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Xu H, Yu B, Wei W, Chen X, Gao C, Liu J, Guo L, Song W, Liu L, Wu J. Improving tyrosol production efficiency through shortening the allosteric signal transmission distance of pyruvate decarboxylase. Appl Microbiol Biotechnol 2023; 107:3535-3549. [PMID: 37099057 DOI: 10.1007/s00253-023-12540-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/22/2023] [Accepted: 04/14/2023] [Indexed: 04/27/2023]
Abstract
Tyrosol is an important chemical in medicine and chemical industries, which can be synthesized by a four-enzyme cascade pathway constructed in our previous study. However, the low catalytic efficiency of pyruvate decarboxylase from Candida tropicalis (CtPDC) in this cascade is a rate-limiting step. In this study, we resolved the crystal structure of CtPDC and investigated the mechanism of allosteric substrate activation and decarboxylation of this enzyme toward 4-hydroxyphenylpyruvate (4-HPP). In addition, based on the molecular mechanism and structural dynamic changes, we conducted protein engineering of CtPDC to improve decarboxylation efficiency. The conversion of the best mutant, CtPDCQ112G/Q162H/G415S/I417V (CtPDCMu5), had over two-fold improvement compared to the wild-type. Molecular dynamic (MD) simulation revealed that the key catalytic distances and allosteric transmission pathways were shorter in CtPDCMu5 than in the wild type. Furthermore, when CtPDC in the tyrosol production cascade was replaced with CtPDCMu5, the tyrosol yield reached 38 g·L-1 with 99.6% conversion and 1.58 g·L-1·h-1 space-time yield in 24 h through further optimization of the conditions. Our study demonstrates that protein engineering of the rate-limiting enzyme in the tyrosol synthesis cascade provides an industrial-scale platform for the biocatalytic production of tyrosol. KEY POINTS: • Protein engineering of CtPDC based on allosteric regulation improved the catalytic efficiency of decarboxylation. • The application of the optimum mutant of CtPDC removed the rate-limiting bottleneck in the cascade. • The final titer of tyrosol reached 38 g·L-1 in 24 h in 3 L bioreactor.
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Affiliation(s)
- Huanhuan Xu
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi, 214122, China
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Bicheng Yu
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi, 214122, China
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Wanqing Wei
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Cong Gao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Jia Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Liang Guo
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Wei Song
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi, 214122, China
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Jing Wu
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi, 214122, China.
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2
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Solovjeva ON. New Role of Water in Transketolase Catalysis. Int J Mol Sci 2023; 24:ijms24032068. [PMID: 36768400 PMCID: PMC9917271 DOI: 10.3390/ijms24032068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023] Open
Abstract
Transketolase catalyzes the interconversion of keto and aldo sugars. Its coenzyme is thiamine diphosphate. The binding of keto sugar with thiamine diphosphate is possible only after C2 deprotonation of its thiazole ring. It is believed that deprotonation occurs due to the direct transfer of a proton to the amino group of its aminopyrimidine ring. Using mass spectrometry, it is shown that a water molecule is directly involved in the deprotonation process. After the binding of thiamine diphosphate with transketolase and its subsequent cleavage, a thiamine diphosphate molecule is formed with a mass increased by one oxygen molecule. After fragmentation, a thiamine diphosphate molecule is formed with a mass reduced by one and two hydrogen atoms, that is, HO and H2O are split off. Based on these data, it is assumed that after the formation of holotransketolase, water is covalently bound to thiamine diphosphate, and carbanion is formed as a result of its elimination. This may be a common mechanism for other thiamine enzymes. The participation of a water molecule in the catalysis of the one-substrate transketolase reaction and a possible reason for the effect of the acceptor substrate on the affinity of the donor substrate for active sites are also shown.
