Catalyzes the last common step of the biosynthesis of aromatic amino acids, produced via the shikimic acid pathway. 5-O-(1-carboxyvinyl)-3-phosphoshikimate = chorismate + phosphate Metabolic intermediate biosynthesis; chorismate biosynthesis; chorismate from D-erythrose 4-phosphate and phosphoenolpyruvate: step 7/7. Homotetramer. A number of isoforms are produced. According to EST sequences. Belongs to the chorismate synthase family.