A Highly Glyphosate-Resistant EPSPS Mutant from Laboratory Evolution

EPSP synthase is the target enzyme of glyphosate herbicides. Due to extensive use glyphosate, it very important obtain EPSPS genes with high resistance for development transgenic crops. GR79-EPSPS a class I certain isolated from glyphosate-contaminated soil. After more than 1000 generations, Y40I substitution was identified, and had nearly 1.8-fold decrease in Km [PEP] 1.7-fold increase Ki[glyphosate] compared wild-type enzyme. Enzyme dynamics molecular analysis showed that near hinge region EPSPS, affinity binding amino acid residues active site decreased due substitution, resulting an resistance. These results provide evidence combination directed evolution rational design protein engineering.