(R)-2-methyl-3-oxopropanoate + NAD(+) + CoA + H2O <=> propanoyl-CoA + hydrogencarbonate + NADH + H(+)
(r)-2-methyl-3-oxopropanoate + nad(+) + coa + h2o <=> propanoyl-coa + hydrogencarbonate + nadh + h(+)