CH1 domain (first constant Ig domain of the heavy chain) in immunoglobulin heavy epsilon and gamma chain; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin constant-1 set domain of epsilon and gamma chains. It belongs to a family composed of the first immunoglobulin constant-1 set domain of alpha, delta, epsilon, gamma, and mu heavy chains. This domain is found on the Fab antigen-binding fragment. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. There are two types of light chains: kappa and lambda; each is composed of a constant domain and a variable domain. There are five types of heavy chains: alpha, delta, epsilon, gamma, and mu, all consisting of a variable domain (VH) with three (alpha, delta and gamma) or four (epsilon and mu) constant domains (CH1 to CH4). Ig molecules are modular proteins, in which the variable and constant domains have clear, conserved sequence patterns. This group belongs to the C1-set of IgSF domains, which are classical Ig-like domains resembling the antibody constant domain. C1-set domains are found almost exclusively in molecules involved in the immune system, such as in immunoglobulin light and heavy chains, in the major histocompatibility complex (MHC) class I and II complex molecules, and in various T-cell receptors.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90109487 126 GPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICN 205
Cdd:cd21817   1 APSVFPLAPCCKSTNGSSVTLGCLVTGYFPEPVTVTWNSGSLTSGVKTFPAVLQSSGLYTTSSQVTVPSSSWGSQTFTCN 80

                        90
                ....*....|....
gi 90109487 206 VNHKPSNTKVDKKV 219
Cdd:cd21817  81 VEHKPSSTKVDKKI 94

CH1 domain (first constant Ig domain of the heavy chain) in immunoglobulin heavy epsilon and gamma chain; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin constant-1 set domain of epsilon and gamma chains. It belongs to a family composed of the first immunoglobulin constant-1 set domain of alpha, delta, epsilon, gamma, and mu heavy chains. This domain is found on the Fab antigen-binding fragment. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. There are two types of light chains: kappa and lambda; each is composed of a constant domain and a variable domain. There are five types of heavy chains: alpha, delta, epsilon, gamma, and mu, all consisting of a variable domain (VH) with three (alpha, delta and gamma) or four (epsilon and mu) constant domains (CH1 to CH4). Ig molecules are modular proteins, in which the variable and constant domains have clear, conserved sequence patterns. This group belongs to the C1-set of IgSF domains, which are classical Ig-like domains resembling the antibody constant domain. C1-set domains are found almost exclusively in molecules involved in the immune system, such as in immunoglobulin light and heavy chains, in the major histocompatibility complex (MHC) class I and II complex molecules, and in various T-cell receptors.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90109487 126 GPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICN 205
Cdd:cd21817   1 APSVFPLAPCCKSTNGSSVTLGCLVTGYFPEPVTVTWNSGSLTSGVKTFPAVLQSSGLYTTSSQVTVPSSSWGSQTFTCN 80

                        90
                ....*....|....
gi 90109487 206 VNHKPSNTKVDKKV 219
Cdd:cd21817  81 VEHKPSSTKVDKKI 94

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 90109487    11 LVQPGGSLRLSCAASGFTINAS-WIHWVRQAPGKGLEWVgaIYPYSGYTNYaDSVKGRFTISADTSKNTAYLQMNSLRAE 89
Cdd:pfam07686   7 TVALGGSVTLPCTYSSSMSEAStSVYWYRQPPGKGPTFL--IAYYSNGSEE-GVKKGRFSGRGDPSNGDGSLTIQNLTLS 83

                          90       100       110
                  ....*....|....*....|....*....|
gi 90109487    90 DTAVYYCARWGHStspwaMDYWGQGTLVTV 119
Cdd:pfam07686  84 DSGTYTCAVIPSG-----EGVFGKGTRLTV 108

Immunoglobulin C-Type;

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 90109487    143 TAALGCLVKDYFPEPVTVSW--NSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGT-QTYICNVNH 208
Cdd:smart00407   1 KATLVCLVSGFYPPDITVTWlrNGQEVTEGVSTTDPLKNSDGTYFLSSYLTVPASTWESgDVYTCQVTH 69

CH1 domain (first constant Ig domain of the heavy chain) in immunoglobulin heavy epsilon and gamma chain; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin constant-1 set domain of epsilon and gamma chains. It belongs to a family composed of the first immunoglobulin constant-1 set domain of alpha, delta, epsilon, gamma, and mu heavy chains. This domain is found on the Fab antigen-binding fragment. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. There are two types of light chains: kappa and lambda; each is composed of a constant domain and a variable domain. There are five types of heavy chains: alpha, delta, epsilon, gamma, and mu, all consisting of a variable domain (VH) with three (alpha, delta and gamma) or four (epsilon and mu) constant domains (CH1 to CH4). Ig molecules are modular proteins, in which the variable and constant domains have clear, conserved sequence patterns. This group belongs to the C1-set of IgSF domains, which are classical Ig-like domains resembling the antibody constant domain. C1-set domains are found almost exclusively in molecules involved in the immune system, such as in immunoglobulin light and heavy chains, in the major histocompatibility complex (MHC) class I and II complex molecules, and in various T-cell receptors.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90109487 126 GPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICN 205
Cdd:cd21817   1 APSVFPLAPCCKSTNGSSVTLGCLVTGYFPEPVTVTWNSGSLTSGVKTFPAVLQSSGLYTTSSQVTVPSSSWGSQTFTCN 80

