Accepted name: methylmalonate-semialdehyde dehydrogenase (CoA-acylating)
Reaction: 2-methyl-3-oxopropanoate + CoA + H2O + NAD+ = propanoyl-CoA + HCO3- + NADH
Glossary: methylmalonate semialdehyde = 2-methyl-3-oxopropanoate
Other name(s): MSDH; MMSA dehydrogenase; iolA (gene name); methylmalonate-semialdehyde dehydrogenase (acylating)
Systematic name: 2-methyl-3-oxopropanoate:NAD+ 3-oxidoreductase (CoA-propanoylating)
Comments: Also converts 3-oxopropanoate into acetyl-CoA [3]. The reaction occurs in two steps with the decarboxylation process preceding CoA-binding [3]. Bicarbonate rather than CO2 is released as a final product [3].
1.  Sokatch, J.R., Sanders, L.E. and Marshall, V.P. Oxidation of methylmalonate semialdehyde to propionyl coenzyme A in Pseudomonas aeruginosa grown on valine. J. Biol. Chem. 243 (1968) 2500–2506. [PMID: 4297649]
2.  Dubourg, H., Stines-Chaumeil, C., Didierjean, C., Talfournier, F., Rahuel-Clermont, S., Branlant, G. and Aubry, A. Expression, purification, crystallization and preliminary X-ray diffraction data of methylmalonate-semialdehyde dehydrogenase from Bacillus subtilis. Acta Crystallogr. D Biol. Crystallogr. 60 (2004) 1435–1437. [PMID: 15272169]
3.  Stines-Chaumeil, C., Talfournier, F. and Branlant, G. Mechanistic characterization of the MSDH (methylmalonate semialdehyde dehydrogenase) from Bacillus subtilis. Biochem. J. 395 (2006) 107–115. [PMID: 16332250]
[EC created 1972, modified 2014]