ID   B2MG_HORSE              Reviewed;         118 AA.
AC   P30441; Q540U6; Q6YLH6;
DT   01-APR-1993, integrated into UniProtKB/Swiss-Prot.
DT   01-APR-1993, sequence version 1.
DT   03-AUG-2022, entry version 140.
DE   RecName: Full=Beta-2-microglobulin;
DE   Flags: Precursor;
GN   Name=B2M;
OS   Equus caballus (Horse).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Laurasiatheria; Perissodactyla; Equidae; Equus.
OX   NCBI_TaxID=9796;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=8344729; DOI=10.1007/bf00210486;
RA   Ellis S.A., Martin A.J.;
RT   "Nucleotide sequence of horse beta 2-microglobulin cDNA.";
RL   Immunogenetics 38:383-383(1993).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND CHARACTERIZATION.
RX   PubMed=12557059; DOI=10.1007/s00251-002-0514-0;
RA   Tallmadge R.L., Lear T.L., Johnson A.K., Guerin G., Millon L.V.,
RA   Carpenter S.L., Antczak D.F.;
RT   "Characterization of the beta(2)-microglobulin gene of the horse.";
RL   Immunogenetics 54:725-733(2003).
CC   -!- FUNCTION: Component of the class I major histocompatibility complex
CC       (MHC). Involved in the presentation of peptide antigens to the immune
CC       system (By similarity). {ECO:0000250}.
CC   -!- SUBUNIT: Heterodimer of an alpha chain and a beta chain. Beta-2-
CC       microglobulin is the beta-chain of major histocompatibility complex
CC       class I molecules (By similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the beta-2-microglobulin family. {ECO:0000305}.
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DR   EMBL; X69083; CAA48827.1; -; mRNA.
DR   EMBL; AY124653; AAM77008.1; -; Genomic_DNA.
DR   EMBL; AY124656; AAM77009.1; -; Genomic_DNA.
DR   EMBL; AY124654; AAM77009.1; JOINED; Genomic_DNA.
DR   EMBL; AY124655; AAM77009.1; JOINED; Genomic_DNA.
DR   EMBL; AY124659; AAM77010.1; -; Genomic_DNA.
DR   EMBL; AY124657; AAM77010.1; JOINED; Genomic_DNA.
DR   EMBL; AY124658; AAM77010.1; JOINED; Genomic_DNA.
DR   EMBL; AY124662; AAM77011.1; -; Genomic_DNA.
DR   EMBL; AY124660; AAM77011.1; JOINED; Genomic_DNA.
DR   EMBL; AY124661; AAM77011.1; JOINED; Genomic_DNA.
DR   EMBL; AY124665; AAM77012.1; -; Genomic_DNA.
DR   EMBL; AY124663; AAM77012.1; JOINED; Genomic_DNA.
DR   EMBL; AY124664; AAM77012.1; JOINED; Genomic_DNA.
DR   EMBL; AY124668; AAM77013.1; -; Genomic_DNA.
DR   EMBL; AY124666; AAM77013.1; JOINED; Genomic_DNA.
DR   EMBL; AY124667; AAM77013.1; JOINED; Genomic_DNA.
DR   EMBL; AY124671; AAM77014.1; -; Genomic_DNA.
DR   EMBL; AY124669; AAM77014.1; JOINED; Genomic_DNA.
DR   EMBL; AY124670; AAM77014.1; JOINED; Genomic_DNA.
DR   PIR; I46244; S30566.
DR   RefSeq; NP_001075971.1; NM_001082502.3.
DR   RefSeq; XP_005602652.1; XM_005602595.2.
DR   AlphaFoldDB; P30441; -.
DR   SMR; P30441; -.
DR   STRING; 9796.ENSECAP00000048553; -.
DR   PaxDb; P30441; -.
DR   PeptideAtlas; P30441; -.
DR   PRIDE; P30441; -.
DR   Ensembl; ENSECAT00000001009; ENSECAP00000000811; ENSECAG00000000685.
DR   GeneID; 100034203; -.
DR   KEGG; ecb:100034203; -.
DR   CTD; 567; -.
DR   VGNC; VGNC:15722; B2M.
DR   GeneTree; ENSGT00690000102227; -.
DR   HOGENOM; CLU_163066_0_0_1; -.
DR   InParanoid; P30441; -.
DR   OMA; FHPPKID; -.
DR   OrthoDB; 1556447at2759; -.
DR   TreeFam; TF334167; -.
DR   Proteomes; UP000002281; Chromosome 1.
DR   Bgee; ENSECAG00000000685; Expressed in leukocyte and 23 other tissues.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0042612; C:MHC class I protein complex; IEA:UniProtKB-KW.
DR   GO; GO:0042613; C:MHC class II protein complex; IBA:GO_Central.
DR   GO; GO:0023026; F:MHC class II protein complex binding; IBA:GO_Central.
DR   GO; GO:0019886; P:antigen processing and presentation of exogenous peptide antigen via MHC class II; IBA:GO_Central.
DR   GO; GO:0002474; P:antigen processing and presentation of peptide antigen via MHC class I; IEA:UniProtKB-KW.
DR   GO; GO:0006955; P:immune response; IEA:InterPro.
DR   GO; GO:0002503; P:peptide antigen assembly with MHC class II protein complex; IBA:GO_Central.
DR   GO; GO:0050870; P:positive regulation of T cell activation; IBA:GO_Central.
DR   CDD; cd05770; IgC_beta2m; 1.
DR   Gene3D; 2.60.40.10; -; 1.
DR   InterPro; IPR015707; B2Microglobulin.
DR   InterPro; IPR007110; Ig-like_dom.
DR   InterPro; IPR036179; Ig-like_dom_sf.
DR   InterPro; IPR013783; Ig-like_fold.
DR   InterPro; IPR003006; Ig/MHC_CS.
DR   InterPro; IPR003597; Ig_C1-set.
DR   PANTHER; PTHR19944:SF62; PTHR19944:SF62; 1.
DR   Pfam; PF07654; C1-set; 1.
DR   SMART; SM00407; IGc1; 1.
DR   SUPFAM; SSF48726; SSF48726; 1.
DR   PROSITE; PS50835; IG_LIKE; 1.
DR   PROSITE; PS00290; IG_MHC; 1.
PE   1: Evidence at protein level;
KW   Disulfide bond; Immunity; Immunoglobulin domain; MHC I; Reference proteome;
KW   Secreted; Signal.
FT   SIGNAL          1..20
FT                   /evidence="ECO:0000250"
FT   CHAIN           21..118
FT                   /note="Beta-2-microglobulin"
FT                   /id="PRO_0000018778"
FT   DOMAIN          22..115
FT                   /note="Ig-like C1-type"
FT   DISULFID        45..99
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00114"
SQ   SEQUENCE   118 AA;  13426 MW;  67BDBFDD4D01FB38 CRC64;
     MARVVALVLL GLLSLTGLEA VPRVPKVQVY SRHPAENGKP NFLNCYVSGF HPPEIEIDLL
     KNGEKMKVDR SDLSFSKDWS FYLLVHTDFT PNGVDEYSCR VQHSTLKDPL IVKWDRDL