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Affiliation(s)
- Olga N Solovjeva
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119234 Moscow, Russia
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3
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Xia H, Kang Y, Ma Z, Hu C, Yang Q, Zhang X, Yang S, Dai J, Chen X. Evolutionary and reverse engineering in Saccharomyces cerevisiae reveals a Pdr1p mutation-dependent mechanism for 2-phenylethanol tolerance. Microb Cell Fact 2022; 21:269. [PMID: 36564756 PMCID: PMC9789650 DOI: 10.1186/s12934-022-01996-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND 2-Phenylethanol (2-PE), a higher alcohol with a rose-like odor, inhibits growth of the producer strains. However, the limited knowledge regarding 2-PE tolerance mechanisms renders our current knowledge base insufficient to inform rational design. RESULTS To improve the growth phenotype of Saccharomyces cerevisiae under a high 2-PE concentration, adaptive laboratory evolution (ALE) was used to generate an evolved 19-2 strain. Under 2-PE stress, its OD600 and growth rate increased by 86% and 22% than that of the parental strain, respectively. Through whole genome sequencing and reverse engineering, transcription factor Pdr1p mutation (C862R) was revealed as one of the main causes for increased 2-PE tolerance. Under 2-PE stress condition, Pdr1p mutation increased unsaturated fatty acid/saturated fatty acid ratio by 42%, and decreased cell membrane damage by 81%. Using STRING website, we identified Pdr1p interacted with some proteins, which were associated with intracellular ergosterol content, reactive oxygen species (ROS), and the ATP-binding cassette transporter. Also, the results of transcriptional analysis of genes encoded these proteins confirmed that Pdr1p mutation induced the expression of these genes. Compared with those of the reference strain, the ergosterol content of the PDR1_862 strain increased by 72%-101%, and the intracellular ROS concentration decreased by 38% under 2-PE stress. Furthermore, the Pdr1p mutation also increased the production of 2-PE (11% higher). CONCLUSIONS In the present work, we have demonstrated the use of ALE as a powerful tool to improve yeast tolerance to 2-PE. Based on the reverse engineering, transcriptional and physiological analysis, we concluded that Pdr1p mutation significantly enhanced the 2-PE tolerance of yeast by regulating the fatty acid proportion, intracellular ergosterol and ROS. It provides new insights on Pdr1p mediated 2-PE tolerance, which could help in the design of more robust yeasts for natural 2-PE synthesis.
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Affiliation(s)
- Huili Xia
- grid.411410.10000 0000 8822 034XKey Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), National “111” Center for Cellular Regulation and Molecular Pharmaceutics, College of Bioengineering, Hubei University of Technology, Wuhan, Hubei 430068 People’s Republic of China
| | - Yue Kang
- grid.411410.10000 0000 8822 034XKey Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), National “111” Center for Cellular Regulation and Molecular Pharmaceutics, College of Bioengineering, Hubei University of Technology, Wuhan, Hubei 430068 People’s Republic of China
| | - Zilin Ma
- grid.411410.10000 0000 8822 034XKey Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), National “111” Center for Cellular Regulation and Molecular Pharmaceutics, College of Bioengineering, Hubei University of Technology, Wuhan, Hubei 430068 People’s Republic of China
| | - Cuiyu Hu
- grid.411410.10000 0000 8822 034XKey Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), National “111” Center for Cellular Regulation and Molecular Pharmaceutics, College of Bioengineering, Hubei University of Technology, Wuhan, Hubei 430068 People’s Republic of China
| | - Qiao Yang
- grid.443668.b0000 0004 1804 4247ABI Group, College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan, 316022 Zhejiang China
| | - Xiaoling Zhang
- grid.443668.b0000 0004 1804 4247ABI Group, College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan, 316022 Zhejiang China
| | - Shihui Yang
- grid.34418.3a0000 0001 0727 9022State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
| | - Jun Dai
- grid.411410.10000 0000 8822 034XKey Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), National “111” Center for Cellular Regulation and Molecular Pharmaceutics, College of Bioengineering, Hubei University of Technology, Wuhan, Hubei 430068 People’s Republic of China ,grid.443668.b0000 0004 1804 4247ABI Group, College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan, 316022 Zhejiang China ,grid.34418.3a0000 0001 0727 9022State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
| | - Xiong Chen
- grid.411410.10000 0000 8822 034XKey Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), National “111” Center for Cellular Regulation and Molecular Pharmaceutics, College of Bioengineering, Hubei University of Technology, Wuhan, Hubei 430068 People’s Republic of China
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4
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Meng W, Ma C, Xu P, Gao C. Biotechnological production of chiral acetoin. Trends Biotechnol 2022; 40:958-973. [DOI: 10.1016/j.tibtech.2022.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 01/13/2022] [Accepted: 01/13/2022] [Indexed: 11/28/2022]
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5
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Cui Z, Mao Y, Zhao Y, Zheng M, Wang Z, Ma H, Chen T. One-pot efficient biosynthesis of (3 R)-acetoin from pyruvate by a two-enzyme cascade. Catal Sci Technol 2020. [DOI: 10.1039/d0cy01332c] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Opening the possibility of sustainable industrial (3R)-acetoin biomanufacturing in vitro.
