/Lrfn2, SALM2/Lrfn1, SALM3/Lrfn4, SALM4/Lrfn3, and SALM5/Lrfn5. SALMs share a similar domain structure, containing leucine-rich repeats (LRRs), an immunoglobulin (Ig) domain, and a fibronectin III (FNIII) domain, followed by a transmembrane domain and a C-terminal PDZ-binding motif. SALM5 is implicated in autism spectrum disorders (ASDs) and schizophrenia, induces presynaptic differentiation in contacting axons. SALM5 interacts with the Ig domains of LAR (Leukocyte common Antigen-Related) family receptor protein tyrosine phosphatases (LAR-RPTPs; LAR, PTPdelta, and PTPsigma). In addition, PTPdelta is implicated in ASDs, ADHD, bipolar disorder, and restless leg syndrome. Studies have shown that LAR-RPTPs are novel and splicing-dependent presynaptic ligands for SALM5, and that they mediate SALM5-dependent presynaptic differentiation. Furthermore, SALM5 maintains AMPA receptor (AMPAR)-mediated excitatory synaptic transmission through mechanisms involving the interaction of SALM5 with LAR-RPTPs. This group belongs to the I-set of immunoglobulin superfamily (IgSF) domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409421 [Multi-domain] Cd Length: 88 Bit Score: 45.93 E-value: 4.05e-06

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 528501372  230 LACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGSEMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd05764    20 LRCKARGDPEPAIHWISPEGKLISNSSRTLVYDNGTLDILITTVKDTGAFTCIASNPAGEATARVELHI 88

Immunoglobulin variable domain (IgV); The members here are composed of the immunoglobulin variable domain (IgV). The IgV family contains the standard Ig superfamily V-set AGFCC'C"/DEB domain topology, and are components of immunoglobulin (Ig) and T cell receptors. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. In Ig, each chain is composed of one variable domain (IgV) and one or more constant domains (IgC); these names reflect the fact that the variability in sequences is higher in the variable domain than in the constant domain. Within the variable domain, there are regions of even more variability called the hypervariable or complementarity-determining regions (CDRs) which are responsible for antigen binding. A predominant feature of most Ig domains is the disulfide bridge connecting 2 beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E and, D strands in one sheet and A', G, F, C, C', and C" strands in the other.

Pssm-ID: 409355 [Multi-domain] Cd Length: 111 Bit Score: 45.79 E-value: 7.00e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  317 EQVTLTCEATG-DPTPTITWsfgtrVFTEGEQEQQKRIYQASWTRPEQHKGPDGEVLVRSDARVSSLTLKYPQYTDAGQY 395
Cdd:cd00099    14 ESVTLSCEVSSsFSSTYIYW-----YRQKPGQGPEFLIYLSSSKGKTKGGVPGRFSGSRDGTSSFSLTISNLQPEDSGTY 88


                  ....*....
gi 528501372  396 LCTARNAIG 404
Cdd:cd00099    89 YCAVSESGG 97

Immunoglobulin (Ig)-like domain found in neuregulin (NRG)-1; The members here are composed of the immunoglobulin (Ig)-like domain found in neuregulin (NRG)-1. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. NRG-1 belongs to the neuregulin gene family which is comprised of four genes. This group represents NRG-1. NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, and heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. The NRG-1 protein binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. NRG-1 has multiple functions, for example, in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival.

Pssm-ID: 409476 Cd Length: 93 Bit Score: 45.37 E-value: 7.13e-06

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 528501372  430 EGNPANISCEVLAHPSDVSITWLRDGFQLPNANT-SNIKIHNTPSASYLEVNPESQSDFGNYNCTTSNEIGTES 502
Cdd:cd05895    13 AGSKLVLRCETSSEYPSLRFKWFKNGKEINRKNKpENIKIQKKKKKSELRINKASLADSGEYMCKVSSKLGNDS 86

IL-1 receptor-like protein; Provisional

Pssm-ID: 165173 [Multi-domain] Cd Length: 227 Bit Score: 47.99 E-value: 9.16e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   64 RPDISVIRNDET---SSTLTIYNAKVDNAGTYRCVASSGDQDAEATVNLKIYQKiTFTnvpspQEFTEGDNAIIVC---D 137
Cdd:PHA02826   82 RTKIKKITHNEIgdrSENLWIGNVINIDEGIYICTISSGNICEESTIRLTFDSG-TIN-----YQFNSGKDSKLHCygtD 155

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 528501372  138 VISS--PPPTVLWKYKGAKIQFDKdvRFKTLSNN-HLQIRGIRKTDEGVYTCEGRI 190
Cdd:PHA02826  156 GISStfKDYTLTWYKNGNIVLYTD--RIQLRNNNsTLVIKSATHDDSGIYTCNLRF 209

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 44.94 E-value: 9.44e-06

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 528501372   430 EGNPANISCEVLAHPsDVSITWLRDGFQLPNanTSNIKIHNTPSASYLEVNPESQSDFGNYNCTTSNEIGTES 502
Cdd:pfam07679   14 EGESARFTCTVTGTP-DPEVSWFKDGQPLRS--SDRFKVTYEGGTYTLTISNVQPDDSGKYTCVATNSAGEAE 83

Fibronectin type 3 domain [General function prediction only];

Pssm-ID: 442628 [Multi-domain] Cd Length: 603 Bit Score: 49.62 E-value: 1.06e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  493 TTSNEIGTESREF-IMIPADVPSAPSIGEVQPYSSTAQVLFEEPESTGGVpvLKYRAEWRAVGRGKWVqRVYEVKDglSS 571
Cdd:COG3401   212 TDTGGESAPSNEVsVTTPTTPPSAPTGLTATADTPGSVTLSWDPVTESDA--TGYRVYRSNSGDGPFT-KVATVTT--TS 286

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  572 VTVTGLKPETDYEVKMSAINGKG-EGDSSPSMVFKTEHVREPSPPILEGTlQPKGNSLKVKWIKQDDGGspITHYLVRYK 650
Cdd:COG3401   287 YTDTGLTNGTTYYYRVTAVDAAGnESAPSNVVSVTTDLTPPAAPSGLTAT-AVGSSSITLSWTASSDAD--VTGYNVYRS 363

                         170       180       190       200       210       220       230
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 528501372  651 AREDSEWKPEIRLPSGSEYVmLIGLDWDTEYDVFVVAENQQGKSKPGTLTFRTSSEPTATTDSMEDGPGLNTGVIVG 727
Cdd:COG3401   364 TSGGGTYTKIAETVTTTSYT-DTGLTPGTTYYYKVTAVDAAGNESAPSEEVSATTASAASGESLTASVDAVPLTDVA 439

C-terminal immunoglobulin (Ig)-like domain of myotilin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myotilin. Mytolin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to the latter family contain multiple Ig-like domains and function as scaffolds, modulating the actin cytoskeleton. Myotilin is most abundant in skeletal and cardiac muscle and is involved in maintaining sarcomere integrity. It binds to alpha-actinin, filamin, and actin. Mutations in myotilin lead to muscle disorders. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409473 Cd Length: 92 Bit Score: 44.76 E-value: 1.34e-05

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 528501372  116 TFTNVPSPQEFTEGDNAIIVCDVISSPPPTVLWKYKGAKIQFDKDvRFKTLSNNH----LQIRGIRKTDEGVYT 185
Cdd:cd05892     2 MFIQKPQNKKVLEGDPVRLECQISAIPPPQIFWKKNNEMLQYNTD-RISLYQDNCgricLLIQNANKKDAGWYT 74

Immunoglobulin (Ig)-like domain in neuregulins; The members here are composed of the immunoglobulin (Ig)-like domain in neuregulins (NRGs). NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. There are four members of the neuregulin gene family (NRG-1, NRG-2, NRG-3, and NRG-4). The NRG-1 protein, binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. The other NRGs proteins bind one or the other or both of these ErbBs. NRG-1 has multiple functions: in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors, while in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. Less is known of the functions of the other NRGs. NRG-2 and NRG-3 are expressed predominantly in the nervous system. NRG-2 is expressed by motor neurons and terminal Schwann cells, and is concentrated near synaptic sites and may be a signal that regulates synaptic differentiation. NRG-4 has been shown to direct pancreatic islet cell development towards the delta-cell lineage.

Pssm-ID: 409408 [Multi-domain] Cd Length: 92 Bit Score: 44.42 E-value: 1.71e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   30 EISVGESRFFLCEVIGG--AKEIDWFApAGEKIEPGRPDISVIRNDETSSTLTIYNAKVDNAGTYRCVASSGDQDAEATV 107
Cdd:cd05750    10 TVQEGSKLVLKCEATSEnpSPRYRWFK-DGKELNRKRPKNIKIRNKKKNSELQINKAKLEDSGEYTCVVENILGKDTVTG 88


                  ....
gi 528501372  108 NLKI 111
Cdd:cd05750    89 NVTV 92

Fourth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409548 [Multi-domain] Cd Length: 96 Bit Score: 44.47 E-value: 1.78e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  302 PKITYLESQTTTEMDEQVTLTCEATGDPTPTITWSFGTRVFTEGEQeqqkriyqaswTRPEQHKGPDGEVlvrsdarVSS 381
Cdd:cd20956     2 PVLLETFSEQTLQPGPSVSLKCVASGNPLPQITWTLDGFPIPESPR-----------FRVGDYVTSDGDV-------VSY 63

                          90       100
                  ....*....|....*....|....*.
gi 528501372  382 LTLKYPQYTDAGQYLCTARNAIGETV 407
Cdd:cd20956    64 VNISSVRVEDGGEYTCTATNDVGSVS 89

Second immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 (also known as Neph2). This protein has five Ig-like domains, one transmembrane domain, and a cytoplasmic tail. Included in this group is mammalian Kirrel (Neph1), Kirrel2 (Neph3), and Drosophila RST (irregular chiasm C-roughest) protein. These proteins contain multiple Ig domains, have properties of cell adhesion molecules, and are important in organ development.

