Second immunoglobulin (Ig)-like domain of interleukin-1 receptor-2 (IL1R2), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of interleukin-1 receptor-2 (IL1R2). 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 the IL-1 receptor, type II (IL1R2) represented in this group. Mature IL1R2 consists of three IG-like domains, a transmembrane domain, and a short cytoplasmic domain. It lacks the large cytoplasmic domain of mature IL1R1 and 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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755492114 148 VSYLQISALSTTGLLVCPDLKEFISSNADGKIQWYKGAILLDKGNKEFLSAGDPTRLLISNTSMDDAGYYRCVMTFTYNG 227
Cdd:cd05897    1 ISYPQILFTSTSGKLVCPDLSEFTINRTDVEIQWYKDSLLLDKDNEKFLSVKGSTHLLIHDVSLNDSGYYTCKLTFTHEG 80

                         90
                 ....*....|....*
gi 755492114 228 QEYNITRNIELRVKG 242
Cdd:cd05897   81 KKYNITRSIELRIVK 95

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755492114  249 PVIISPLETIPASLGSRLIVPCKVflgTGTSSNTIVWwlanstfisaaYPRGRVTEGLHHQYSENDENYveVSLIFDPVT 328
Cdd:pfam13927   2 PVITVSPSSVTVREGETVTLTCEA---TGSPPPTITW-----------YKNGEPISSGSTRSRSLSGSN--STLTISNVT 65

                          90
                  ....*....|....
gi 755492114  329 REDlHTDFKCVASN 342
Cdd:pfam13927  66 RSD-AGTYTCVASN 78

Second immunoglobulin (Ig)-like domain of interleukin-1 receptor-2 (IL1R2), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of interleukin-1 receptor-2 (IL1R2). 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 the IL-1 receptor, type II (IL1R2) represented in this group. Mature IL1R2 consists of three IG-like domains, a transmembrane domain, and a short cytoplasmic domain. It lacks the large cytoplasmic domain of mature IL1R1 and 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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755492114 148 VSYLQISALSTTGLLVCPDLKEFISSNADGKIQWYKGAILLDKGNKEFLSAGDPTRLLISNTSMDDAGYYRCVMTFTYNG 227
Cdd:cd05897    1 ISYPQILFTSTSGKLVCPDLSEFTINRTDVEIQWYKDSLLLDKDNEKFLSVKGSTHLLIHDVSLNDSGYYTCKLTFTHEG 80

                         90
                 ....*....|....*
gi 755492114 228 QEYNITRNIELRVKG 242
Cdd:cd05897   81 KKYNITRSIELRIVK 95

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755492114 149 SYLQISALSTTGLLVCPDLKEFISSNADGKIQWYKGAILLdKGNKEFLSAGDptRLLISNTSMDDAGYYRCVMTFTYNGQ 228
Cdd:cd05757    2 RYKQKLPITKGGKITCPDLDDYKNENVLPPIQWYKDCKPL-QGDKRFIPKGS--KLLIQNVTEEDAGNYTCKFTYTHNGK 78

                         90
                 ....*....|....
gi 755492114 229 EYNITRNIELRVKG 242
Cdd:cd05757   79 QYNVTRTISLTVTE 92

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). 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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755492114 150 YLQISALSTTGLLVCPDLKEFISSNAD-GKIQWYKGAILLDKGNKEFlsAGDPTRLLISNTSMDDAGYYRCVMTFTYNGQ 228
Cdd:cd20994    3 YKQKVPFTSGGRIVCPHLDFFKDENNNlPKVQWYKDCKPLLLDDKRF--AGLESDLLIFNVTVQDQGNYTCHTSYTYMGK 80

                         90
                 ....*....|....
gi 755492114 229 EYNITRNIELRVKG 242
Cdd:cd20994   81 QYNISRTISLIVLE 94

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). 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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755492114 146 PHVSYLQISALSTTgllvCPDLKEFISSNADGKIQWYKGAILLDKGNkEFLSAGDPTRLLISNTSMDdaGYYRCVMTFTY 225
Cdd:cd20993    4 PVIAYIEYGGRTIT----CPDLDGIKPPSVSPTVTWYHECNAFGNFN-DRVPKGDKLVIHVMLEHYQ--GNYTCVVTYET 76

                         90
                 ....*....|....*..
gi 755492114 226 NGQEYNITRNIELRVKG 242
Cdd:cd20993   77 KGRTIKLTRTVNVKVVG 93

First immunoglobulin (Ig)-like domain of X-linked interleukin-1 receptor accessory protein-like 1 (IL1RAPL-1), and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain of X-linked interleukin-1 receptor accessory protein-like 1 (IL1RAPL-1). 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. IL1RAPL is encoded by a gene on the X-chromosome, this gene is wholly or partially deleted in multiple cases of non-syndromic intellectual disability. This group also contains IL1RAPL-2 which is also encoded by a gene on the X-chromosome and is a candidate for another non-syndromic intellectual disability loci.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755492114  48 EFKSELRLEGEPVVLRCPL-----APHSDISSSSHSFLTWSK----LDSSQLIPRDEPRMWVKGNILWILPAVQQDSGTY 118
Cdd:cd05896    6 DLKKYMVLAGEPVRIKCALfygyiRTNYSMAQSAGLSLMWYKssgpGDFEEPIIFDGVRMSKEEDSIWFRPAELQDSGLY 85

                         90
                 ....*....|....*....
gi 755492114 119 ICTFRNASHCEQMSVELKV 137
Cdd:cd05896   86 TCVLRNSTYCMKVSMSLTV 104

