FEATURES

FAMILY

DESCRIPTION

Also known as B2MG_HUMAN, B2M. Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. Exogenously applied M.tuberculosis EsxA or EsxA-EsxB (or EsxA expressed in host) binds B2M and decreases its export to the cell surface (total protein levels do not change), probably leading to defects in class I antigen presentation (PubMed:25356553). Heterodimer of an alpha chain and a beta chain. Beta-2-microglobulin is the beta-chain of major histocompatibility complex class I molecules. Polymers of beta 2-microglobulin can be found in tissues from patients on long-term hemodialysis. B2M alone (not in complex with HLA-I) interacts with M.tuberculosis EsxA (ESAT-6) and an EsxA-EsxB (CFP-10) complex; the tripartite complex can be detected in the host endoplasmic reticulum (PubMed:25356553). The B2M-EsxA complex can be detected in patients with pleural tuberculosis and is stable from pH 4.0 to 8.0 and in the presence of 2M NaCl (PubMed:25356553). Forms a heterotrimer with HLA-E and a self- or a foreign peptide (PubMed:9427624). Forms a heterotrimer with HLA-G and a self-peptide (PubMed:17056715). Forms a heterotrimer with HLA-F and a self-peptide (PubMed:10605026). Forms a heterotrimer with MR1 and a metabolite antigen.

EXTERNAL LINKS

B2M

Beta-2-microglobulin

B2M

Molecular Synopsis