Pssm-ID: 409416 Cd Length: 98 Bit Score: 44.36 E-value: 2.11e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  417 APKILGSVAVYTWEGNPANISCEVLAHPSDVSITWLRDGFQLPNANTSNIKIHN---TPSASYLEVNPESQSDFGNYNCT 493
Cdd:cd05759     1 DPVIEGGPVISLQAGVPYNLTCRARGAKPAAEIIWFRDGEQLEGAVYSKELLKDgkrETTVSTLLITPSDLDTGRTFTCR 80

                          90
                  ....*....|.
gi 528501372  494 TSNEIGTESRE 504
Cdd:cd05759    81 ARNEAIPNGKE 91

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor (R) and similar proteins; member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor (R) and related proteins. The VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. The VEGFR family consists of three members: VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1) and VEGFR-3 (Flt-4). VEGF-A interacts with both VEGFR-1 and VEGFR-2. VEGFR-1 binds strongest to VEGF; VEGF-2 binds more weakly. VEGFR-3 appears not to bind VEGF, but binds other members of the VEGF family (VEGF-C and -D). VEGFRs bind VEGFs with high affinity with the IG-like domains. VEGF-A is important to the growth and maintenance of vascular endothelial cells and to the development of new blood- and lymphatic-vessels in physiological and pathological states. VEGFR-2 is a major mediator of the mitogenic, angiogenic, and microvascular permeability-enhancing effects of VEGF-A. VEGFR-1 may play an inhibitory part in these processes by binding VEGF and interfering with its interaction with VEGFR-2. VEGFR-1 has a signaling role in mediating monocyte chemotaxis. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. VEGFR-3 has been shown to be involved in tumor angiogenesis and growth. This group also contains alpha-type platelet-derived growth factor receptor precursor (PDGFR)-alpha (CD140a), and PDGFR-beta (CD140b). PDGFRs alpha and beta have an extracellular component with five Ig-like domains, a transmembrane segment, and a cytoplasmic portion that has protein tyrosine kinase activity.

Pssm-ID: 409404 Cd Length: 102 Bit Score: 44.45 E-value: 2.29e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   25 TPAHG-EISVGESRFFLCEVIGGAKEI---DWFAPAGEKIEPG--RPDISVIRND--ETSSTLTIYNAKVDNAGTYRCVA 96
Cdd:cd05742     7 PNAEPtVLPQGETLVLNCTANVNLNEVvdfQWTYPSEKEGKLAllKPDIKVDWSEpgEFVSTLTIPEATLKDSGTYTCAA 86

                          90
                  ....*....|....*.
gi 528501372   97 SSGDQDAEATVNLKIY 112
Cdd:cd05742    87 RSGVMKKEKQTSVSVH 102

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 43.32 E-value: 2.88e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 528501372    21 QVDITPAHGEISVGESRFFLCEVIGGAK-EIDWFAPaGEKIEPGRpdISVIRNDETSSTLTIYNAKVDNAGTYRCVAS 97
Cdd:pfam13927    3 VITVSPSSVTVREGETVTLTCEATGSPPpTITWYKN-GEPISSGS--TRSRSLSGSNSTLTISNVTRSDAGTYTCVAS 77

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 43.29 E-value: 3.22e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   20 LQVDITPAHGEISVGESRFFLCEVIG-GAKEIDWFapagekiEPGRPDISVIRNDETS-STLTIYNAKVDNAGTYRCVAS 97
Cdd:cd20957     2 LSATIDPPVQTVDFGRTAVFNCSVTGnPIHTVLWM-------KDGKPLGHSSRVQILSeDVLVIPSVKREDKGMYQCFVR 74

                          90
                  ....*....|....
gi 528501372   98 SGDQDAEATVNLKI 111
Cdd:cd20957    75 NDGDSAQATAELKL 88

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 42.70 E-value: 3.36e-05

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 528501372  434 ANISCEVLAHPsDVSITWLRDGFQLPNANTSNIKIHNTPsaSYLEVNPESQSDFGNYNCTTSNEIGTES 502
Cdd:cd00096     1 VTLTCSASGNP-PPTITWYKNGKPLPPSSRDSRRSELGN--GTLTISNVTLEDSGTYTCVASNSAGGSA 66

Fourth immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the fourth immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted, and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143223 Cd Length: 69 Bit Score: 42.94 E-value: 3.42e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  319 VTLTCEATGDPTPTITWSfgtrvfTEGEQEQQKRIYqaswtrpeqHKGPDGEVLVRsDARVSsltlkypqytDAGQYLCT 398
Cdd:cd05746     1 VQIPCSAQGDPEPTITWN------KDGVQVTESGKF---------HISPEGYLAIR-DVGVA----------DQGRYECV 54


                  ....*...
gi 528501372  399 ARNAIGET 406
Cdd:cd05746    55 ARNTIGYA 62

C5 immunoglobulin (Ig) domain of cardiac myosin binding protein C (MyBP-C); The members here are composed of the C5 immunoglobulin (Ig) domain of cardiac myosin binding protein C (MyBP-C). MyBP-C consists of repeated domains, Ig and fibronectin type 3, and various linkers. Three isoforms of MYBP-C exist: slow-skeletal (ssMyBP-C), fast-skeletal (fsMyBP-C), and cardiac (cMyBP-C). cMYBP-C has insertions between and inside domains and an additional cardiac-specific Ig domain at the N-terminus. For cMYBP_C an interaction has been demonstrated between this C5 domain and the Ig C8 domain.

Pssm-ID: 409475 Cd Length: 86 Bit Score: 43.29 E-value: 3.87e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  318 QVTLTCEATGDPTPTITWSFGTRVFTEGEqeqqkriyqaswtrpeqhkgpdGEVLVRSDARVSSLTLKYPQYTDAGQYLC 397
Cdd:cd05894    12 KLRLDVPISGEPAPTVTWSRGDKAFTATE----------------------GRVRVESYKDLSSFVIEGAEREDEGVYTI 69

                          90
                  ....*....|....*..
gi 528501372  398 TARNAIGETVQPVSLEV 414
Cdd:cd05894    70 TVTNPVGEDHASLFVKV 86

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 2 (VEGFR-2); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 2 (VEGFR-2). The VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. VEGFRs bind VEGFs with high affinity at the Ig-like domains. VEGFR-2 (KDR/Flk-1) is a major mediator of the mitogenic, angiogenic and microvascular permeability-enhancing effects of VEGF-A; VEGF-A is important to the growth and maintenance of vascular endothelial cells and to the development of new blood- and lymphatic-vessels in physiological and pathological states. VEGF-A also interacts with VEGFR-1, which it binds more strongly than VEGFR-2. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409450 Cd Length: 89 Bit Score: 43.38 E-value: 3.92e-05

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 528501372  236 GFPEPIVTWRRNNAPLESGNKYSFnedGSEMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKVFV 300
Cdd:cd05864    28 GYPPPEIKWYKNGIPIESNHTIKA---GHVLTIMEVTEKDAGNYTVVLTNPISKEKQRHTFSLVV 89

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 43.46 E-value: 3.97e-05

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 528501372  218 TNATADMGFSTLLACDPDGFPEPIVTWRRNNAP-------LESGNKYSFNEDGSeMTVLDVTKLDEGDYTCIAKNKAG 288
Cdd:cd20954     9 VDANVAAGQDVMLHCQADGFPTPTVTWKKATGStpgeykdLLYDPNVRILPNGT-LVFGHVQKENEGHYLCEAKNGIG 85

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 43.22 E-value: 4.05e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  319 VTLTCEATGDPTPTITWSFGTRVFTEGeqeqqKRIyqaswtrpeqHKGPDGEVLVRSDARvssltlkypqyTDAGQYLCT 398
Cdd:cd04969    20 VIIECKPKASPKPTISWSKGTELLTNS-----SRI----------CILPDGSLKIKNVTK-----------SDEGKYTCF 73

                          90
                  ....*....|....*.
gi 528501372  399 ARNAIGETVQPVSLEV 414
Cdd:cd04969    74 AVNFFGKANSTGSLSV 89

C-terminal immunoglobulin (Ig)-like domain of myotilin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myotilin. Mytolin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to the latter family contain multiple Ig-like domains and function as scaffolds, modulating the actin cytoskeleton. Myotilin is most abundant in skeletal and cardiac muscle and is involved in maintaining sarcomere integrity. It binds to alpha-actinin, filamin, and actin. Mutations in myotilin lead to muscle disorders. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409473 Cd Length: 92 Bit Score: 43.22 E-value: 4.44e-05

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 528501372  225 GFSTLLACDPDGFPEPIVTWRRNNAPLE-SGNKYSFNEDGS---EMTVLDVTKLDEGDYTCIAKNKAG 288
Cdd:cd05892    15 GDPVRLECQISAIPPPQIFWKKNNEMLQyNTDRISLYQDNCgriCLLIQNANKKDAGWYTVSAVNEAG 82

Immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan, also known as HSPG2, and similar proteins. Perlecan consists of five domains: domain I has three putative heparan sulfate attachment sites, domain II has four LDL receptor-like repeats, and one Ig-like repeat, domain III resembles the short arm of laminin chains, domain IV has multiple Ig-like repeats (21 repeats in human perlecan), and domain V resembles the globular G domain of the laminin A chain and internal repeats of EGF. Perlecan may participate in a variety of biological functions including cell binding, LDL-metabolism, basement membrane assembly and selective permeability, calcium binding, and growth- and neurite-promoting activities.

