title: Discovery and directed evolution of a glyphosate tolerance gene.
abstract: The herbicide glyphosate is effectively detoxified by N-acetylation. We screened a collection of microbial isolates and discovered enzymes exhibiting glyphosate N-acetyltransferase (GAT) activity. Kinetic properties of the discovered enzymes were insufficient to confer glyphosate tolerance to transgenic organisms. Eleven iterations of DNA shuffling improved enzyme efficiency by nearly four orders of magnitude from 0.87 mM-1 min-1 to 8320 mM-1 min-1. From the fifth iteration and beyond, GAT enzymes conferred increasing glyphosate tolerance to Escherichia coli, Arabidopsis, tobacco, and maize. Glyphosate acetylation provides an alternative strategy for supporting glyphosate use on crops.
authors.affiliation: Verdia, Inc. Redwood City, CA 94063, USA. linda.castle@verdiainc.com
authors.forename: Linda A
authors.initials: LA
authors.lastname: Castle
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Siehl
authors.forename: Rebecca
authors.initials: R
authors.lastname: Gorton
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Patten
authors.forename: Yong Hong
authors.initials: YH
authors.lastname: Chen
authors.forename: Sean
authors.initials: S
authors.lastname: Bertain
authors.forename: Hyeon-Je
authors.initials: HJ
authors.lastname: Cho
authors.forename: Nicholas
authors.initials: N
authors.lastname: Duck
authors.forename: James
authors.initials: J
authors.lastname: Wong
authors.forename: Donglong
authors.initials: D
authors.lastname: Liu
authors.forename: Michael W
authors.initials: MW
authors.lastname: Lassner
mesh_terms: D000107:Acetylation; D000123:Acetyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001407:Bacillus / Q000201:enzymology; D002384:Catalysis; D032621:DNA Shuffling; D019020:Directed Molecular Evolution; D004351:Drug Resistance; D004926:Escherichia coli / Q000235:genetics; D015723:Gene Library; D014644:Genetic Variation; D005998:Glycine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000633:toxicity*; D006540:Herbicides / Q000378:metabolism / Q000633:toxicity*; D007700:Kinetics; D008969:Molecular Sequence Data; D016296:Mutagenesis; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics; D011994:Recombinant Proteins / Q000378:metabolism; D011995:Recombination, Genetic; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D014170:Transformation, Genetic; D003313:Zea mays / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D000097797:Glyphosate
chemical_list: D000123:Acetyltransferases; D005998:Glycine; D006540:Herbicides; D011994:Recombinant Proteins; D000097797:Glyphosate; C486861:glyphosate N-acetyltransferase