Class Ia major histocompatibility complex (MHC) immunoglobulin domain of MIC-A and MIC-B; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the Class Ia major histocompatibility complex (MHC) immunoglobulin domain of MIC-A and MIC-B. MIC-A and MIC-B are homologs that serve as stress-inducible antigens on epithelial and epithelially derived cells. Both serve as ligands for the widely expressed activating immunoreceptor NKG2D, a C-type lectin-like activating immunoreceptor. MIC-B is very similar in structure to MIC-A and likely interacts with NKG2D in an analogous manner. The interdomain flexibility observed in the MIC-A structures, a feature unique to MIC proteins among MHC class I proteins and homologs, is also displayed by MIC-B, with an interdomain relationship intermediate between the two examples of MIC-A structures. Mapping sequence variations onto the structures of MIC-A and MIC-B reveals patterns completely distinct from those displayed by classical MHC class I proteins, with a number of substitutions falling on positions likely to affect interactions with NKG2D, but with other positions lying distant from the NKG2D binding sites or buried within the core of the proteins. Members of the IgC 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 and the IgC domain is involved in oligomerization and molecular interactions.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 203 RTVPPMVNVTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNTQQWGDVLPDGNGTYQTWVATRIRQGEEQRFTC 282
Cdd:cd21017     1 RTVPPMVNVTRSEASEGNITVTCRASGFYPWNITLSWRQDGVSLSHDTQQWGDVLPDGNGTYQTWVATRICQGEEQRFTC 80

                          90
                  ....*....|....*
gi 1881044987 283 YMEHSGNHGTHPVPS 297
Cdd:cd21017    81 YMEHSGNHSTHPVPS 95

Class Ia major histocompatibility complex (MHC) immunoglobulin domain of MIC-A and MIC-B; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the Class Ia major histocompatibility complex (MHC) immunoglobulin domain of MIC-A and MIC-B. MIC-A and MIC-B are homologs that serve as stress-inducible antigens on epithelial and epithelially derived cells. Both serve as ligands for the widely expressed activating immunoreceptor NKG2D, a C-type lectin-like activating immunoreceptor. MIC-B is very similar in structure to MIC-A and likely interacts with NKG2D in an analogous manner. The interdomain flexibility observed in the MIC-A structures, a feature unique to MIC proteins among MHC class I proteins and homologs, is also displayed by MIC-B, with an interdomain relationship intermediate between the two examples of MIC-A structures. Mapping sequence variations onto the structures of MIC-A and MIC-B reveals patterns completely distinct from those displayed by classical MHC class I proteins, with a number of substitutions falling on positions likely to affect interactions with NKG2D, but with other positions lying distant from the NKG2D binding sites or buried within the core of the proteins. Members of the IgC 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 and the IgC domain is involved in oligomerization and molecular interactions.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 203 RTVPPMVNVTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNTQQWGDVLPDGNGTYQTWVATRIRQGEEQRFTC 282
Cdd:cd21017     1 RTVPPMVNVTRSEASEGNITVTCRASGFYPWNITLSWRQDGVSLSHDTQQWGDVLPDGNGTYQTWVATRICQGEEQRFTC 80

                          90
                  ....*....|....*
gi 1881044987 283 YMEHSGNHGTHPVPS 297
Cdd:cd21017    81 YMEHSGNHSTHPVPS 95

Immunoglobulin C-Type;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1881044987  222 TVTCRASSFYPRNITLTWRQDGVSLSHNTQQWgDVLPDGNGTYQTWVATRIRQ---GEEQRFTCYMEHSGNHGT 292
Cdd:smart00407   3 TLVCLVSGFYPPDITVTWLRNGQEVTEGVSTT-DPLKNSDGTYFLSSYLTVPAstwESGDVYTCQVTHEGLKEP 75

