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Wang HL, Sun HP, Zheng PR, Cheng RT, Liu ZW, Yuan H, Gao WY, Li H. Re-investigation of in vitro activity of acetohydroxyacid synthase I holoenzyme from Escherichia coli. Arch Biochem Biophys 2024; 754:109962. [PMID: 38499055 DOI: 10.1016/j.abb.2024.109962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/14/2024] [Accepted: 03/15/2024] [Indexed: 03/20/2024]
Abstract
Acetohydroxyacid synthase (AHAS) is one of the key enzymes of the biosynthesis of branched-chain amino acids, it is also an effective target for the screening of herbicides and antibiotics. In this study we present a method for preparing Escherichia coli AHAS I holoenzyme (EcAHAS I) with exceptional stability, which provides a solid ground for us to re-investigate the in vitro catalytic properties of the protein. The results show EcAHAS I synthesized in this way exhibits similar function to Bacillus subtilis acetolactate synthase in its catalysis with pyruvate and 2-ketobutyrate (2-KB) as dual-substrate, producing four 2-hydroxy-3-ketoacids including (S)-2-acetolactate, (S)-2-aceto-2-hydroxybutyrate, (S)-2-propionyllactate, and (S)-2-propionyl-2-hydroxybutyrate. Quantification of the reaction indicates that the two substrates almost totally consume, and compound (S)-2-aceto-2- hydroxybutyrate forms in the highest yield among the four major products. Moreover, the protein also condenses two molecules of 2-KB to furnish (S)-2-propionyl-2-hydroxybutyrate. Further exploration manifests that EcAHAS I ligates pyruvate/2-KB and nitrosobenzene to generate two arylhydroxamic acids N-hydroxy-N-phenylacetamide and N-hydroxy-N-phenyl- propionamide. These findings enhance our comprehension of the catalytic characteristics of EcAHAS I. Furthermore, the application of this enzyme as a catalyst in construction of C-N bonds displays promising potential.
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Affiliation(s)
- Hai-Ling Wang
- College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi, 710069, China
| | - Hui-Peng Sun
- College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi, 710069, China
| | - Pei-Rong Zheng
- College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi, 710069, China
| | - Rui-Tong Cheng
- College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi, 710069, China
| | - Zhi-Wen Liu
- College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi, 710069, China
| | - Heng Yuan
- College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi, 710069, China
| | - Wen-Yun Gao
- College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi, 710069, China.
| | - Heng Li
- College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi, 710069, China.
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Mrowicka M, Mrowicki J, Dragan G, Majsterek I. The importance of thiamine (vitamin B1) in humans. Biosci Rep 2023; 43:BSR20230374. [PMID: 37389565 PMCID: PMC10568373 DOI: 10.1042/bsr20230374] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 06/11/2023] [Accepted: 06/14/2023] [Indexed: 07/01/2023] Open
Abstract
Thiamine (thiamin, B1) is a vitamin necessary for proper cell function. It exists in a free form as a thiamine, or as a mono-, di- or triphosphate. Thiamine plays a special role in the body as a coenzyme necessary for the metabolism of carbohydrates, fats and proteins. In addition, it participates in the cellular respiration and oxidation of fatty acids: in malnourished people, high doses of glucose result in acute thiamine deficiency. It also participates in energy production in the mitochondria and protein synthesis. In addition, it is also needed to ensure the proper functioning of the central and peripheral nervous system, where it is involved in neurotransmitter synthesis. Its deficiency leads to mitochondrial dysfunction, lactate and pyruvate accumulation, and consequently to focal thalamic degeneration, manifested as Wernicke's encephalopathy or Wernicke-Korsakoff syndrome. It can also lead to severe or even fatal neurologic and cardiovascular complications, including heart failure, neuropathy leading to ataxia and paralysis, confusion, or delirium. The most common risk factor for thiamine deficiency is alcohol abuse. This paper presents current knowledge of the biological functions of thiamine, its antioxidant properties, and the effects of its deficiency in the body.
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Affiliation(s)
- Małgorzata Mrowicka
- Małgorzata Mrowicka, Jerzy Mrowicki, Grzegorz Dragan, Ireneusz Majsterek, Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, Mazowiecka 5, 92-215 Lodz, Poland
| | - Jerzy Mrowicki
- Małgorzata Mrowicka, Jerzy Mrowicki, Grzegorz Dragan, Ireneusz Majsterek, Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, Mazowiecka 5, 92-215 Lodz, Poland
| | - Grzegorz Dragan
- Małgorzata Mrowicka, Jerzy Mrowicki, Grzegorz Dragan, Ireneusz Majsterek, Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, Mazowiecka 5, 92-215 Lodz, Poland
| | - Ireneusz Majsterek
- Małgorzata Mrowicka, Jerzy Mrowicki, Grzegorz Dragan, Ireneusz Majsterek, Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, Mazowiecka 5, 92-215 Lodz, Poland
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Zou Y, Zhang Y, Liu X, Song H, Cai Q, Wang S, Yi C, Chen J. Research Progress of Benzothiazole and Benzoxazole Derivatives in the Discovery of Agricultural Chemicals. Int J Mol Sci 2023; 24:10807. [PMID: 37445983 DOI: 10.3390/ijms241310807] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/24/2023] [Accepted: 06/26/2023] [Indexed: 07/15/2023] Open
Abstract
Benzoxazole and benzothiazole have a broad spectrum of agricultural biological activities, such as antibacterial, antiviral, and herbicidal activities, which are important fused heterocyclic scaffold structures in agrochemical discovery. In recent years, great progress has been made in the research of benzoxazoles and benzothiazoles, especially in the development of herbicides and insecticides. With the widespread use of benzoxazoles and benzothiazoles, there may be more new products containing benzoxazoles and benzothiazoles in the future. We systematically reviewed the application of benzoxazoles and benzothiazoles in discovering new agrochemicals in the past two decades and summarized the antibacterial, fungicidal, antiviral, herbicidal, and insecticidal activities of the active compounds. We also discussed the structural-activity relationship and mechanism of the active compounds. This work aims to provide inspiration and ideas for the discovery of new agrochemicals based on benzoxazole and benzothiazole.
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Affiliation(s)
- Yue Zou
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Yong Zhang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Xing Liu
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Hongyi Song
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Qingfeng Cai
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Sheng Wang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Chongfen Yi
- Guizhou Rice Research Institute, Guizhou Academy of Agricultural Sciences, Guiyang 550025, China
| | - Jixiang Chen
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
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Prajapati S, Rabe von Pappenheim F, Tittmann K. Frontiers in the enzymology of thiamin diphosphate-dependent enzymes. Curr Opin Struct Biol 2022; 76:102441. [PMID: 35988322 DOI: 10.1016/j.sbi.2022.102441] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 07/07/2022] [Accepted: 07/11/2022] [Indexed: 11/25/2022]
Abstract
Enzymes that use thiamin diphosphate (ThDP), the biologically active derivative of vitamin B1, as a cofactor play important roles in cellular metabolism in all domains of life. The analysis of ThDP enzymes in the past decades have provided a general framework for our understanding of enzyme catalysis of this protein family. In this review, we will discuss recent advances in the field that include the observation of "unusual" reactions and reaction intermediates that highlight the chemical versatility of the thiamin cofactor. Further topics cover the structural basis of cooperativity of ThDP enzymes, novel insights into the mechanism and structure of selected enzymes, and the discovery of "superassemblies" as reported, for example, acetohydroxy acid synthase. Finally, we summarize recent findings in the structural organisation and mode of action of 2-keto acid dehydrogenase multienzyme complexes and discuss future directions of this exciting research field.
