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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565  34 VRVRVLPEVRGRLGGTVELPCHLLPPTT-ERVSQVTWQRLD-GTVVAAFHPSFGVDFPNSqfnkDRLSFVRAKQeaNADL 111
Cdd:cd20989    1 VRVQVPPEVRGFLGGSVTLPCHLLPPNMvTHVSQVTWQRHDeHGSVAVFHPKQGPSFPES----ERLSFVAARL--GAEL 74

                         90       100       110
                 ....*....|....*....|....*....|....*...
gi 564326565 112 RDATLAFRGLRVEDEGNYTCEFATFPNGTRRGVTWLRV 149
Cdd:cd20989   75 RNASLAMFGLRVEDEGNYTCEFATFPQGSRSGDTWLRV 112

Second immunoglobulin (Ig) domain of Nectin-2 and Nectin-like protein 5, and similar domains; member of the C1-set of the Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig) domain of nectin-2 (also known as poliovirus receptor related protein 2 or Cluster of Differentiation 112 (CD112)), nectin-like protein 5 (CD155), and similar proteins. Nectins and Nectin-like molecules are a family of Ca(2+)-independent immunoglobulin-like transmembrane glycoproteins belonging to the class of adhesion receptors, consisting of nine members (nectins 1 through 4 and nectin-like proteins 1 through 5). Nectins are synaptic cell adhesion molecules (CAMs) which facilitate adhesion and signaling at various intracellular junctions. Nectins form homophilic cis-dimers, followed by homophilic and heterophilic trans-dimers involved in cell-cell adhesion. Nectin-2 and nectin-3 localize at Sertoli-spermatid junctions where they form heterophilic trans-interactions between the cells that are essential for the formation and maintenance of the junctions and for spermatid development. CD155 is the fifth member in the nectin-like molecule family, and functions as the receptor of poliovirus; therefore, CD155 is also referred to as Necl-5, or PVR. In contrast to all other family members, CD155 lacks self-adhesion capacity, yet it shares with nectins the feature to interact with other nectins. For instance, CD155 heterophilically trans-interacts with nectin-3, thereby contributing significantly to the establishment of adherens junctions between epithelial cells. This group belongs to the Constant 1 (C1)-set of IgSF domains, which has one beta-sheet that is formed by strands A-B-E-D and the other strands by G-F-C-C'.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565 153 PENHAEAQEVTIGPQSVAVARCISTGGRPPARITWISSLGGEARDIQEPGLQAGTVTVISRYSMVPVGRADGVKVTCRVE 232
Cdd:cd07703    1 PKNSAEAQEVQAGGIPVPVARCVSANGRPPARISWSSTLNGNANTTQVPGPDSGTVTVTSEYSLVPTPEANGKEVTCKVE 80

                         90
                 ....*....|....*..
gi 564326565 233 HESLEEPELLPVILSVR 249
Cdd:cd07703   81 HETLEEPQLLPVTLSVR 97

First immunoglobulin variable (IgV) domain of nectin-2, nectin-like protein 5, and similar domains; The members here are composed of the second immunoglobulin (Ig) domain of nectin-2 (also known as poliovirus receptor related protein 2 or Cluster of Differentiation 112 (CD112)), nectin-like protein 5 (CD155), and similar proteins. Nectins and Nectin-like molecules are a family of Ca(2+)-independent immunoglobulin-like transmembrane glycoproteins belonging to the class of adhesion receptors, consisting of nine members (nectins 1 through 4 and nectin-like proteins 1 through 5). Nectins are synaptic cell adhesion molecules (CAMs) which facilitate adhesion and signaling at various intracellular junctions. Nectins form homophilic cis-dimers, followed by homophilic and heterophilic trans-dimers involved in cell-cell adhesion. Nectin-2 and nectin-3 localize at Sertoli-spermatid junctions where they form heterophilic trans-interactions between the cells that are essential for the formation and maintenance of the junctions and for spermatid development. CD155 is the fifth member in the nectin-like molecule family, and functions as the receptor of poliovirus; therefore, CD155 is also referred to as Necl-5, or PVR. In contrast to all other family members, CD155 lacks self-adhesion capacity, yet it shares with nectins the feature to interact with other nectins. For instance, CD155 heterophilically trans-interacts with nectin-3, thereby contributing significantly to the establishment of adherens junctions between epithelial cells. This group belongs to the Constant 1 (C1)-set of IgSF domains, which has one beta-sheet that is formed by strands A-B-E-D and the other strands by G-F-C-C'.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565  34 VRVRVLPEVRGRLGGTVELPCHLLPPTT-ERVSQVTWQRLD-GTVVAAFHPSFGVDFPNSqfnkDRLSFVRAKQeaNADL 111
Cdd:cd20989    1 VRVQVPPEVRGFLGGSVTLPCHLLPPNMvTHVSQVTWQRHDeHGSVAVFHPKQGPSFPES----ERLSFVAARL--GAEL 74