Class Ia major histocompatibility complex (MHC) immunoglobulin domain of MIC-A and MIC-B; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the Class Ia major histocompatibility complex (MHC) immunoglobulin domain of MIC-A and MIC-B. MIC-A and MIC-B are homologs that serve as stress-inducible antigens on epithelial and epithelially derived cells. Both serve as ligands for the widely expressed activating immunoreceptor NKG2D, a C-type lectin-like activating immunoreceptor. MIC-B is very similar in structure to MIC-A and likely interacts with NKG2D in an analogous manner. The interdomain flexibility observed in the MIC-A structures, a feature unique to MIC proteins among MHC class I proteins and homologs, is also displayed by MIC-B, with an interdomain relationship intermediate between the two examples of MIC-A structures. Mapping sequence variations onto the structures of MIC-A and MIC-B reveals patterns completely distinct from those displayed by classical MHC class I proteins, with a number of substitutions falling on positions likely to affect interactions with NKG2D, but with other positions lying distant from the NKG2D binding sites or buried within the core of the proteins. Members of the IgC 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 and the IgC domain is involved in oligomerization and molecular interactions.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 203 RTVPPMVNVTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNTQQWGDVLPDGNGTYQTWVATRIRQGEEQRFTC 282
Cdd:cd21017     1 RTVPPMVNVTRSEASEGNITVTCRASGFYPWNITLSWRQDGVSLSHDTQQWGDVLPDGNGTYQTWVATRICQGEEQRFTC 80

                          90
                  ....*....|....*
gi 1881044987 283 YMEHSGNHGTHPVPS 297
Cdd:cd21017    81 YMEHSGNHSTHPVPS 95

Class I Histocompatibility antigen, domains alpha 1 and 2;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987  24 EPHSLRYNLMVLSQDGSVQSGFLAEGHLDGQPFLRYD--RQKRRAKPQGQWAEDVlGAKTWDTETEDLTENGQ----DLR 97
Cdd:pfam00129   1 GSHSLRYFYTAVSRPGLGEPRFIAVGYVDDTQFVRFDsdAANPRMEPRAPWIEQE-GPEYWERETQIAKGNEQifreNLR 79

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987  98 RTLTHIKDQKGGLHSLQEIRVCEIHED-SSTRGSRHFYYDGELFLSQNLETQESTVpqssrAQTLAMNVTNFWkEDAMKT 176
Cdd:pfam00129  80 TLLGYYNQSEGGSHTLQWMYGCDVGPDgRLLRGYEQFAYDGKDYIALNEDLRSWTA-----ADPAAQITKRKW-EAAGEA 153

                         170       180
                  ....*....|....*....|..
gi 1881044987 177 KTHYRAMQADCLQKLQRYLKSG 198
Cdd:pfam00129 154 ERQRAYLEGECVEWLRRYLENG 175

Class Ib major histocompatibility complex (MHC) immunoglobulin domain of human leukocyte antigen H; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the Class Ib major histocompatibility complex (MHC) immunoglobulin domain of human leukocyte antigen H (HLA-H). HLA-H (also known as hereditary hemochromatosis protein; HFE) is a major histocompatibility complex (MHC) class I-like protein that is mutated in Hereditary Hemochromatosis. HFE is a protein of 343 amino acids that includes a signal peptide, an extracellular transferrin receptor-binding region (a1 and a2), an immunoglobulin-like domain (a3), a transmembrane region, and a short cytoplasmic tail. HFE binds beta-2-microglobulin to form a heterodimer expressed at the cell surface. It binds transferrin receptor (TFRC) in its extracellular alpha1-alpha2 domain. HFE plays an important part in the regulation of hepcidin expression in response to iron overload and the liver is important in the pathophysiology of HFE-associated hemochromatosis. Nine HFE splicing variants have been reported with transcripts lacking exon 2 or exon 3, or exons 2-3, 2-4, or 2-5. Diverse mutations involving HFE introns and exons discovered in persons with hemochromatosis or their family members cause or probably cause high iron phenotypes. Class I MHC proteins bind antigenic peptide fragments and present them to CD8+ T lymphocytes. Class I molecules consist of a transmembrane alpha chain and a small chain called the beta-2-microglobulin. The alpha chain contains three extracellular domains, two of which fold together to form the peptide-binding cleft (alpha1 and alpha2), and one which has an Ig fold (alpha3). Peptide binding to class I molecules occurs in the endoplasmic reticulum (ER) and involves both chaperones and dedicated factors to assist in peptide loading. Class I MHC molecules are expressed on most nucleated cells.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 203 RTVPPMVNVTcSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNTQQWGDVLPDGNGTYQTWVATRIRQGEEQRFTC 282
Cdd:cd21021     1 QQVPPLVKVT-HHVTSSVTTLRCRALNYYPQNITMKWLKDKQPMDAKEFEPKDVLPNGDGTYQGWITLAVPPGEEQRYTC 79