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Affiliation(s)
- Sabin Prajapati
- Department of Molecular Enzymology, Göttingen Center of Molecular Biosciences, Georg-August University Göttingen, Julia-Lermontowa-Weg 3, D-37077 Göttingen, Germany; Max-Planck-Institute for Multidisciplinary Sciences, Am Fassberg 11, D-37077 Göttingen, Germany.
| | - Fabian Rabe von Pappenheim
- Department of Molecular Enzymology, Göttingen Center of Molecular Biosciences, Georg-August University Göttingen, Julia-Lermontowa-Weg 3, D-37077 Göttingen, Germany; Max-Planck-Institute for Multidisciplinary Sciences, Am Fassberg 11, D-37077 Göttingen, Germany.
| | - Kai Tittmann
- Department of Molecular Enzymology, Göttingen Center of Molecular Biosciences, Georg-August University Göttingen, Julia-Lermontowa-Weg 3, D-37077 Göttingen, Germany; Max-Planck-Institute for Multidisciplinary Sciences, Am Fassberg 11, D-37077 Göttingen, Germany.
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5
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Engineering the 2-Oxoglutarate Dehydrogenase Complex to Understand Catalysis and Alter Substrate Recognition. REACTIONS 2022. [DOI: 10.3390/reactions3010011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The E. coli 2-oxoglutarate dehydrogenase complex (OGDHc) is a multienzyme complex in the tricarboxylic acid cycle, consisting of multiple copies of three components, 2-oxoglutarate dehydrogenase (E1o), dihydrolipoamide succinyltransferase (E2o) and dihydrolipoamide dehydrogenase (E3), which catalyze the formation of succinyl-CoA and NADH (+H+) from 2-oxoglutarate. This review summarizes applications of the site saturation mutagenesis (SSM) to engineer E. coli OGDHc with mechanistic and chemoenzymatic synthetic goals. First, E1o was engineered by creating SSM libraries at positions His260 and His298.Variants were identified that: (a) lead to acceptance of substrate analogues lacking the 5-carboxyl group and (b) performed carboligation reactions producing acetoin-like compounds with good enantioselectivity. Engineering the E2o catalytic (core) domain enabled (a) assignment of roles for pivotal residues involved in catalysis, (b) re-construction of the substrate-binding pocket to accept substrates other than succinyllysyldihydrolipoamide and (c) elucidation of the mechanism of trans-thioesterification to involve stabilization of a tetrahedral oxyanionic intermediate with hydrogen bonds by His375 and Asp374, rather than general acid–base catalysis which has been misunderstood for decades. The E. coli OGDHc is the first example of a 2-oxo acid dehydrogenase complex which was evolved to a 2-oxo aliphatic acid dehydrogenase complex by engineering two consecutive E1o and E2o components.
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Yu S, Zheng B, Chen Z, Huo YX. Metabolic engineering of Corynebacterium glutamicum for producing branched chain amino acids. Microb Cell Fact 2021; 20:230. [PMID: 34952576 PMCID: PMC8709942 DOI: 10.1186/s12934-021-01721-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 12/11/2021] [Indexed: 11/10/2022] Open
Abstract
Background Branched chain amino acids (BCAAs) are widely applied in the food, pharmaceutical, and animal feed industries. Traditional chemical synthetic and enzymatic BCAAs production in vitro has been hampered by expensive raw materials, harsh reaction conditions, and environmental pollution. Microbial metabolic engineering has attracted considerable attention as an alternative method for BCAAs biosynthesis because it is environmentally friendly and delivers high yield. Main text Corynebacterium glutamicum (C. glutamicum) possesses clear genetic background and mature gene manipulation toolbox, and has been utilized as industrial host for producing BCAAs. Acetohydroxy acid synthase (AHAS) is a crucial enzyme in the BCAAs biosynthetic pathway of C. glutamicum, but feedback inhibition is a disadvantage. We therefore reviewed AHAS modifications that relieve feedback inhibition and then investigated the importance of AHAS modifications in regulating production ratios of three BCAAs. We have comprehensively summarized and discussed metabolic engineering strategies to promote BCAAs synthesis in C. glutamicum and offer solutions to the barriers associated with BCAAs biosynthesis. We also considered the future applications of strains that could produce abundant amounts of BCAAs. Conclusions Branched chain amino acids have been synthesized by engineering the metabolism of C. glutamicum. Future investigations should focus on the feedback inhibition and/or transcription attenuation mechanisms of crucial enzymes. Enzymes with substrate specificity should be developed and applied to the production of individual BCAAs. The strategies used to construct strains producing BCAAs provide guidance for the biosynthesis of other high value-added compounds.
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Affiliation(s)
- Shengzhu Yu
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Haidian District, Beijing, 100081, China
| | - Bo Zheng
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Haidian District, Beijing, 100081, China
| | - Zhenya Chen
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Haidian District, Beijing, 100081, China.
| | - Yi-Xin Huo
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Haidian District, Beijing, 100081, China
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Gao H, Tuyishime P, Zhang X, Yang T, Xu M, Rao Z. Engineering of microbial cells for L-valine production: challenges and opportunities. Microb Cell Fact 2021; 20:172. [PMID: 34461907 PMCID: PMC8406616 DOI: 10.1186/s12934-021-01665-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 08/24/2021] [Indexed: 11/10/2022] Open
Abstract
L-valine is an essential amino acid that has wide and expanding applications with a suspected growing market demand. Its applicability ranges from animal feed additive, ingredient in cosmetic and special nutrients in pharmaceutical and agriculture fields. Currently, fermentation with the aid of model organisms, is a major method for the production of L-valine. However, achieving the optimal production has often been limited because of the metabolic imbalance in recombinant strains. In this review, the constrains in L-valine biosynthesis are discussed first. Then, we summarize the current advances in engineering of microbial cell factories that have been developed to address and overcome major challenges in the L-valine production process. Future prospects for enhancing the current L-valine production strategies are also discussed.
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Affiliation(s)
- Hui Gao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Philibert Tuyishime
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Xian Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Taowei Yang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Meijuan Xu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, Jiangsu, China.
| | - Zhiming Rao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, Jiangsu, China.
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Alvarado O, García-Meseguer R, Ruiz-Pernía JJ, Tuñon I, Delgado EJ. Mechanistic study of the biosynthesis of R-phenylacetylcarbinol by acetohydroxyacid synthase enzyme using hybrid quantum mechanics/molecular mechanics simulations. Arch Biochem Biophys 2021; 707:108849. [PMID: 33832752 DOI: 10.1016/j.abb.2021.108849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The biosynthesis of R-phenylacetylcarbinol (R-PAC) by the acetohydroxy acid synthase, (AHAS) is addressed by molecular dynamics simulations (MD), hybrid quantum mechanics/molecular mechanics (QM/MM), and QM/MM free energy calculations. The results show the reaction starts with the nucleophilic attack of the C2α atom of the HEThDP intermediate on the Cβ atom of the carbonyl group of benzaldehyde substrate via the formation of a transition state (TS1) with the HEThDP intermediate under 4'-aminopyrimidium (APH+) form. The calculated activation free energy for this step is 17.4 kcal mol-1 at 27 °C. From this point, the reaction continues with the abstraction of Hβ atom of the HEThDP intermediate by the Oβ atom of benzaldehyde to form the intermediate I. The reaction is completed with the cleavage of the bond C2α-C2 to form the product R-PAC and to regenerate the ylide intermediate under the APH+ form, allowing in this way to reinitiate to the catalytic cycle once more. The calculated activation barrier for this last step is 15.9 kcal mol-1 at 27 °C.
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Affiliation(s)
- Omar Alvarado
- Departamento de Físico-Química, Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile; Departamento de Química, Facultad de Ciencias, Universidad del Bío-Bío, Avenida Collao 1202, Concepción, Chile
| | - Rafael García-Meseguer
- School of Mathematics, University of Bristol, Bristol, UK; Department of Physical Chemistry, Universitat de Valencia, 46100, Burjassot, Spain
| | | | - Iñaki Tuñon
- Department of Physical Chemistry, Universitat de Valencia, 46100, Burjassot, Spain
| | - Eduardo J Delgado
- Departamento de Físico-Química, Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile.