Pssm-ID: 143220 Cd Length: 78 Bit Score: 42.48 E-value: 5.42e-05

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 528501372  230 LACDPDGFPEPIVTWRRNNAPL-ESGNKYSFNEDG-SEMTVLDVTKLDEGDYTCIAKNKAGeseqelslKVFVQP 302
Cdd:cd05743     6 FTCVATGVPTPIINWRLNWGHVpDSARVSITSEGGyGTLTIRDVKESDQGAYTCEAINTRG--------MVFGIP 72

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 42.76 E-value: 5.49e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  211 IRIRQAETnATADMGFSTLLACDPDGFPEPIVTW---RRNNAPLESGNKYSFNEDGSeMTVLDVTKLDEGDYTCIAKNKA 287
Cdd:cd20969     4 IRDRKAQQ-VFVDEGHTVQFVCRADGDPPPAILWlspRKHLVSAKSNGRLTVFPDGT-LEVRYAQVQDNGTYLCIAANAG 81

                          90
                  ....*....|.
gi 528501372  288 GESEQELSLKV 298
Cdd:cd20969    82 GNDSMPAHLHV 92

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1) and similar proteins; The members here are composed of the fourth immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. Also included in this group is NCAM-2 (also known as OCAM/mamFas II and RNCAM) NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE). One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 409395 [Multi-domain] Cd Length: 96 Bit Score: 42.90 E-value: 5.63e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  219 NATADMGFSTLLACDPDGFPEPIVTWRRnnapleSGNKYSFNE---DG----------SEMTVLDVTKLDEGDYTCIAKN 285
Cdd:cd05732    10 NQTAVELEQITLTCEAEGDPIPEITWRR------ATRGISFEEgdlDGrivvrgharvSSLTLKDVQLTDAGRYDCEASN 83

                          90
                  ....*....|...
gi 528501372  286 KAGESEQELSLKV 298
Cdd:cd05732    84 RIGGDQQSMYLEV 96

Immunoglobulin-like domain protein; Provisional

Pssm-ID: 165230 Cd Length: 500 Bit Score: 47.02 E-value: 5.78e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   72 NDETSSTLTIYNAKVDNAGTYRCVASSGDQDAEATVNLKIYQKITFtnvpspQEFTEGDN-AIIVCDVISSP--PPTVLW 148
Cdd:PHA02914  341 DDLKNSTLTIKKAHINNAGCYEAQAFMGKFKEECRHCFKVADHVFF------KWNTEGDNeTKVACYAAQYDmqPFSILW 414


                  ....*..
gi 528501372  149 KYKGAKI 155
Cdd:PHA02914  415 KSNGVSF 421

Immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain from the C-terminus of human titin x and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is gigantic; depending on isoform composition it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone and appears to function similar to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 143224 [Multi-domain] Cd Length: 92 Bit Score: 42.73 E-value: 6.20e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  423 SVAVYtwEGNPANISCEVLAHPSDvSITWLRDGfqLPNANTSNIKIHNTPSASYLEVNPESQSDFGNYNCTTSNEIGTES 502
Cdd:cd05747    12 SLTVS--EGESARFSCDVDGEPAP-TVTWMREG--QIIVSSQRHQITSTEYKSTFEISKVQMSDEGNYTVVVENSEGKQE 86


                  ....*
gi 528501372  503 REFIM 507
Cdd:cd05747    87 AQFTL 91

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 42.45 E-value: 6.54e-05

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 528501372  127 TEGDNAIIVCDVISSPPPTVLWKYKGAKIQFDKDVRFktLSNNHLQIRGIRKTDEGVYTCEG 188
Cdd:cd04969    15 AKGGDVIIECKPKASPKPTISWSKGTELLTNSSRICI--LPDGSLKIKNVTKSDEGKYTCFA 74

Immunoglobulin (Ig)-like domain of titin and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain found in titin-like proteins and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is a giant protein; depending on isoform composition, it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone. It appears to function similarly to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. Within the sarcomere, titin is also attached to or is associated with myosin binding protein C (MyBP-C). MyBP-C appears to contribute to the generation of passive tension by titin and like titin has repeated Ig-like and FN-III domains. Also included in this group are worm twitchin and insect projectin, thick filament proteins of invertebrate muscle which also have repeated Ig-like and FN-III domains.

Pssm-ID: 409406 [Multi-domain] Cd Length: 82 Bit Score: 42.19 E-value: 6.69e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  317 EQVTLTCEATGDPTPTITWSFGTRVFTEgeqeqqkriyqaswtrpeqhkgpDGEVLVRSDARVSSLTLKYPQYTDAGQYL 396
Cdd:cd05748     8 ESLRLDIPIKGRPTPTVTWSKDGQPLKE-----------------------TGRVQIETTASSTSLVIKNAKRSDSGKYT 64

                          90
                  ....*....|....*....
gi 528501372  397 CTARNAIGETVqpVSLEVR 415
Cdd:cd05748    65 LTLKNSAGEKS--ATINVK 81

Third immunoglobulin-like domain of the human WFIKKN (WAP, follistatin, immunoglobulin, Kunitz and NTR domain-containing protein), and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin-like domain of the human WFIKKN (WAP, follistatin, immunoglobulin, Kunitz and NTR domain-containing protein) and similar proteins. WFIKKN is a secreted protein that consists of multiple types of protease inhibitory modules, including two tandem Kunitz-type protease inhibitor-domains. The Ig superfamily is a heterogenous group of proteins built on a common fold comprised of a sandwich of two beta sheets. Members of the Ig superfamily are components of immunoglobulin, neuroglia, cell surface glycoproteins, such as T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, such as butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409422 [Multi-domain] Cd Length: 95 Bit Score: 42.54 E-value: 7.11e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  302 PKITYLESQTTTEMDEQVTLTCEATGDPTPTITWsfgtrvftEGEQEQQKRIYqaswTRPEQHKgpdGEVLVRSdarVSS 381
Cdd:cd05765     1 PALVNSPTHQTVKVGETASFHCDVTGRPQPEITW--------EKQVPGKENLI----MRPNHVR---GNVVVTN---IGQ 62

                          90       100
                  ....*....|....*....|...
gi 528501372  382 LTLKYPQYTDAGQYLCTARNAIG 404
Cdd:cd05765    63 LVIYNAQPQDAGLYTCTARNSGG 85

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 42.18 E-value: 7.57e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 528501372   120 VPSPQEFTEGDNAIIVCDVI-SSPPPTVLWKYKGAKI--QFDKDVRFKTLSNNHLQIRGIRKTDEGVYTCEGR 189
Cdd:pfam00047    2 APPTVTVLEGDSATLTCSAStGSPGPDVTWSKEGGTLieSLKVKHDNGRTTQSSLLISNVTKEDAGTYTCVVN 74

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

Pssm-ID: 409397 [Multi-domain] Cd Length: 97 Bit Score: 42.48 E-value: 7.75e-05

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 528501372  117 FTNVPSPQEFTEGDNAIIVCDVISSPPPTVLWKY-KGAKI-QFDKDV----RFKTLSNNHLQIRGIRKTDEGVYTCE 187
Cdd:cd05734     4 FVVQPNDQDGIYGKAVVLNCSADGYPPPTIVWKHsKGSGVpQFQHIVplngRIQLLSNGSLLIKHVLEEDSGYYLCK 80

Second Ig-like domain of Junctional adhesion molecule-1 (JAM1); a member of the I-set of IgSF domains; The members here are composed of the second Ig-like domain of Junctional adhesion molecule-1 (JAM1). JAM1 is an immunoglobulin superfamily (IgSF) protein with two Ig-like domains in its extracellular region; it plays a role in the formation of endothelial and epithelial tight junction and acts as a receptor for mammalian reovirus sigma-1. The IgSF is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The second Ig-like domain of JAM1 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, the A strand of the I-set is discontinuous but lacks a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors.

Pssm-ID: 409542 Cd Length: 97 Bit Score: 42.69 E-value: 8.23e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  209 PTIRIRQAETNAtadmGFSTLLACDPDGFPEPIVTWRRNNAPLE---------SGNKYSFNEDGSEMTVLDVTKLDEGDY 279
Cdd:cd20950     1 PTVNIPSSATIG----NRAVLTCSEPDGSPPSEYTWFKDGVVMPtnpkstrafSNSSYSLDPTTGELVFDPLSASDTGEY 76


                  ....*....
gi 528501372  280 TCIAKNKAG 288
Cdd:cd20950    77 SCEARNGYG 85

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 42.38 E-value: 8.46e-05

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 528501372  116 TFTNVPSPQ-EFTEGDNAIIVCDVISSPPPTVLWKYKGAKIQFDKDVRfkTLSNNHLQIRGIRKTDEGVYTCEG 188
Cdd:cd20978     2 KFIQKPEKNvVVKGGQDVTLPCQVTGVPQPKITWLHNGKPLQGPMERA--TVEDGTLTIINVQPEDTGYYGCVA 73

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409442 Cd Length: 92 Bit Score: 42.15 E-value: 9.02e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  319 VTLTCEATGDPTPTITWSFGTRVFTEGEQEQQKRiyqASWTrpeqhkgpdgevlvrsdarvssLTLKYPQYTDAGQYLCT 398
Cdd:cd05856    22 VRLKCVASGNPRPDITWLKDNKPLTPPEIGENKK---KKWT----------------------LSLKNLKPEDSGKYTCH 76


                  ....*..
gi 528501372  399 ARNAIGE 405
Cdd:cd05856    77 VSNRAGE 83

First immunoglobulin (Ig)-like domain of fibroblast growth factor receptor (FGFR); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of fibroblast growth factor receptor (FGFR). Fibroblast growth factors (FGFs) participate in morphogenesis, development, angiogenesis, and wound healing. These FGF-stimulated processes are mediated by four FGFR tyrosine kinases (FGRF1-4). FGFRs are comprised of an extracellular portion consisting of three Ig-like domains, a transmembrane helix, and a cytoplasmic portion having protein tyrosine kinase activity. The highly conserved Ig-like domains 2 and 3, and the linker region between D2 and D3 define a general binding site for all FGFs.

Pssm-ID: 409362 Cd Length: 94 Bit Score: 42.19 E-value: 9.70e-05

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 528501372  441 LAHPSD------------VSITWLRDGFQLPNANTSNIkihntpSASYLEVNPESQSDFGNYNCTTSNEIGTESREFIM 507
Cdd:cd04973    20 SAHPGDllqlrcrlrddvQSINWTKDGVQLGENNRTRI------TGEEVQIKDAVPRDSGLYACVTSSPSGSDTTYFSV 92

Immunoglobulin variable domain (IgV); The members here are composed of the immunoglobulin variable domain (IgV). The IgV family contains the standard Ig superfamily V-set AGFCC'C"/DEB domain topology, and are components of immunoglobulin (Ig) and T cell receptors. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. In Ig, each chain is composed of one variable domain (IgV) and one or more constant domains (IgC); these names reflect the fact that the variability in sequences is higher in the variable domain than in the constant domain. Within the variable domain, there are regions of even more variability called the hypervariable or complementarity-determining regions (CDRs) which are responsible for antigen binding. A predominant feature of most Ig domains is the disulfide bridge connecting 2 beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E and, D strands in one sheet and A', G, F, C, C', and C" strands in the other.

