Reaction catalyzed by dihydroorotate dehydrogenase (NAD+) (1.3.1.14), dihydroorotate dehydrogenase (quinone) (1.3.5.2), dihydroorotate dehydrogenase (fumarate) (1.3.98.1)

		+		acceptor	=			+		reduced acceptor
	(S)-dihydroorotate	+		acceptor	=		orotate	+		reduced acceptor