                        90
                ....*....|....
gi 90109487 206 VNHKPSNTKVDKKV 219
Cdd:cd21817  81 VEHKPSSTKVDKKI 94

CH1 domain (first constant Ig domain of the heavy chain) in immunoglobulin heavy alpha, delta, epsilon, gamma, and mu chains; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin constant-1 set domain of alpha, delta, epsilon, gamma, and mu heavy chains. This domain is found on the Fab antigen-binding fragment. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. There are two types of light chains: kappa and lambda; each is composed of a constant domain and a variable domain. There are five types of heavy chains: alpha, delta, epsilon, gamma, and mu, all consisting of a variable domain (VH) with three (alpha, delta and gamma) or four (epsilon and mu) constant domains (CH1 to CH4). Ig molecules are modular proteins, in which the variable and constant domains have clear, conserved sequence patterns. This group belongs to the C1-set of IgSF domains, which are classical Ig-like domains resembling the antibody constant domain. C1-set domains are found almost exclusively in molecules involved in the immune system, such as in immunoglobulin light and heavy chains, in the major histocompatibility complex (MHC) class I and II complex molecules, and in various T-cell receptors.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90109487 126 GPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSW---NSGALTSGVHTFPAVLQSSGLYSLSSVVTV-PSSSLGTQT 201
Cdd:cd04985   1 APTVFPLQSATKSQSNGPVALGCLISDYFPESITVSWqknTNSITSGFTRTFPVVLRSGGDYSCSSQLTVpLQEWNSGEV 80

                        90
                ....*....|....*...
gi 90109487 202 YICNVNHKPSNTKVDKKV 219
Cdd:cd04985  81 YKCQVQHSASNSKQEKDV 98

Immunoglobulin (Ig) variable (V) domain of T-cell receptor (TCR) gamma chain; The members here are composed of the immunoglobulin (Ig) variable (V) domain of the gamma chain of gamma/delta T-cell receptors (TCRs). TCRs mediate antigen recognition by T lymphocytes, and are heterodimers consisting of alpha and beta chains or gamma and delta chains. Each chain contains a variable (V) and a constant (C) region. The majority of T cells contain alpha/beta TCRs, but a small subset contain gamma/delta TCRs. Alpha/beta TCRs recognize antigens as peptide fragments presented by major histocompatibility complex (MHC) molecules. Gamma/delta TCRs recognize intact protein antigens directly without antigen processing and recognize MHC independently of the bound peptide. Gamma/delta T cells can also be stimulated by non-peptide antigens such as small phosphate- or amine-containing compounds. The variable domain of gamma/delta TCRs is responsible for antigen recognition and is located at the N-terminus of the receptor. Members of this group contain the standard Ig superfamily V-set AGFCC'C"/DEB domain topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90109487  13 QPGGSLRLSCAASGFTINASWIHWVRQAPGKGLEWVgaIYPYSGYTNYADS--VKGRFTISADTSKNTAYLQMNSLRAED 90
Cdd:cd04982  11 EESKSVTISCKVSGIDFSTTYIHWYRQKPGQALERL--LYVSSTSAVRKDSgkTKNKFEARKDVGKSTSTLTITNLEKED 88

                        90
                ....*....|....*.
gi 90109487  91 TAVYYCARWGHSTSPW 106
Cdd:cd04982  89 SATYYCAYWESGSGYY 104

Immunoglobulin C1-set domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90109487   129 VFPLAPSSKSTsGGTAALGCLVKDYFPEPVTVSW--NSGALTSGVHTFPAVLQSSGLYSLSSV-VTVPSSSLGTQTYICN 205
Cdd:pfam07654   1 VYVFPPSPEEL-GKPNTLTCLVTGFYPPDITVTWlkNGQEVTEGVKTTPPSPNSDWTYQLSSYlTVTPSDWESGDEYTCR 79

