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Xu R, Bao Y, Jiao F, Li M, Zhang X, Zhang F, Guo J. Unraveling the atomic mechanisms underlying glyphosate insensitivity in EPSPS: implications of distal mutations. J Biomol Struct Dyn 2024:1-12. [PMID: 38400730 DOI: 10.1080/07391102.2024.2318472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 02/08/2024] [Indexed: 02/26/2024]
Abstract
5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS), as an indispensable enzyme in the shikimate pathway, is the specific target of grasser killer glyphosate (GPJ). GPJ is a competitive inhibitor of phosphoenolpyruvate (PEP), which is the natural substrate of EPSPS. A novel Ls-EPSPS gene variant discovered from Liliaceae, named ELs-EPSPS, includes five distal mutations, E112V, D142N, T351S, D425G, and R496G, endowing high GPJ insensitivity. However, the implicit molecular mechanism of the enhanced tolerance/insensitivity of GPJ in ELs-EPSPS is not fully understood. Herein, we try to interpret the hidden molecular mechanism using computational methods. Computational results reveal the enhanced flexibility of apo EPSPS upon mutations. The enhanced affinity of the initial binding substrate shikimate-3-phosphate (S3P), and the higher probability of second ligands PEP/GPJ entering the pocket are observed in the ELs-EPSPS-S3P system. Docking and MD results further confirmed the decreased GPJ-induced EPSPS inhibition upon mutations. And, the alterations of K98 and R179 side-chain orientations upon mutations are detrimental to GPJ binding at the active site. Additionally, the oscillation of side chain K98, in charge of PEP location, improves the proximity effect for substrates in the dual-substrate systems upon mutations. Our results clarify that the enhanced GPJ tolerance of EPSPS is achieved from decreased competitive inhibition of GPJ at the atomic perspective, and this finding further contributes to the cultivation of EPSPS genes with higher GPJ tolerance/insensitivity and a mighty renovation for developing glyphosate-resistant crops.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Ran Xu
- Centre in Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao, China
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yiqiong Bao
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Fangfang Jiao
- Centre in Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao, China
| | - Mengrong Li
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Xiaoxiao Zhang
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Feng Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Jingjing Guo
- Centre in Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao, China
- Engineering Research Centre of Applied Technology on Machine Translation and Artificial Intelligence, Macao Polytechnic University, Macao, China
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Schwedt I, Schöne K, Eckert M, Pizzinato M, Winkler L, Knotkova B, Richts B, Hau JL, Steuber J, Mireles R, Noda-Garcia L, Fritz G, Mittelstädt C, Hertel R, Commichau FM. The low mutational flexibility of the EPSP synthase in Bacillus subtilis is due to a higher demand for shikimate pathway intermediates. Environ Microbiol 2023; 25:3604-3622. [PMID: 37822042 DOI: 10.1111/1462-2920.16518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 09/21/2023] [Indexed: 10/13/2023]
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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Affiliation(s)
- Inge Schwedt
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Kerstin Schöne
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Maike Eckert
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Manon Pizzinato
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Laura Winkler
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Barbora Knotkova
- Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August University of Göttingen, Göttingen, Germany
| | - Björn Richts
- Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August University of Göttingen, Göttingen, Germany
| | - Jann-Louis Hau
- FG Cellular Microbiology, Institute of Biology, University of Hohenheim, Stuttgart, Germany
| | - Julia Steuber
- FG Cellular Microbiology, Institute of Biology, University of Hohenheim, Stuttgart, Germany
| | - Raul Mireles
- Department of Plant Pathology and Microbiology, Hebrew University, Rehovot, Israel
| | - Lianet Noda-Garcia
- Department of Plant Pathology and Microbiology, Hebrew University, Rehovot, Israel
| | - Günter Fritz
- FG Cellular Microbiology, Institute of Biology, University of Hohenheim, Stuttgart, Germany
| | - Carolin Mittelstädt
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Robert Hertel
- 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
| | - Fabian M Commichau
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
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3
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Gao X, Hu F, Cui H, Zhu X, Wang L, Zhang K, Li D, Ji J, Luo J, Cui J. Glyphosate decreases survival, increases fecundity, and alters the microbiome of the natural predator Harmonia axyridis (ladybird beetle). ENVIRONMENTAL RESEARCH 2023; 238:117174. [PMID: 37739152 DOI: 10.1016/j.envres.2023.117174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 09/13/2023] [Accepted: 09/17/2023] [Indexed: 09/24/2023]
Abstract
Glyphosate is a widely-used herbicide that shows toxicity to non-target organisms. The predatory natural enemy Harmonia axyridis may ingest glyphosate present in pollen and aphid prey. The present study characterized the responses of adult H. axyridis to environmentally relevant concentrations of glyphosate (5, 10, and 20 mg/L) for one or five days. There were no obvious effects on adult H. axyridis survival rates or fecundity in response to 5 or 10 mg/L glyphosate. However, exposure to 20 mg/L glyphosate significantly reduced the survival rate and increased fecundity. Analysis of the adult H. axyridis microbiota with 16S rRNA sequencing demonstrated changes in the relative and/or total abundance of specific taxa, including Serratia, Enterobacter, Staphylococcus, and Hafnia-Obesumbacterium. These changes in symbiotic bacterial abundance may have led to changes in survival rates or fecundity of this beetle. This is the first report of herbicide-induced stimulation of fecundity in a non-target predatory natural enemy, reflecting potentially unexpected risks of glyphosate exposure in adult H. axyridis. Although glyphosate resistant crops have been widely planted, the results of this study indicate a need to strengthen glyphosate management to prevent over-use, which could cause glyphosate toxicity and threaten environmental and human health.
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Affiliation(s)
- Xueke Gao
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China; Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Fangmei Hu
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China; Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China; Zhongjian township People's Government of Qianxi county, Bijie, 551500, Guizhou, China
| | - Huanfei Cui
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China; Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Xiangzhen Zhu
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China; Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Li Wang
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China; Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Kaixin Zhang
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China; Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Dongyang Li
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China; Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Jichao Ji
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China; Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China.
| | - Junyu Luo
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China; Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China.
| | - Jinjie Cui
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China; Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China.
