Cell wall formation. Adds enolpyruvyl to UDP-N-acetylglucosamine (By similarity). Target for the antibiotic fosfomycin. Involved in heteroresistance to antibiotic fosfomycin. Heteroresistance is the ability of a clonal population to grow one or several subpopulations at a frequency of 10(-7) to 10(-3) in the presence of a higher antibiotic concentration than that predicted to be effective by measurement of the minimum inhibitory concentration (MIC) (PubMed:23571543). phosphoenolpyruvate + UDP-N-acetyl-alpha-D-glucosamine = phosphate + UDP-N-acetyl-3-O-(1-carboxyvinyl)-alpha-D-glucosamine Cell wall biogenesis; peptidoglycan biosynthesis. No heteroresistance to fosfomycin. Belongs to the EPSP synthase family. MurA subfamily.