EPSP synthase

5-enolpyruvylshikimate 3-phosphate (EPSP) synthase is a key enzyme for the biosynthesis of aromatic amino acids in plants and many microbes. Consequently, it is a target for drugs and herbicides. EPSP synthase catalyzes the addition of phosphoenol pyruvate (PEP) to shikimate-3-phosphate, generating 5-enolpyruvylshikimate-3-phosphate, which is a precursor for phenylalanine and tyrosine.

The enzyme has two domains, with the active site found in the interdomain cleft. There is a substantial structural change upon substrate binding, resulting in a closed formation. Glyphosate (also known as Roundup) occupies the binding site of the second substrate, phosphoenol pyruvate.