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
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 90903247 159 TC-SATARPAPMVFWKVPRSGIENSTvTLSHPNGTTSVTSILHIKDPKNQVGKEVICQVLHLGTVTDFKQTVN 230
Cdd:cd05719  22 TCiSANGKPPASVTWETDLKGEASTT-QVRGSNGTVTVTSRYRLVPSREADGQPLTCVVEHPSLEKDQRISVT 93

Immunoglobulin V-Type;

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903247     47 ASLKCSL-QNAQEALIVTWQKKK-AVSPENMVTFSENHGVVIQPAYKDKINITQLGLQNS-TITFWNITLEDEGCYMCLF 123
Cdd:smart00406   2 VTLSCKFsGSTFSSYYVSWVRQPpGKGLEWLGYIGSNGSSYYQESYKGRFTISKDTSKNDvSLTISNLRVEDTGTYYCAV 81

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.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903247    47 ASLKCSLQNAQEALIVTWQKKKAVSPENMvtfsenhgvviqpaykdKINITQLGLQNSTITFWNITLEDEGCYMCLFNTF 126
Cdd:pfam00047  14 ATLTCSASTGSPGPDVTWSKEGGTLIESL-----------------KVKHDNGRTTQSSLLISNVTKEDAGTYTCVVNNP 76

                          90
                  ....*....|
gi 90903247   127 GFGKISGTAC 136
Cdd:pfam00047  77 GGSATLSTSL 86

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.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 90903247   143 PIVSLHYKFSEDHLNITCSA-TARPAPMVFWKVPRSGIENSTVTlSHPNGTTSVTSILHIKDPKNQVGkEVICQVLHLG 220
Cdd:pfam00047   1 SAPPTVTVLEGDSATLTCSAsTGSPGPDVTWSKEGGTLIESLKV-KHDNGRTTQSSLLISNVTKEDAG-TYTCVVNNPG 77

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 90903247  31 QVQVVTQdEREQLYTPASLKCSLQNAQEALI--VTWQKKKAVSPENMVTFSENHGVVIQPAYKDKINIT--QLGLQNSTI 106
Cdd:cd05718   2 RVQVPTE-VTGFLGGSVTLPCSLTSPGTTKItqVTWMKIGAGSSQNVAVFHPQYGPSVPNPYAERVEFLaaRLGLRNATL 80

                        90       100       110
                ....*....|....*....|....*....|...
gi 90903247 107 TFWNITLEDEGCYMCLFNTFGFGKISGTACLTV 139
Cdd:cd05718  81 RIRNLRVEDEGNYICEFATFPQGNRQGTTWLRV 113

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 90903247  32 VQVVTQdEREQLYTPASLKCSLQ---NAQEALIVTWQKKKavSPENMVTFSENHGVVIQPAYKDKINITQLG--LQNSTI 106
Cdd:cd20989   3 VQVPPE-VRGFLGGSVTLPCHLLppnMVTHVSQVTWQRHD--EHGSVAVFHPKQGPSFPESERLSFVAARLGaeLRNASL 79

                        90       100       110
                ....*....|....*....|....*....|...
gi 90903247 107 TFWNITLEDEGCYMCLFNTFGFGKISGTACLTV 139
Cdd:cd20989  80 AMFGLRVEDEGNYTCEFATFPQGSRSGDTWLRV 112

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 90903247  48 SLKCSLQNAQEALIVTWQKKKAVSPENMVTFSENHGVVIQPAYKDKINITQLGLQNSTITFWNITLEDEGCYMCLFNTFG 127
Cdd:cd05887  18 SLKCLIEVNETITQISWEKIHGKSSQTVAVHHPQYGISIQGEYQGRVSFKNYSLNDATITLHNVGFSDSGKYICKAVTFP 97

                        90
                ....*....|..
gi 90903247 128 FGKISGTACLTV 139
Cdd:cd05887  98 LGNAQSSTTVTV 109

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.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903247    47 ASLKCSLQNAQEALIVTWQKKKAVSPENMvtfsenhgvviqpaykdKINITQLGLQNSTITFWNITLEDEGCYMCLFNTF 126
Cdd:pfam00047  14 ATLTCSASTGSPGPDVTWSKEGGTLIESL-----------------KVKHDNGRTTQSSLLISNVTKEDAGTYTCVVNNP 76