                         90       100       110
                 ....*....|....*....|....*....|....*...
gi 564326565 112 RDATLAFRGLRVEDEGNYTCEFATFPNGTRRGVTWLRV 149
Cdd:cd20989   75 RNASLAMFGLRVEDEGNYTCEFATFPQGSRSGDTWLRV 112

Second immunoglobulin (Ig) domain of Nectin-2 and Nectin-like protein 5, and similar domains; member of the C1-set of the Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig) domain of nectin-2 (also known as poliovirus receptor related protein 2 or Cluster of Differentiation 112 (CD112)), nectin-like protein 5 (CD155), and similar proteins. Nectins and Nectin-like molecules are a family of Ca(2+)-independent immunoglobulin-like transmembrane glycoproteins belonging to the class of adhesion receptors, consisting of nine members (nectins 1 through 4 and nectin-like proteins 1 through 5). Nectins are synaptic cell adhesion molecules (CAMs) which facilitate adhesion and signaling at various intracellular junctions. Nectins form homophilic cis-dimers, followed by homophilic and heterophilic trans-dimers involved in cell-cell adhesion. Nectin-2 and nectin-3 localize at Sertoli-spermatid junctions where they form heterophilic trans-interactions between the cells that are essential for the formation and maintenance of the junctions and for spermatid development. CD155 is the fifth member in the nectin-like molecule family, and functions as the receptor of poliovirus; therefore, CD155 is also referred to as Necl-5, or PVR. In contrast to all other family members, CD155 lacks self-adhesion capacity, yet it shares with nectins the feature to interact with other nectins. For instance, CD155 heterophilically trans-interacts with nectin-3, thereby contributing significantly to the establishment of adherens junctions between epithelial cells. This group belongs to the Constant 1 (C1)-set of IgSF domains, which has one beta-sheet that is formed by strands A-B-E-D and the other strands by G-F-C-C'.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565 153 PENHAEAQEVTIGPQSVAVARCISTGGRPPARITWISSLGGEARDIQEPGLQAGTVTVISRYSMVPVGRADGVKVTCRVE 232
Cdd:cd07703    1 PKNSAEAQEVQAGGIPVPVARCVSANGRPPARISWSSTLNGNANTTQVPGPDSGTVTVTSEYSLVPTPEANGKEVTCKVE 80

                         90
                 ....*....|....*..
gi 564326565 233 HESLEEPELLPVILSVR 249
Cdd:cd07703   81 HETLEEPQLLPVTLSVR 97

Immunoglobulin V-Type;

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565    49 TVELPCHLLPPTTERvSQVTWQR---LDGTVVAAFHPSFGVDFPNSQFnKDRLSFVRakqeaNADLRDATLAFRGLRVED 125
Cdd:smart00406   1 SVTLSCKFSGSTFSS-YYVSWVRqppGKGLEWLGYIGSNGSSYYQESY-KGRFTISK-----DTSKNDVSLTISNLRVED 73

                   ....*...
gi 564326565   126 EGNYTCEF 133
Cdd:smart00406  74 TGTYYCAV 81

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565  251 PPEVSISGYDDNWYLGrSEATLTCEVRSNPEPTgYDWS------TTSGVFPASAVAQGSQLLVHSVDRMVNTTFICTATN 324
Cdd:pfam13927   1 KPVITVSPSSVTVREG-ETVTLTCEATGSPPPT-ITWYkngepiSSGSTRSRSLSGSNSTLTISNVTRSDAGTYTCVASN 78

