Plays a role in valine and pyrimidine metabolism. Binds fatty acyl-CoA (By similarity). 2-methyl-3-oxopropanoate + CoA + H2O + NAD(+) = H(+) + hydrogencarbonate + NADH + propanoyl-CoA 3-oxopropanoate + CoA + NAD(+) = acetyl-CoA + CO2 + NADH 3-oxopropanoate + CoA + NADP(+) = acetyl-CoA + CO2 + NADPH Homotetramer. Belongs to the aldehyde dehydrogenase family.