Reaction catalyzed by N-acetylglucosaminyldiphosphoundecaprenol N-acetyl-beta-D-mannosaminyltransferase (2.4.1.187)

		+			=			+
	UDP-N-acetyl-alpha-D-mannosamine	+		N-acetyl-alpha-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol	=		UDP	+		N-acetyl-beta-D-mannosaminyl-(1->4)-N-acetyl-alpha-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol