Reaction catalyzed by GDP-Man:Man1GlcNAc2-PP-dolichol alpha-1,3-mannosyltransferase (2.4.1.132)

		+		tetrasaccharide-diphosphoryl-lipid	=			+		mannosyl-alpha-1,3-tetrasaccharide-diphosphoryl-lipid
	GDPmannose	+		tetrasaccharide-diphosphoryl-lipid	=		GDP	+		mannosyl-alpha-1,3-tetrasaccharide-diphosphoryl-lipid