First immunoglobulin variable (IgV) domain of nectin-2, nectin-like protein 5, and similar domains; The members here are composed of the second immunoglobulin (Ig) domain of nectin-2 (also known as poliovirus receptor related protein 2 or Cluster of Differentiation 112 (CD112)), nectin-like protein 5 (CD155), and similar proteins. Nectins and Nectin-like molecules are a family of Ca(2+)-independent immunoglobulin-like transmembrane glycoproteins belonging to the class of adhesion receptors, consisting of nine members (nectins 1 through 4 and nectin-like proteins 1 through 5). Nectins are synaptic cell adhesion molecules (CAMs) which facilitate adhesion and signaling at various intracellular junctions. Nectins form homophilic cis-dimers, followed by homophilic and heterophilic trans-dimers involved in cell-cell adhesion. Nectin-2 and nectin-3 localize at Sertoli-spermatid junctions where they form heterophilic trans-interactions between the cells that are essential for the formation and maintenance of the junctions and for spermatid development. CD155 is the fifth member in the nectin-like molecule family, and functions as the receptor of poliovirus; therefore, CD155 is also referred to as Necl-5, or PVR. In contrast to all other family members, CD155 lacks self-adhesion capacity, yet it shares with nectins the feature to interact with other nectins. For instance, CD155 heterophilically trans-interacts with nectin-3, thereby contributing significantly to the establishment of adherens junctions between epithelial cells. This group belongs to the Constant 1 (C1)-set of IgSF domains, which has one beta-sheet that is formed by strands A-B-E-D and the other strands by G-F-C-C'.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565  34 VRVRVLPEVRGRLGGTVELPCHLLPPTT-ERVSQVTWQRLD-GTVVAAFHPSFGVDFPNSqfnkDRLSFVRAKQeaNADL 111
Cdd:cd20989    1 VRVQVPPEVRGFLGGSVTLPCHLLPPNMvTHVSQVTWQRHDeHGSVAVFHPKQGPSFPES----ERLSFVAARL--GAEL 74

                         90       100       110
                 ....*....|....*....|....*....|....*...
gi 564326565 112 RDATLAFRGLRVEDEGNYTCEFATFPNGTRRGVTWLRV 149
Cdd:cd20989   75 RNASLAMFGLRVEDEGNYTCEFATFPQGSRSGDTWLRV 112

First immunoglobulin variable (IgV) domain of poliovirus receptor (PVR, also known as CD155 and necl-5), and similar domains; The members here are composed of the first immunoglobulin (Ig) domain of poliovirus receptor (PVR, also known as CD155 and nectin-like protein 5 (necl-5)). Poliovirus (PV) binds to its cellular receptor (PVR/CD155) to initiate infection. CD155 is a membrane-anchored, single-span glycoprotein; its extracellular region has three Ig-like domains. There are four different isotypes of CD155 (referred to as alpha, beta, gamma, and delta), that result from alternate splicing of the CD155 mRNA, and have identical extracellular domains. CD155-beta and CD155-gamma are secreted; CD155-alpha and CD155-delta are membrane-bound and function as PV receptors. The virus recognition site is contained in the amino-terminal domain, D1. Having the virus attachment site on the receptor distal from the plasma membrane may be important for successful initiation of infection of cells by the virus. CD155 binds in the poliovirus "canyon" with a footprint similar to that of the intercellular adhesion molecule-1 receptor on human rhinoviruses. This group also includes the first Ig-like domain of nectin-1 (also known as poliovirus receptor related protein(PVRL)1; CD111), nectin-3 (also known as PVRL 3), nectin-4 (also known as PVRL4; LNIR receptor)and DNAX accessory molecule 1 (DNAM-1; CD226).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565  34 VRVRVLPEVRGRLGGTVELPCHLLPPTTERVSQVTWQRLDG---TVVAAFHPSFGVDFPNSQfnKDRLSFVRAKQeanaD 110
Cdd:cd05718    1 QRVQVPTEVTGFLGGSVTLPCSLTSPGTTKITQVTWMKIGAgssQNVAVFHPQYGPSVPNPY--AERVEFLAARL----G 74

                         90       100       110
                 ....*....|....*....|....*....|....*....
gi 564326565 111 LRDATLAFRGLRVEDEGNYTCEFATFPNGTRRGVTWLRV 149
Cdd:cd05718   75 LRNATLRIRNLRVEDEGNYICEFATFPQGNRQGTTWLRV 113

