In enzymology, a methylmalonate-semialdehyde dehydrogenase (acylating) (EC 188.8.131.52) is an enzyme that catalyzes the chemical reaction
- 2-methyl-3-oxopropanoate + CoA + H2O + NAD+ propanoyl-CoA + HCO3- + NADH
The 4 substrates of this enzyme are 2-methyl-3-oxopropanoate, CoA, H2O, and NAD+, whereas its 3 products are propanoyl-CoA, HCO3-, and NADH.
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 2-methyl-3-oxopropanoate:NAD+ 3-oxidoreductase (CoA-propanoylating). Other names in common use include MSDH, and MMSA dehydrogenase. This enzyme participates in 3 metabolic pathways: inositol metabolism, valine, leucine and isoleucine degradation, and propanoate metabolism.
As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code 1T90.
- Sokatch JR, Sanders LE, Marshall VP (1968). "Oxidation of methylmalonate semialdehyde to propionyl coenzyme A in Pseudomonas aeruginosa grown on valine". J. Biol. Chem. 243 (10): 2500–6. PMID 4297649.
- Rahuel-Clermont S, Branlant G, Aubry A (2004). "Expression, purification, crystallization and preliminary X-ray diffraction data of methylmalonate-semialdehyde dehydrogenase from Bacillus subtilis". Acta Crystallogr. D 60 (Pt 8): 1435–7. doi:10.1107/S0907444904012533. PMID 15272169.
- Stines-Chaumeil C, Talfournier F, Branlant G (2006). "Mechanistic characterization of the MSDH (methylmalonate semialdehyde dehydrogenase) from Bacillus subtilis". Biochem. J. 395 (1): 107–15. doi:10.1042/BJ20051525. PMC 1409689. PMID 16332250.