Cell wall formation (PubMed:1512209). Adds enolpyruvyl to UDP-N-acetylglucosamine (PubMed:1512209, PubMed:20392080). Target for the antibiotic fosfomycin. phosphoenolpyruvate + UDP-N-acetyl-alpha-D-glucosamine = phosphate + UDP-N-acetyl-3-O-(1-carboxyvinyl)-alpha-D-glucosamine Competitively inhibited by UDP-N-acetylglucosamine 3'-phosphate, with a Ki of 7 uM (PubMed:21445328). In vitro inhibited by covalent binding of fosfomycin and the fungal product terreic acid in the presence of substrate UDP-N-acetylglucosamine, with an inactivation rate constant of 102 M(-1)sec(-1) for terreic acid (PubMed:20392080). Cell wall biogenesis; peptidoglycan biosynthesis. Belongs to the EPSP synthase family. MurA subfamily.