                  ....*.
gi 1881044987 283 YMEHSG 288
Cdd:cd21021    80 QVEHPG 85

Class Ib major histocompatibility complex (MHC) immunoglobulin domain of Qa-1 and similar proteins; member of the C1-set of Ig superfamily (IgSF) domains; Class Ib major histocompatibility complex (MHC) immunoglobulin domain of Qa-1 and similar proteins. Qa-1 presents hydrophobic peptides including Qdm derived from the leader sequence of classical MHC I molecules for immune surveillance by NK cells. Qa-1 bound peptides derived from the TCR Vbeta8.2 of activated T cells also activates CD8+ regulatory T cells to control autoimmunity and maintain self-tolerance. Four allotypes of Qa-1 (Qa-1a-d) are expressed that are highly conserved in sequence but have several variations that could affect peptide binding to Qa-1 or TCR recognition. Class I MHC proteins bind antigenic peptide fragments and present them to CD8+ T lymphocytes. Class I molecules consist of a transmembrane alpha chain and a small chain called the beta-2-microglobulin. The alpha chain contains three extracellular domains, two of which fold together to form the peptide-binding cleft (alpha1 and alpha2), and one which has an Ig fold (alpha3). Peptide binding to class I molecules occurs in the endoplasmic reticulum (ER) and involves both chaperones and dedicated factors to assist in peptide loading. Class I MHC molecules are expressed on most nucleated cells.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 203 RTVPPMVNVTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNtQQWGDVLPDGNGTYQTWVATRIRQGEEQRFTC 282
Cdd:cd21013     1 RSDPPKAHVTHHPRSEGYVTLRCWALGFYPADITLTWQLNGEELTQD-MEFVETRPAGDGTFQKWASVVVPLGKEQKYTC 79

                  ....*.
gi 1881044987 283 YMEHSG 288
Cdd:cd21013    80 HVEHEG 85

Class Ia major histocompatibility complex (MHC) immunoglobulin domain of human leukocyte antigen (HLA) B and similar proteins; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the class Ia major histocompatibility complex (MHC) immunoglobulin domain of human leukocyte antigen (HLA) B and similar proteins. The classical class I molecules (HLA-A, -B, and -C) are responsible for the presentation of endogenous antigen to CD8+ T cells. The receptor is a heterodimer, and is composed of a heavy alpha chain and smaller beta chain. The alpha chain is encoded by a variant HLA-B gene, and the beta chain (beta-2-microglobulin) is an invariant beta-2-microglobulin molecule. The beta-2-microglobulin protein is coded for by a separate region of the human genome. Human leukocyte antigen (HLA) B*3501 (B35) is a common human allele involved in mediating protective immunity against HIV. Class I MHC proteins bind antigenic peptide fragments and present them to CD8+ T lymphocytes. Class I molecules consist of a transmembrane alpha chain and a small chain called the beta-2-microglobulin. The alpha chain contains three extracellular domains, two of which fold together to form the peptide-binding cleft (alpha1 and alpha2), and one which has an Ig fold (alpha3). Peptide binding to class I molecules occurs in the endoplasmic reticulum (ER) and involves both chaperones and dedicated factors to assist in peptide loading. Class I MHC molecules are expressed on most nucleated cells.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 202 RRTVPPMVNVTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNTqQWGDVLPDGNGTYQTWVATRIRQGEEQRFT 281
Cdd:cd21026     1 QRADPPKTHVTHHPISDHEATLRCWALGFYPAEITLTWQRDGEDQTQDT-ELVETRPAGDRTFQKWAAVVVPSGEEQRYT 79