                          90
                  ....*....|
gi 90903247   127 GFGKISGTAC 136
Cdd:pfam00047  77 GGSATLSTSL 86

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.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 90903247   143 PIVSLHYKFSEDHLNITCSA-TARPAPMVFWKVPRSGIENSTVTlSHPNGTTSVTSILHIKDPKNQVGkEVICQVLHLG 220
Cdd:pfam00047   1 SAPPTVTVLEGDSATLTCSAsTGSPGPDVTWSKEGGTLIESLKV-KHDNGRTTQSSLLISNVTKEDAG-TYTCVVNNPG 77

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

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 90903247     71 SPENMVTFSENHGVVIqpAYKDKINITQLGlQNSTITFWNITLEDEGCYMCLFnTFGFGKISGTACLTV 139
Cdd:smart00410  21 SPPPEVTWYKQGGKLL--AESGRFSVSRSG-STSTLTISNVTPEDSGTYTCAA-TNSSGSASSGTTLTV 85

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
                ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 90903247 159 TC-SATARPAPMVFWKVPRSGIENSTVTLSHPNGTTSVTSILHIKdPKNQV-GKEVICQVLH 218
Cdd:cd07703  21 RCvSANGRPPARISWSSTLNGNANTTQVPGPDSGTVTVTSEYSLV-PTPEAnGKEVTCKVEH 81

BARF1; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903247   56 AQEALIVTWQKKKAVSPENMVTFSE----NHGVVIQPAYKDKINITQ-----LGLQNSTITFWNI----TLEDEGCYMCL 122
Cdd:PHA03376  26 GERVTLTSYWRRVSLGPEIEVSWFKlgpgEEQVLIGRMHHDVIFIEWpfrgfFDIHRSANTFFLVvtaaNISHDGNYLCR 105

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903247  123 FNtFGFGKISGTACLTVyVQPI-VSLHYKFSE----DHLNITCSATARPAPMVFWKVPRSGIENSTVT----LSHPNGTT 193
Cdd:PHA03376 106 MK-LGETEVTKQEHLSV-VKPLtLSVHSERSQfpdfSVLTVTCTVNAFPHPHVQWLMPEGVEPAPTAAnggvMKEKDGSL 183

                        170
                 ....*....|.
gi 90903247  194 SVTSILHIKDP 204
Cdd:PHA03376 184 SVAVDLSLPKP 194

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 90903247 156 LNITCSATARPAPMVFWKVPRSGIENSTVtlsHPNGTTSVTSILHIKDPKNQVGKEVICQV 216
Cdd:cd00096   1 VTLTCSASGNPPPTITWYKNGKPLPPSSR---DSRRSELGNGTLTISNVTLEDSGTYTCVA 58

Immunoglobulin-like domain protein; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903247   21 VMAAVVLCTAQVQVVTQDEREQLytpaSLKCSLQNAQEALIVTWQKKKAVSPENMVTFSenhgvvIQPAYKDKINITQLG 100
Cdd:PHA02914   8 IIFAVCCASESYNIFLRNEDEEL----ALTCILPAAKMADKVVLIKGNDMNNTKEIESS------INNAGEDNVCYCGDP 77

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903247  101 LQNSTITFWNITLEDEGCYMCLFNtfgFGK-ISGTACLTVYVQPIVSLHY-KFSEDHLNITCSATA---RPAPMVFWKVP 175
Cdd:PHA02914  78 DKEYSFIEENIGEHEDGDFKCIFY---LGDnESHKHEILVRKAPKIDTTFlEFNDKHTCICCKIDKpmnQDALKVFFVAG 154

                        170       180       190       200       210
                 ....*....|....*....|....*....|....*....|....*....|.
gi 90903247  176 RSGIENSTVTLSHPNGTTSVTSILHIKDPK-NQVGKEVICQVLHLGTVTDF 225
Cdd:PHA02914 155 GVNVDGNFLGKKDFNNDPSNRTVKLCADKShDDTAREALCGVEYFGALKEL 205