(S)-1-pyrroline-5-carboxylate + a ubiquinol + H(+) => a ubiquinone + L-proline
(s)-1-pyrroline-5-carboxylate + a ubiquinol + h(+) => a ubiquinone + l-proline
(S)-1-pyrroline-5-carboxylate + a ubiquinol + H(+) => a ubiquinone + L-proline
(s)-1-pyrroline-5-carboxylate + a ubiquinol + h(+) => a ubiquinone + l-proline