5-enolpyruvylshikimate-3-phosphate synthase from Agrobacterium sp. strain CP4 (CP4 EPSPS)

The 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) from Agrobacterium sp. strain CP4—commonly referred to as CP4 EPSPS—is an enzyme belonging to the transferase class that catalyzes the sixth step in the shikimate pathway, a metabolic route crucial for the production of aromatic amino acids and associated secondary metabolites in plants, bacteria, and fungi. Unlike native plant and most bacterial (Class I) EPSPS enzymes, CP4 EPSPS (a Class II enzyme) is highly resistant to inhibition by glyphosate, the active ingredient in many herbicides, due to key differences in active-site amino acid residues and overall enzyme conformation. This unique glyphosate insensitivity allows plants genetically engineered to express the CP4 EPSPS gene to survive and grow in the presence of glyphosate, which otherwise would block aromatic amino acid biosynthesis and kill the plant. The CP4 EPSPS enzyme is widely used in commercial 'Roundup Ready' crops and is one of the best-characterized transgenes for glyphosate tolerance

Other names

CP4 5-enolpyruvylshikimate-3-phosphate synthaseCP4-EPSPSglyphosate-resistant EPSPSClass II EPSPSEPSP synthase (CP4, glyphosate-tolerant type)

Glyphosate competitively inhibits plant (Class I) EPSPS but does not inhibit CP4 EPSPS (Class II) due to altered binding-site conformation. Expression of CP4 EPSPS in transgenic plants allows catalysis of the normal shikimate pathway reaction in presence of glyphosate, enabling survival and growth