Characterization of a Glyphosate-Tolerant Enzyme from Streptomyces svecius: A Distinct Class of 5‑Enolpyruvylshikimate-3-phosphate Synthases

• Published in: Journal of agricultural and food chemistry 2021-05, Vol.69 (17), p.5096-5104
• Main Authors: Griffin, Samantha L, Chekan, Jonathan R, Lira, Justin M, Robinson, Andrew E, Yerkes, Carla N, Siehl, Daniel L, Wright, Terry R, Nair, Satish K, Cicchillo, Robert M
• Format: Article
• Language: English
• Subjects: 3-Phosphoshikimate 1-Carboxyvinyltransferase - genetics; Biotechnology and Biological Transformations; Glycine - analogs & derivatives; Glycine - pharmacology; Glyphosate; Herbicide Resistance - genetics; Herbicides - pharmacology; Streptomyces - genetics
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.1c00439

Natural and modified versions of the 5-enolpyruvylshikimate-3-phosphate synthase (epsps) gene have been used to confer tolerance to the broad-spectrum herbicide glyphosate in a variety of commercial crops. The most widely utilized trait was obtained from the Agrobacterium tumefaciens strain CP4 and has been commercialized in several glyphosate-tolerant crops. The EPSPS gene products are enzymes that have been divided into three classes based on sequence similarity, sensitivity to glyphosate, and steady-state catalytic parameters. Herein, we describe the informatics-guided identification and biochemical and structural characterization of a novel EPSPS from Streptomyces sviceus (DGT-28 EPSPS). The data suggest DGT-28 EPSPS and other closely related homologues exemplify a distinct new class (Class IV) of EPSPS enzymes that display intrinsic tolerance to high concentrations of glyphosate (Ki ≥ 5000 μM). We further demonstrate that dgt-28 epsps, when transformed into stable plants, provides robust (≥4× field rates) vegetative/reproductive herbicide tolerance and has utility in weed-control systems comparable to that of commercialized events.