Second immunoglobulin (Ig) domain of poliovirus receptor (PVR, also known as CD155 and Necl-5), and similar domains; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig) domain of poliovirus receptor (PVR, also known as CD155 and nectin-like protein 5 (Necl-5)) and similar proteins. Poliovirus (PV) binds to its cellular receptor (PVR/CD155) to initiate infection. CD155 is a membrane-anchored, single-span glycoprotein; its extracellular region has three Ig-like domains. There are four different isotypes of CD155 (referred to as alpha, beta, gamma, and delta), these result from alternate splicing of the CD155 mRNA, and have identical extracellular domains. CD155-beta and CD155-gamma are secreted, while CD155-alpha and CD155-delta are membrane-bound and function as PV receptors. The virus recognition site is contained in the amino-terminal domain, D1. Having the virus attachment site on the receptor distal from the plasma membrane may be important for successful initiation of infection of cells by the virus. CD155 binds in the poliovirus "canyon" and has a footprint similar to that of the intercellular adhesion molecule-1 receptor on human rhinoviruses. This group also includes the second Ig-like domain of nectin-1, also known as poliovirus receptor related protein(PVRL)1 or CD111.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565 153 PENHAEAQEVT-IGPQSVAVARCISTGGRPPARITWISSLGGEARDIQEPGlQAGTVTVISRYSMVPVGRADGVKVTCRV 231
Cdd:cd05719    1 PTNSLEGGPALlIGGEPTLVATCISANGKPPASVTWETDLKGEASTTQVRG-SNGTVTVTSRYRLVPSREADGQPLTCVV 79

                         90
                 ....*....|....*..
gi 564326565 232 EHESLEEPELLPVILSV 248
Cdd:cd05719   80 EHPSLEKDQRISVTLNV 96

First immunoglobulin variable (IgV) domain of nectin-1, and similar domains; The members here are composed of the first immunoglobulin (Ig) domain of nectin-1 (also known as poliovirus receptor related protein 1 (PVRL1) or cluster of differentiation (CD) 111). Nectin-1 belongs to the nectin family comprised of four transmembrane glycoproteins (nectins-1 through -4). Nectins are synaptic cell adhesion molecules (CAMs) which facilitate adhesion and signaling at various intracellular junctions. Nectins form homophilic cis-dimers, followed by homophilic and heterophilic trans-dimers involved in cell-cell adhesion. In addition nectins heterophilically trans-interact with other CAMs such as nectin-like molecules (Necls), nectin-1 for example, has been shown to trans-interact with Necl-1. Nectins also interact with various other proteins, including the actin filament (F-actin)-binding protein, afadin. Mutation in the human nectin-1 gene is associated with cleft lip/palate ectodermal dysplasia syndrome (CLPED1). Nectin-1 is a major receptor for herpes simplex virus through interaction with the viral envelope glycoprotein D.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565  36 VRVLPEVRGRLGGTVELPCHL---LPPTteRVSQVTWQRL-DGTV--VAAFHPSFGVDFPNSQfnKDRLSFVrakqeaNA 109
Cdd:cd05886    3 VQVNDSMSGFIGTDVVLHCSFanpLPSV--KITQVTWQKStNGSKqnVAIYNPSMGVSVLPPY--RERVTFL------NP 72

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|.
gi 564326565 110 DLRDATLAFRGLRVEDEGNYTCEFATFPNGTRRGVTWLRVI 150
Cdd:cd05886   73 SFTDGTIRLSRLELEDEGVYICEFATFPTGNRESQLNLTVM 113

Immunoglobulin V-Type;

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565    49 TVELPCHLLPPTTERvSQVTWQR---LDGTVVAAFHPSFGVDFPNSQFnKDRLSFVRakqeaNADLRDATLAFRGLRVED 125
Cdd:smart00406   1 SVTLSCKFSGSTFSS-YYVSWVRqppGKGLEWLGYIGSNGSSYYQESY-KGRFTISK-----DTSKNDVSLTISNLRVED 73

                   ....*...
gi 564326565   126 EGNYTCEF 133
Cdd:smart00406  74 TGTYYCAV 81

Immunoglobulin V-set domain; This domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565   40 PEVRGRLGGTVELPCHLLPPTTERVSQVTWQRLDG-----TVVAAFHPSFGVDFPnsqfnKDRLSFvrakqEANADLRDA 114
Cdd:pfam07686   4 REVTVALGGSVTLPCTYSSSMSEASTSVYWYRQPPgkgptFLIAYYSNGSEEGVK-----KGRFSG-----RGDPSNGDG 73

                          90       100       110
                  ....*....|....*....|....*....|....*
gi 564326565  115 TLAFRGLRVEDEGNYTCEFATFPNGTRRGVTWLRV 149
Cdd:pfam07686  74 SLTIQNLTLSDSGTYTCAVIPSGEGVFGKGTRLTV 108

