ATP + hydrogencarbonate + propanoyl-CoA = (S)-methylmalonyl-CoA + ADP + H(+) + phosphate Metabolic intermediate metabolism; propanoyl-CoA degradation; succinyl-CoA from propanoyl-CoA: step 1/3. Probably a dodecamer composed of six biotin-containing alpha subunits and six beta subunits. Mutant lacks PCCase activity. Mutation has no effect on erythromycin production. Belongs to the AccD/PCCB family.