                  ....
gi 90109487   206 VNHK 209
Cdd:pfam07654  80 VEHE 83

CH1 domain (first constant Ig domain of the heavy chain) in immunoglobulin heavy mu chain; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin constant-1 set domain of mu chains. It belongs to a family composed of the first immunoglobulin constant-1 set domain of alpha, delta, epsilon, gamma, and mu heavy chains. This domain is found on the Fab antigen-binding fragment. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. There are two types of light chains: kappa and lambda; each is composed of a constant domain and a variable domain. There are five types of heavy chains: alpha, delta, epsilon, gamma, and mu, all consisting of a variable domain (VH) with three (alpha, delta and gamma) or four (epsilon and mu) constant domains (CH1 to CH4). Ig molecules are modular proteins, in which the variable and constant domains have clear, conserved sequence patterns. This group belongs to the C1-set of IgSF domains, which are classical Ig-like domains resembling the antibody constant domain. C1-set domains are found almost exclusively in molecules involved in the immune system, such as in immunoglobulin light and heavy chains, in the major histocompatibility complex (MHC) class I and II complex molecules, and in various T-cell receptors.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90109487 127 PSVFPLAPSSkSTSGGTAALGCLVKDYFPEPVTVSWNSG--ALTSGVHTFPAVLqSSGLYSLSSVVTVPSSSLGTQTYI- 203
Cdd:cd21819   2 PTLFPLVSCG-SSTSDPVTVGCLATDFLPDSITFSWTDDnnSLTTGVKTYPSVL-TGGTYTASSQLQVPESEWKSKENFy 79

                        90
                ....*....|....*...
gi 90109487 204 CNVNHkpSNTKVDKKVEP 221
Cdd:cd21819  80 CKVEH--PGGNKEVPVPK 95

Immunoglobulin (Ig) variable (V) domain of T-cell receptor (TCR) alpha chain and similar proteins; The members here are composed of the immunoglobulin (Ig) variable domain of the alpha chain of alpha/beta T-cell antigen receptors (TCRs). TCRs mediate antigen recognition by T lymphocytes, and are composed of alpha and beta, or gamma and delta polypeptide chains with variable (V) and constant (C) regions. This group represents the variable domain of the alpha chain of TCRs and also includes the variable domain of delta chains of TCRs. Alpha/beta TCRs recognize antigen as peptide fragments presented by major histocompatibility complex (MHC) molecules. The variable domain of TCRs is responsible for antigen recognition, and is located at the N-terminus of the receptor. Gamma/delta TCRs recognize intact protein antigens directly without antigen processing and recognize MHC independently of the bound peptide. Members of this group contain standard Ig superfamily V-set AGFCC'C"/DEB domain topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90109487  12 VQPGGSLRLSCAASgfTINASWIHWVRQAPGKGLEWVgaIYPYSGYTNYAdsvKGRFTISADTSKNTAYLQMNSLRAEDT 91
Cdd:cd04983  10 VQEGENVTLNCNYS--TSTFYYLFWYRQYPGQGPQFL--IYISSDSGNKK---KGRFSATLDKSRKSSSLHISAAQLSDS 82

                        90       100       110
                ....*....|....*....|....*....|.
gi 90109487  92 AVYYCArwghsTSPWAMDY---WGQGTLVTV 119
Cdd:cd04983  83 AVYFCA-----LSESGGTGkltFGKGTRLTV 108

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90109487      7 SGGGLVQPGGSLRLSCAASGFTinASWIHWVRQapgkGLEWVGAiypysgytnyadsvKGRFTISadTSKNTAYLQMNSL 86
Cdd:smart00410   1 PPSVTVKEGESVTLSCEASGSP--PPEVTWYKQ----GGKLLAE--------------SGRFSVS--RSGSTSTLTISNV 58

                           90       100       110
                   ....*....|....*....|....*....|...
gi 90109487     87 RAEDTAVYYCARWGHSTSPWAmdywgqGTLVTV 119
Cdd:smart00410  59 TPEDSGTYTCAATNSSGSASS------GTTLTV 85

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 90109487 128 SVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSW--NSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQ-TYIC 204
Cdd:cd00098   1 TVTLLPPSPEEKGGGKVTLVCLVSGFYPKDITVTWlkNGVPLTSGVSTSSPVEPNDGTYSVTSSLTVPPSDWDEGaTYTC 80

