3-(methylsulfanyl)propanoyl-CoA + oxidized [electron-transfer flavoprotein] + H(+) = 3-(methylsulfanyl)acryloyl-CoA + reduced [electron-transfer flavoprotein]
3-(methylsulfanyl)propanoyl-coa + oxidized [electron-transfer flavoprotein] + h(+) = 3-(methylsulfanyl)acryloyl-coa + reduced [electron-transfer flavoprotein]