First immunoglobulin variable (IgV) domain of nectin-3 (also known as poliovirus receptor related protein 3), and similar domains; The members here are composed of the first immunoglobulin (Ig) domain of nectin-3 (also known as poliovirus receptor related protein 3 (PVRL3) or cluster of differentiation (CD) 113). Nectin-3 belongs to the nectin family comprised of four transmembrane glycoproteins (nectins-1 through -4). Nectins are synaptic cell adhesion molecules (CAMs) which participate in adhesion and signaling at various intracellular junctions. Nectins form homophilic cis-dimers, followed by homophilic and heterophilic trans-dimers involved in cell-cell adhesion. For example, during spermatid development, the nectin-3,-2 trans-interaction is required for the formation of Sertoli cell-spermatid junctions in testis, and during morphogenesis of the ciliary body, the nectin-3,-1 trans-interaction is important for apex-apex adhesion between the pigment and non-pigment layers of the ciliary epithelia. Nectins also heterophilically trans-interact with other CAMs such as nectin-like molecules (Necls); nectin-3 for example, trans-interacts with Necl-5, regulating cell movement and proliferation. Other proteins with which nectin-3 interacts include the actin filament-binding protein, afadin, integrin alpha-beta3, Par-3, and PDGF receptor; its interaction with PDGF receptor regulates the latter's signaling for anti-apoptosis.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565  38 VLPEVRGRLGGTVELPChlLPPTTERVSQVTWQRLDGT---VVAAFHPSFGVDFPNSQfnKDRLSFvrakqeANADLRDA 114
Cdd:cd05887    5 VEPHVTAVWGKNVSLKC--LIEVNETITQISWEKIHGKssqTVAVHHPQYGISIQGEY--QGRVSF------KNYSLNDA 74

                         90       100       110
                 ....*....|....*....|....*....|....*.
gi 564326565 115 TLAFRGLRVEDEGNYTCEFATFPNGTRRGVTWLRVI 150
Cdd:cd05887   75 TITLHNVGFSDSGKYICKAVTFPLGNAQSSTTVTVL 110

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565    40 PEVRGRLGGTVELPCHLlppTTERVSQVTWQRLDGTVVAafhpsfgvdfpnsqfNKDRLSFVRakqeanaDLRDATLAFR 119
Cdd:smart00410   2 PSVTVKEGESVTLSCEA---SGSPPPEVTWYKQGGKLLA---------------ESGRFSVSR-------SGSTSTLTIS 56

                           90       100       110
                   ....*....|....*....|....*....|
gi 564326565   120 GLRVEDEGNYTCEfATFPNGTRRGVTWLRV 149
Cdd:smart00410  57 NVTPEDSGTYTCA-ATNSSGSASSGTTLTV 85

Second immunoglobulin (Ig)-like domain of nectin-like molcule-1 (Necl-1); member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin (Ig)-like domain of nectin-like molcule-1 (Necl-1; also known as cell adhesion molecule3 (CADM3)). These nectin-like molecules have similar domain structures to those of nectins. At least five nectin-like molecules have been identified (Necl-1 through Necl-5). These have an extracellular region containing three Ig-like domains, one transmembrane region, and one cytoplasmic region. The N-terminal Ig-like domain of the extracellular region belongs to the V-type subfamily of Ig domains is essential to cell-cell adhesion and plays a part in the interaction with the envelope glycoprotein D of various viruses. Necl-1 and Necl-2 have Ca(2+)-independent homophilic and heterophilic cell-cell adhesion activity. Necl-1 is specifically expressed in neural tissue and is important to the formation of synapses, axon bundles, and myelinated axons. Necl-2 is expressed in a wide variety of tissues and is a putative tumour suppressor gene which is downregulated in aggressive neuroblastoma. Ig domains are likely to participate in ligand binding and recognition.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 564326565 170 AVARCISTGGRPPARITWI---SSLGGEARDIQEPGlQAGTVTVISRYSMVPVGRADGVKVTCRVEHESLEE 238
Cdd:cd07705   22 AKLRCTSSGSKPAANIKWRkgdQELEGAPTSVQEDG-NGKTFTVSSSVEFQVTREDDGAEITCSVGHESLHD 92