                  ....*..
gi 1881044987 282 CYMEHSG 288
Cdd:cd21026    80 CHVQHEG 86

Class Ia major histocompatibility complex (MHC) immunoglobulin domain of RT1-Aa; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the Class Ia major histocompatibility complex (MHC) immunoglobulin domain of RT1-Aa. While most mammalian species transport these peptides into the ER via a single allele of TAP, rats have evolved different TAPs, TAP-A and TAP-B, RT1-Aa and RT1-A1c, which are associated with TAP-A and TAP-B. The rat MHC class Ia molecule RT1-Aa has the unusual capacity to bind long peptides ending in arginine, such as MTF-E, a thirteen-residue, maternally transmitted minor histocompatibility antigen. Class I MHC proteins bind antigenic peptide fragments and present them to CD8+ T lymphocytes. Class I molecules consist of a transmembrane alpha chain and a small chain called the beta-2-microglobulin. The alpha chain contains three extracellular domains, two of which fold together to form the peptide-binding cleft (alpha1 and alpha2), and one which has an Ig fold (alpha3). Peptide binding to class I molecules occurs in the endoplasmic reticulum (ER) and involves both chaperones and dedicated factors to assist in peptide loading. Class I MHC molecules are expressed on most nucleated cells.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 203 RTVPPMVNVTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNtQQWGDVLPDGNGTYQTWVATRIRQGEEQRFTC 282
Cdd:cd21015     1 RSDPPEAHVTLHPRPEGDVTLRCWALGFYPADITLTWQLNGEDLTQD-MELVETRPAGDGTFQKWASVVVPLGKEQNYTC 79

                  ....*.
gi 1881044987 283 YMEHSG 288
Cdd:cd21015    80 RVEHEG 85

Class Ia major histocompatibility complex (MHC) immunoglobulin domain of human leukocyte antigen (HLA) A; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the class Ia major histocompatibility complex (MHC) immunoglobulin domain of human leukocyte antigen (HLA) A. The classical class I molecules (HLA-A, -B, and -C) are responsible for the presentation of endogenous antigen to CD8+ T cells. The receptor is a heterodimer, and is composed of a heavy alpha chain and smaller beta chain. The alpha chain is encoded by a variant HLA-A gene, and the beta chain (beta-2-microglobulin) is an invariant beta-2-microglobulin molecule. The beta-2-microglobulin protein is coded for by a separate region of the human genome. HLA-A2 is associated with spontaneous abortions, HIV, and Hodgkin lymphoma. Class I molecules consist of a transmembrane alpha chain and a small chain called the beta-2-microglobulin. The alpha chain contains three extracellular domains, two of which fold together to form the peptide-binding cleft (alpha1 and alpha2), and one which has an Ig fold (alpha3). Peptide binding to class I molecules occurs in the endoplasmic reticulum (ER) and involves both chaperones and dedicated factors to assist in peptide loading. Class I MHC molecules are expressed on most nucleated cells.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 202 RRTVPPMVNVTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNTQqWGDVLPDGNGTYQTWVATRIRQGEEQRFT 281
Cdd:cd21027     1 QRTDAPKTHMTHHAVSDHEATLRCWALSFYPAEITLTWQRDGEDQTQDTE-LVETRPAGDGTFQKWAAVVVPSGQEQRYT 79

                  ....*..
gi 1881044987 282 CYMEHSG 288
Cdd:cd21027    80 CHVQHEG 86

Class Ib major histocompatibility complex (MHC) immunoglobulin domain of HLA-Cw3 and HLA-Cw4; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the Class Ib major histocompatibility complex (MHC) immunoglobulin domain of HLA-Cw3 and HLA-Cw4. HLA-C belongs to the MHC class I heavy chain receptors. The C receptor is a heterodimer consisting of a HLA-C mature gene product and beta-2-microglobulin. The mature C chain is anchored in the membrane. MHC Class I molecules, like HLA-C, are expressed in nearly all cells, and present small peptides to the immune system which surveys for non-self peptides. HLA-C is a locus on chromosome 6, which encodes for a large number of HLA-C alleles that are Class-I MHC receptors. Class Ib histocompatibility leukocyte antigens (HLA)-Cw3 and (HLA)-Cw4 are ligands for the natural killer (NK) cell inhibitory receptors KIR2DL2 and KIR2DL1, respectively. HLA-Cw3 and related alleles (HLA-Cw1, -Cw7, and -Cw8) contain Ser77 and Asn80 and interact with KIR that are reactive with the GL183 antibody Class I MHC proteins bind antigenic peptide fragments and present them to CD8+ T lymphocytes. HLA-Cw4 and related alleles (HLA-Cw2, -Cw5, and -Cw6) have Asn77 and Lys80 and are recognized by KIR reactive with the EB6 15 or HP-3E4 16 antibody. Members of the IgC 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, and the IgC domain is involved in oligomerization and molecular interactions.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 202 RRTVPPMVNVTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNTQqWGDVLPDGNGTYQTWVATRIRQGEEQRFT 281
Cdd:cd21025     1 QRAEHPKTHVTHHPVSDHEATLRCWALGFYPAEITLTWQWDGEDQTQDTE-LVETRPAGDGTFQKWAAVVVPSGEEQRYT 79