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Hertel R, Gibhardt J, Martienssen M, Kuhn R, Commichau FM. Molecular mechanisms underlying glyphosate resistance in bacteria. Environ Microbiol 2021; 23:2891-2905. [PMID: 33876549 DOI: 10.1111/1462-2920.15534] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/10/2021] [Accepted: 04/14/2021] [Indexed: 11/29/2022]
Abstract
Glyphosate is a nonselective herbicide that kills weeds and other plants competing with crops. Glyphosate specifically inhibits the 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase, thereby depleting the cell of EPSP serving as a precursor for biosynthesis of aromatic amino acids. Glyphosate is considered to be toxicologically safe for animals and humans. Therefore, it became the most-important herbicide in agriculture. However, its intensive application in agriculture is a serious environmental issue because it may negatively affect the biodiversity. A few years after the discovery of the mode of action of glyphosate, it has been observed that bacteria evolve glyphosate resistance by acquiring mutations in the EPSP synthase gene, rendering the encoded enzyme less sensitive to the herbicide. The identification of glyphosate-resistant EPSP synthase variants paved the way for engineering crops tolerating increased amounts of the herbicide. This review intends to summarize the molecular mechanisms underlying glyphosate resistance in bacteria. Bacteria can evolve glyphosate resistance by (i) reducing glyphosate sensitivity or elevating production of the EPSP synthase, by (ii) degrading or (iii) detoxifying glyphosate and by (iv) decreasing the uptake or increasing the export of the herbicide. The variety of glyphosate resistance mechanisms illustrates the adaptability of bacteria to anthropogenic substances due to genomic alterations.
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Affiliation(s)
- Robert Hertel
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| | - Johannes Gibhardt
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| | - Marion Martienssen
- Institute of Environmental Technology, Chair of Biotechnology of Water Treatment, BTU Cottbus-Senftenberg, Cottbus, 03046, Germany
| | - Ramona Kuhn
- Institute of Environmental Technology, Chair of Biotechnology of Water Treatment, BTU Cottbus-Senftenberg, Cottbus, 03046, Germany
| | - Fabian M Commichau
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
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5
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Döring J, Rettke D, Rödel G, Pompe T, Ostermann K. Surface Functionalization by Hydrophobin-EPSPS Fusion Protein Allows for the Fast and Simple Detection of Glyphosate. BIOSENSORS 2019; 9:E104. [PMID: 31470576 PMCID: PMC6784374 DOI: 10.3390/bios9030104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/15/2019] [Accepted: 08/26/2019] [Indexed: 02/04/2023]
Abstract
Glyphosate, the most widely used pesticide worldwide, is under debate due to its potentially cancerogenic effects and harmful influence on biodiversity and environment. Therefore, the detection of glyphosate in water, food or environmental probes is of high interest. Currently detection of glyphosate usually requires specialized, costly instruments, is labor intensive and time consuming. Here we present a fast and simple method to detect glyphosate in the nanomolar range based on the surface immobilization of glyphosate's target enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) via fusion to the hydrophobin Ccg2 and determination of enzyme activity with a malachite green assay, which is a common photometric technique to measure inorganic phosphate (Pi). The assay demonstrates a new approach for a fast and simple detection of pesticides.
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Affiliation(s)
- Julia Döring
- Institute of Genetics, Technische Universität Dresden, Zellescher Weg 20b, 01217 Dresden, Germany.
| | - David Rettke
- Institute of Biochemistry, Leipzig University, Johannisallee 21-23, 04103 Leipzig, Germany
| | - Gerhard Rödel
- Institute of Genetics, Technische Universität Dresden, Zellescher Weg 20b, 01217 Dresden, Germany
| | - Tilo Pompe
- Institute of Biochemistry, Leipzig University, Johannisallee 21-23, 04103 Leipzig, Germany
| | - Kai Ostermann
- Institute of Genetics, Technische Universität Dresden, Zellescher Weg 20b, 01217 Dresden, Germany
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6
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Wicke D, Schulz LM, Lentes S, Scholz P, Poehlein A, Gibhardt J, Daniel R, Ischebeck T, Commichau FM. Identification of the first glyphosate transporter by genomic adaptation. Environ Microbiol 2019; 21:1287-1305. [PMID: 30666812 DOI: 10.1111/1462-2920.14534] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/17/2019] [Accepted: 01/18/2019] [Indexed: 01/12/2023]
Abstract
The soil bacterium Bacillus subtilis can get into contact with growth-inhibiting substances, which may be of anthropogenic origin. Glyphosate is such a substance serving as a nonselective herbicide. Glyphosate specifically inhibits the 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase, which generates an essential precursor for de novo synthesis of aromatic amino acids in plants, fungi, bacteria and archaea. Inhibition of the EPSP synthase by glyphosate results in depletion of the cellular levels of aromatic amino acids unless the environment provides them. Here, we have assessed the potential of B. subtilis to adapt to glyphosate at the genome level. In contrast to Escherichia coli, which evolves glyphosate resistance by elevating the production and decreasing the glyphosate sensitivity of the EPSP synthase, B. subtilis primarily inactivates the gltT gene encoding the high-affinity glutamate/aspartate symporter GltT. Further adaptation of the gltT mutants to glyphosate led to the inactivation of the gltP gene encoding the glutamate transporter GltP. Metabolome analyses confirmed that GltT is the major entryway of glyphosate into B. subtilis. GltP, the GltT homologue of E. coli also transports glyphosate into B. subtilis. Finally, we found that GltT is involved in uptake of the herbicide glufosinate, which inhibits the glutamine synthetase.
