2.4.1.293 UDP-alpha-D-glucose + [GalNAc-alpha-(1->4)]4-GalNAc-alpha-(1->3)-diNAcBac-diphospho-tritrans,heptacis-undecaprenol = UDP + [GalNAc-alpha-(1->4)]2-[Glc-beta-(1->3)]-[GalNAc-alpha-(1->4)]2-GalNAc-alpha-(1->3)-diNAcBac-diphospho-tritrans,heptacis-undecaprenol - -