Pssm-ID: 409355 [Multi-domain] Cd Length: 111 Bit Score: 42.71 E-value: 9.91e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   22 VDITPAHGEISVGESRFFLCEVIGGAKE--IDWF--------------APAGEKIEPGRPD-ISVIRNDETSSTLTIYNA 84
Cdd:cd00099     1 VTQSPRSLSVQEGESVTLSCEVSSSFSStyIYWYrqkpgqgpefliylSSSKGKTKGGVPGrFSGSRDGTSSFSLTISNL 80

                          90       100
                  ....*....|....*....|..
gi 528501372   85 KVDNAGTYRCVASSGDQDAEAT 106
Cdd:cd00099    81 QPEDSGTYYCAVSESGGTDKLT 102

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 41.61 E-value: 1.11e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   118 TNVPSPQEFTEGDNAIIVCDVISSPPPTVLWkYKGAKIqfdkdvrfktLSNNH-LQIRGIRKTDEGVYTCEGRIKARGEV 196
Cdd:pfam13895    3 VLTPSPTVVTEGEPVTLTCSAPGNPPPSYTW-YKDGSA----------ISSSPnFFTLSVSAEDSGTYTCVARNGRGGKV 71


                   ....*....
gi 528501372   197 dFRSIKVVV 205
Cdd:pfam13895   72 -SNPVELTV 79

Second immunoglobulin (Ig)-like domain of protein tyrosine kinase (PTK) 7; The members here are composed of the second immunoglobulin (Ig)-like domain in protein tyrosine kinase (PTK) 7, also known as CCK4. PTK7 is a subfamily of the receptor protein tyrosine kinase family, and is referred to as an RPTK-like molecule. RPTKs transduce extracellular signals across the cell membrane and play important roles in regulating cell proliferation, migration, and differentiation. PTK7 is organized as an extracellular portion having seven Ig-like domains, a single transmembrane region, and a cytoplasmic tyrosine kinase-like domain. PTK7 is considered a pseudokinase as it has several unusual residues in some of the highly conserved tyrosine kinase (TK) motifs; it is predicted to lack TK activity. PTK7 may function as a cell-adhesion molecule. PTK7 mRNA is expressed at high levels in placenta, melanocytes, liver, lung, pancreas, and kidney. PTK7 is overexpressed in several cancers, including melanoma and colon cancer lines.

Pssm-ID: 409417 Cd Length: 95 Bit Score: 42.22 E-value: 1.17e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 528501372  230 LACDPDGFPEPIVTWRRNNAPL-ESGNKYSFNEDGSEMTVLDVTKLDEGDYTCIAKNKAGE--SEQELSLKV 298
Cdd:cd05760    21 LRCHIDGHPRPTYQWFRDGTPLsDGQGNYSVSSKERTLTLRSAGPDDSGLYYCCAHNAFGSvcSSQNFTLSI 92

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor (VEGFR); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor (VEGFR). The VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. The VEGFR family consists of three members, VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), and VEGFR-3 (Flt-4). VEGFRs bind VEGFs with high affinity at the Ig-like domains. VEGF-A is important to the growth and maintenance of vascular endothelial cells and to the development of new blood- and lymphatic-vessels in physiological and pathological states. VEGFR-2 is a major mediator of the mitogenic, angiogenic, and microvascular permeability-enhancing effects of VEGF-A. VEGFR-1 may play an inhibitory part in these processes by binding VEGF and interfering with its interaction with VEGFR-2. VEGFR-1 has a signaling role in mediating monocyte chemotaxis. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. VEGFR-3 has been shown to be involved in tumor angiogenesis and growth. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409365 Cd Length: 90 Bit Score: 41.82 E-value: 1.24e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 528501372  236 GFPEPIVTWRRNNAPLESGNKYsfnEDGSEMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKVFV 300
Cdd:cd04976    29 AYPPPEVVWYKDGLPLTEKARY---LTRHSLIIKEVTEEDTGNYTILLSNKQSNVFKNLTATLVV 90

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 41.80 E-value: 1.32e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 528501372    24 ITPAHGEISVGESRFFLCEVIGGAK--EIDWFAPAGEKIEPgrPDISVIRNDETSSTLTIYNAKVDNAGTYRCVAS 97
Cdd:pfam00047    1 SAPPTVTVLEGDSATLTCSASTGSPgpDVTWSKEGGTLIES--LKVKHDNGRTTQSSLLISNVTKEDAGTYTCVVN 74

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 41.67 E-value: 1.45e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  230 LACDPDGFPEPIVTWRRNNAPLE-SGNKYSFNEDGSEMTVLDVTKLDEGDYTCIAKNKAG 288
Cdd:cd04978    19 LICEAEGNPQPTITWRLNGVPIEpAPEDMRRTVDGRTLIFSNLQPNDTAVYQCNASNVHG 78

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 40.78 E-value: 1.76e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 528501372   39 FLCEVIGGAK-EIDWFAPaGEKIEPGrpDISVIRNDETSSTLTIYNAKVDNAGTYRCVASSGDQDAEAT 106
Cdd:cd00096     3 LTCSASGNPPpTITWYKN-GKPLPPS--SRDSRRSELGNGTLTISNVTLEDSGTYTCVASNSAGGSASA 68

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409391 [Multi-domain] Cd Length: 98 Bit Score: 41.48 E-value: 1.78e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  319 VTLTCEATGDPTPTITWSfgtrvfTEGEQeqqkriyqaSWTRPEQHKGPDGEVLVrsdARVSSLTLKYPQYTDAGQYLCT 398
Cdd:cd05726    17 VTFQCETKGNPQPAIFWQ------KEGSQ---------NLLFPYQPPQPSSRFSV---SPTGDLTITNVQRSDVGYYICQ 78

                          90
                  ....*....|....*.
gi 528501372  399 ARNAIGETVQPVSLEV 414
Cdd:cd05726    79 ALNVAGSILAKAQLEV 94

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 41.53 E-value: 1.78e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  319 VTLTCEATGDPTPTITW--SFGTrvfTEGEqeqqkriYQASWTRPEQHKGPDGevlvrsdarvsSLTLKYPQYTDAGQYL 396
Cdd:cd20954    19 VMLHCQADGFPTPTVTWkkATGS---TPGE-------YKDLLYDPNVRILPNG-----------TLVFGHVQKENEGHYL 77


                  ....*...
gi 528501372  397 CTARNAIG 404
Cdd:cd20954    78 CEAKNGIG 85

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 41.23 E-value: 1.83e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 528501372  121 PSPQEFTEGDNAIIVCdvisSPP-----PTVLWKYKGAKIQfDKDVRFKTLSNNHLQIRGIRKTDEGVYTC 186
Cdd:cd05724     4 PSDTQVAVGEMAVLEC----SPPrghpePTVSWRKDGQPLN-LDNERVRIVDDGNLLIAEARKSDEGTYKC 69

Fourth immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues, and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409388 Cd Length: 84 Bit Score: 41.03 E-value: 1.86e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  218 TNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDgSEMTVLDVTKLDEGDYTCIAKNKAGESEQELSLK 297
Cdd:cd05723     5 SNIYAHESMDIVFECEVTGKPTPTVKWVKNGDVVIPSDYFKIVKE-HNLQVLGLVKSDEGFYQCIAENDVGNAQASAQLI 83


                  .
gi 528501372  298 V 298
Cdd:cd05723    84 I 84

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 41.38 E-value: 2.11e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  212 RIRQAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNkysfNEDGSEMTVLDVTKL-------------DEGD 278
Cdd:cd07693     2 RIVEHPSDLIVSKGDPATLNCKAEGRPTPTIQWLKNGQPLETDK----DDPRSHRIVLPSGSLfflrvvhgrkgrsDEGV 77

                          90
                  ....*....|..
gi 528501372  279 YTCIAKNKAGES 290
Cdd:cd07693    78 YVCVAHNSLGEA 89

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 40.98 E-value: 2.46e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 528501372  115 ITFTNVPSPQEFTEGDNAIIVCDVISSPPPTVLWKYKGAKIQfdKDVRFKTLSNNHLQIRGIRKTDEGVYTC 186
Cdd:cd20957     2 LSATIDPPVQTVDFGRTAVFNCSVTGNPIHTVLWMKDGKPLG--HSSRVQILSEDVLVIPSVKREDKGMYQC 71

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 41.14 E-value: 2.56e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 528501372  121 PSPQEFTEGDNAIIVCDVISSPPPTVLWK---------YKgaKIQFDKDVRFktLSNNHLQIRGIRKTDEGVYTCE 187
Cdd:cd20954     8 PVDANVAAGQDVMLHCQADGFPTPTVTWKkatgstpgeYK--DLLYDPNVRI--LPNGTLVFGHVQKENEGHYLCE 79

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor, and similar domains; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three Ig-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans. This group also contains fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409393 [Multi-domain] Cd Length: 95 Bit Score: 41.05 E-value: 2.76e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 528501372  230 LACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGSEMTVLDVTKL---DEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd05729    24 LECGAGGNPMPNITWLKDGKEFKKEHRIGGTKVEEKGWSLIIERAiprDKGKYTCIVENEYGSINHTYDVDV 95

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 40.84 E-value: 3.09e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  128 EGDNAIIVCDVISSPPPTVLWKYKGAK-IQFDKDVRFKTLSNNHLQIRGIRKTDEGVYTC 186
Cdd:cd20969    16 EGHTVQFVCRADGDPPPAILWLSPRKHlVSAKSNGRLTVFPDGTLEVRYAQVQDNGTYLC 75

