May play a role in chloroplast biogenesis. chorismate = prephenate Allosterically inhibited by tyrosine and phenylalanine (PubMed:10564818). According to another report, seems not to be repressed by tyrosine and phenylalanine (PubMed:25160622). Activated by tryptophan, cysteine and histidine (PubMed:10564818, PubMed:25160622). Does not follow Michaelis-Menten kinetics but displays a positive cooperativity with a Hill coefficient of 2.1 indicating that substrate binding at one active site of the homodimer enhances interaction at the second active site (PubMed:25160622). kcat is 13.0 sec(-1) with chorismate as substrate (at pH 8) (PubMed:25160622). Metabolic intermediate biosynthesis; prephenate biosynthesis; prephenate from chorismate: step 1/1. Homodimer. Expressed in roots, stems, cauline leaves, flowers and siliques, and at lower levels in rosette leaves. Not induced by wounding or bacterial pathogen. Due to contradictory results, it is uncertain whether tyrosine and phenylalanine act as allosteric inhibitors.