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9
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Hasan MM, Rima R. Genetic engineering to improve essential and conditionally essential amino acids in maize: transporter engineering as a reference. Transgenic Res 2021; 30:207-220. [PMID: 33583006 DOI: 10.1007/s11248-021-00235-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 01/21/2021] [Indexed: 11/27/2022]
Abstract
Ruminants and humans are unable to synthesize essential amino acids (EAAs) and conditionally essential amino acids (CEAAs) under normal conditions and need to acquire them from plant sources. Maize plays, as a major crop, a central role in global food security. However, maize is deficient in several EAAs and CEAAs. Genetic engineering has been successfully used to enrich the EAA content of maize to some extent, including the content of Lys, Trp, and Met. However, research on other EAAs is lacking. Genetic engineering provides several viable approaches for increasing the EAA content in maize, including transformation of a single gene, transformation of multiple genes in a single cassette, overexpression of putative amino acid transporters, engineering the amino acid biosynthesis pathway including silencing of feedback inhibition enzymes, and overexpression of major enzymes in this pathway. These challenging processes require a deep understanding of the biosynthetic and metabolic pathways of individual amino acids, and the interaction of individual amino acids with other metabolic pathways.
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Affiliation(s)
- Md Mahmudul Hasan
- Department of Nutrition and Food Technology, Jashore University of Science and Technology, Jashore, 7408, Bangladesh.
- The Key Laboratory of Plant-Soil Interactions, Ministry of Education, Center for Resources, Environment and Food Security, Department of Plant Nutrition, China Agricultural University, Beijing, 100193, China.
| | - Rima Rima
- Faculty of Food Science and Nutrition, Poznan University of Life Sciences, Poznan, Poland
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10
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Alvarado O, García-Meseguer R, Ruiz-Pernía JJ, Tuñon I, Delgado EJ. Mechanistic study of the biosynthesis of R-phenylcarbinol by acetohydroxyacid synthase enzyme using hybrid quantum mechanics/molecular mechanics simulations. Arch Biochem Biophys 2021; 701:108807. [PMID: 33587902 DOI: 10.1016/j.abb.2021.108807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 11/26/2022]
Abstract
The biosynthesis of R-phenylacetylcarbinol (R-PAC) by the acetohydroxy acid synthase, (AHAS) is addressed by molecular dynamics simulations (MD), hybrid quantum mechanics/molecular mechanics (QM/MM), and QM/MM free energy calculations. The results show the reaction starts with the nucleophilic attack of the C2α atom of the HEThDP intermediate on the Cβ atom of the carbonyl group of benzaldehyde substrate via the formation of a transition state (TS1) with the HEThDP intermediate under 4'-aminopyrimidium (APH+) form. The calculated activation free energy for this step is 17.4kcal mol-1 at 27 °C. From this point, the reaction continues with the abstraction of Hβ atom of the HEThDP intermediate by the Oβ atom of benzaldehyde to form the intermediate I. The reaction is completed with the cleavage of the bond C2α-C2 to form the product R-PAC and to regenerate the ylide intermediate under the APH+ form, allowing in this way to reinitiate to the catalytic cycle once more. The calculated activation barrier for this last step is 15.9kcal mol-1 at 27 °C.
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Affiliation(s)
- Omar Alvarado
- Departamento de Físico-Química, Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile; Departamento de Química, Facultad de Ciencias, Universidad del Bío-Bío, Avenida Collao 1202, Concepción, Chile
| | - Rafael García-Meseguer
- School of Mathematics, University of Bristol, Bristol, United Kingdom; Department of Physical Chemistry, Universitat de Valencia, 46100, Burjassot, Spain
| | | | - Iñaki Tuñon
- Department of Physical Chemistry, Universitat de Valencia, 46100, Burjassot, Spain
| | - Eduardo J Delgado
- Departamento de Físico-Química, Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile.
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11
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Molecular architecture of the acetohydroxyacid synthase holoenzyme. Biochem J 2020; 477:2439-2449. [DOI: 10.1042/bcj20200292] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/09/2020] [Accepted: 06/11/2020] [Indexed: 01/03/2023]
Abstract
The acetohydroxyacid synthase (AHAS) holoenzyme catalyzes the first step of branch-chain amino acid biosynthesis and is essential for plants and bacteria. It consists of a regulatory subunit (RSU) and a catalytic subunit (CSU). The allosteric mechanism of the AHAS holoenzyme has remained elusive for decades. Here, we determined the crystal structure of the AHAS holoenzyme, revealing the association between the RSU and CSU in an A2B2 mode. Structural analysis in combination with mutational studies demonstrated that the RSU dimer forms extensive interactions with the CSU dimer, in which a conserved salt bridge between R32 and D120 may act as a trigger to open the activation loop of the CSU, resulting in the activation of the CSU by the RSU. Our study reveals the activation mechanism of the AHAS holoenzyme.
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Li S, Peng F, Xiao Y, Gong Q, Bao Z, Li Y, Wu X. Mechanisms of High Concentration Valine-Mediated Inhibition of Peach Tree Shoot Growth. FRONTIERS IN PLANT SCIENCE 2020; 11:603067. [PMID: 33193558 PMCID: PMC7658097 DOI: 10.3389/fpls.2020.603067] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 10/09/2020] [Indexed: 05/10/2023]
Abstract
The vigorous growth of the new shoots of the peach tree was not beneficial to high quality and efficient cultivation. High concentration of amino acids can inhibit plant growth, but the mechanism is not clear. In this study, we explored the regulatory effects of seven amino acids (phenylalanine, valine, leucine, isoleucine, serine, D-alanine, and proline) (10 g⋅L-1) on the growth of peach trees. The results showed that phenylalanine, valine, and proline inhibited peach seedling growth and valine has the most significant effect and it can promote the root growth of peach seedlings. Compared with paclobutrazol, valine treatment improves net photosynthetic rate and fruit quality without reducing shoot diameter or puncture strength, and it does not affect leaf morphology. Valine enhanced the expression of PpSnRK1 (sucrose non-fermenting-1-related protein kinase) and inhibited the expression of PpTOR (Target of Rapamycin) and PpS6K (Ribosomal S6 kinase). The gibberellin content was significantly reduced in the valine treatment group. The endogenous valine content of peach seedlings was increased, acetohydroxyacid synthase (AHAS, E.C. 2.2.1.6) activity was inhibited by feedback, isoleucine synthesis was decreased, the relative amounts of branched chain amino acids were unbalanced, and growth was inhibited. However, isoleucine spraying after valine treatment could increase the content of isoleucine and alleviate the inhibition of valine on the shoot growth. In conclusion, valine is environmentally friendly to inhibit the growth of new shoots of peach trees by regulating the balance of PpSnRK1 and PpTOR and the synthesis of isoleucine.
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Affiliation(s)
- Suhong Li
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an, China
| | - Futian Peng
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an, China
- *Correspondence: Futian Peng,
| | - Yuansong Xiao
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an, China
- Yuansong Xiao,
| | | | - Ziyi Bao
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an, China
| | - Yanyan Li
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an, China
| | - Xuelian Wu
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an, China
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13
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Mendoza F, Medina FE, Jiménez VA, Jaña GA. Catalytic Role of Gln202 in the Carboligation Reaction Mechanism of Yeast AHAS: A QM/MM Study. J Chem Inf Model 2019; 60:915-922. [DOI: 10.1021/acs.jcim.9b00863] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fernanda Mendoza
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Autopista Concepción-Talcahuano, 7100 Talcahuano, Chile
| | - Fabiola E. Medina
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Autopista Concepción-Talcahuano, 7100 Talcahuano, Chile
| | - Verónica A. Jiménez
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Autopista Concepción-Talcahuano, 7100 Talcahuano, Chile
| | - Gonzalo A. Jaña
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Autopista Concepción-Talcahuano, 7100 Talcahuano, Chile
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14
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Xie Y, Zhang C, Wang Z, Wei C, Liao N, Wen X, Niu C, Yi L, Wang Z, Xi Z. Fluorogenic Assay for Acetohydroxyacid Synthase: Design and Applications. Anal Chem 2019; 91:13582-13590. [PMID: 31603309 DOI: 10.1021/acs.analchem.9b02739] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Acetohydroxyacid synthase (AHAS) exists in plants and many microorganisms (including gut flora) but not in mammals, making it an attractive drug target. Fluorescent-based methods should be practical for high-throughput screening of inhibitors. Herein, we describe the development of the first AHAS fluorogenic assay based on an intramolecular charge transfer (ICT)-based fluorescent probe. The assay is facile, sensitive, and continuous and can be applied toward various AHASs from different species, AHAS mutants, and crude cell lysates. The fluorogenic assay was successfully applied for (1) high-throughput screening of commerical herbicides toward different AHASs for choosing matching herbicides, (2) identification of a Soybean AHAS gene with broad-spectrum herbicide resistance, and (3) identification of selective inhibitors toward intestinal-bacterial AHASs. Among the AHAS inhibitors, an active agent was found for selective inhibition of obesity-associated Ruminococcus torques growth, implying the possibility of AHAS inhibitors for the ultimate goal toward antiobesity therapeutics. The fluorogenic assay opens the door for high-throughput programs in AHAS-related fields, and the design principle might be applied for development of fluorogenic assays of other synthases.
