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The low mutational flexibility of the EPSP synthase in Bacillus subtilis is due to a higher demand for shikimate pathway intermediates |
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| Authors: | Inge Schwedt Kerstin Schöne Maike Eckert Manon Pizzinato Laura Winkler Barbora Knotkova Björn Richts Jann-Louis Hau Julia Steuber Raul Mireles Lianet Noda-Garcia Günter Fritz Carolin Mittelstädt Robert Hertel Fabian M. Commichau |
| Affiliation: | 1. FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany Contribution: Conceptualization, Investigation, Methodology, Supervision, Resources, Visualization;2. FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany Contribution: Investigation, Methodology, Supervision;3. FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany Contribution: Investigation;4. FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany Contribution: Investigation;5. Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August University of Göttingen, Göttingen, Germany Contribution: Investigation;6. Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August University of Göttingen, Göttingen, Germany Contribution: Investigation, Supervision;7. FG Cellular Microbiology, Institute of Biology, University of Hohenheim, Stuttgart, Germany;8. FG Cellular Microbiology, Institute of Biology, University of Hohenheim, Stuttgart, Germany Contribution: Supervision;9. Department of Plant Pathology and Microbiology, Hebrew University, Rehovot, Israel Contribution: Investigation;10. Department of Plant Pathology and Microbiology, Hebrew University, Rehovot, Israel Contribution: Supervision;11. FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany Contribution: Supervision;12. FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany Department of Genomic and Applied Microbiology, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Göttingen, Germany Contribution: Investigation, Formal analysis;13. FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany |
| Abstract: | Glyphosate (GS) inhibits the 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase that is required for aromatic amino acid, folate and quinone biosynthesis in Bacillus subtilis and Escherichia coli. The inhibition of the EPSP synthase by GS depletes the cell of these metabolites, resulting in cell death. Here, we show that like the laboratory B. subtilis strains also environmental and undomesticated isolates adapt to GS by reducing herbicide uptake. Although B. subtilis possesses a GS-insensitive EPSP synthase, the enzyme is strongly inhibited by GS in the native environment. Moreover, the B. subtilis EPSP synthase mutant was only viable in rich medium containing menaquinone, indicating that the bacteria require a catalytically efficient EPSP synthase under nutrient-poor conditions. The dependency of B. subtilis on the EPSP synthase probably limits its evolvability. In contrast, E. coli rapidly acquires GS resistance by target modification. However, the evolution of a GS-resistant EPSP synthase under non-selective growth conditions indicates that GS resistance causes fitness costs. Therefore, in both model organisms, the proper function of the EPSP synthase is critical for the cellular viability. This study also revealed that the uptake systems for folate precursors, phenylalanine and tyrosine need to be identified and characterized in B. subtilis. |
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