Figure 1

The shikimate pathway converts phosphoenolpyruvate and erythrose 4-phosphate to chorismate and aromatic amino acids in higher plants. Chorismate is an essential precursor in the major route of Tyr and Phe biosynthesis as well as in the other route of Tyr biosynthesis via anthranilate, which is catalysed by ASα and ASβ using chorismate as the substrate. The dotted lines indicate more than one reaction, and the solid lines indicate only one step in the reaction. AS anthranilate synthase, CM chorismate mutase, CS chorismate synthase, DAHPS 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase, DHF dihydrofolate, ESPS 3-phosphoshikimate 1-carboxyvinyltransferase, p-ABA para-aminobenzoic acid, SK shikimate kinase, THF tetrahydrofolate.