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Affiliation(s)
- Dennis Wicke
- Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, 37077, Göttingen, Germany
| | - Lisa M Schulz
- Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, 37077, Göttingen, Germany
| | - Sabine Lentes
- Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, 37077, Göttingen, Germany
| | - Patricia Scholz
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center of Molecular Biosciences (GZMB), University of Goettingen, 37077, Göttingen, Germany
| | - Anja Poehlein
- Department of Genomic and Applied Microbiology, Institute for Microbiology and Genetics, University of Goettingen, 37077, Göttingen, Germany
| | - Johannes Gibhardt
- Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, 37077, Göttingen, Germany
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology, Institute for Microbiology and Genetics, University of Goettingen, 37077, Göttingen, Germany
| | - Till Ischebeck
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center of Molecular Biosciences (GZMB), University of Goettingen, 37077, Göttingen, Germany
| | - Fabian M Commichau
- Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, 37077, Göttingen, Germany
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Fernando N, Manalil S, Florentine SK, Chauhan BS, Seneweera S. Glyphosate Resistance of C3 and C4 Weeds under Rising Atmospheric CO2. FRONTIERS IN PLANT SCIENCE 2016; 7:910. [PMID: 27446140 PMCID: PMC4916228 DOI: 10.3389/fpls.2016.00910] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 06/08/2016] [Indexed: 05/25/2023]
Abstract
The present paper reviews current knowledge on how changes of plant metabolism under elevated CO2 concentrations (e[CO2]) can affect the development of the glyphosate resistance of C3 and C4 weeds. Among the chemical herbicides, glyphosate, which is a non-selective and post-emergence herbicide, is currently the most widely used herbicide in global agriculture. As a consequence, glyphosate resistant weeds, particularly in major field crops, are a widespread problem and are becoming a significant challenge to future global food production. Of particular interest here it is known that the biochemical processes involved in photosynthetic pathways of C3 and C4 plants are different, which may have relevance to their competitive development under changing environmental conditions. It has already been shown that plant anatomical, morphological, and physiological changes under e[CO2] can be different, based on (i) the plant's functional group, (ii) the available soil nutrients, and (iii) the governing water status. In this respect, C3 species are likely to have a major developmental advantage under a CO2 rich atmosphere, by being able to capitalize on the overall stimulatory effect of e[CO2]. For example, many tropical weed grass species fix CO2 from the atmosphere via the C4 photosynthetic pathway, which is a complex anatomical and biochemical variant of the C3 pathway. Thus, based on our current knowledge of CO2 fixing, it would appear obvious that the development of a glyphosate-resistant mechanism would be easier under an e[CO2] in C3 weeds which have a simpler photosynthetic pathway, than for C4 weeds. However, notwithstanding this logical argument, a better understanding of the biochemical, genetic, and molecular measures by which plants develop glyphosate resistance and how e[CO2] affects these measures will be important before attempting to innovate sustainable technology to manage the glyphosate-resistant evolution of weeds under e[CO2]. Such information will be of essential in managing weed control by herbicide use, and to thus ensure an increase in global food production in the event of increased atmospheric [CO2] levels.
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Affiliation(s)
- Nimesha Fernando
- School of Applied and Biomedical Sciences, Faculty of Science and Technology, Federation University, Mount Helen Campus, Ballarat, VICAustralia
| | - Sudheesh Manalil
- School of Plant Biology, UWA Institute of Agriculture, The University of Western Australia, Crawley, WAAustralia
- Amrita University, CoimbatoreIndia
- The Centre for Plant Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Toowoomba, QLDAustralia
| | - Singarayer K. Florentine
- School of Applied and Biomedical Sciences, Faculty of Science and Technology, Federation University, Mount Helen Campus, Ballarat, VICAustralia
| | - Bhagirath S. Chauhan
- The Centre for Plant Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Toowoomba, QLDAustralia
| | - Saman Seneweera
- Centre for Crop Health, University of Southern Queensland, Toowoomba, QLDAustralia
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Wang L, Peng R, Tian Y, Han J, Zhao W, Wang B, Liu M, Yao Q. Characterization of a class II 5-enopyruvylshikimate-3-phosphate synthase with high tolerance to glyphosate from Sinorhizobium fredii. World J Microbiol Biotechnol 2014; 30:2967-73. [PMID: 25151150 DOI: 10.1007/s11274-014-1724-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 08/16/2014] [Indexed: 10/24/2022]
Abstract
5-Enopyruvylshikimate-3-phosphate synthase (EPSP synthase) is an important enzyme in the shikimate pathway mediating the biosynthesis of aromatic compounds in plants and microorganisms. A novel class II EPSP synthase AroA S. fredii from Sinorhizobium fredii NGR234 was overexpressed in Escherichia coli BL21. It was purified to homogeneity and its catalytic properties were studied. The enzyme exhibited optimum catalytic activity at pH 8.0 and 50 °C. It was stable below 40 °C, and over a broad range of pH 5.0-9.0. The EPSP synthase was increasingly activated by 100 mM of the chlorides of NH4 (+), K(+), Na(+) and Li(+). Kinetic analysis of AroA S. fredii suggested that the enzyme exhibited a high glyphosate tolerance and high level of affinity for phosphoenolpyruvate, which indicates the enzyme with a high potential for structural and functional studies and its potential usage for the generation of transgenic crops resistant to the herbicide.
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Affiliation(s)
- Lijuan Wang
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, 2901 Beidi Road, Shanghai, China,
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9
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Caetano MS, Freitas MP, da Cunha EFF, Ramalho TC. Construction and assessment of reaction models of Class I EPSP synthase. Part II: investigation of the EPSP ketal. J Biomol Struct Dyn 2013; 31:393-402. [PMID: 22877309 DOI: 10.1080/07391102.2012.703066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Although the proposed mechanisms are reasonable, there are still many questions about the 5-enolpyruvyl shikimate-3-phosphate (EPSP) synthase mechanism that are difficult to answer by experimental means alone. EPSP synthase is a key enzyme in the shikimic acid pathway, which is found only in plants and some micro-organisms and is also molecular target of glyphosate, active component of one of the top-selling herbicides. In the study of reaction mechanism of EPSP synthase, in addition to inorganic phosphate and EPSP products, after long time at equilibrium, it was shown that a side product is formed, the EPSP ketal. In this line, studies using density functional theory (DFT) techniques were performed to investigate the reaction mechanism of formation of EPSP and the corresponding ketal. Our findings indicate some key amino acid residues in the EPSP synthase mechanism and a possible route for the formation of the EPSP ketal.