                  ....*..
gi 1881044987 282 CYMEHSG 288
Cdd:cd21025    80 CHVQHEG 86

Class Ia major histocompatibility complex (MHC) immunoglobulin domain of H2-Dd; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the Class Ia major histocompatibility complex (MHC) immunoglobulin domain of H2-Dd. Mouse MHC is composed of 11 subclasses. It includes the classical MHC class I (MHC-Ia) that comprises H-2D, H-2K and H-2L subclasses, the non-classical MHC class I (MHCIb) that comprises H-2Q, H-2M and H-2T subclasses, the classical MHC class II (MHC-IIa) that includes H-2A(I-A) and H-2E(I-E) subclasses, and the non-classical MHC class II (MHC-IIb) comprises H-2M and H-2O. H-2K, H-2D, and H-2L are 80 to 90% homologous at the amino acid level yet appear to be involved in different recognition reactions and are differentially expressed on lymphoid cells. Class I MHC proteins bind antigenic peptide fragments and present them to CD8+ T lymphocytes. Class I molecules consist of a transmembrane alpha chain and a small chain called the beta-2-microglobulin. The alpha chain contains three extracellular domains, two of which fold together to form the peptide-binding cleft (alpha1 and alpha2), and one which has an Ig fold (alpha3). Peptide binding to class I molecules occurs in the endoplasmic reticulum (ER) and involves both chaperones and dedicated factors to assist in peptide loading. Class I MHC molecules are expressed on most nucleated cells.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 204 TVPPMVNVTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNtQQWGDVLPDGNGTYQTWVATRIRQGEEQRFTCY 283
Cdd:cd21020     3 TDPPKAHVTHHRRPEGDVTLRCWALGFYPADITLTWQLNGEELTQE-MELVETRPAGDGTFQKWASVVVPLGKEQKYTCH 81

                  ....*
gi 1881044987 284 MEHSG 288
Cdd:cd21020    82 VEHEG 86

Class Ib major histocompatibility complex (MHC) immunoglobulin domain of Qa-2; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the Class Ib major histocompatibility complex (MHC) immunoglobulin domain of QA-2. Qa-2 is a nonclassical MHC Ib antigen, which has been implicated in both innate and adaptive immune responses, as well as embryonic development. Qa-2 has an unusual peptide binding specificity in that it requires two dominant C-terminal anchor residues and is capable of associating with a substantially more diverse array of peptide sequences than other nonclassical MHC. Class I MHC proteins bind antigenic peptide fragments and present them to CD8+ T lymphocytes. Class I molecules consist of a transmembrane alpha chain and a small chain called the beta-2-microglobulin. The alpha chain contains three extracellular domains, two of which fold together to form the peptide-binding cleft (alpha1 and alpha2), and one which has an Ig fold (alpha3). Peptide binding to class I molecules occurs in the endoplasmic reticulum (ER) and involves both chaperones and dedicated factors to assist in peptide loading. Class I MHC molecules are expressed on most nucleated cells.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 204 TVPPMVNVTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNtQQWGDVLPDGNGTYQTWVATRIRQGEEQRFTCY 283
Cdd:cd21014     2 TDPPKAHVTHHPRSYGAVTLRCWALGFYPADITLTWQLNGEELTQD-MELVETRPAGDGTFQKWASVVVPLGKEQNYTCH 80

