butanoyl-CoA + FAD + H(+) = (2E)-butenoyl-CoA + FADH2
butanoyl-coa + fad + h(+) = (2e)-butenoyl-coa + fadh2
butanoyl-CoA + FAD + H(+) = (2E)-butenoyl-CoA + FADH2
butanoyl-coa + fad + h(+) = (2e)-butenoyl-coa + fadh2