Immunoglobulin-like domain of human Aortic Preferentially Expressed Protein-1 (APEG-1) and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin I-set (IgI) domain of the Human Aortic Preferentially Expressed Protein-1 (APEG-1) and similar proteins. APEG-1 is a novel specific smooth muscle differentiation marker predicted to play a role in the growth and differentiation of arterial smooth muscle cells (SMCs). The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the human APEG-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409567 Cd Length: 91 Bit Score: 40.53 E-value: 3.28e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 528501372  236 GFPEPIVTWRRNNAPLESgNKYSFNEDGSE----MTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd20975    26 GEPKPVVSWLRNRQPVRP-DQRRFAEEAEGglcrLRILAAERGDAGFYTCKAVNEYGARQCEARLEV 91

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409442 Cd Length: 92 Bit Score: 40.61 E-value: 3.64e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 528501372  224 MGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGSEMTVLDVTKLDEGDYTCIAKNKAGE 289
Cdd:cd05856    18 VGSSVRLKCVASGNPRPDITWLKDNKPLTPPEIGENKKKKWTLSLKNLKPEDSGKYTCHVSNRAGE 83

Third immunoglobulin (Ig) domain of contactin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409357 [Multi-domain] Cd Length: 88 Bit Score: 40.61 E-value: 3.67e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  209 PTIRIRQAETnATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESgnKYSFNEDGSEMTVLDVTKLDEGDYTCIAKNKAG 288
Cdd:cd04968     1 PSIKVRFPAD-TYALKGQTVTLECFALGNPVPQIKWRKVDGSPSS--QWEITTSEPVLEIPNVQFEDEGTYECEAENSRG 77

                          90
                  ....*....|....*...
gi 528501372  289 eseqelslKVFVQPKITY 306
Cdd:cd04968    78 --------KDTVQGRIIV 87

C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein (also known as myomesin-2). Myomesin and M-protein are both structural proteins localized to the M-band, a transverse structure in the center of the sarcomere, and are candidates for M-band bridges. Both proteins are modular, consisting mainly of repetitive Ig-like and fibronectin type III (FnIII) domains. Myomesin is expressed in all types of vertebrate striated muscle; M-protein has a muscle-type specific expression pattern. Myomesin is present in both slow and fast fibers; M-protein is present only in fast fibers. It has been suggested that myomesin acts as a molecular spring with alternative splicing as a means of modifying its elasticity.

Pssm-ID: 319300 Cd Length: 92 Bit Score: 40.27 E-value: 4.11e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 528501372  230 LACDPDGFPEPIVTWRRNNAPLESGNKYSFN-EDGSE--MTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd05737    21 LTCNVWGDPPPEVSWLKNDQALAFLDHCNLKvEAGRTvyFTINGVSSEDSGKYGLVVKNKYGSETSDVTVSV 92

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 40.18 E-value: 4.99e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  317 EQVTLTCEATGDPTPTITWSFGTRVFTEGEQEqqkriyqaswtrpeqhkgpdgeVLVRSDARvsSLTLKYPQYTDAGQYL 396
Cdd:cd20970    18 ENATFMCRAEGSPEPEISWTRNGNLIIEFNTR----------------------YIVRENGT--TLTIRNIRRSDMGIYL 73

                          90
                  ....*....|..
gi 528501372  397 CTARNAIGETVQ 408
Cdd:cd20970    74 CIASNGVPGSVE 85

Fourth immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues, and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409388 Cd Length: 84 Bit Score: 39.87 E-value: 5.00e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 528501372  119 NVPSPQEFTEGDNAIIVCDVISSPPPTVLWKYKG-AKIQFDkdvRFKTLSNNHLQIRGIRKTDEGVYTC 186
Cdd:cd05723     2 KKPSNIYAHESMDIVFECEVTGKPTPTVKWVKNGdVVIPSD---YFKIVKEHNLQVLGLVKSDEGFYQC 67

C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin, and similar domains; member of the I-set IgSF domains; The members here are composed of the C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin and similar proteins, including Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. In humans these proteins are called Titin. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig-like domain of the Twitchin is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins (titin, telokin, and twitchin), the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D.

Pssm-ID: 409541 [Multi-domain] Cd Length: 89 Bit Score: 39.62 E-value: 6.95e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 528501372  430 EGNPANISCEVLAHPSDVsITWLRDGFQLpNANTSNIKIHNTpSASYLEVNPESQSDFGNYNCTTSNEIGTES 502
Cdd:cd20949    13 EGQSATILCEVKGEPQPN-VTWHFNGQPI-SASVADMSKYRI-LADGLLINKVTQDDTGEYTCRAYQVNSIAS 82

First immunoglobulin (Ig) domain of contactin-2; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-2-like. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. It may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module by contacts between IG domains 1 and 4, and domains 2 and 3. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-2 is also expressed in retinal amacrine cells in the developing chick retina, corresponding to the period of formation and maturation of AC processes. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409437 [Multi-domain] Cd Length: 97 Bit Score: 39.91 E-value: 7.83e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 528501372  123 PQEFTEGdNAIIVCDVISSPPPTVLWKYKGAKIQFDKDVRFKTLSNNHLQIRGIRKTDEGVYTCEGrIKARGEV 196
Cdd:cd05850    15 PEGSAEE-KVTLACRARASPPATYRWKMNGTELKMEPDSRYRLVAGNLVISNPVKAKDAGSYQCLA-SNRRGTV 86

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 39.05 E-value: 1.02e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 528501372  221 TADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDgSEMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd20957    12 TVDFGRTAVFNCSVTGNPIHTVLWMKDGKPLGHSSRVQILSE-DVLVIPSVKREDKGMYQCFVRNDGDSAQATAELKL 88

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 39.15 E-value: 1.22e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  303 KITYLESQTTTEMDEQVTLTCEATGDPTPTITWSfgtrvftegeqeqqkriyqaswtrpeqhkgpDGEVLVRSDARVS-- 380
Cdd:cd20968     1 KITRPPTNVTIIEGLKAVLPCTTMGNPKPSVSWI-------------------------------KGDDLIKENNRIAvl 49

                          90       100       110
                  ....*....|....*....|....*....|....*...
gi 528501372  381 ---SLTLKYPQYTDAGQYLCTARNAIGETV-QPVSLEV 414
Cdd:cd20968    50 esgSLRIHNVQKEDAGQYRCVAKNSLGIAYsKPVTIEV 87

First immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409387 Cd Length: 97 Bit Score: 39.00 E-value: 1.30e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 528501372  219 NATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESG---NKYSFNeDGS----EMTVLDVTKLDEGDYTCIAKNK 286
Cdd:cd05722    10 DIVAMRGGPVVLNCSAESDPPPKIEWKKDGVLLNLVsdeRRQQLP-NGSllitSVVHSKHNKPDEGFYQCVAQNE 83

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 39.02 E-value: 1.34e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  302 PKITY-LESQTTTEMDeQVTLTCEATGDPTPTITWSFGTRVFTEGEQeqqkriyqaswtrpeqHKgpdgeVLVRSDARVS 380
Cdd:cd05744     1 PHFLQaPGDLEVQEGR-LCRFDCKVSGLPTPDLFWQLNGKPVRPDSA----------------HK-----MLVRENGRHS 58

                          90       100       110
                  ....*....|....*....|....*....|....
gi 528501372  381 sLTLKYPQYTDAGQYLCTARNAIGETVQPVSLEV 414
Cdd:cd05744    59 -LIIEPVTKRDAGIYTCIARNRAGENSFNAELVV 91

Immunoglobulin (Ig)-like ectodomain of the LRIG1 (Leucine-rich Repeats And Immunoglobulin-like Domains Protein 1) and similar proteins; member of the I-set of IgSF domains; The members here are composed of subgroup of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. The ectodomain of LRIG1 has two distinct regions: the proposed 15 LRRs and three Ig-like domains closer to the membrane. LRIG1 has been reported to interact with many receptor tyrosine kinases, GDNF/c-Ret, E-cadherin, JAK/STAT, c-Met, and the EGFR family signaling systems. Immunoglobulin Superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The structure of the LRIG1 extracellular Ig domain lacks a C" strand and thus is better described as a member of the I-set of IgSF domains.

Pssm-ID: 409420 [Multi-domain] Cd Length: 91 Bit Score: 38.75 E-value: 1.39e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  321 LTCEATGDPTPTITWsfgtrvftegeQEQQKRIYQASWTRpEQHKGPDGEVLVRSDARVSsltlkypqytDAGQYLCTAR 400
Cdd:cd05763    19 LECAATGHPTPQIAW-----------QKDGGTDFPAARER-RMHVMPEDDVFFIVDVKIE----------DTGVYSCTAQ 76

                          90
                  ....*....|....
gi 528501372  401 NAIGETVQPVSLEV 414
Cdd:cd05763    77 NSAGSISANATLTV 90

Third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule 1 (NCAM-1); member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions) through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain.

Pssm-ID: 143207 [Multi-domain] Cd Length: 95 Bit Score: 39.14 E-value: 1.39e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   33 VGESRFFLCEVIGGAKEIDWFAPAGEKIEPGRPDISVirnDETSSTLTIYNAKVDNAGTYRCVASSGDQDAEATVNLKIY 112
Cdd:cd05730    17 LGQSVTLACDADGFPEPTMTWTKDGEPIESGEEKYSF---NEDGSEMTILDVDKLDEAEYTCIAENKAGEQEAEIHLKVF 93


                  ..
gi 528501372  113 QK 114
Cdd:cd05730    94 AK 95

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 38.38 E-value: 1.52e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  128 EGDNAIIVCDVISSPPPTVLWKYKGAKIQFDKdvRFKTLSNNHLQIRGIRKTDEGVYTCE 187
Cdd:cd05745     1 EGQTVDFLCEAQGYPQPVIAWTKGGSQLSVDR--RHLVLSSGTLRISRVALHDQGQYECQ 58

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 38.72 E-value: 1.53e-03

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|.
gi 528501372   238 PEPIVTWRRNNAPLESGNKYSFNEDG---SEMTVLDVTKLDEGDYTCIAKN 285
Cdd:pfam00047   25 PGPDVTWSKEGGTLIESLKVKHDNGRttqSSLLISNVTKEDAGTYTCVVNN 75

C-terminal immunoglobulin (Ig)-like domain of M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of M-protein (also known as myomesin-2). M-protein is a structural protein localized to the M-band, a transverse structure in the center of the sarcomere, and is a candidate for M-band bridges. M-protein is modular consisting mainly of repetitive IG-like and fibronectin type III (FnIII) domains and has a muscle-type specific expression pattern. M-protein is present in fast fibers.