Immunoglobulin Constant-1 (C1)-set domain; The members here are composed of C1-set domains, classical Ig-like domains resembling the antibody constant domain. Members of the IgC1 family are components of immunoglobulin, T-cell receptors, CD1 cell surface glycoproteins, secretory glycoproteins A/C, and major histocompatibility complex (MHC) class I/II molecules. In immunoglobulins, each chain is composed of one variable domain (IgV) and one or more IgC domains. These names reflect the fact that the variability in sequences is higher in the variable domain than in the constant domain. The IgV domain is responsible for antigen binding, while the IgC domain is involved in oligomerization and molecular interactions. 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 strands by G, F, C, and C'.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565 154 ENHAEAQEVTIGPQSVAVARCISTGGRPP-ARITWISSlGGEARDIQEPG----LQAGTVTVISRYSMVPVGRADGVKVT 228
Cdd:cd00098    1 TVTLLPPSPEEKGGGKVTLVCLVSGFYPKdITVTWLKN-GVPLTSGVSTSspvePNDGTYSVTSSLTVPPSDWDEGATYT 79

                         90
                 ....*....|....*.
gi 564326565 229 CRVEHESLEEPELLPV 244
Cdd:cd00098   80 CVVTHESLKSPLSKTW 95

Immunoglobulin (Ig)-like domain of myelin oligodendrocyte glycoprotein (MOG); The members here are composed of the immunoglobulin (Ig)-like domain of myelin oligodendrocyte glycoprotein (MOG). MOG, a minor component of the myelin sheath, is an important CNS-specific autoantigen, linked to the pathogenesis of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). It is a transmembrane protein having an extracellular Ig domain. MOG is expressed in the CNS on the outermost lamellae of the myelin sheath, and on the surface of oligodendrocytes, and may participate in the completion, compaction, and/or maintenance of myelin. This group also includes butyrophilin (BTN). BTN is the most abundant protein in bovine milk-fat globule membrane (MFGM).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564326565  42 VRGRLGGTVELPCHLLPPTTERVSQVTWQRldgtvvAAFHPSF-----GVDFPNSQFN--KDRLSFVRakqEANADLRdA 114
Cdd:cd05713   10 ILALVGEDAELPCHLSPKMSAEHMEVRWFR------SQFSPVVhlyrdGQDQEEEQMPeyRGRTELLK---DAIAEGS-V 79

                         90
                 ....*....|....*....
gi 564326565 115 TLAFRGLRVEDEGNYTCEF 133
Cdd:cd05713   80 ALRIHNVRPSDEGQYTCFF 98

Second immunoglobulin (Ig)-like domain of nectin-like molecule-3 (Necl-3); member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin (Ig)-like domain of nectin-like molecule-3 (Necl-3; also known as cell adhesion molecule 2 (CADM2)). Nectin-like molecules have similar domain structures to those of nectins. At least five nectin-like molecules have been identified (Necl-1 through Necl-5). These have an extracellular region containing three Ig-like domains, one transmembrane region, and one cytoplasmic region. Necl-3 has been shown to accumulate in tissues of the central and peripheral nervous system where it is expressed in ependymal cells and myelinated axons. It is observed at the interface between the axon shaft and the myelin sheath. Ig domains are likely to participate in ligand binding and recognition.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 564326565 174 CISTGGRPPARITWISSLG--GEARDIQEPGLQAGTVTVISRYSMVPVGRADGVKVTCRVEHESL 236
Cdd:cd05884   27 CKTSGSKPAADIRWFKNDKevKDVKYLKAEDANRKTFTVSSSLDFHVDRDDDGVAITCRVDHESL 91

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.

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gi 564326565 270 ATLTCEVRSNPEPTgYDWS------TTSGVFPASAVAQGSQLLVHSVDRMVNTTFICTATNAVGTGRAEQV 334
Cdd:cd00096    1 VTLTCSASGNPPPT-ITWYkngkplPPSSRDSRRSELGNGTLTISNVTLEDSGTYTCVASNSAGGSASASV 70

Tapasin-R immunoglobulin-like domain; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin-like domain on Tapasin-R. Tapasin is a V-C1 (variable-constant) immunoglobulin superfamily molecule present in the endoplasmic reticulum (ER), where it links MHC class I molecules to the transporter associated with antigen processing (TAP). Tapasin-R is a tapasin-related protein that contains similar structural motifs to Tapasin, with some marked differences, especially in the V domain, transmembrane and cytoplasmic regions. The majority of Tapasin-R is located within the ER; however, there may be some expression of Tapasin-R at the cell surface. Tapasin-R lacks an obvious ER retention signal.

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gi 564326565 204 QAGTVTVISRYSMVPVGRADGVKVTCRVEHESLEEP 239
Cdd:cd05771   61 VDGTYSISSYLTLEPGTENRGATYTCRVTHVSLEEP 96