Catalyzes the conversion of methylglyoxal (MG) or glyoxal (GO) to D-lactate or glycolic acid respectively in a single glutathione (GSH)-independent step. May play a role in detoxifying endogenously produced glyoxals. Involved in protection against glyoxal-induced cell death. H2O + methylglyoxal = (R)-lactate + H(+) kcat is 13.8 min(-1) with methylglyoxal as substrate and 356.4 min(-1) with glyoxal as substrate. Ubiquitously localized throughout the whole cells with higher expression in the nucleus. Expressed exclusively in the intestine. Belongs to the peptidase C56 family.