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Affiliation(s)
- Zhenzhen Cui
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education)
- SynBio Research Platform
- Collaborative Innovation Center of Chemical Science and Engineering
- School of Chemical Engineering and Technology
- Tianjin University
| | - Yufeng Mao
- Biodesign Center
- Key Laboratory of Systems Microbial Biotechnology
- Tianjin Institute of Industrial Biotechnology
- Chinese Academy of Sciences
- Tianjin 300308
| | - Yujiao Zhao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education)
- SynBio Research Platform
- Collaborative Innovation Center of Chemical Science and Engineering
- School of Chemical Engineering and Technology
- Tianjin University
| | - Meiyu Zheng
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education)
- SynBio Research Platform
- Collaborative Innovation Center of Chemical Science and Engineering
- School of Chemical Engineering and Technology
- Tianjin University
| | - Zhiwen Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education)
- SynBio Research Platform
- Collaborative Innovation Center of Chemical Science and Engineering
- School of Chemical Engineering and Technology
- Tianjin University
| | - Hongwu Ma
- Biodesign Center
- Key Laboratory of Systems Microbial Biotechnology
- Tianjin Institute of Industrial Biotechnology
- Chinese Academy of Sciences
- Tianjin 300308
| | - Tao Chen
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education)
- SynBio Research Platform
- Collaborative Innovation Center of Chemical Science and Engineering
- School of Chemical Engineering and Technology
- Tianjin University
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6
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Planas F, McLeish MJ, Himo F. Computational Study of Enantioselective Carboligation Catalyzed by Benzoylformate Decarboxylase. ACS Catal 2019. [DOI: 10.1021/acscatal.9b01084] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Ferran Planas
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-10691 Stockholm, Sweden
| | - Michael J. McLeish
- Department of Chemistry and Chemical Biology, Indiana University−Purdue University Indianapolis, Indianapolis, Indiana 46202, United States
| | - Fahmi Himo
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-10691 Stockholm, Sweden
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7
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In-Cell NMR: Analysis of Protein-Small Molecule Interactions, Metabolic Processes, and Protein Phosphorylation. Int J Mol Sci 2019; 20:ijms20020378. [PMID: 30658393 PMCID: PMC6359726 DOI: 10.3390/ijms20020378] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/11/2019] [Accepted: 01/13/2019] [Indexed: 01/31/2023] Open
Abstract
Nuclear magnetic resonance (NMR) spectroscopy enables the non-invasive observation of biochemical processes, in living cells, at comparably high spectral and temporal resolution. Preferably, means of increasing the detection limit of this powerful analytical method need to be applied when observing cellular processes under physiological conditions, due to the low sensitivity inherent to the technique. In this review, a brief introduction to in-cell NMR, protein–small molecule interactions, posttranslational phosphorylation, and hyperpolarization NMR methods, used for the study of metabolites in cellulo, are presented. Recent examples of method development in all three fields are conceptually highlighted, and an outlook into future perspectives of this emerging area of NMR research is given.