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10
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Sun YC, Chen YC, Tian ZX, Li FM, Wang XY, Zhang J, Xiao ZL, Lin M, Gilmartin N, Dowling DN, Wang YP. Novel AroA with high tolerance to glyphosate, encoded by a gene of Pseudomonas putida 4G-1 isolated from an extremely polluted environment in China. Appl Environ Microbiol 2005; 71:4771-6. [PMID: 16085874 PMCID: PMC1183292 DOI: 10.1128/aem.71.8.4771-4776.2005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2004] [Accepted: 02/24/2005] [Indexed: 11/20/2022] Open
Abstract
Glyphosate has been used globally as a safe herbicide for weed control. It inhibits 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase (AroA), which is a key enzyme in the aromatic amino acid biosynthetic pathway in microorganisms and plants. A Pseudomonas putida strain, 4G-1, was isolated from a soil heavily contaminated by glyphosate in China. Its AroA-encoding gene (aroA) has been cloned, sequenced, and expressed in Escherichia coli. Phylogenetic analysis revealed that this AroA belongs neither to class I nor to class II AroA enzymes. When compared with E. coli AroA, 4G-1 AroA shows similar values for K(m)[PEP], K(m)[S3P], and specific enzyme activity. Moreover, 4G-1 AroA exhibits high tolerance to glyphosate, which indicates a protein with a high potential for structural and functional studies of AroA in general and its potential usage for the generation of transgenic crops resistant to the herbicide.
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Affiliation(s)
- Yi-Cheng Sun
- National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100081, People's Republic of China
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11
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Priestman MA, Funke T, Singh IM, Crupper SS, Schönbrunn E. 5-Enolpyruvylshikimate-3-phosphate synthase from Staphylococcus aureus is insensitive to glyphosate. FEBS Lett 2005; 579:728-32. [PMID: 15670836 DOI: 10.1016/j.febslet.2004.12.057] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2004] [Revised: 12/17/2004] [Accepted: 12/17/2004] [Indexed: 11/18/2022]
Abstract
The enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) catalyzes the penultimate step of the shikimate pathway, and is the target of the broad-spectrum herbicide glyphosate. Kinetic analysis of the cloned EPSPS from Staphylococcus aureus revealed that this enzyme exerts a high tolerance to glyphosate, while maintaining a high affinity for its substrate phosphoenolpyruvate. Enzymatic activity is markedly influenced by monovalent cations such as potassium or ammonium, which is due to an increase in catalytic turnover. However, insensitivity to glyphosate appears to be independent from the presence of cations. Therefore, we propose that the Staphylococcus aureus EPSPS should be classified as a class II EPSPS. This research illustrates a critical mechanism of glyphosate resistance naturally occurring in certain pathogenic bacteria.
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Affiliation(s)
- Melanie A Priestman
- Department of Medicinal Chemistry, University of Kansas, 4040a Malott Hall, Lawrence, KS 66049, USA
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12
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Pipke R, Amrhein N. Carbon-phosphorus lyase activity in permeabilized cells ofArthrobactersp. GLP-1. FEBS Lett 2001. [DOI: 10.1016/0014-5793(88)80301-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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13
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Studelska DR, Klug CA, Beusen DD, McDowell LM, Schaefer J. Long-Range Distance Measurements of Protein Binding Sites by Rotational-Echo Double-Resonance NMR. J Am Chem Soc 1996. [DOI: 10.1021/ja951509a] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniel R. Studelska
- Department of Chemistry, Washington University Center for Molecular Design, Washington University School of Medicine, St. Louis, Missouri 63130
| | - Christopher A. Klug
- Department of Chemistry, Washington University Center for Molecular Design, Washington University School of Medicine, St. Louis, Missouri 63130
| | - Denise D. Beusen
- Department of Chemistry, Washington University Center for Molecular Design, Washington University School of Medicine, St. Louis, Missouri 63130
| | - Lynda M. McDowell
- Department of Chemistry, Washington University Center for Molecular Design, Washington University School of Medicine, St. Louis, Missouri 63130
| | - Jacob Schaefer
- Department of Chemistry, Washington University Center for Molecular Design, Washington University School of Medicine, St. Louis, Missouri 63130
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14
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Selvapandiyan A, Majumder K, Fattah FA, Ahmad S, Arora N, Bhatnagar RK. Point mutation of a conserved arginine (104) to lysine introduces hypersensitivity to inhibition by glyphosate in the 5-enolpyruvylshikimate-3-phosphate synthase of Bacillus subtilis. FEBS Lett 1995; 374:253-6. [PMID: 7589547 DOI: 10.1016/0014-5793(95)01124-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The role of a conserved arginine (R104) in the putative phosphoenol pyruvate binding region of 5-enolpyruvyl shikimate-3-phosphate synthase of Bacillus subtilis has been investigated. Employing site directed mutagenesis arginine was substituted by lysine or glutamine. Native and mutant proteins were expressed and purified to near homogeneity. Estimation of Michaelis and inhibitor constants of the native and mutant proteins exhibited altered substrate-inhibitor binding mode and constants. Mutation R104K hypersensitized the enzyme reaction to inhibition by glyphosate. The role of R104 in discriminating between glyphosate and phosphoenol pyruvate is discussed.