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Affiliation(s)
- Yonghui Xie
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, National Pesticide Engineering Research Center (Tianjin), College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Changyu Zhang
- State Key Laboratory of Organic-Inorganic Composites and Beijing Key Lab of Bioprocess , Beijing University of Chemical Technology (BUCT) , Beijing 100029 , P. R. China
| | - Zhihua Wang
- State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , P. R. China
| | - Chao Wei
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, National Pesticide Engineering Research Center (Tianjin), College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Ningjing Liao
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, National Pesticide Engineering Research Center (Tianjin), College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Xin Wen
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, National Pesticide Engineering Research Center (Tianjin), College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Congwei Niu
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, National Pesticide Engineering Research Center (Tianjin), College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Long Yi
- State Key Laboratory of Organic-Inorganic Composites and Beijing Key Lab of Bioprocess , Beijing University of Chemical Technology (BUCT) , Beijing 100029 , P. R. China.,Collaborative Innovation Center of Chemical Science and Engineering , Nankai University , Tianjin 300071 , P. R. China
| | - Zejian Wang
- State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , P. R. China
| | - Zhen Xi
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, National Pesticide Engineering Research Center (Tianjin), College of Chemistry , Nankai University , Tianjin 300071 , P. R. China.,Collaborative Innovation Center of Chemical Science and Engineering , Nankai University , Tianjin 300071 , P. R. China
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15
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Liu Y, Wang X, Zhan J, Hu J. The 138th residue of acetohydroxyacid synthase in Corynebacterium glutamicum is important for the substrate binding specificity. Enzyme Microb Technol 2019; 129:109357. [DOI: 10.1016/j.enzmictec.2019.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 05/12/2019] [Accepted: 06/01/2019] [Indexed: 11/28/2022]
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16
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Murphy BP, Tranel PJ. Target-Site Mutations Conferring Herbicide Resistance. PLANTS 2019; 8:plants8100382. [PMID: 31569336 PMCID: PMC6843678 DOI: 10.3390/plants8100382] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 09/25/2019] [Accepted: 09/26/2019] [Indexed: 12/01/2022]
Abstract
Mutations conferring evolved herbicide resistance in weeds are known in nine different herbicide sites of action. This review summarizes recently reported resistance-conferring mutations for each of these nine target sites. One emerging trend is an increase in reports of multiple mutations, including multiple amino acid changes at the glyphosate target site, as well as mutations involving two nucleotide changes at a single amino acid codon. Standard reference sequences are suggested for target sites for which standards do not already exist. We also discuss experimental approaches for investigating cross-resistance patterns and for investigating fitness costs of specific target-site mutations.
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Affiliation(s)
- Brent P Murphy
- Department of Crop Sciences, University of Illinois, Urbana, IL 61801, USA.
| | - Patrick J Tranel
- Department of Crop Sciences, University of Illinois, Urbana, IL 61801, USA.
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17
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Abstract
Tuberculosis (TB) is a major issue in global health and affects millions of people each year. Multidrug-resistant tuberculosis (MDR-TB) annually causes many deaths worldwide. Development of a way to diagnose and treat patients with MDR-TB can potentially reduce the incidence of the disease. The current study reviews the risk factors, pattern of progression, mechanism of resistance, and interaction between bacteria and the host immune system, which disrupts the immune response. It also targets the components of Mycobacterium tuberculosis (Mtb) and diagnosis and treatment options that could be available for clinical use in the near future. Mutations play an important role in development of MDR-TB and the selection of appropriate mutations can help to understand the type of resistance in patients to anti-TB drugs. In this way, they can be initially treated with proper and effective therapeutic choices, which can accelerate the course of treatment and improve patient health. Targeting the components and enzymes of Mtb is necessary for understanding bacterial survival and finding a way to destroy the pathogen and allow patients to recover faster and prevent the spread of disease, especially resistant strains.
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Affiliation(s)
- Majid Faridgohar
- Infectious Diseases Research Center, Kashan University of Medical Sciences, Kashan, Iran.,Department of Microbiology and Immunology, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, Iran
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18
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Li Y, Netherland MD, Zhang C, Hong H, Gong P. In silico identification of genetic mutations conferring resistance to acetohydroxyacid synthase inhibitors: A case study of Kochia scoparia. PLoS One 2019; 14:e0216116. [PMID: 31063467 PMCID: PMC6504096 DOI: 10.1371/journal.pone.0216116] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 04/14/2019] [Indexed: 12/17/2022] Open
Abstract
Mutations that confer herbicide resistance are a primary concern for herbicide-based chemical control of invasive plants and are often under-characterized structurally and functionally. As the outcome of selection pressure, resistance mutations usually result from repeated long-term applications of herbicides with the same mode of action and are discovered through extensive field trials. Here we used acetohydroxyacid synthase (AHAS) of Kochia scoparia (KsAHAS) as an example to demonstrate that, given the sequence of a target protein, the impact of genetic mutations on ligand binding could be evaluated and resistance mutations could be identified using a biophysics-based computational approach. Briefly, the 3D structures of wild-type (WT) and mutated KsAHAS-herbicide complexes were constructed by homology modeling, docking and molecular dynamics simulation. The resistance profile of two AHAS-inhibiting herbicides, tribenuron methyl and thifensulfuron methyl, was obtained by estimating their binding affinity with 29 KsAHAS (1 WT and 28 mutated) using 6 molecular mechanical (MM) and 18 hybrid quantum mechanical/molecular mechanical (QM/MM) methods in combination with three structure sampling strategies. By comparing predicted resistance with experimentally determined resistance in the 29 biotypes of K. scoparia field populations, we identified the best method (i.e., MM-PBSA with single structure) out of all tested methods for the herbicide-KsAHAS system, which exhibited the highest accuracy (up to 100%) in discerning mutations conferring resistance or susceptibility to the two AHAS inhibitors. Our results suggest that the in silico approach has the potential to be widely adopted for assessing mutation-endowed herbicide resistance on a case-by-case basis.
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Affiliation(s)
- Yan Li
- Bennett Aerospace, Inc., Cary, North Carolina, United States of America
| | - Michael D. Netherland
- Environmental Laboratory, U.S. Army Engineer Research and Development Center, Vicksburg, Mississippi, United States of America
| | - Chaoyang Zhang
- School of Computing Sciences and Computer Engineering, University of Southern Mississippi, Hattiesburg, Mississippi, United States of America
| | - Huixiao Hong
- Division of Bioinformatics and Biostatistics, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, United States of America
| | - Ping Gong
- Environmental Laboratory, U.S. Army Engineer Research and Development Center, Vicksburg, Mississippi, United States of America
- * E-mail:
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19
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Fartyal D, Agarwal A, James D, Borphukan B, Ram B, Sheri V, Agrawal PK, Achary VMM, Reddy MK. Developing dual herbicide tolerant transgenic rice plants for sustainable weed management. Sci Rep 2018; 8:11598. [PMID: 30072810 PMCID: PMC6072789 DOI: 10.1038/s41598-018-29554-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 07/14/2018] [Indexed: 11/25/2022] Open
Abstract
Herbicides are important constituents of modern integrated weed management system. However, the continuous use of a single herbicide leads to the frequent evolution of resistant weeds which further challenges their management. To overcome this situation, alternating use of multiple herbicides along with conventional weed-management practices is suitable and recommended. The development of multiple herbicide-tolerant crops is still in its infancy, and only a few crops with herbicide tolerance traits have been reported and commercialized. In this study, we developed transgenic rice plants that were tolerant to both bensulfuron methyl (BM) and glufosinate herbicides. The herbicide tolerant mutant variant of rice AHAS (Acetohydroxyacid synthase) was overexpressed along with codon optimized bacterial bar gene. The developed transgenic lines showed significant tolerance to both herbicides at various stages of plant development. The selected transgenic lines displayed an increased tolerance against 100 μM BM and 30 mg/L phosphinothricin during seed germination stage. Foliar applications further confirmed the dual tolerance to 300 μM BM and 2% basta herbicides without any significant growth and yield penalties. The development of dual-herbicide-tolerant transgenic plants adds further information to the knowledge of crop herbicide tolerance for sustainable weed management in modern agricultural system.
