Reaction catalyzed by 3-oxosteroid 1-dehydrogenase (1.3.99.4)

		+			=			+
	11beta,17alpha,21-trihydroxypregn-4-ene-3,20-dione	+		phenazine methosulfate	=		1,4-pregnene-17alpha,21-diol-3,11,20-trione	+		reduced phenazine methosulfate