                        90
                ....*....|....*
gi 90109487 205 NVNHKPSNTKVDKKV 219
Cdd:cd00098  81 VVTHESLKSPLSKTW 95

Immunoglobulin (Ig) variable (V) domain of Cluster of Differentiation (CD) 8 beta chain; The members here are composed of the immunoglobulin (Ig)-like domain in Cluster of Differentiation (CD) 8 beta. The CD8 glycoprotein plays an essential role in the control of T-cell selection, maturation, and the T-cell receptor (TCR)-mediated response to peptide antigen. CD8 is comprised of alpha and beta subunits and is expressed as either an alpha/alpha or alpha/beta dimer. Both dimeric isoforms can serve as a coreceptor for T cell activation and differentiation, however they have distinct physiological roles, different cellular distributions, unique binding partners, etc. Each CD8 subunit is comprised of an extracellular domain containing a V-type Ig-like domain, a single pass transmembrane portion, and a short intracellular domain. Members of this group contain standard Ig superfamily V-set AGFCC'C"/DEB domain topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90109487  11 LVQPGGSLRLSCAASGFTINASwIHWVR--QAPGKG--LEWVgAIYPYSGYTNYADSVKG-RFTISADTSKNTAYLQMNS 85
Cdd:cd07700   9 LVQTNQTVKMSCEAKTSPKNTR-IYWLRqrQAPSKDshFEFL-ASWDPSKGIVYGEGVDQeKLIILSDSDSSRYILSLMS 86

                        90       100       110
                ....*....|....*....|....*....|....
gi 90109487  86 LRAEDTAVYYCARWGhstSPwaMDYWGQGTLVTV 119
Cdd:cd07700  87 VKPEDSGTYFCMTVG---SP--ELIFGTGTKLSV 115

CH3 domain (third constant Ig domain of the heavy chain) in immunoglobulin heavy alpha, gamma, and delta chains, and CH4 domain (fourth constant Ig domain of the heavy chain) in immunoglobulin heavy alpha, epsilon, and mu chains; member of the C1-set of I; The members here are composed of the third and fourth immunoglobulin constant domain (IgC) of alpha, delta, gamma and alpha, epsilon, and mu heavy chains, respectively. This domain is found on the Fc fragment. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. There are two types of light chains: kappa and lambda; each is composed of a constant domain and a variable domain. There are five types of heavy chains: alpha, delta, epsilon, gamma, and mu, all consisting of a variable domain (VH) with three (alpha, delta and gamma) or four (epsilon and mu) constant domains (CH1 to CH4). Ig molecules are modular proteins, in which the variable and constant domains have clear, conserved sequence patterns.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|
gi 90109487 127 PSVFPLAPSSKS-TSGGTAALGCLVKDYFPEPVTVSWNSG 165
Cdd:cd05768   1 PSVYLLPPPEEElSLNETVTLTCLVKGFYPEDIFVSWLQN 40

Immunoglobulin light chain Constant domain; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig) light chain constant (C) domain. 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. There are five types of heavy chains (alpha, gamma, delta, epsilon, and mu), which determine the type of immunoglobulin: IgA, IgG, IgD, IgE, and IgM, respectively. In higher vertebrates, there are two types of light chain, designated kappa and lambda, which seem to be functionally identical, and can associate with any of the heavy chains.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90109487 127 PSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSW--NSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGT-QTYI 203
Cdd:cd07699   2 PSVTIFPPSSEELSSGKATLVCLINKFYPGFATVTWkvDGSTVSSGVTTSKTEQQSDNTYSMSSYLTLSSSDWNKhKVYT 81

                        90
                ....*....|....*...
gi 90109487 204 CNVNHKPSNTKVDKKVEP 221
Cdd:cd07699  82 CEVTHEGLSSTITKSFNR 99

Gammadelta T-cell antigen receptor, variable (V) domain; The members here are composed of the immunoglobulin (Ig) variable (V) domain of the gamma/delta T-cell receptors (TCRs). TCRs mediate antigen recognition by T lymphocytes, and are heterodimers consisting of alpha and beta chains or gamma and delta chains. Each chain contains a variable (V) and a constant (C) region. The majority of T cells contain alpha/beta TCRs, but a small subset contain gamma/delta TCRs. Alpha/beta TCRs recognize antigen as peptide fragments presented by major histocompatibility complex (MHC) molecules. Gamma/delta TCRs recognize intact protein antigens; they recognize protein antigens directly and without antigen processing, and MHC independently of the bound peptide. Gamma/delta T cells can also be stimulated by non-peptide antigens such as small phosphate- or amine-containing compounds. The variable domain of gamma/delta TCRs is responsible for antigen recognition and is located at the N-terminus of the receptor. Members of this group contain standard Ig superfamily V-set AGFCC'C"/DEB domain topology.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90109487  12 VQPGGSLRLSCAASGFTINASWIHWVRQAPGKGLEWvgaIYPYSGytNYADSVKGRFTISADTSKNTAYLQMNSLRAEDT 91
Cdd:cd20988  10 VSVGKPVTLKCSMKGEAISNYYINWYRKTQGNTMTF---IYREGG--IYGPGFKDNFRGDIDSSNNLAVLKILEASERDE 84

                        90       100       110
                ....*....|....*....|....*....|...
gi 90109487  92 AVYYCArwghSTSPWAMDY-----WGQGTLVTV 119
Cdd:cd20988  85 GSYYCA----SDTPGGGREydpliFGKGTYLTV 113