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Affiliation(s)
- Dhirendra Fartyal
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.,Uttarakhand Technical University, Dehradun, Uttarakhand, India
| | - Aakrati Agarwal
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.,Plant Molecular Biology Lab, Department of Botany, University of Delhi, New Delhi, India
| | - Donald James
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Bhabesh Borphukan
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Babu Ram
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.,Uttarakhand Technical University, Dehradun, Uttarakhand, India
| | - Vijay Sheri
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Pawan K Agrawal
- National Agricultural Science Fund, Indian Council of Agricultural Research, New Delhi, India
| | - V Mohan Murali Achary
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - M K Reddy
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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20
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Structural insights into the mechanism of inhibition of AHAS by herbicides. Proc Natl Acad Sci U S A 2018; 115:E1945-E1954. [PMID: 29440497 DOI: 10.1073/pnas.1714392115] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Acetohydroxyacid synthase (AHAS), the first enzyme in the branched amino acid biosynthesis pathway, is present only in plants and microorganisms, and it is the target of >50 commercial herbicides. Penoxsulam (PS), which is a highly effective broad-spectrum AHAS-inhibiting herbicide, is used extensively to control weed growth in rice crops. However, the molecular basis for its inhibition of AHAS is poorly understood. This is despite the availability of structural data for all other classes of AHAS-inhibiting herbicides. Here, crystallographic data for Saccharomyces cerevisiae AHAS (2.3 Å) and Arabidopsis thaliana AHAS (2.5 Å) in complex with PS reveal the extraordinary molecular mechanisms that underpin its inhibitory activity. The structures show that inhibition of AHAS by PS triggers expulsion of two molecules of oxygen bound in the active site, releasing them as substrates for an oxygenase side reaction of the enzyme. The structures also show that PS either stabilizes the thiamin diphosphate (ThDP)-peracetate adduct, a product of this oxygenase reaction, or traps within the active site an intact molecule of peracetate in the presence of a degraded form of ThDP: thiamine aminoethenethiol diphosphate. Kinetic analysis shows that PS inhibits AHAS by a combination of events involving FAD oxidation and chemical alteration of ThDP. With the emergence of increasing levels of resistance toward front-line herbicides and the need to optimize the use of arable land, these data suggest strategies for next generation herbicide design.
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21
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Lonhienne T, Garcia MD, Noble C, Harmer J, Fraser JA, Williams CM, Guddat LW. High Resolution Crystal Structures of the Acetohydroxyacid Synthase‐Pyruvate Complex Provide New Insights into Its Catalytic Mechanism. ChemistrySelect 2017. [DOI: 10.1002/slct.201702128] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Thierry Lonhienne
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Mario D. Garcia
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Chris Noble
- Centre for Advanced Imaging The University of Queensland Brisbane 4072 QLD Australia
| | - Jeffrey Harmer
- Centre for Advanced Imaging The University of Queensland Brisbane 4072 QLD Australia
| | - James A. Fraser
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Craig M. Williams
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Luke W. Guddat
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
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22
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Zhang Y, Zhou X, Xie Y, Greenberg MM, Xi Z, Zhou C. Thiol Specific and Tracelessly Removable Bioconjugation via Michael Addition to 5-Methylene Pyrrolones. J Am Chem Soc 2017; 139:6146-6151. [PMID: 28407468 DOI: 10.1021/jacs.7b00670] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
5-Methylene pyrrolones (5MPs) are highly thiol-specific and tracelessly removable bioconjugation tools. 5MPs are readily prepared from primary amines in one step. 5MPs exhibit significantly improved stability under physiologically relevant conditions and cysteine specificity compared to commonly used analogues, maleimides. Michael addition of thiol to 5MPs occurs rapidly, cleanly, and does not generate a stereocenter. The conjugates efficiently release thiols via retro-Michael reaction in alkaline buffer (pH 9.5) or via thiol exchange at pH 7.5. This unique property makes 5MPs valuable for the controlled release of conjugated cargo and temporary thiol protection. The utilization of 5MPs for protein immobilization and pull-down of active complexes is illustrated using E. coli. acetohydroxyacid synthase isozyme I.
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Affiliation(s)
- Yingqian Zhang
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry, Nankai University , Tianjin 300071, China
| | - Xiaoping Zhou
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry, Nankai University , Tianjin 300071, China
| | - Yonghui Xie
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry, Nankai University , Tianjin 300071, China
| | - Marc M Greenberg
- Department of Chemistry, Johns Hopkins University , 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Zhen Xi
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry, Nankai University , Tianjin 300071, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300071, China
| | - Chuanzheng Zhou
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry, Nankai University , Tianjin 300071, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300071, China
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23
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The 2.0 Å X-ray structure for yeast acetohydroxyacid synthase provides new insights into its cofactor and quaternary structure requirements. PLoS One 2017; 12:e0171443. [PMID: 28178302 PMCID: PMC5298238 DOI: 10.1371/journal.pone.0171443] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 01/20/2017] [Indexed: 11/19/2022] Open
Abstract
Acetohydroxyacid synthase (AHAS) catalyzes the first step of branched-chain amino acid biosynthesis, a pathway essential to the life-cycle of plants and micro-organisms. The catalytic subunit has thiamin diphosphate (ThDP) and flavin adenine dinucleotide (FAD) as indispensable co-factors. A new, high resolution, 2.0 Å crystal structure of Saccharomyces cerevisiae AHAS reveals that the dimer is asymmetric, with the catalytic centres having distinct structures where FAD is trapped in two different conformations indicative of different redox states. Two molecules of oxygen (O2) are bound on the surface of each active site and a tunnel in the polypeptide appears to passage O2 to the active site independently of the substrate. Thus, O2 appears to play a novel “co-factor” role in this enzyme. We discuss the functional implications of these features of the enzyme that have not previously been described.
