In enzymology, methylenetetrahydrofolate dehydrogenase (NAD+) () is an enzyme that catalyzes the chemical reaction.

The two substrates of this enzyme are 5,10-methylenetetrahydrofolate and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are 5,10-methenyltetrahydrofolate, reduced NADH, and a proton.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 5,10-methylenetetrahydrofolate:NAD+ oxidoreductase. This enzyme is also called methylenetetrahydrofolate dehydrogenase (NAD+). This enzyme participates in one carbon pool by folate.

Structural studies As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes and .

References