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Affiliation(s)
- A Selvapandiyan
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
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15
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Majumder K, Selvapandiyan A, Fattah FA, Arora N, Ahmad S, Bhatnagar RK. 5-Enolpyruvylshikimate-3-phosphate Synthase of Bacillus subtilis is an Allosteric Enzyme. Analysis of Arg24Asp, Pro105Ser and His385Lys mutations suggests a hidden phosphoenol pyruvate-binding site. ACTA ACUST UNITED AC 1995. [DOI: 10.1111/j.1432-1033.1995.0099l.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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16
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Majumder K, Selvapandiyan A, Fattah FA, Arora N, Ahmad S, Bhatnagar RK. 5-Enolpyruvylshikimate-3-phosphate synthase of Bacillus subtilis is an allosteric enzyme. Analysis of Arg24-->Asp, Pro105-->Ser and His385-->Lys mutations suggests a hidden phosphoenolpyruvate-binding site. EUROPEAN JOURNAL OF BIOCHEMISTRY 1995; 229:99-106. [PMID: 7744055 DOI: 10.1111/j.1432-1033.1995.tb20443.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
5-Enolpyruvylshikimate-3-phosphate synthase of Bacillus subtilis has been cloned, expressed and purified to near homogeneity. Clustal alignment of the amino acid sequences from different bacteria revealed several conserved residues located in the N-terminal, middle and C-terminal domains. The role of conserved Arg24, Pro105, and His385 residues has been examined by site-directed mutagenesis. Steady-state kinetic analysis of the native synthase exhibited allosteric behaviour, a feature thought to be unique amongst bacterial and plant 5-enolpyruvylshikimate-3-phosphate synthase enzymes investigated so far. Both substrates, phosphoenolpyruvate (P-pyruvate) and shikimate 3-phosphate have multiple interaction sites. There are two sites for P-pyruvate binding, catalytic and non-catalytic. Glyphosate (N-phosphonomethyl glycine) competes for binding at the catalytic site and does not interact at the secondary site. Glyphosate in the absence of ammonium ions increases cooperativity of P-pyruvate binding and favors dimerization of the enzyme through an interaction between P-pyruvate-binding sites. The ammonium-ion-activated 5-enolpyruvylshikimate-3-phosphate synthase displays no cooperativity with respect to P-pyruvate. Absence of ammonium ions decreases affinity for substrates and introduces cooperativity. Cooperativity was also introduced in the enzyme by point mutations, Arg24-->Asp and His385-->Lys. The latter mutant of the native enzyme exists as a dimer and aggregates to a tetrameric form in the presence of glyphosate. The occurrence of multimeric forms of the synthase has been demonstrated by staining for the enzyme activity on the native gel and by resolving purified enzyme preparations on a sucrose density gradient. A model describing the alteration in the aggregation status of the enzyme by the inhibitor, activator and the substrates has been proposed.
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Affiliation(s)
- K Majumder
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
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17
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Sikorski JA, Miller MJ, Braccolino DS, Cleary DG, Corey SD, Font JL, Gruys KJ, Han CY, Lin KC, Pansegrau PD, Ream JE, Schnur D, Shah A, Walker MC. EPSP Synthase: The Design and Synthesis of Bisubstrate Inhibitors Incorporating Novel 3-Phosphate Mimics. PHOSPHORUS SULFUR 1993. [DOI: 10.1080/10426509308032372] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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18
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Huynh QK. Photo-oxidation of 5-enolpyruvoylshikimate-3-phosphate synthase from Escherichia coli: evidence for a reactive imidazole group (His385) at the herbicide glyphosate-binding site. Biochem J 1993; 290 ( Pt 2):525-30. [PMID: 8452542 PMCID: PMC1132305 DOI: 10.1042/bj2900525] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Photo-oxidation of Escherichia coli 5-enolpyruvoylshikimate-3-phosphate synthase, a target for the non-selective herbicide glyphosate (N-phosphonomethylglycine), in the presence of pyridoxal 5'-phosphate resulted in irreversible inactivation of the enzyme. The inactivation followed pseudo-first-order and saturation kinetics with a Kinact. of 50 microM. The inactivation is specifically prevented by preincubation of the enzyme with the combination of shikimate 3-phosphate and glyphosate. Increasing glyphosate concentration during preincubation resulted in a decreasing rate of inactivation. On 95% inactivation, approximately one histidine per molecule of enzyme was oxidized. Tryptic mapping of the enzyme modified in the absence and presence of shikimate 3-phosphate and glyphosate as well as analyses of the histidine content in the isolated peptides indicated that His385, in the peptide Asn383-Asp-His-Arg386, was the site of oxidation. These results suggest that His385 is the most accessible reactive imidazole group under these conditions and is located close to the glyphosate-binding site.
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Affiliation(s)
- Q K Huynh
- Department of Protein Biochemistry, Monsanto Company, St. Louis, MO 63198
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19
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Gruys KJ, Walker MC, Sikorski JA. Substrate synergism and the steady-state kinetic reaction mechanism for EPSP synthase from Escherichia coli. Biochemistry 1992; 31:5534-44. [PMID: 1344882 DOI: 10.1021/bi00139a016] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Previous studies of Escherichia coli 5-enolpyruvoylshikimate-3-phosphate synthase (EPSPS, EC 2.5.1.19) have suggested that the kinetic reaction mechanism for this enzyme in the forward direction is equilibrium ordered with shikimate 3-phosphate (S3P) binding first followed by phosphoenolpyruvate (PEP). Recent results from this laboratory, however, measuring direct binding of PEP and PEP analogues to free EPSPS suggest more random character to the enzyme. Steady-state kinetic and spectroscopic studies presented here indicate that E. coli EPSPS does indeed follow a random kinetic mechanism. Initial velocity studies with S3P and PEP show competitive substrate inhibition by PEP added to a normal intersecting pattern. Substrate inhibition is proposed to occur by competitive binding of PEP at the S3P site [Ki(PEP) = 6-8 mM]. To test for a productive EPSPS.PEP binary complex, the reaction order of EPSPS was evaluated with shikimic acid and PEP as substrates. The mechanism for this reaction is equilibrium ordered with PEP binding first giving a Kia value for PEP in agreement with the independently measured Kd of 0.39 mM (shikimate Km = 25 mM). Results from this study also show that the 3-phosphate moiety of S3P offers 8.7 kcal/mol in binding energy versus a hydroxyl in this position. Over 60% of this binding energy is expressed in binding of substrate to enzyme rather than toward increasing kcat. Glyphosate inhibition of shikimate turnover was poor with approximately 8 x 10(4) loss in binding capacity compared to the normal reaction, consistent with the independently measured Kd of 12 mM for the EPSPS.glyphosate binary complex. The EPSPS.glyphosate complex induces shikimate binding, however, by a factor of 7 greater than EPSPS.PEP. Carboxyallenyl phosphate and (Z)-3-fluoro-PEP were found to be strong inhibitors of the enzyme that have surprising affinity for the S3P binding domain in addition to the PEP site as measured both kinetically and by direct observation with 31P NMR. The collective data indicate that the true kinetic mechanism for EPSPS in the forward direction is random with synergistic binding occurring between substrates and inhibitors. The synergism explains how the mechanism can be random with S3P and PEP, but yet equilibrium ordered with PEP binding first for shikimate turnover. Synergism also accounts for how glyphosate can be a strong inhibitor of the normal reaction, but poor versus shikimate turnover.
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Affiliation(s)
- K J Gruys
- New Products Division, Monsanto Agricultural Company, St. Louis, Missouri 63167
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20
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Sost D, Amrhein N. Substitution of Gly-96 to Ala in the 5-enolpyruvylshikimate-3-phosphate synthase of Klebsiella pneumoniae results in a greatly reduced affinity for the herbicide glyphosate. Arch Biochem Biophys 1990; 282:433-6. [PMID: 2241161 DOI: 10.1016/0003-9861(90)90140-t] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The aroA gene of Klebsiella pneumoniae encoding the shikimate pathway enzyme 5-enolpyruvylshikimate 3-phosphate (EPSP) synthase, which is the target of the herbicide glyphosate, was cloned and sequenced from both the wild-type and the glyphosate-resistant mutant K. pneumoniae K1, which possesses a glyphosate-insensitive EPSP synthase. Both genes were expressed in Escherichia coli and were capable of complementing an auxotrophic aroA mutation. The transformed cells showed increased tolerance to glyphosate due to the overproduction of either the mutant or the wild type EPSP synthase. Nucleotide sequence analysis of the K. pneumoniae aroA gene indicated a protein-coding region of 427 amino acids with a derived Mr for the EPSP synthase of 45,976. Comparison of the two aroA alleles showed a single base change resulting in a substitution of Gly-96 to Ala in the deduced amino acid sequence. By comparison with other known EPSP synthase sequences the mutation was shown to be located in a highly conserved region, indicating that this region is essential for the binding of the herbicide glyphosate.
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Affiliation(s)
- D Sost
- Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität Bochum, Federal Republic of Germany
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21
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Affiliation(s)
- R Bentley
- Department of Chemistry, University of Sheffield, U.K
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22
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Anderson KS, Sikorski JA, Johnson KA. A tetrahedral intermediate in the EPSP synthase reaction observed by rapid quench kinetics. Biochemistry 1988; 27:7395-406. [PMID: 3061457 DOI: 10.1021/bi00419a034] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Direct evidence for an enzyme-bound intermediate in the EPSP synthase reaction pathway has been obtained by rapid chemical quench-flow studies. The transient-state kinetic analysis has led to the following complete scheme: (formula; see text) Values for all 12 rate constants were obtained. Substrate trapping experiments in the forward and reverse reactions established the kinetically preferred order of binding and release of substrates and products and showed that shikimate 3-phosphate (S3P) and 5-enolpyruvoylshikimate 3-phosphate (EPSP) dissociate at rates greater than turnover in each direction. Pre-steady-state bursts of product formation were observed in the reaction in each direction indicating a rate-limiting step following catalysis. Single turnover experiments with enzyme in excess over substrate demonstrated the formation of a transient intermediate in both the forward and reverse reactions. In these experiments, the enzymatic reaction was observed by employing a radiolabel in the enol moiety of either phosphoenol pyruvate (PEP) or EPSP. The separation and quantitation of reaction products were accomplished by HPLC monitoring radioactivity. The intermediate was observed as the transient production of radiolabeled pyruvate, formed due to the breakdown of the intermediate in the acid quench used to stop the reaction. The intermediate was observed within 5-10 ms after the substrates were mixed with enzyme and decayed in a reaction paralleling the formation of product in each direction. Thus, the kinetics demonstrate directly the kinetic competence of the presumed intermediate. No pyruvate was formed, on a time scale which is relevant to catalysis, after incubation of the enzyme with dideoxy-S3P and PEP or with EPSP in the absence of phosphate; and so, the intermediate does not accumulate under these conditions. The intermediate broke down to form PEP and EPSP in addition to pyruvate when the reaction was quenched with base rather than acid; therefore, the intermediate must contain the elements of each product. Other experiments were designed to measure directly the phosphate binding rate and further constrain the PEP binding rate. The overall solution equilibrium constant in the forward direction was determined to be 180 by quantitation of radiolabeled reactants and products in equilibrium after incubation with a low enzyme concentration. The internal, active site equilibrium constant was obtained by incubation of radiolabeled S3P with excess enzyme and high concentrations of phosphate and PEP to provide the ratio of [EPSP]/[S3P] = 2.3, which is largely a measure of K4.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K S Anderson
- Monsanto Agricultural Company, A Unit of Monsanto Company, St. Louis, Missouri 63167
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23
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Huynh QK. Evidence for a reactive gamma-carboxyl group (Glu-418) at the herbicide glyphosate binding site of 5-enolpyruvylshikimate-3-phosphate synthase from Escherichia coli. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37830-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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24
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Pipke R, Amrhein N. Degradation of the Phosphonate Herbicide Glyphosate by
Arthrobacter atrocyaneus
ATCC 13752. Appl Environ Microbiol 1988; 54:1293-6. [PMID: 16347639 PMCID: PMC202644 DOI: 10.1128/aem.54.5.1293-1296.1988] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Of nine authentic
Arthrobacter
strains tested, only
A. atrocyaneus
ATCC 13752 was capable of using the herbicide glyphosate [
N
-(phosphonomethyl)glycine] as its sole source of phosphorus. Contrary to the previously isolated
Arthrobacter
sp. strain GLP-1, which degrades glyphosate via sarcosine,
A. atrocyaneus
metabolized glyphosate to aminomethylphosphonic acid. The carbon of aminomethylphosphonic acid was entirely converted to CO
2
. This is the first report on glyphosate degradation by a bacterial strain without previous selection for glyphosate utilization as a source of phosphorus.