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24
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25
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Liu Y, Li Y, Wang X. Acetohydroxyacid synthases: evolution, structure, and function. Appl Microbiol Biotechnol 2016; 100:8633-49. [DOI: 10.1007/s00253-016-7809-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 07/28/2016] [Accepted: 08/12/2016] [Indexed: 10/21/2022]
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26
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Lonhienne T, Nouwens A, Williams CM, Fraser JA, Lee Y, West NP, Guddat LW. Commercial Herbicides Can Trigger the Oxidative Inactivation of Acetohydroxyacid Synthase. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201511985] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Thierry Lonhienne
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Amanda Nouwens
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Craig M. Williams
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - James A. Fraser
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Yu‐Ting Lee
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Nicholas P. West
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Luke W. Guddat
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
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27
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Lonhienne T, Nouwens A, Williams CM, Fraser JA, Lee Y, West NP, Guddat LW. Commercial Herbicides Can Trigger the Oxidative Inactivation of Acetohydroxyacid Synthase. Angew Chem Int Ed Engl 2016; 55:4247-51. [DOI: 10.1002/anie.201511985] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 01/22/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Thierry Lonhienne
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Amanda Nouwens
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Craig M. Williams
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - James A. Fraser
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Yu‐Ting Lee
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Nicholas P. West
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
| | - Luke W. Guddat
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 QLD Australia
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28
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Cheng M, Yoshiyasu H, Okano K, Ohtake H, Honda K. Redirection of the Reaction Specificity of a Thermophilic Acetolactate Synthase toward Acetaldehyde Formation. PLoS One 2016; 11:e0146146. [PMID: 26731734 PMCID: PMC4701669 DOI: 10.1371/journal.pone.0146146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 12/13/2015] [Indexed: 11/18/2022] Open
Abstract
Acetolactate synthase and pyruvate decarboxylase are thiamine pyrophosphate-dependent enzymes that convert pyruvate into acetolactate and acetaldehyde, respectively. Although the former are encoded in the genomes of many thermophiles and hyperthermophiles, the latter has been found only in mesophilic organisms. In this study, the reaction specificity of acetolactate synthase from Thermus thermophilus was redirected to catalyze acetaldehyde formation to develop a thermophilic pyruvate decarboxylase. Error-prone PCR and mutant library screening led to the identification of a quadruple mutant with 3.1-fold higher acetaldehyde-forming activity than the wild-type. Site-directed mutagenesis experiments revealed that the increased activity of the mutant was due to H474R amino acid substitution, which likely generated two new hydrogen bonds near the thiamine pyrophosphate-binding site. These hydrogen bonds might result in the better accessibility of H+ to the substrate-cofactor-enzyme intermediate and a shift in the reaction specificity of the enzyme.
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Affiliation(s)
- Maria Cheng
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2–1 Yamadaoka, Suita, Osaka 565–0871, Japan
| | - Hayato Yoshiyasu
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2–1 Yamadaoka, Suita, Osaka 565–0871, Japan
| | - Kenji Okano
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2–1 Yamadaoka, Suita, Osaka 565–0871, Japan
| | - Hisao Ohtake
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2–1 Yamadaoka, Suita, Osaka 565–0871, Japan
| | - Kohsuke Honda
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2–1 Yamadaoka, Suita, Osaka 565–0871, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Chiyoda-ku, Tokyo 102–0076, Japan
- * E-mail:
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29
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Li H, Liu N, Wang WT, Wang JY, Gao WY. Cloning and characterization of GST fusion tag stabilized large subunit of Escherichia coli acetohydroxyacid synthase I. J Biosci Bioeng 2016; 121:21-26. [DOI: 10.1016/j.jbiosc.2015.05.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 05/07/2015] [Accepted: 05/18/2015] [Indexed: 10/22/2022]
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30
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Functional evaluation of residues in the herbicide-binding site of Mycobacterium tuberculosis acetohydroxyacid synthase by site-directed mutagenesis. Enzyme Microb Technol 2015. [DOI: 10.1016/j.enzmictec.2015.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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31
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Eram MS, Sarafuddin B, Gong F, Ma K. Characterization of acetohydroxyacid synthase from the hyperthermophilic bacterium Thermotoga maritima. Biochem Biophys Rep 2015; 4:89-97. [PMID: 29124191 PMCID: PMC5668897 DOI: 10.1016/j.bbrep.2015.08.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/24/2015] [Accepted: 08/24/2015] [Indexed: 11/30/2022] Open
Abstract
Acetohydroxyacid synthase (AHAS) is the key enzyme in branched chain amino acid biosynthesis pathway. The enzyme activity and properties of a highly thermostable AHAS from the hyperthermophilic bacterium Thermotoga maritima is being reported. The catalytic and regulatory subunits of AHAS from T. maritima were over-expressed in Escherichia coli. The recombinant subunits were purified using a simplified procedure including a heat-treatment step followed by chromatography. A discontinuous colorimetric assay method was optimized and used to determine the kinetic parameters. AHAS activity was determined to be present in several Thermotogales including T. maritima. The catalytic subunit of T. maritima AHAS was purified approximately 30-fold, with an AHAS activity of approximately 160±27 U/mg and native molecular mass of 156±6 kDa. The regulatory subunit was purified to homogeneity and showed no catalytic activity as expected. The optimum pH and temperature for AHAS activity were 7.0 and 85 °C, respectively. The apparent Km and Vmax for pyruvate were 16.4±2 mM and 246±7 U/mg, respectively. Reconstitution of the catalytic and regulatory subunits led to increased AHAS activity. This is the first report on characterization of an isoleucine, leucine, and valine operon (ilv operon) enzyme from a hyperthermophilic microorganism and may contribute to our understanding of the physiological pathways in Thermotogales. The enzyme represents the most active and thermostable AHAS reported so far. First report of AHAS from a hyperthermophilic bacterium. Catalytic and regulatory subunits of AHAS of T. maritima was expressed in E. coli. Recombinant proteins were purified using a simplified procedure. Enzyme represents the most active and thermostable AHAS reported so far. Kinetic parameters were determined for the purified recombinant enzyme
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Key Words
- AHAS, acetohydroxyacid synthase
- Acetohydroxyacid synthase
- BCAA, branched chain amino acid
- Branched-chain amino acids
- CCE, crude cell extract
- CFE, cell-free extract
- HTCCE, heat-treated crude cell extract
- Hyperthermophiles
- IB, inclusion body
- IMAC, immobilized metal affinity chromatography
- TPP, thiamine pyrophosphate
- Thermotogales
- TmAHAS, Thermotoga maritima acetohydroxyacid synthase
- ilv, isoleucine, leucine, valine
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Affiliation(s)
- Mohammad S Eram
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
| | - Benozir Sarafuddin
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
| | - Frank Gong
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
| | - Kesen Ma
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
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Development of ssDNA aptamers as potent inhibitors of Mycobacterium tuberculosis acetohydroxyacid synthase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1338-50. [PMID: 25988243 DOI: 10.1016/j.bbapap.2015.05.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 04/22/2015] [Accepted: 05/09/2015] [Indexed: 01/01/2023]
Abstract
Acetohydroxyacid synthase (AHAS) from Mycobacterium tuberculosis (Mtb) is a promising potential drug target for an emerging class of new anti-tuberculosis agents. In this study, we identify short (30-mer) single-stranded DNA aptamers as a novel class of potent inhibitors of Mtb-AHAS through an in vitro DNA-SELEX method. Among all tested aptamers, two candidate aptamers (Mtb-Apt1 and Mtb-Apt6) demonstrated the greatest inhibitory potential against Mtb-AHAS activity with IC50 values in the low nanomolar range (28.94±0.002 and 22.35±0.001 nM respectively). Interestingly, inhibition kinetics analysis of these aptamers showed different modes of enzyme inhibition (competitive and mixed type of inhibition respectively). Secondary structure-guided mutational modification analysis of Mtb-Apt1 and Mtb-Apt6 identified the minimal region responsible for their inhibitory action and consequently led to 17-mer and 20-mer shortened aptamers that retained equivalent or greater inhibitory potential. Notably, a modeling and docking exercise investigated the binding site of these two potent inhibitory aptamers on the target protein and showed possible involvement of some key catalytic dimer interface residues of AHAS in the DNA-protein interactions that lead to its potent inhibition. Importantly, these two short candidate aptamers, Mtb-Apt1 (17-mer) and Mtb-Apt6 (20-mer), also demonstrated significant growth inhibition against multidrug-resistant (MDR-TB) and extensively drug-resistant (XDR-TB) strains of tuberculosis with very low MIC of 5.36 μg/ml and 6.24 μg/ml, respectively and no significant cytotoxicity against mammalian cell line. This is the first report of functional inhibitory aptamers against Mtb-AHAS and provides the basis for development of these aptamers as novel and strong anti-tuberculosis agents.
