Putative D-isomer specific 2-hydroxyacid dehydrogenases. 2-Hydroxyacid dehydrogenases catalyze the conversion of a wide variety of D-2-hydroxy acids to their corresponding keto acids. The general mechanism is (R)-lactate + acceptor to pyruvate + reduced acceptor. Formate/glycerate and related dehydrogenases of the D-specific 2-hydroxyacid dehydrogenase superfamily include groups such as formate dehydrogenase, glycerate dehydrogenase, L-alanine dehydrogenase, and S-adenosylhomocysteine yydrolase. Despite often low sequence identity, these proteins typically have a characteristic arrangement of 2 similar subdomains of the alpha/beta Rossmann fold NAD+ binding form. The NAD+ binding domain is inserted within the linear sequence of the mostly N-terminal catalytic domain, which has a similar domain structure to the internal NAD binding domain. Structurally, these domains are connected by extended alpha helices and create a cleft in which NAD is bound, primarily to the C-terminal portion of the 2nd (internal) domain. Some related proteins have similar structural subdomain but with a tandem arrangement of the catalytic and NAD-binding subdomains in the linear sequence. While many members of this family are dimeric, alanine DH is hexameric and phosphoglycerate DH is tetrameric.

Glycosyltransferase family 29 (sialyltransferase). Members of this family belong to glycosyltransferase family 29.