Recognizes a protein of 12 kDa，identified as B-2 microglobulin. Major histocompatibility complex (MHC) class 1 molecules bind to antigens for presentation on the surface of cells. The proteasome is responsible for producing these antigens from the components of foreign pathogens. MHC class 1 molecules consist of an heavy chain that contains three subdomains (1，2，3) and a non-covalent associating light chain，known as B-2-Microglobulin. B-2-Microglobulin associates with the 3 subdomain of the heavy chain and forms an immunoglobulin domain-like structure that mediates proper folding and expression of MHC class 1 molecules. The 1 and 2 domains of the heavy chain form the peptide antigen-binding cleft. Mutations in the B-2-Microglobulin gene can enhance the progression of malignant melanoma phenotypes.