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Affiliation(s)
- R Pipke
- Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität Bochum, D-4630 Bochum, Federal Republic of Germany
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25
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Huynh QK, Kishore GM, Bild GS. 5-Enolpyruvyl shikimate 3-phosphate synthase from Escherichia coli. Identification of Lys-22 as a potential active site residue. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(19)35414-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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26
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Huynh QK. Reaction of 5-enol-pyruvoylshikimate-3-phosphate synthase with diethyl pyrocarbonate: evidence for an essential histidine residue. Arch Biochem Biophys 1987; 258:233-9. [PMID: 3310899 DOI: 10.1016/0003-9861(87)90340-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
5-enol-Pyruvoylshikimate-3-phosphate synthase catalyzes the reversible condensation of phosphoenolpyruvate and shikimate 3-phosphate to yield 5-enol-pyruvoylshikimate 3-phosphate and inorganic phosphate. The enzyme is a target for the nonselective herbicide glyphosate (N-phosphonomethylglycine). Diethyl pyrocarbonate inactivated this enzyme with a second-order rate constant of 220 M-1 min-1 at pH 7.0 and 0 degrees C. The rate of inactivation is pH dependent and the pH inactivation rate data show the involvement of a group with a pKa of 6.8. Almost all of the original activity was recovered by treatment of the inactivated enzyme with hydroxylamine. The difference spectrum of the inactivated and native enzyme reveals a single peak at 242 nm but no trough at around 278 nm is observed. Complete inactivation required the modification of four histidine residues per molecule of the enzyme. However, statistical analysis of the residual activity and the extent of modification shows that among the four modifiable residues, only one is critical for activity. Furthermore, this inactivation is prevented by the substrates of the enzyme. The above results indicated that one histidine is located within or very close to the active site and may play an important role in catalysis.
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Affiliation(s)
- Q K Huynh
- Department of Biological Sciences, Monsanto Company, St. Louis, Missouri 63198
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27
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Duncan K, Edwards RM, Coggins JR. The pentafunctional arom enzyme of Saccharomyces cerevisiae is a mosaic of monofunctional domains. Biochem J 1987; 246:375-86. [PMID: 2825635 PMCID: PMC1148286 DOI: 10.1042/bj2460375] [Citation(s) in RCA: 109] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The nucleotide sequence of the Saccharomyces cerevisiae ARO1 gene which encodes the arom multifunctional enzyme has been determined. The protein sequence deduced for the pentafunctional arom polypeptide is 1588 amino acids in length and has a calculated Mr of 174555. Functional regions within the polypeptide chain have been identified by comparison with the sequences of the five monofunctional Escherichia coli enzymes whose activities correspond with those of the arom multifunctional enzyme. The observed homologies demonstrate that the arom polypeptide is a mosaic of functional domains and are consistent with the hypothesis that the ARO1 gene evolved by the linking of ancestral E. coli-like genes.
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Affiliation(s)
- K Duncan
- Department of Biochemistry, University of Glasgow, U.K
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28
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Fischer RS, Rubin JL, Gaines CG, Jensen RA. Glyphosate sensitivity of 5-enol-pyruvylshikimate-3-phosphate synthase from Bacillus subtilis depends upon state of activation induced by monovalent cations. Arch Biochem Biophys 1987; 256:325-34. [PMID: 3111378 DOI: 10.1016/0003-9861(87)90453-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The 5-enol-pyruvylshikimate-3-phosphate (EPSP) synthase from Bacillus subtilis was activated by monovalent cations, catalytic activity being negligible in the absence of monovalent cations. The order of cation effectiveness (NH4+ greater than K+ greater than Rb+ greater than Na+ = Cs+ = Li+) indicated that the extent of activation was directly related to the unhydrated cation radius. Ammonium salts, at physiological concentrations, were dramatically more effective than other cations. Activation by ammonium was instantaneous, was not influenced by the counter ion, and gave a hyperbolic saturation curve. Hill plots did not show detectable cooperativity in the binding of ammonium. Double-reciprocal plots indicated that ammonium increases the maximal velocity and decreases the apparent Michaelis constants of EPSP synthase with respect to both phosphoenol pyruvate (PEP) and shikimate 3-phosphate (S3P). A direct relationship between sensitivity to inhibition by glyphosate and the activation state of EPSP synthase was demonstrated. Hill plots indicated a single value for glyphosate binding throughout the range of ammonium activation. Double-reciprocal plots of substrate saturation data obtained with ammonium-activated enzyme in the presence of glyphosate showed glyphosate to behave as a competitive inhibitor with respect to PEP and as a mixed-type inhibitor relative to S3P. The increased glyphosate sensitivity of ammonium-activated EPSP synthase is attributed to a lowering of the inhibitor constant of glyphosate with respect to PEP. Erroneous underestimates of sensitivities of some bacterial EPSP synthases to inhibition by glyphosate may result from failure to recognize cation requirements of EPSP synthases.
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29
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Pipke R, Amrhein N, Jacob GS, Schaefer J, Kishore GM. Metabolism of glyphosate in an Arthrobacter sp. GLP-1. EUROPEAN JOURNAL OF BIOCHEMISTRY 1987; 165:267-73. [PMID: 2439330 DOI: 10.1111/j.1432-1033.1987.tb11437.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The metabolism of glyphosate [N-(phosphonomethyl)glycine] in a bacterium tentatively identified as an Arthrobacter sp., capable of growth on this herbicide as its sole phosphorus source, has been investigated using solid-state NMR techniques as well as radiotracer analysis. The pathway involves the conversion of glyphosate to glycine, a C1 unit and phosphate. The phosphonomethyl carbon is specifically incorporated into the amino acids serine, cysteine, methionine, and histidine, as well as into purine bases and thymine, indicating the involvement of tetrahydrofolate in single-carbon transfer reactions. Glycine derived from glyphosate is utilized in purine and protein biosynthesis. This pathway for glyphosate degradation in a gram-positive bacterium is similar to that previously reported for Pseudomonas sp. PG2982 [Jacob et al. (1985) J. Biol. Chem. 260, 5899-5905] and is distinct from that reported for soil metabolism of glyphosate where aminomethylphosphonic acid has been shown to be a major metabolite. Preliminary evidence is presented which indicates that the conversion of glyphosate to glycine and the C1 unit involves the intermediate formation of sarcosine. Thus, the primary event in glyphosate degradation by Arthrobacter sp. GLP-1 is the cleavage of its C-P bound. This report constitutes the first demonstration of the metabolism of glyphosate in a gram-positive bacterium.
