The epsps gene codes for the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) that is present in all plants, bacteria and fungi. The epsps gene put into GT73 was isolated from strain CP4 of the common soil bacterium Agrobacterium tumefaciens and is a glyphosate tolerant form of EPSPS. The EPSPS enzyme is part of an important biochemical pathway in plants called the shikimate pathway, which is involved in the production of aromatic amino acids and other aromatic compounds. When conventional canola plants are treated with glyphosate, the plants cannot produce the aromatic amino acids needed to grow and survive. EPSPS is not present in mammals, birds or aquatic life forms, which do not synthesize their own aromatic amino acids. For this reason, glyphosate has little toxicity to these organisms. The EPSPS enzyme is naturally present in foods derived from plant and microbial sources.

The canola line GT73 contains a second gene that codes for a modified version of glyphosate oxidase (GOX) enzyme that is ubiquitous in nature. The goxv247 gene inserted into GT73 was isolated from strain LBAA of the bacterium Ochrobactrum anthropi. Glyphosate oxidase (GOX) enzyme accelerates the normal breakdown of the herbicide glyphosate into two non-toxic compounds, aminomethylphosphonic acid (AMPA) and glyoxylate. AMPA is the principal breakdown product of glyphosate and is degraded by several microorganisms, while glyoxylate is commonly found in plant cells and is broken down by the glyoxylic pathway for lipid metabolism.