In enzymology, a malonate-semialdehyde dehydrogenase (acetylating) () is an enzyme that catalyzes the chemical reaction 3-oxopropanoate + CoA + NAD(P)+ acetyl-CoA + CO2 + NAD(P)H The 4 substrates of this enzyme are 3-oxopropanoate, CoA, NAD+, and NADP+, whereas its 4 products are acetyl-CoA, CO2, NADH, and NADPH. This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 3-oxopropanoate:NAD(P)+ oxidoreductase (decarboxylating, CoA-acetylating). This enzyme is also called malonic semialdehyde oxidative decarboxylase. This enzyme participates in 4 metabolic pathways: inositol metabolism, alanine and aspartate metabolism, beta-alanine metabolism, and propanoate metabolism. References Further reading EC 1.2.1 NADPH-dependent enzymes NADH-dependent enzymes Enzymes of unknown structure