Reaction catalyzed by 3-(aryl)acrylate reductase (1.3.8.15)

		+		electron-transfer flavoprotein EtfA-EtfB	=			+		reduced electron-transfer flavoprotein EtfA-EtfB
	phloretate	+		electron-transfer flavoprotein EtfA-EtfB	=		4-coumarate	+		reduced electron-transfer flavoprotein EtfA-EtfB