butanoyl-CoA + CO2 => (2S)-ethylmalonyl-CoA + H(+)
butanoyl-coa + co2 => (2s)-ethylmalonyl-coa + h(+)
butanoyl-CoA + CO2 => (2S)-ethylmalonyl-CoA + H(+)
butanoyl-coa + co2 => (2s)-ethylmalonyl-coa + h(+)