a 4-carboxy-3-alkylbut-(2E)-enoyl-[ACP] + H(+) = a 3-alkylbut-(2E)-enoyl-[ACP] + CO2
a 4-carboxy-3-alkylbut-(2e)-enoyl-[acp] + h(+) = a 3-alkylbut-(2e)-enoyl-[acp] + co2
a 4-carboxy-3-alkylbut-(2E)-enoyl-[ACP] + H(+) = a 3-alkylbut-(2E)-enoyl-[ACP] + CO2
a 4-carboxy-3-alkylbut-(2e)-enoyl-[acp] + h(+) = a 3-alkylbut-(2e)-enoyl-[acp] + co2