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Guo Y, Han M, Xu J, Zhang W. Analysis of acetohydroxyacid synthase variants from branched-chain amino acids-producing strains and their effects on the synthesis of branched-chain amino acids in Corynebacterium glutamicum. Protein Expr Purif 2015; 109:106-12. [DOI: 10.1016/j.pep.2015.02.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/03/2015] [Accepted: 02/06/2015] [Indexed: 11/29/2022]
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Cavalcanti JHF, Esteves-Ferreira AA, Quinhones CGS, Pereira-Lima IA, Nunes-Nesi A, Fernie AR, Araújo WL. Evolution and functional implications of the tricarboxylic acid cycle as revealed by phylogenetic analysis. Genome Biol Evol 2014; 6:2830-48. [PMID: 25274566 PMCID: PMC4224347 DOI: 10.1093/gbe/evu221] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The tricarboxylic acid (TCA) cycle, a crucial component of respiratory metabolism, is composed of a set of eight enzymes present in the mitochondrial matrix. However, most of the TCA cycle enzymes are encoded in the nucleus in higher eukaryotes. In addition, evidence has accumulated demonstrating that nuclear genes were acquired from the mitochondrial genome during the course of evolution. For this reason, we here analyzed the evolutionary history of all TCA cycle enzymes in attempt to better understand the origin of these nuclear-encoded proteins. Our results indicate that prior to endosymbiotic events the TCA cycle seemed to operate only as isolated steps in both the host (eubacterial cell) and mitochondria (alphaproteobacteria). The origin of isoforms present in different cell compartments might be associated either with gene-transfer events which did not result in proper targeting of the protein to mitochondrion or with duplication events. Further in silico analyses allow us to suggest new insights into the possible roles of TCA cycle enzymes in different tissues. Finally, we performed coexpression analysis using mitochondrial TCA cycle genes revealing close connections among these genes most likely related to the higher efficiency of oxidative phosphorylation in this specialized organelle. Moreover, these analyses allowed us to identify further candidate genes which might be used for metabolic engineering purposes given the importance of the TCA cycle during development and/or stress situations.
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Affiliation(s)
- João Henrique Frota Cavalcanti
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, MG, Brazil Max-Planck-Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, MG, Brazil
| | - Alberto A Esteves-Ferreira
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, MG, Brazil Max-Planck-Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, MG, Brazil
| | - Carla G S Quinhones
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, MG, Brazil Max-Planck-Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, MG, Brazil
| | - Italo A Pereira-Lima
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, MG, Brazil Max-Planck-Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, MG, Brazil
| | - Adriano Nunes-Nesi
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, MG, Brazil Max-Planck-Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, MG, Brazil
| | - Alisdair R Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, MG, Brazil Max-Planck-Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, MG, Brazil
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Characterization and modification of enzymes in the 2-ketoisovalerate biosynthesis pathway of Ralstonia eutropha H16. Appl Microbiol Biotechnol 2014; 99:761-74. [DOI: 10.1007/s00253-014-5965-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/15/2014] [Accepted: 07/16/2014] [Indexed: 11/27/2022]
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36
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Generation of branched-chain amino acids resistant Corynebacterium glutamicum acetohydroxy acid synthase by site-directed mutagenesis. BIOTECHNOL BIOPROC E 2014. [DOI: 10.1007/s12257-013-0843-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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37
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Jin J, Qi X, Yao D, Mao B, Li J, Zhang Q, Chen C. Rational Design and Screening Study of Novel Lead Compound Based on Acetohydroxyacid Synthase Structure. Chem Biol Drug Des 2014; 84:316-24. [DOI: 10.1111/cbdd.12320] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 03/03/2014] [Accepted: 03/03/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Jingnan Jin
- College of Science Huazhong Agricultural University Wuhan 430070 China
| | - Xiaojuan Qi
- College of Science Huazhong Agricultural University Wuhan 430070 China
| | - Dandan Yao
- College of Science Huazhong Agricultural University Wuhan 430070 China
| | - Bangqiang Mao
- College of Science Huazhong Agricultural University Wuhan 430070 China
| | - Jianhong Li
- Department of Plant Protection Huazhong Agricultural University Wuhan 430070 China
| | - Qingye Zhang
- College of Science Huazhong Agricultural University Wuhan 430070 China
| | - Changshui Chen
- College of Science Huazhong Agricultural University Wuhan 430070 China
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Jaña GA, Delgado EJ, Medina FE. How Important Is the Synclinal Conformation of Sulfonylureas To Explain the Inhibition of AHAS: A Theoretical Study. J Chem Inf Model 2014; 54:926-32. [DOI: 10.1021/ci400721y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gonzalo A. Jaña
- Departamento
de CienciasQuímicas, Facultad de Ciencias
Exactas, Sede Concepción, Universidad Andres Bello, Concepción, Chile
| | - Eduardo J. Delgado
- Computational
Biological Chemistry Group, Faculty of Chemical
Sciencies, Universidad de Concepción, Concepción, Chile
| | - Fabiola E. Medina
- Departamento
de CienciasQuímicas, Facultad de Ciencias
Exactas, Sede Concepción, Universidad Andres Bello, Concepción, Chile
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Sánchez L, Jaña GA, Delgado EJ. A QM/MM study on the reaction pathway leading to 2-Aceto-2-hydroxybutyrate in the catalytic cycle of AHAS. J Comput Chem 2014; 35:488-94. [DOI: 10.1002/jcc.23523] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 11/30/2013] [Accepted: 12/15/2013] [Indexed: 11/05/2022]
Affiliation(s)
- Leslie Sánchez
- Computational Biological Chemistry Group, Faculty of Chemical Sciences; Universidad de Concepción; Concepción
| | - Gonzalo A. Jaña
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Sede Concepción; Universidad Andrés Bello; Concepcion
| | - Eduardo J. Delgado
- Computational Biological Chemistry Group, Faculty of Chemical Sciences; Universidad de Concepción; Concepción
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40
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García-Garijo A, Palma F, Lluch C, Tejera NA. Physiological and biochemical responses of common vetch to the imazamox accumulation. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2013; 73:321-325. [PMID: 24184452 DOI: 10.1016/j.plaphy.2013.10.013] [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: 07/23/2013] [Accepted: 10/10/2013] [Indexed: 06/02/2023]
Abstract
Common vetch (Vicia sativa L.) is a forage and grain legume, widely distributed throughout the world. Alterations induced by the herbicide imazamox on plant growth, acetohydroxyacid synthase activity, total free amino acids, as well as concentrations of valine, leucine, isoleucine and imazamox in young and mature leaves were investigated at 2 and 7 days after the herbicide application. Plant growth decreased significantly after 7 days of imazamox treatment. The herbicide was detected in both young and mature leaves inducing an inhibition of acetohydroxyacid synthase activity in the former and consequently decreasing valine and leucine contents in this organ. At the same time, the treatment caused an increase of total free amino acids in young leaves, presumably as result of proteolysis stimulation in such conditions. Given that these effects were not observed in mature leaves, we suggest a different sensitivity of the acetohydroxyacid synthase activity to imazamox depending on leaf age. Common vetch seems not to degrade imazamox since the herbicide was accumulated in shoot with increasing treatment time. To our knowledge, no physiological and biochemical studies of common vetch responses to imazamox have been previously reported.
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Affiliation(s)
- Amaranta García-Garijo
- Departamento de Fisiología Vegetal, Facultad de Ciencias, Universidad de Granada, Campus de Fuentenueva s/n, 18071 Granada, Spain
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41
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Bunik VI, Tylicki A, Lukashev NV. Thiamin diphosphate-dependent enzymes: from enzymology to metabolic regulation, drug design and disease models. FEBS J 2013; 280:6412-42. [PMID: 24004353 DOI: 10.1111/febs.12512] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 07/29/2013] [Accepted: 08/21/2013] [Indexed: 02/06/2023]
Abstract
Bringing a knowledge of enzymology into research in vivo and in situ is of great importance in understanding systems biology and metabolic regulation. The central metabolic significance of thiamin (vitamin B1 ) and its diphosphorylated derivative (thiamin diphosphate; ThDP), and the fundamental differences in the ThDP-dependent enzymes of metabolic networks in mammals versus plants, fungi and bacteria, or in health versus disease, suggest that these enzymes are promising targets for biotechnological and medical applications. Here, the in vivo action of known regulators of ThDP-dependent enzymes, such as synthetic structural analogs of the enzyme substrates and thiamin, is analyzed in light of the enzymological data accumulated during half a century of research. Mimicking the enzyme-specific catalytic intermediates, the phosphonate analogs of 2-oxo acids selectively inhibit particular ThDP-dependent enzymes. Because of their selectivity, use of these compounds in cellular and animal models of ThDP-dependent enzyme malfunctions improves the validity of the model and its predictive power when compared with the nonselective and enzymatically less characterized oxythiamin and pyrithiamin. In vitro studies of the interaction of thiamin analogs and their biological derivatives with potential in vivo targets are necessary to identify and attenuate the analog selectivity. For both the substrate and thiamin synthetic analogs, in vitro reactivities with potential targets are highly relevant in vivo. However, effective concentrations in vivo are often higher than in vitro studies would suggest. The significance of specific inihibition of the ThDP-dependent enzymes for the development of herbicides, antibiotics, anticancer and neuroprotective strategies is discussed.