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755492114  249 PVIISPLETIPASLGSRLIVPCKVflgTGTSSNTIVWwlanstfisaaYPRGRVTEGLHHQYSENDENYveVSLIFDPVT 328
Cdd:pfam13927   2 PVITVSPSSVTVREGETVTLTCEA---TGSPPPTITW-----------YKNGEPISSGSTRSRSLSGSN--STLTISNVT 65

                          90
                  ....*....|....
gi 755492114  329 REDlHTDFKCVASN 342
Cdd:pfam13927  66 RSD-AGTYTCVASN 78

Immunoglobulin domain; This is an immunoglobulin domain which can be found in Interleukin-18 receptor alpha (IL-18Ra). IL-18Ra ectodomain folds into three immunoglobulin (Ig)-like domains, similar to IL-1 receptors. Each domain comprises a two-layer sandwich of six to nine beta-strands and contains at least one intra-domain disulfide bond.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 755492114   91 IPRDEPRMWVKGNILWILPAVQQDSGTYICTFRNASH-----CEQMSVELKVFKNT--EASLPHVSYL 151
Cdd:pfam18452  61 ITESSPHIIQEGNALWFLPVGVNDSGSYICRPRIRSPqdeacCLKIILEVQPKTNAscSGSVTNELYL 128

Third immunoglobulin domain of interleukin-1 receptor accessory protein (IL1RAP); The members here are composed of the third immunoglobulin Ig interleukin-1 receptor accessory protein (IL1RAP). The interleukin 1 receptor accessory protein (IL-1RAP), also known as IL-1R3, is a coreceptor of type 1 interleukin 1 receptor (IL-1R1) and is required for transmission of IL-1 signaling. The activated IL-1 receptor complex, which consists of IL-1R1 and IL-1RAP, induces multiple cellular responses including NF-kappa-B activation, IL-2 secretion, and IL-2 promoter activation. Signaling involves the recruitment of adapter molecules such as TOLLIP, MYD88, and IRAK1 or IRAK2 via the respective Toll/IL-1 receptor (TIR) domains of the receptor/coreceptor subunits. Moreover, IL1RAP is known to be the accessory co-receptor that activates signal transduction upon IL-36 binding to IL-36R. IL-36 cytokines, which are a subfamily of the IL-1 superfamily, bind to the IL-36 receptor (IL-36R) and use IL1RAP as a co-receptor.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755492114 249 PVIISPLETI--PASLGSRLIVPCKVFLGTGTSSNTIVWWLANSTFISAAYPRGRVTEGLHHQYSEnDENYVEVsLIFDP 326
Cdd:cd20931    1 PQIYSPNDRVvyEKEPGEELLIPCTVYFSFLMDSRNEVWWTIDGKKPDDVTIDVTINESISYSSTE-DETRTQI-LSIKK 78

                         90       100
                 ....*....|....*....|....*....
gi 755492114 327 VTREDLHTDFKCVASNPRSSQSLHTTVKE 355
Cdd:cd20931   79 VTPEDLKRNYVCHARNAKGEVEKAAKVKQ 107

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 755492114 162 LVCPdlkefISSNADGKIQWYK-GAILLDKGNKEFLSAGDPTRLLISNTSMDDAGYYRCVMTFTYNGQE 229
Cdd:cd00096    3 LTCS-----ASGNPPPTITWYKnGKPLPPSSRDSRRSELGNGTLTISNVTLEDSGTYTCVASNSAGGSA 66

Domain C2 of human cardiac Myosin Binding Protein C and similar domains; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig) Domain C2 of human cardiac Myosin Binding Protein C (MyBP-C) and similar domains. MyBP-C is a thick filament protein involved in the regulation of muscle contraction. Mutations in cardiac MyBP-C gene are the second most frequent cause of hypertrophic cardiomyopathy. MyBP-C binds to myosin with two binding sites, one at its C-terminus and another at its N-terminus. The N-terminal binding site, consisting of immunoglobulin (lg) domains C1 and C2 connected by a flexible linker, interacts with the S2 segment of myosin in a phosphorylation-regulated manner. The C1 and C2 Ig domains can bind to and activate or inhibit the thin filament. 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 structures of the Ig domains of MyBP-C lack this strand and thus belong to the I-set of Ig superfamily domains. 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.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 755492114 173 SNADGKIQWYK-GAILLDKGNKEFLSAGDPTRLLISNTSMDDAGYYRCV 220
Cdd:cd20967   22 ADPDAEVKWYKdGQELQSSSKVIFESIGAKRTLTVQQASLADAGEYQCV 70

Immunoglobulin I-set domain;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 755492114   81 TWSKlDSSQLIPRDEPRMWVKGNI--LWILPAVQQDSGTYICTFRNASHCEQMSVELKV 137
Cdd:pfam07679  33 SWFK-DGQPLRSSDRFKVTYEGGTytLTISNVQPDDSGKYTCVATNSAGEAEASAELTV 90

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755492114  54 RLEGEPVVLRCPLAPHSDISssshsfLTWSKldSSQLIPRDEPRMWVKGNILWILPAVQQDSGTYICTFRNASHCEQMSV 133
Cdd:cd20978   13 VKGGQDVTLPCQVTGVPQPK------ITWLH--NGKPLQGPMERATVEDGTLTIINVQPEDTGYYGCVATNEIGDIYTET 84

                 ....
gi 755492114 134 ELKV 137
Cdd:cd20978   85 LLHV 88