Anti-MAT2B antibodies are used in the immunodetection of the protein methionine adenosyltransferase 2 non-catalytic beta subunit. In humans, the canonical protein has a reported length of 334 amino acid residues and a mass of 37.6 kDa. Alternative splicing is reported to yield 5 different isoforms for this protein. It is widely expressed across many tissue types. A member of a the DTDP-4-dehydrorhamnose reductase protein family, MAT2B is a regulatory subunit of S-adenosylmethionine synthetase 2, an enzyme that catalyzes the formation of S-adenosylmethionine from methionine and ATP. Synonyms for this target antigen include MATIIbeta, Nbla02999, SDR23E1, TGR, methionine adenosyltransferase 2 subunit beta, and MAT-II.