ID   B2MG_ICTPU              Reviewed;         116 AA.
AC   O42197;
DT   30-MAY-2003, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1998, sequence version 1.
DT   25-MAY-2022, entry version 87.
DE   RecName: Full=Beta-2-microglobulin;
DE   Flags: Precursor;
GN   Name=b2m;
OS   Ictalurus punctatus (Channel catfish) (Silurus punctatus).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Actinopterygii; Neopterygii; Teleostei; Ostariophysi; Siluriformes;
OC   Ictaluridae; Ictalurus.
OX   NCBI_TaxID=7998;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA / MRNA].
RX   PubMed=9745011; DOI=10.1007/s002510050441;
RA   Criscitiello M.F., Benedetto R., Antao A., Wilson M.R., Chinchar V.G.,
RA   Miller N.W., Clem L.W., McConnell T.J.;
RT   "Beta 2-microglobulin of ictalurid catfishes.";
RL   Immunogenetics 48:339-343(1998).
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; AF016041; AAC67230.1; -; mRNA.
DR   EMBL; AF016042; AAC64991.1; -; Genomic_DNA.
DR   RefSeq; NP_001187001.1; NM_001200072.1.
DR   AlphaFoldDB; O42197; -.
DR   SMR; O42197; -.
DR   STRING; 7998.ENSIPUP00000010741; -.
DR   GeneID; 100304470; -.
DR   KEGG; ipu:100304470; -.
DR   CTD; 791742; -.
DR   OrthoDB; 1556447at2759; -.
DR   Proteomes; UP000221080; Chromosome 5.
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: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   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   3: Inferred from homology;
KW   Disulfide bond; Immunity; Immunoglobulin domain; MHC I; Secreted; Signal.
FT   SIGNAL          1..19
FT                   /evidence="ECO:0000255"
FT   CHAIN           20..116
FT                   /note="Beta-2-microglobulin"
FT                   /id="PRO_0000018809"
FT   DOMAIN          24..111
FT                   /note="Ig-like C1-type"
FT   DISULFID        44..99
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00114"
SQ   SEQUENCE   116 AA;  13187 MW;  4ECAA5E0B5E8801D CRC64;
     MKFLLSFVVL AVFSASAFAK ESPPKIQVYS RNPGEFGKEN TLICHVSDFH PPDITIDLLK
     NGEVIPNAEQ TDLAFEKGWK FHLTKSVSFT PTSNDKFTCR VRHLKETKNI SWEPDM