Catalyzes the transfer of the enolpyruvyl moiety of phosphoenolpyruvate (PEP) to the 5-hydroxyl of shikimate-3-phosphate (S3P) to produce enolpyruvyl shikimate-3-phosphate and inorganic phosphate. 3-phosphoshikimate + phosphoenolpyruvate = 5-O-(1-carboxyvinyl)-3-phosphoshikimate + phosphate Competitively inhibited by glyphosate, (R)-difluoromethyl and (R)-phosphonate analogs of the tetrahedral reaction intermediate. Metabolic intermediate biosynthesis; chorismate biosynthesis; chorismate from D-erythrose 4-phosphate and phosphoenolpyruvate: step 6/7. Monomer. Introduced by genetic manipulation and expressed in glyphosate-tolerant soybean, canola, cotton and maize by Monsanto. Developed to provide new weed-control options for farmers. Expression of this protein in plants imparts high levels of glyphosate tolerance. Belongs to the EPSP synthase family.