Figure 1.

The last steps of the shikimate pathway. Erythrose 4-phosphate (E4P) and phosphoenolpyruvate (PEP) are used as building blocks to synthesise shikimate (top right) in four enzymatic steps. Shikimate is phosphorylated by shikimate kinase at the expense of ATP to shikimate-3-phosphate (step 5). In step six, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) catalyses the conversion of shikimate-3-phosphate to 5-enolpyruvylshikimate-3-phosphate (EPSP, left). EPSPS is the target of the broad-band herbicide glyphosate. The seventh step of the common pathway is catalysed by chorismate synthase involving the stereospecific anti-1,4-elimination of the 3-phosphate and the 6proR-hydrogen (bottom).