preferred_name: alpha-D-mannosyl-(1->3)-N-acetyl-alpha-D-glucosaminyl-di-trans,octa-cis-undecaprenyl diphosphate + GDP + H(+) => N-acetyl-alpha-D-glucosaminyl-di-trans,octa-cis-undecaprenyl diphosphate + GDP-alpha-D-mannose