The cp4 epsps gene encodes for a version of EPSPS that is highly
tolerant to inhibition by glyphosate and therefore leads to
increased tolerance to glyphosate-containing herbicides.
The glyphosate-tolerant epsps gene was isolated from the CP4 strain
of the common soil bacterium Agrobacterium tumefaciens.
Glyphosate specifically binds to and inactivates the enzyme EPSPS,
which is part of an important plant biochemical pathway called the
shikimate pathway. The shikimate pathway is involved in the
biosynthesis of the aromatic amino acids tyrosine, phenylalanine
and tryptophan, as well as other aromatic compounds. When plants
are treated with glyphosate herbicides they cannot produce the
aromatic amino acids that are essential to their survival and,
LMOs containing the glyphosate-tolerant epsps gene allow farmers to
use glyphosate-containing herbicides for weed control, which will
kill the weeds but not the LMO.