Reaction catalyzed by 4-hydroxythreonine-4-phosphate dehydrogenase (1.1.1.262)

		+		NAD(P)+	=			+		NAD(P)H
	4-(phosphonooxy)threonine	+		NAD(P)+	=		2-amino-3-oxo-4-phosphonooxybutyrate	+		NAD(P)H