Pssm-ID: 143299 Cd Length: 92 Bit Score: 38.74 E-value: 1.60e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 528501372  230 LACDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGSE---MTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd05891    21 LTCTVFGNPDPEVIWFKNDQDIELSEHYSVKLEQGKyasLTIKGVTSEDSGKYSINVKNKYGGETVDVTVSV 92

Immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan, also known as HSPG2, and similar proteins. Perlecan consists of five domains: domain I has three putative heparan sulfate attachment sites, domain II has four LDL receptor-like repeats, and one Ig-like repeat, domain III resembles the short arm of laminin chains, domain IV has multiple Ig-like repeats (21 repeats in human perlecan), and domain V resembles the globular G domain of the laminin A chain and internal repeats of EGF. Perlecan may participate in a variety of biological functions including cell binding, LDL-metabolism, basement membrane assembly and selective permeability, calcium binding, and growth- and neurite-promoting activities.

Pssm-ID: 143220 Cd Length: 78 Bit Score: 38.24 E-value: 1.66e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  317 EQVTLTCEATGDPTPTITWSFgtrvftegeqeqqkriyqaSWTrpeqHKGPDGEVLVRSDARVSSLTLKYPQYTDAGQYL 396
Cdd:cd05743     2 ETVEFTCVATGVPTPIINWRL-------------------NWG----HVPDSARVSITSEGGYGTLTIRDVKESDQGAYT 58


                  ....*...
gi 528501372  397 CTARNAIG 404
Cdd:cd05743    59 CEAINTRG 66

Third immunoglobulin-like domain of the human WFIKKN (WAP, follistatin, immunoglobulin, Kunitz and NTR domain-containing protein), and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin-like domain of the human WFIKKN (WAP, follistatin, immunoglobulin, Kunitz and NTR domain-containing protein) and similar proteins. WFIKKN is a secreted protein that consists of multiple types of protease inhibitory modules, including two tandem Kunitz-type protease inhibitor-domains. The Ig superfamily is a heterogenous group of proteins built on a common fold comprised of a sandwich of two beta sheets. Members of the Ig superfamily are components of immunoglobulin, neuroglia, cell surface glycoproteins, such as T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, such as butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409422 [Multi-domain] Cd Length: 95 Bit Score: 38.68 E-value: 1.90e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   25 TPAHGEISVGESRFFLCEVIGGAK-EIDWfapagEKIEPGRPDIsVIRNDETSST--------LTIYNAKVDNAGTYRCV 95
Cdd:cd05765     6 SPTHQTVKVGETASFHCDVTGRPQpEITW-----EKQVPGKENL-IMRPNHVRGNvvvtnigqLVIYNAQPQDAGLYTCT 79


                  .
gi 528501372   96 A 96
Cdd:cd05765    80 A 80

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 38.33 E-value: 2.11e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   317 EQVTLTCEA-TGDPTPTITWSFGTRVFTEGEQEQQKRIYQaswtrpeqhkgpdgevlvrsdaRVSSLTLKYPQYTDAGQY 395
Cdd:pfam00047   12 DSATLTCSAsTGSPGPDVTWSKEGGTLIESLKVKHDNGRT----------------------TQSSLLISNVTKEDAGTY 69

                           90
                   ....*....|.
gi 528501372   396 LCTARNAIGET 406
Cdd:pfam00047   70 TCVVNNPGGSA 80

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor(R); member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor(R). The VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. The VEGFR family consists of three members, VEGFR-1 (also known as Flt-1), VEGFR-2 (also known as KDR or Flk-1) and VEGFR-3 (also known as Flt-4). VEGF_A interacts with both VEGFR-1 and VEGFR-2. VEGFR-1 binds strongest to VEGF, VEGF-2 binds more weakly. VEGFR-3 appears not to bind VEGF, but binds other members of the VEGF family (VEGF-C and -D). VEGFRs bind VEGFs with high affinity with the IG-like domains. VEGF-A is important to the growth and maintenance of vascular endothelial cells and to the development of new blood- and lymphatic-vessels in physiological and pathological states. VEGFR-2 is a major mediator of the mitogenic, angiogenic and microvascular permeability-enhancing effects of VEGF-A. VEGFR-1 may play an inhibitory part in these processes by binding VEGF and interfering with its interaction with VEGFR-2. VEGFR-1 has a signaling role in mediating monocyte chemotaxis. VEGFR-2 and -1 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. VEGFR-3 has been shown to be involved in tumor angiogenesis and growth.

Pssm-ID: 409448 Cd Length: 102 Bit Score: 38.58 E-value: 2.17e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   25 TPAHGEISVGESRFFLCEV---IGGAKEIDWFAPaGEKIEPG---RPDISVIRND--ETSSTLTIYNAKVDNAGTYRCVA 96
Cdd:cd05862     7 PPKPVELLVGEKLVLNCTArteLNVGVDFQWDYP-GKKEQRRasvRRRRKQQSSEatEFSSTLTIDNVTLSDKGLYTCAA 85

                          90
                  ....*....|....*..
gi 528501372   97 SSGDQDAEATVNLKIYQ 113
Cdd:cd05862    86 SSGPMFKKNSTSVIVHE 102

IL-1 receptor-like protein; Provisional

Pssm-ID: 165173 [Multi-domain] Cd Length: 227 Bit Score: 40.67 E-value: 2.31e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  162 RFKTLSNNHLQIRG-------IRKTDEGVYTCegRIKARGEVDFRSIKVVVNVlPTIRIRQAEtnatadmGFSTLLAC-D 233
Cdd:PHA02826   84 KIKKITHNEIGDRSenlwignVINIDEGIYIC--TISSGNICEESTIRLTFDS-GTINYQFNS-------GKDSKLHCyG 153

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 528501372  234 PDG----FPEPIVTWRRNNAPLESGNKYSFNEDGSEMTVLDVTKLDEGDYTC---IAKN 285
Cdd:PHA02826  154 TDGisstFKDYTLTWYKNGNIVLYTDRIQLRNNNSTLVIKSATHDDSGIYTCnlrFNKN 212

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 38.33 E-value: 2.39e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 528501372  430 EGNPANISCEVLAHPSDVsITWLRDGFQLpnANTSNIKIHNTPSASYLEVNPESQSDFGNYNCTTSNEIGTES 502
Cdd:cd20972    15 EGSKVRLECRVTGNPTPV-VRWFCEGKEL--QNSPDIQIHQEGDLHSLIIAEAFEEDTGRYSCLATNSVGSDT 84

Sixth immunoglobulin (Ig) domain of contactin; The members here are composed of the sixth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409359 Cd Length: 102 Bit Score: 38.30 E-value: 2.52e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  303 KITYLESQTTTEMDEQVTLTCEATGDPTP--TITWSFGTRV--FTEGEQEQQKRIYQASwtrpeqhkgpDGEVLVRSdar 378
Cdd:cd04970     4 RITLAPSNADITVGENATLQCHASHDPTLdlTFTWSFNGVPidLEKIEGHYRRRYGKDS----------NGDLEIVN--- 70

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|
gi 528501372  379 vssltlkyPQYTDAGQYLCTARNAIGETVQPVSLEVRYAP 418
Cdd:cd04970    71 --------AQLKHAGRYTCTAQTVVDSDSASATLVVRGPP 102

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 37.76 E-value: 2.56e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372   218 TNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESgnkysfnedGSEMTVLDVTKLDEGDYTCIAKNKAGeSEQELSLK 297
Cdd:pfam13895    7 SPTVVTEGEPVTLTCSAPGNPPPSYTWYKDGSAISS---------SPNFFTLSVSAEDSGTYTCVARNGRG-GKVSNPVE 76


                   ...
gi 528501372   298 VFV 300
Cdd:pfam13895   77 LTV 79

Immunoglobulin domain I1 of the titin I-band and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin domain I1 of the titin I-band and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig I1 domain of the titin I-band is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409543 [Multi-domain] Cd Length: 94 Bit Score: 38.17 E-value: 2.57e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 528501372  429 WEGNPANISCEVLAHPSDVsITWLRDGFQL-PNANTSNIKIHNTPSASYLEVNPESQSDFGNYNCTTSNEIGTES 502
Cdd:cd20951    13 WEKSDAKLRVEVQGKPDPE-VKWYKNGVPIdPSSIPGKYKIESEYGVHVLHIRRVTVEDSAVYSAVAKNIHGEAS 86

Fourth immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the fourth immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted, and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143223 Cd Length: 69 Bit Score: 37.55 E-value: 2.68e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 528501372  436 ISCEVLAHPSDVsITWLRDGFQLpnanTSNIKIHNTPsASYLEVNPESQSDFGNYNCTTSNEIGTES 502
Cdd:cd05746     3 IPCSAQGDPEPT-ITWNKDGVQV----TESGKFHISP-EGYLAIRDVGVADQGRYECVARNTIGYAS 63

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 37.95 E-value: 3.02e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 528501372  117 FTNVPSPQEFTEGDNAIIVCDVISSPPPTVLWKYKGAKIQFDKDVRFKTLSNNH-LQIRGIRKTDEGVYTC 186
Cdd:cd20972     4 FIQKLRSQEVAEGSKVRLECRVTGNPTPVVRWFCEGKELQNSPDIQIHQEGDLHsLIIAEAFEEDTGRYSC 74

Immunoglobulin (Ig)-like domain of human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) domains 2, 4, and 6, and similar domains; The members here are composed of the second, fourth, and sixth immunoglobulin (Ig)-like domains in human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) protein subfamily. The CEA family is a group of anchored or secreted glycoproteins expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions; it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two [D1, D4] or four [D1-D4] Ig-like domains on the cell surface.

