Reaction catalyzed by ribose-phosphate diphosphokinase (2.7.6.1)

		+			=			+
	(R)9-(2-phosphonylmethoxypropyl)adenine	+		5-phospho-alpha-D-ribose 1-diphosphate	=		(R)9-(2-phosphonylmethoxypropyl)adenine-diphosphate	+		D-ribose 5-phosphate