Reaction catalyzed by GDP-mannose:cellobiosyl-diphosphopolyprenol alpha-mannosyltransferase (2.4.1.252)

		+			=			+
	GDP-mannose	+		D-Glc-beta-(1->4)-Glc-alpha-1-diphosphopolyprenol	=		GDP	+		D-Man-alpha-(1->3)-D-Glc-beta-(1->4)-D-Glc-alpha-1-diphosphopolyprenol