                  ....*
gi 1881044987 284 MEHSG 288
Cdd:cd21014    81 VNHEG 85

Class Ia major histocompatibility complex (MHC) immunoglobulin domain of H-2Kb; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the Class Ia major histocompatibility complex (MHC) immunoglobulin domain of H-2Kb. H-2Kb is an alloantigen for the 2C T cell receptor (TCR). H-2Kb forms a complex with beta-2-microglobulin, and a peptide, including VSV-8 (RGYVYNGL), SEV-9 (FAPGNYPAL), and OVA-8 (SIINFEKL). Comparison of the OVA-8, VSV-8, and SEV-9 complexes with H-2Kb indicates that four side chains (Lys-66, Glu-152, Arg-155, and Trp-167) adopt peptide-specific conformations. H-2Kb paralogs include H-2Db, H-2Kbml and H-2KbI1s. Class I MHC proteins bind antigenic peptide fragments and present them to CD8+ T lymphocytes. Class I molecules consist of a transmembrane alpha chain and a small chain called the beta-2-microglobulin. The alpha chain contains three extracellular domains, two of which fold together to form the peptide-binding cleft (alpha1 and alpha2), and one which has an Ig fold (alpha3). Peptide binding to class I molecules occurs in the endoplasmic reticulum (ER) and involves both chaperones and dedicated factors to assist in peptide loading. Class I MHC molecules are expressed on most nucleated cells.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 203 RTVPPMVNVTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNtQQWGDVLPDGNGTYQTWVATRIRQGEEQRFTC 282
Cdd:cd21019     1 RTDSPKAHVTHHSRPEDKVTLRCWALGFYPADITLTWQLNGEELIQD-MELVETRPAGDGTFQKWASVVVPLGKEQYYTC 79

                  ....*.
gi 1881044987 283 YMEHSG 288
Cdd:cd21019    80 HVYHQG 85

Immunoglobulin C-Type;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1881044987  222 TVTCRASSFYPRNITLTWRQDGVSLSHNTQQWgDVLPDGNGTYQTWVATRIRQ---GEEQRFTCYMEHSGNHGT 292
Cdd:smart00407   3 TLVCLVSGFYPPDITVTWLRNGQEVTEGVSTT-DPLKNSDGTYFLSSYLTVPAstwESGDVYTCQVTHEGLKEP 75

immunoglobulin domain of neonatal Fc receptor, major histocompatibility complex (MHC)-like; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin domain of neonatal Fc receptor (FcRn). FcRn performs two distinct functions: the transport of maternal immunoglobulin G (IgG) to pre- or neonatal mammals which provides passive immunity and protection of IgG from normal serum protein catabolism. FcRn is related to class I MHC proteins, but lacks a functional peptide binding groove. Class I MHC proteins bind antigenic peptide fragments and present them to CD8+ T lymphocytes. Class I molecules consist of a transmembrane alpha chain and a small chain called the beta-2-microglobulin. The alpha chain contains three extracellular domains, two of which fold together to form the peptide-binding cleft (alpha1 and alpha2), and one which has an Ig fold (alpha3). Peptide binding to class I molecules occurs in the endoplasmic reticulum (ER) and involves both chaperones and dedicated factors to assist in peptide loading. Class I MHC molecules are expressed on most nucleated cells.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 206 PPMVNVTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNTqqwGDVLPDGNGTYQTWVATRIRQGEEQRFTCYME 285
Cdd:cd21011     5 PPSMRLKARPGSPGFSVLTCSAFSFYPPELQLRFLRNGLAAGSGE---GDFGPNGDGSFHAWSSLTVKSGDEHHYRCVVQ 81

                  ...
gi 1881044987 286 HSG 288
Cdd:cd21011    82 HAG 84

Class II major histocompatibility complex (MHC) beta chain immunoglobulin domain; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig) domain of major histocompatibility complex (MHC) class II beta chain. MHC class II molecules play a key role in the initiation of the antigen-specific immune reponse. These molecules have been shown to be expressed constitutively on the cell surface of professional antigen-presenting cells (APCs), including B-lymphocytes, monocytes, and macrophages in both humans and mice. The expression of these molecules has been shown to be induced in nonprofessional APCs such as keratinocyctes and they are also expressed on the surface of activated human T cells and on T cells from other species. The MHC II molecules present antigenic peptides to CD4(+) T-lymphocytes. These peptides derive mostly from proteolytic processing via the endocytic pathway of antigens internalized by the APC. These peptides bind to the MHC class II molecules in the endosome before they are transported to the cell surface. MHC class II molecules are heterodimers, comprised of two similarly-sized membrane-spanning chains, alpha and beta. Each chain has two globular domains (N- and C-terminal) and a membrane-anchoring transmembrane segment. The two chains form a compact four-domain structure. The peptide-binding site is a cleft in the structure.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 204 TVPPMVNVTCSE-VSEGNI-TVTCRASSFYPRNITLTWRQDGVSLSHNTQQwGDVLPDGNGTYQTWV--ATRIRQGEeqR 279
Cdd:cd05766     1 RVQPSVKVSPTKtGPLEHPnLLVCSVTGFYPAEIEVKWFRNGQEETAGVVS-TELIPNGDWTFQILVmlETTPRRGD--V 77