Pssm-ID: 409402 [Multi-domain] Cd Length: 89 Bit Score: 37.76 E-value: 3.13e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 528501372  230 LACDPDGFPEPIVtWRRNNAPLESGNKYSFNEDGSEMTVLDVTKLDEGDYTCIAKN 285
Cdd:cd05740    20 LTCEPETQNTSYL-WWFNGQSLPVTPRLTLSNGNRTLTLLNVTREDAGAYQCEISN 74

Sixth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the sixth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409551 Cd Length: 94 Bit Score: 37.86 E-value: 3.54e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  222 ADMGFSTLLACD-PDGFPEPIVTWRRNNAPLESGNKYSFNEDGSEMTVLDVTKLD---EGDYTCIAKNKAGESEQELSLK 297
Cdd:cd20959    14 AQVGMRAQLHCGvPGGDLPLNIRWTLDGQPISDDLGITVSRLGRRSSILSIDSLEashAGNYTCHARNSAGSASYTAPLT 93


                  .
gi 528501372  298 V 298
Cdd:cd20959    94 V 94

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1); The members here are composed of the fourth Ig domain of Neural Cell Adhesion Molecule 1(NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM) and heterophilic (NCAM-non-NCAM) interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 143277 [Multi-domain] Cd Length: 97 Bit Score: 38.04 E-value: 3.58e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  212 RIRQAETNATADMGFSTLLACDPDGFPEPIVTWRRNNAPLESGNKysfNEDG----------SEMTVLDVTKLDEGDYTC 281
Cdd:cd05869     4 KITYVENQTAMELEEQITLTCEASGDPIPSITWRTSTRNISSEEK---TLDGhivvrsharvSSLTLKYIQYTDAGEYLC 80

                          90
                  ....*....|....*..
gi 528501372  282 IAKNKAGESEQELSLKV 298
Cdd:cd05869    81 TASNTIGQDSQSMYLEV 97

First immunoglobulin (Ig) domain of contactin-5; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-5. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains, anchored to the membrane by glycosylphosphatidylinositol. The different contactins show different expression patterns in the central nervous system. In rats, a lack of contactin-5 (NB-2) results in an impairment of the neuronal activity in the auditory system. Contactin-5 is expressed specifically in the postnatal nervous system, peaking at about 3 weeks postnatal. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala; lower levels of expression have been detected in the corpus callosum, caudate nucleus, and spinal cord. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409435 Cd Length: 96 Bit Score: 38.00 E-value: 3.67e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  316 DEQVTLTCEATGDPTPTITWSF-GTRVFTEGEqeqqkriYQASWTrpeqhkgpDGEVLVRSDARVssltlkypqyTDAGQ 394
Cdd:cd05848    19 EKKVILNCEARGNPVPTYRWLRnGTEIDTESD-------YRYSLI--------DGNLIISNPSEV----------KDSGR 73

                          90
                  ....*....|
gi 528501372  395 YLCTARNAIG 404
Cdd:cd05848    74 YQCLATNSIG 83

Fifth domain (immunoglobulin-like) of Trk receptors TrkA, TrkB, and TrkC; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth domain of Trk receptors TrkA, TrkB, and TrkC, an immunoglobulin (Ig)-like domain which binds to neurotrophin. The Trk family of receptors are tyrosine kinase receptors. They are activated by dimerization, leading to autophosphorylation of intracellular tyrosine residues, and triggering the signal transduction pathway. TrkA, TrkB, and TrkC share significant sequence homology and domain organization. The first three domains are leucine-rich domains while the fourth and fifth domains are Ig-like domains playing a part in ligand binding. TrkA, TrkB, and TrkC mediate the trophic effects of the neurotrophin Nerve Growth Factor (NGF) family. TrkA is recognized by NGF. TrkB is recognized by brain-derived neurotrophic factor (BDNF) and neurotrophin (NT)-4. TrkC is recognized by NT-3. NT-3 is promiscuous as in some cell systems it activates TrkA and TrkB receptors. TrkA is a receptor found in all major NGF targets, including the sympathetic, trigeminal, and dorsal root ganglia, cholinergic neurons of the basal forebrain, and the striatum. TrKB transcripts are found throughout multiple structures of the central and peripheral nervous systems. The TrkC gene is expressed throughout the mammalian nervous system. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409360 Cd Length: 96 Bit Score: 37.77 E-value: 3.76e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 528501372  235 DGFPEPIVTWRRNNAPLESgNKY---SFNEDGSEMTV------LDV-TKLDEGDYTCIAKNKAGESEQELS 295
Cdd:cd04971    23 RGNPKPTLTWYHNGAVLNE-SDYirtEIHYEAATPTEyhgclkFDNpTHVNNGNYTLVASNEYGQDSKSIS 92

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 37.56 E-value: 3.97e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  304 ITYLESQTTTEmDEQVTLTCEATGDPTPTITWsfgtrvFTEGEqeqqkriyqaswtrpEQHKGPDGEVLVRSDARVSSLT 383
Cdd:cd20972     5 IQKLRSQEVAE-GSKVRLECRVTGNPTPVVRW------FCEGK---------------ELQNSPDIQIHQEGDLHSLIIA 62

                          90       100
                  ....*....|....*....|.
gi 528501372  384 LKYPQytDAGQYLCTARNAIG 404
Cdd:cd20972    63 EAFEE--DTGRYSCLATNSVG 81

Fourth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409548 [Multi-domain] Cd Length: 96 Bit Score: 37.54 E-value: 3.99e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 528501372  230 LACDPDGFPEPIVTWRRNNAPLESGNKYSF----NEDG---SEMTVLDVTKLDEGDYTCIAKNKAGE 289
Cdd:cd20956    21 LKCVASGNPLPQITWTLDGFPIPESPRFRVgdyvTSDGdvvSYVNISSVRVEDGGEYTCTATNDVGS 87

First immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R), and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R; also known as cluster of differentiation (CD) 121). IL-1 alpha and IL-1 beta are cytokines which participate in the regulation of inflammation, immune responses, and hematopoiesis. These cytokines bind to the IL-1 receptor type 1 (IL1R1), which is activated on additional association with interleukin-1 receptor accessory protein (IL1RAP). IL-1 also binds a second receptor designated type II (IL1R2). Mature IL1R1 consists of three Ig-like domains, a transmembrane domain, and a large cytoplasmic domain. Mature IL1R2 is organized similarly except that it has a short cytoplasmic domain. The latter does not initiate signal transduction. A naturally occurring cytokine IL-1RA (IL-1 receptor antagonist) is widely expressed and binds to IL-1 receptors, inhibiting the binding of IL-1 alpha and IL-1 beta.

Pssm-ID: 409414 Cd Length: 96 Bit Score: 37.79 E-value: 4.12e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 528501372  430 EGNPANISCEVLAHP----SDVSITWLRDGFQLPNANTSNIKIHNTPSASYLEvnPESQSDFGNYNCTTSN 496
Cdd:cd05756    14 EGEPDVIKCPLFPNFlaqsAGLNLTWYKNDSETPISFEPDSRIHQEKDKLWFV--PALLEDSGNYYCVVRN 82

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 37.43 E-value: 4.33e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  320 TLTCEATGDPTPTITWSfgtrvfTEGeqeqqkriyqaswtRPEQHKGPDGEVLVRSDarvsSLTLKYPQYTDAGQYLCTA 399
Cdd:cd04978    18 ELICEAEGNPQPTITWR------LNG--------------VPIEPAPEDMRRTVDGR----TLIFSNLQPNDTAVYQCNA 73

                          90
                  ....*....|....*.
gi 528501372  400 RNAIGETVQPVSLEVR 415
Cdd:cd04978    74 SNVHGYLLANAFLHVL 89

Second immunoglobulin (Ig)-like domain of the receptor protein tyrosine phosphatase (RPTP)-F; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in the receptor protein tyrosine phosphatase (RPTP)-F, also known as LAR. LAR belongs to the RPTP type IIa subfamily. Members of this subfamily are cell adhesion molecule-like proteins involved in central nervous system (CNS) development. They have large extracellular portions comprised of multiple Ig-like domains and two to nine fibronectin type III (FNIII) domains and a cytoplasmic portion having two tandem phosphatase domains.

Pssm-ID: 409400 [Multi-domain] Cd Length: 91 Bit Score: 37.30 E-value: 4.75e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 528501372  433 PANISCEVLAHPsDVSITWLRDgFQLPNANTSNIKIHNTPSASyLEVNPESQSDFGNYNCTTSNEIGT 500
Cdd:cd05738    16 TATMLCAASGNP-DPEISWFKD-FLPVDTATSNGRIKQLRSGA-LQIENSEESDQGKYECVATNSAGT 80

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 36.84 E-value: 4.84e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 528501372  232 CDPDGFPEPIVTWRRNNAPLESGNKYSFNEDGSeMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd05745     9 CEAQGYPQPVIAWTKGGSQLSVDRRHLVLSSGT-LRISRVALHDQGQYECQAVNIVGSQRTVAQLTV 74

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 37.53 E-value: 4.90e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 528501372  431 GNPANISCEVLAHPSDvSITWLRDGFQLpNANTSNIKIHNT--PSAS--YLEV--NPESQSDFGNYNCTTSNEIGT 500
Cdd:cd07693    15 GDPATLNCKAEGRPTP-TIQWLKNGQPL-ETDKDDPRSHRIvlPSGSlfFLRVvhGRKGRSDEGVYVCVAHNSLGE 88

Second immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. DSCAM is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409545 Cd Length: 95 Bit Score: 37.52 E-value: 5.08e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  302 PKITYLESQTTTEMDE--QVTLTCEATGDPTPTITWSfgtrVFTEGEQEQQ-----KRIYQASWTrpeqhkgpdgevLVR 374
Cdd:cd20953     2 PKIPGLSKSQPLTVSSasSIALLCPAQGYPAPSFRWY----KFIEGTTRKQavvlnDRVKQVSGT------------LII 65

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 528501372  375 SDARVSsltlkypqytDAGQYLCTARNAI-GETVQPV 410
Cdd:cd20953    66 KDAVVE----------DSGKYLCVVNNSVgGESVETV 92