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Affiliation(s)
- Victoria I Bunik
- A.N. Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, Moscow, Russia; Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
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42
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Nuclear magnetic resonance approaches in the study of 2-oxo acid dehydrogenase multienzyme complexes--a literature review. Molecules 2013; 18:11873-903. [PMID: 24077172 PMCID: PMC6270654 DOI: 10.3390/molecules181011873] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/14/2013] [Accepted: 09/16/2013] [Indexed: 11/17/2022] Open
Abstract
The 2-oxoacid dehydrogenase complexes (ODHc) consist of multiple copies of three enzyme components: E1, a 2-oxoacid decarboxylase; E2, dihydrolipoyl acyl-transferase; and E3, dihydrolipoyl dehydrogenase, that together catalyze the oxidative decarboxylation of 2-oxoacids, in the presence of thiamin diphosphate (ThDP), coenzyme A (CoA), Mg²⁺ and NAD⁺, to generate CO₂, NADH and the corresponding acyl-CoA. The structural scaffold of the complex is provided by E2, with E1 and E3 bound around the periphery. The three principal members of the family are pyruvate dehydrogenase (PDHc), 2-oxoglutarate dehydrogenase (OGDHc) and branched-chain 2-oxo acid dehydrogenase (BCKDHc). In this review, we report application of NMR-based approaches to both mechanistic and structural issues concerning these complexes. These studies revealed the nature and reactivity of transient intermediates on the enzymatic pathway and provided site-specific information on the architecture and binding specificity of the domain interfaces using solubilized truncated domain constructs of the multi-domain E2 component in its interactions with the E1 and E3 components. Where studied, NMR has also provided information about mobile loops and the possible relationship of mobility and catalysis.
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43
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He Y, Niu C, Wen X, Xi Z. Molecular Drug Resistance Prediction for Acetohydroxyacid Synthase Mutants Against Chlorsulfuron Using MB-QSAR. CHINESE J CHEM 2013. [DOI: 10.1002/cjoc.201300417] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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44
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Hailes HC, Rother D, Müller M, Westphal R, Ward JM, Pleiss J, Vogel C, Pohl M. Engineering stereoselectivity of ThDP-dependent enzymes. FEBS J 2013; 280:6374-94. [DOI: 10.1111/febs.12496] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 08/16/2013] [Accepted: 08/21/2013] [Indexed: 01/12/2023]
Affiliation(s)
- Helen C. Hailes
- Department of Chemistry; Christopher Ingold Laboratories; University College London; UK
| | - Dörte Rother
- IBG-1: Biotechnology; Forschungszentrum Jülich Germany
| | - Michael Müller
- Institute of Pharmaceutical Sciences; University of Freiburg; Germany
| | | | - John M. Ward
- Department of Biochemical Engineering; University College London; UK
| | - Jürgen Pleiss
- Institute of Technical Biochemistry; University of Stuttgart; Germany
| | - Constantin Vogel
- Institute of Technical Biochemistry; University of Stuttgart; Germany
| | - Martina Pohl
- IBG-1: Biotechnology; Forschungszentrum Jülich Germany
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45
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He Y, Niu C, Li H, Wen X, Xi Z. Experimental and computational correlation and prediction on herbicide resistance for acetohydroxyacid synthase mutants to Bispyribac. Sci China Chem 2013. [DOI: 10.1007/s11426-013-4841-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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46
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Endo M, Shimizu T, Fujimori T, Yanagisawa S, Toki S. Herbicide-Resistant Mutations in Acetolactate Synthase Can Reduce Feedback Inhibition and Lead to Accumulation of Branched-Chain Amino Acids. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/fns.2013.45067] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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47
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Karanth NM, Sarma SP. The Coil-to-Helix Transition in IlvN Regulates the Allosteric Control of Escherichia coli Acetohydroxyacid Synthase I. Biochemistry 2012. [DOI: 10.1021/bi301415m] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- N. Megha Karanth
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, Karnataka,
India
| | - Siddhartha P. Sarma
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, Karnataka,
India
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48
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Krizevski R, Bar E, Shalit OR, Levy A, Hagel JM, Kilpatrick K, Marsolais F, Facchini PJ, Ben-Shabat S, Sitrit Y, Lewinsohn E. Benzaldehyde is a precursor of phenylpropylamino alkaloids as revealed by targeted metabolic profiling and comparative biochemical analyses in Ephedra spp. PHYTOCHEMISTRY 2012; 81:71-9. [PMID: 22727117 DOI: 10.1016/j.phytochem.2012.05.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 05/13/2012] [Accepted: 05/14/2012] [Indexed: 05/13/2023]
Abstract
Ephedrine and pseudoephedrine are phenylpropylamino alkaloids widely used in modern medicine. Some Ephedra species such as E. sinica Stapf (Ephedraceae), a widely used Chinese medicinal plant (Chinese name: Ma Huang), accumulate ephedrine alkaloids as active constituents. Other Ephedra species, such as E. foeminea Forssk. (syn. E. campylopoda C.A. Mey) lack ephedrine alkaloids and their postulated metabolic precursors 1-phenylpropane-1,2-dione and (S)-cathinone. Solid-phase microextraction analysis of freshly picked young E. sinica and E. foeminea stems revealed the presence of increased benzaldehyde levels in E. foeminea, whereas 1-phenylpropane-1,2-dione was detected only in E. sinica. Soluble protein preparations from E. sinica and E. foeminea stems catalyzed the conversion of benzaldehyde and pyruvate to (R)-phenylacetylcarbinol, (S)-phenylacetylcarbinol, (R)-2-hydroxypropiophenone (S)-2-hydroxypropiophenone and 1-phenylpropane-1,2-dione. The activity, termed benzaldehyde carboxyligase (BCL) required the presence of magnesium and thiamine pyrophosphate and was 40 times higher in E. sinica as compared to E. foeminea. The distribution patterns of BCL activity in E. sinica tissues correlates well with the distribution pattern of the ephedrine alkaloids. (S)-Cathinone reductase enzymatic activities generating (1R,2S)-norephedrine and (1S,1R)-norephedrine were significantly higher in E. sinica relative to the levels displayed by E. foeminea. Surprisingly, (1R,2S)-norephedrine N-methyltransferase activity which is a downstream enzyme in ephedrine biosynthesis was significantly higher in E. foeminea than in E. sinica. Our studies further support that benzaldehyde is the metabolic precursor to phenylpropylamino alkaloids in E. sinica.
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Affiliation(s)
- Raz Krizevski
- Department of Aromatic, Medicinal and Spice Crops, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay 30095, Israel
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49
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Lu J, Brigham CJ, Gai CS, Sinskey AJ. Studies on the production of branched-chain alcohols in engineered Ralstonia eutropha. Appl Microbiol Biotechnol 2012; 96:283-97. [DOI: 10.1007/s00253-012-4320-9] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 07/16/2012] [Accepted: 07/17/2012] [Indexed: 11/25/2022]
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50
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Computer-assisted study on the reaction between pyruvate and ylide in the pathway leading to lactyl–ThDP. J Comput Aided Mol Des 2012; 26:977-82. [DOI: 10.1007/s10822-012-9589-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 07/05/2012] [Indexed: 11/25/2022]
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