                  ....*....
gi 1881044987 280 FTCYMEHSG 288
Cdd:cd05766    78 YTCQVEHSS 86

Signal-regulatory protein (SIRP) immunoglobulin-like domain 2; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in Signal-Regulatory Protein (SIRP), domain 2 (C1 repeat 1). The SIRPs belong to the "paired receptors" class of membrane proteins that comprise several genes coding for proteins with similar extracellular regions, but very different transmembrane/cytoplasmic regions with different (activating or inhibitory) signaling potentials. They are commonly on NK cells, but are also on many myeloid cells. Their extracellular region contains three Immunoglobulin superfamily domains, a single V-set and two C1-set IgSF domains. Their cytoplasmic tails contain either ITIMs or transmembrane regions that have positively charged residues that allow an association with adaptor proteins, such as DAP12/KARAP, containing ITAMs. There are 3 distinct SIRP members: alpha, beta, and gamma. SIRP alpha (also known as CD172a or SRC homology 2 domain-containing protein tyrosine phosphatase substrate 1/Shps-1) is a membrane receptor that interacts with a ligand CD47 expressed on many cells and gives an inhibitory signal through immunoreceptor tyrosine-based inhibition motifs in the cytoplasmic region that interact with phosphatases SHP-1 and SHP-2. SIRP beta has a short cytoplasmic region and associates with a transmembrane adapter protein DAP12 containing immunoreceptor tyrosine-based activation motifs to give an activating signal. SIRP gamma contains a very short cytoplasmic region lacking obvious signaling motifs, but also binds CD47, but with much less affinity.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1881044987 224 TCRASSFYPRNITLTWRQDGVSLShntQQWGDVLPDGNG-TYQTWVATRIRQGEE---QRFTCYMEHS 287
Cdd:cd05772    23 TCKSHGFSPRDITLKWFKNGNELS---ALQTTVFPEGDSvSYSVSSTVQVVLTKDdvhSQLTCEVAHV 87

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 211 VTCSEVSEGNITVTCRASSFYPRNITLTWRQDGVSLSHNTQQWGDVLpdGNGTYQTWVATRIRQGE---EQRFTCYMEHS 287
Cdd:cd21819     8 VSCGSSTSDPVTVGCLATDFLPDSITFSWTDDNNSLTTGVKTYPSVL--TGGTYTASSQLQVPESEwksKENFYCKVEHP 85

                  ....*....
gi 1881044987 288 GNHGTHPVP 296
Cdd:cd21819    86 GGNKEVPVP 94

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 222 TVTCRASSFYPRNITLTWRQDGVSLS----HNTQqwgdVLPDGNGTY----------QTWvatriRQGEEqrFTCYMEHS 287
Cdd:cd05768    20 TLTCLVKGFYPEDIFVSWLQNGEPLPsadyKTTA----PVPESDGSFfvysklnvstADW-----NSGDV--FSCVVGHE 88

                  ...
gi 1881044987 288 GNH 290
Cdd:cd05768    89 ALP 91

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 1881044987 216 VSEGNITVTCRASSFYPRNITLTWRQ------------DGVSLSHNTQQwgdvlpdGNGTYQTWVATRIRQGEEQR---F 280
Cdd:cd05771    12 KPDLPQTLSCHIAGYYPLDVDVEWLReepggsesqvsrDGVSLSSHRQS-------VDGTYSISSYLTLEPGTENRgatY 84

                  ....*.
gi 1881044987 281 TCYMEH 286
Cdd:cd05771    85 TCRVTH 90

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1881044987 204 TVPPMVNVtCSEVSEGNITVTCRASSFYPRNITLTWRQDgvSLSHNTQQWGDVLpDGNGTYQTWVATRIRQGE--EQRFT 281
Cdd:cd21817     3 SVFPLAPC-CKSTNGSSVTLGCLVTGYFPEPVTVTWNSG--SLTSGVKTFPAVL-QSSGLYTTSSQVTVPSSSwgSQTFT 78

                  ....*
gi 1881044987 282 CYMEH 286
Cdd:cd21817    79 CNVEH 83