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 37.23 E-value: 5.58e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 528501372  430 EGNPANISCEVLAHPSDvSITWLRDGFQLpnaNTSNIKIHNTPSASYLEVNPESQSDFGNYNCTTSNEIGTES 502
Cdd:cd20976    15 EGQDFVAQCSARGKPVP-RITWIRNAQPL---QYAADRSTCEAGVGELHIQDVLPEDHGTYTCLAKNAAGQVS 83

Immunoglobulin domain I1 of the titin I-band and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin domain I1 of the titin I-band and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig I1 domain of the titin I-band is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409543 [Multi-domain] Cd Length: 94 Bit Score: 37.02 E-value: 5.84e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  302 PKIT-YLESQTTTEmDEQVTLTCEATGDPTPTITWsfgtrvFTEGEqeqqkriyqaswtrPEQHKGPDGEVLVRSDARVS 380
Cdd:cd20951     1 PEFIiRLQSHTVWE-KSDAKLRVEVQGKPDPEVKW------YKNGV--------------PIDPSSIPGKYKIESEYGVH 59

                          90       100       110
                  ....*....|....*....|....*....|....*
gi 528501372  381 SLTLKYPQYTDAGQYLCTARNAIGETVQPVSLEVR 415
Cdd:cd20951    60 VLHIRRVTVEDSAVYSAVAKNIHGEASSSASVVVE 94

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 2 (NCAM-2); The members here are composed of the fourth Ig domain of Neural Cell Adhesion Molecule NCAM-2 (also known as OCAM/mamFas II and RNCAM). NCAM-2 is organized similarly to NCAM, including five N-terminal Ig-like domains and two fibronectin type III domains. NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE), and may function like NCAM, as an adhesion molecule. One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 143278 [Multi-domain] Cd Length: 98 Bit Score: 37.26 E-value: 5.92e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  219 NATADMGFSTLLACDPDGFPEPIVTWRRnnapleSGNKYSFNE-----DG----------SEMTVLDVTKLDEGDYTCIA 283
Cdd:cd05870    10 NETTVENGAATLSCKAEGEPIPEITWKR------ASDGHTFSEgdkspDGrievkgqhgeSSLHIKDVKLSDSGRYDCEA 83

                          90
                  ....*....|....*
gi 528501372  284 KNKAGESEQELSLKV 298
Cdd:cd05870    84 ASRIGGHQKSMYLDI 98

Second Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the second Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 409392 Cd Length: 88 Bit Score: 37.16 E-value: 6.11e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 528501372  430 EGNPANISCEVLAHPSDVSITWLRDGFqlPNANTSNIKIHNTPSASYLEVNPESQSDFGNYNCTTSNEIGTESR 503
Cdd:cd05727     9 EGWGVVLFCDPPPHYPDLSYRWLLNEF--PNFIPEDGRRFVSQTNGNLYIAKVEASDRGNYSCFVSSPSSTKSV 80

Third immunoglobulin domain in Cluster of Differentiation (CD) 22; member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain in Cluster of Differentiation (CD) 22 (also known as Siglec-2). CD22, a sialic-acid binding immunoglobulin type-lectin (Siglec) family member, is an inhibitory co-receptor of the B-cell receptor (BCR). The inhibitory function of CD22 and its restricted expression on B cells makes CD22 an attractive target against dysregulated B cells that cause autoimmune diseases and B-cell-derived cancers. CD22 plays a vital role in establishing a baseline level of B-cell inhibition, and thus is an important determinant of homeostasis in humoral immunity. Siglecs are primarily expressed on immune cells and recognize sialic acid-containing glycan ligands. Siglecs are organized as an extracellular module composed of Ig-like domains (an N-terminal variable set of Ig-like carbohydrate recognition domains, and 1 to 16 constant Ig-like domains), followed by transmembrane and short cytoplasmic domains. Human Siglecs are classified into two subgroups, one subgroup is comprised of sialoadhesin (Siglec-1), CD22 (Siglec-2), and MAG (Siglec-4, myelin-associated glycoprotein), the other subgroup is comprised of CD33-related Siglecs which include CD33 (Siglec-3) and human Siglecs 5-11. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409531 Cd Length: 88 Bit Score: 37.09 E-value: 6.29e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 528501372  430 EGNPANISCEVLA-HPSDVSITWLRDGFQLPNANTSNIKIHNTpsasylevnpeSQSDFGNYNCTTSNEIGTE 501
Cdd:cd20937    16 EGDSVTMTCEVSSsNPEYTTVSWLKDGTSLKKQNTFTLNLREV-----------TKDQSGKYCCQVSNDVGPG 77

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three IG-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans.

Pssm-ID: 409443 [Multi-domain] Cd Length: 95 Bit Score: 37.14 E-value: 6.52e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  232 CDPDGFPEPIVTWRRNNAPLESGNK---YSFNEDGSEMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd05857    26 CPAAGNPTPTMRWLKNGKEFKQEHRiggYKVRNQHWSLIMESVVPSDKGNYTCVVENEYGSINHTYHLDV 95

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409391 [Multi-domain] Cd Length: 98 Bit Score: 36.86 E-value: 7.44e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 528501372  219 NATADMGFSTLLACDPDGFPEPIVTWRRN--------NAPLESGNKYSFNEDGsEMTVLDVTKLDEGDYTCIAKNKAG 288
Cdd:cd05726     8 DQVVALGRTVTFQCETKGNPQPAIFWQKEgsqnllfpYQPPQPSSRFSVSPTG-DLTITNVQRSDVGYYICQALNVAG 84

Second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R; also known as cluster of differentiation (CD) 121). IL-1 alpha and IL-1 beta are cytokines which participate in the regulation of inflammation, immune responses, and hematopoiesis. These cytokines bind to the IL-1 receptor type 1 (IL1R1), which is activated on additional association with interleukin-1 receptor accessory protein (IL1RAP). IL-1 also binds a second receptor designated type II (IL1R2). Mature IL1R1 consists of three IG-like domains, a transmembrane domain, and a large cytoplasmic domain. Mature IL1R2 is organized similarly except that it has a short cytoplasmic domain. The latter does not initiate signal transduction. A naturally occurring cytokine IL-1RA (IL-1 receptor antagonist) is widely expressed and binds to IL-1 receptors, inhibiting the binding of IL-1 alpha and IL-1 beta. This group also contains ILIR-like 1 (IL1R1L) which maps to the same chromosomal location as IL1R1 and IL1R2.

Pssm-ID: 409415 Cd Length: 92 Bit Score: 36.92 E-value: 7.61e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 528501372  240 PIVTWRRNNAPLESGNKYSFNedGSEMTVLDVTKLDEGDYTCIAK 284
Cdd:cd05757    30 PPIQWYKDCKPLQGDKRFIPK--GSKLLIQNVTEEDAGNYTCKFT 72

Immunoglobulin-like M1 domain from Titin; a member of the I-set of IgSF domains; The members here are composed of the Immunoglobulin-like M1 I-set domain from Titin and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin-M1 domain lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409521 Cd Length: 90 Bit Score: 36.55 E-value: 7.98e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 528501372  242 VTWRRNNAPLESGNKYSFN-EDG-SEMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd20927    32 VTWYFGVRQLENSEKYEITyEDGvAILYVKDITKFDDGTYRCKVVNDYGEDSSYAELFV 90

C5 immunoglobulin (Ig) domain of cardiac myosin binding protein C (MyBP-C); The members here are composed of the C5 immunoglobulin (Ig) domain of cardiac myosin binding protein C (MyBP-C). MyBP-C consists of repeated domains, Ig and fibronectin type 3, and various linkers. Three isoforms of MYBP-C exist: slow-skeletal (ssMyBP-C), fast-skeletal (fsMyBP-C), and cardiac (cMyBP-C). cMYBP-C has insertions between and inside domains and an additional cardiac-specific Ig domain at the N-terminus. For cMYBP_C an interaction has been demonstrated between this C5 domain and the Ig C8 domain.

Pssm-ID: 409475 Cd Length: 86 Bit Score: 36.36 E-value: 8.83e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 528501372  236 GFPEPIVTWRRNNAPLESGNKYSFNE---DGSEMTVLDVTKLDEGDYTCIAKNKAGESEQELSLKV 298
Cdd:cd05894    21 GEPAPTVTWSRGDKAFTATEGRVRVEsykDLSSFVIEGAEREDEGVYTITVTNPVGEDHASLFVKV 86

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

Pssm-ID: 409397 [Multi-domain] Cd Length: 97 Bit Score: 36.70 E-value: 9.47e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  319 VTLTCEATGDPTPTITWSfgtrvFTEGEQEQQKriyqaswtrpeQHKGP-DGEVLVRSDarvSSLTLKYPQYTDAGQYLC 397
Cdd:cd05734    19 VVLNCSADGYPPPTIVWK-----HSKGSGVPQF-----------QHIVPlNGRIQLLSN---GSLLIKHVLEEDSGYYLC 79

                          90
                  ....*....|.
gi 528501372  398 TARNAIGETVQ 408
Cdd:cd05734    80 KVSNDVGADIS 90

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 36.46 E-value: 9.56e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528501372  117 FTNVPSPQEFTEGDNAIIVCDVISSPPPTVLWKYKGAKIQFDKDVRFKTLSNNHLQIRGIRKTDEGVYTCEGRiKARGEV 196
Cdd:cd20976     4 FSSVPKDLEAVEGQDFVAQCSARGKPVPRITWIRNAQPLQYAADRSTCEAGVGELHIQDVLPEDHGTYTCLAK-NAAGQV 82


                  ....*....
gi 528501372  197 DfRSIKVVV 205
Cdd:cd20976    83 S-CSAWVTV 90

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 36.27 E-value: 9.64e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 528501372  121 PSPQEFTEGDNAIIVCDVISSPPPTVLWKYKGAKIQFDKDVRFKTLSNNHLQIRGIRKTDEGVYTCEGR 189
Cdd:cd04978     6 PPSLVLSPGETGELICEAEGNPQPTITWRLNGVPIEPAPEDMRRTVDGRTLIFSNLQPNDTAVYQCNAS 74