Peptidase M20 family, unknown dipeptidase-like subfamily (inferred by homology to be dipeptidases). M20 dipeptidases include a large variety of bacterial enzymes including cytosolic nonspecific dipeptidase (CNDP), Xaa-methyl-His dipeptidase (anserinase),and canosinase. These dipeptidases have been shown to act on a wide range of dipeptides, but not larger peptides. For example, anserinase mainly catalyzes the hydrolysis of N-alpha-acetylhistidine while carnosinase degrades beta-alanyl-L-histidine.