Reaction catalyzed by protein geranylgeranyltransferase type II (2.5.1.60)

		+		Arabidopsis thaliana RAB-ATa protein	=		S-geranylgeranyl-RAB GTPase	+
	geranylgeranyl diphosphate	+		Arabidopsis thaliana RAB-ATa protein	=		S-geranylgeranyl-RAB GTPase	+		diphosphate