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30
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Abstract
The uptake of glyphosate (
N
-[phosphonomethyl]glycine) by an
Arthrobacter
sp. which can utilize this herbicide as its sole source of phosphorus was investigated. Orthophosphate suppressed the expression of the uptake system for glyphosate and also competed with glyphosate for uptake. The
K
m
for glyphosate uptake was 125 μM, and the
K
i
for orthophosphate was 24 μM. Organophosphonates as well as organophosphates inhibited glyphosate uptake, but only organophosphates and orthophosphate suppressed the uptake system. Glyphosate uptake was energy dependent, had a pH optimum of 6 to 7, and was differentially affected by divalent cations.
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Affiliation(s)
- R Pipke
- Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität Bochum, D 4630 Bochum, Federal Republic of Germany
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31
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[44] 3-Phosphoshikimate 1-carboxyvinyltransferase from Pisum sativum. Methods Enzymol 1987. [DOI: 10.1016/s0076-6879(87)42046-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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32
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33
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Duncan K, Coggins JR. The serC-aro A operon of Escherichia coli. A mixed function operon encoding enzymes from two different amino acid biosynthetic pathways. Biochem J 1986; 234:49-57. [PMID: 3518706 PMCID: PMC1146525 DOI: 10.1042/bj2340049] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Sub-cloning experiments aimed at precisely locating the E. coli aroA gene, which encodes the shikimate pathway enzyme 5-enolpyruvylshikimate 3-phosphate synthase, showed that in certain constructions, which remain capable of complementing an auxotrophic aroA mutation, expression of aroA is reduced. DNA sequence analysis revealed that a sequence approx. 1200 base pairs (bp) upstream of aroA is necessary for its expression. An open reading frame was identified in this region which encodes a protein of 362 amino acids with a calculated Mr of 39,834 and which ends 70 bp before the start of the aroA coding sequence. This gene has been identified as serC, the structural gene for 3-phosphoserine aminotransferase, an enzyme of the serine biosynthetic pathway. Both genes are expressed as a polycistronic message which is transcribed from a promotor located 58 bp upstream of serC. Evidence is presented which confirms that the aroA and serC genes constitute an operon which has the novel feature of encoding enzymes from two different amino acid biosynthetic pathways.
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34
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Steinrücken HC, Schulz A, Amrhein N, Porter CA, Fraley RT. Overproduction of 5-enolpyruvylshikimate-3-phosphate synthase in a glyphosate-tolerant Petunia hybrida cell line. Arch Biochem Biophys 1986; 244:169-78. [PMID: 3947056 DOI: 10.1016/0003-9861(86)90106-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Analysis of a Petunia hybrida cell culture (MP4-G) resistant to 1 mM glyphosate revealed a 15- to 20-fold increased level of 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase in the herbicide-tolerant strain. Immunoblotting and enzyme kinetic measurements established that the increased EPSP synthase activity resulted from overproduction of a herbicide-sensitive form of the enzyme. Homogeneous enzyme preparations were obtained from the herbicide-tolerant cell line by sequential ion-exchange, hydroxyapatite, hydrophobic-interaction, and molecular sieve chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and molecular sieve chromatography established the Petunia enzyme to be a monomeric protein with Mr 49,000-55,800. Km values for phosphoenolpyruvate and shikimate 3-phosphate were about 14 and 18 microM, respectively. Glyphosate inhibited the enzyme competitively with phosphoenolpyruvate (Ki = 0.17 microM). These experiments provide further evidence that EPSP synthase is a major site of glyphosate action in plant cells.
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35
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Smart CC, Johänning D, Müller G, Amrhein N. Selective overproduction of 5-enol-pyruvylshikimic acid 3-phosphate synthase in a plant cell culture which tolerates high doses of the herbicide glyphosate. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(17)36242-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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36
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Schulz A, Krüper A, Amrhein N. Differential sensitivity of bacterial 5-enolpyruvylshikimate-3-phosphate synthases to the herbicide glyphosate. FEMS Microbiol Lett 1985. [DOI: 10.1111/j.1574-6968.1985.tb00809.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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37
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Steinrücken HC, Amrhein N. 5-Enolpyruvylshikimate-3-phosphate synthase of Klebsiella pneumoniae 2. Inhibition by glyphosate [N-(phosphonomethyl)glycine]. EUROPEAN JOURNAL OF BIOCHEMISTRY 1984; 143:351-7. [PMID: 6381057 DOI: 10.1111/j.1432-1033.1984.tb08379.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The broad-spectrum, non-selective herbicide glyphosate [N-(phosphonomethyl)glycine] is a potent inhibitor of highly purified 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase (3-phosphoshikimate 1-carboxyvinyltransferase, EC 2.5.1.19) of Klebsiella pneumoniae. The inhibition is competitive with phosphoenolpyruvate (PEP) with Ki = 1 microM at pH 6.8 and non-competitive with shikimate 3-phosphate, EPSP, and inorganic phosphate. Non-herbicidal analogues of glyphosate, such as aminomethylphosphonic acid, bis-N-(phosphonomethyl)glycine and iminodiacetic acid, do not inhibit the enzyme. Inhibition of EPSP synthase by glyphosate strongly increases with increasing pH. Glyphosate protects the enzyme against inactivation by phenylglyoxal, 3-bromopyruvate, and N-ethylmaleimide. It is proposed that glyphosate binds to the PEP-binding site of EPSP synthase as a transition-state analogue of PEP. Other PEP-utilizing enzymes were not found to be subject to inhibition by glyphosate.
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