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8
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Planas F, Sheng X, McLeish MJ, Himo F. A Theoretical Study of the Benzoylformate Decarboxylase Reaction Mechanism. Front Chem 2018; 6:205. [PMID: 29998094 PMCID: PMC6028569 DOI: 10.3389/fchem.2018.00205] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/18/2018] [Indexed: 01/27/2023] Open
Abstract
Density functional theory calculations are used to investigate the detailed reaction mechanism of benzoylformate decarboxylase, a thiamin diphosphate (ThDP)-dependent enzyme that catalyzes the nonoxidative decarboxylation of benzoylformate yielding benzaldehyde and carbon dioxide. A large model of the active site is constructed on the basis of the X-ray structure, and it is used to characterize the involved intermediates and transition states and evaluate their energies. There is generally good agreement between the calculations and available experimental data. The roles of the various active site residues are discussed and the results are compared to mutagenesis experiments. Importantly, the calculations identify off-cycle intermediate species of the ThDP cofactor that can have implications on the kinetics of the reaction.
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Affiliation(s)
- Ferran Planas
- Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, Stockholm, Sweden
| | - Xiang Sheng
- Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, Stockholm, Sweden
| | - Michael J McLeish
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Fahmi Himo
- Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, Stockholm, Sweden
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9
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Mechanistic and Structural Insight to an Evolved Benzoylformate Decarboxylase with Enhanced Pyruvate Decarboxylase Activity. Catalysts 2016. [DOI: 10.3390/catal6120190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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10
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Dzien P, Fages A, Jona G, Brindle KM, Schwaiger M, Frydman L. Following Metabolism in Living Microorganisms by Hyperpolarized (1)H NMR. J Am Chem Soc 2016; 138:12278-86. [PMID: 27556338 DOI: 10.1021/jacs.6b07483] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Dissolution dynamic nuclear polarization (dDNP) is used to enhance the sensitivity of nuclear magnetic resonance (NMR), enabling monitoring of metabolism and specific enzymatic reactions in vivo. dDNP involves rapid sample dissolution and transfer to a spectrometer/scanner for subsequent signal detection. So far, most biologically oriented dDNP studies have relied on hyperpolarizing long-lived nuclear spin species such as (13)C in small molecules. While advantages could also arise from observing hyperpolarized (1)H, short relaxation times limit the utility of prepolarizing this sensitive but fast relaxing nucleus. Recently, it has been reported that (1)H NMR peaks in solution-phase experiments could be hyperpolarized by spontaneous magnetization transfers from bound (13)C nuclei following dDNP. This work demonstrates the potential of this sensitivity-enhancing approach to probe the enzymatic process that could not be suitably resolved by (13)C dDNP MR. Here we measured, in microorganisms, the action of pyruvate decarboxylase (PDC) and pyruvate formate lyase (PFL)-enzymes that catalyze the decarboxylation of pyruvate to form acetaldehyde and formate, respectively. While (13)C NMR did not possess the resolution to distinguish the starting pyruvate precursor from the carbonyl resonances in the resulting products, these processes could be monitored by (1)H NMR at 500 MHz. These observations were possible in both yeast and bacteria in minute-long kinetic measurements where the hyperpolarized (13)C enhanced, via (13)C → (1)H cross-relaxation, the signals of protons binding to the (13)C over the course of enzymatic reactions. In addition to these spontaneous heteronuclear enhancement experiments, single-shot acquisitions based on J-driven (13)C → (1)H polarization transfers were also carried out. These resulted in higher signal enhancements of the (1)H resonances but were not suitable for multishot kinetic studies. The potential of these (1)H-based approaches for measurements in vivo is briefly discussed.
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Affiliation(s)
- Piotr Dzien
- Klinik und Poliklinik für Nuklearmedizin, Technische Universität München , München 81675, Germany
- Cancer Research UK Cancer Institute , Cambridge CB2 0RE, United Kingdom
| | | | | | - Kevin M Brindle
- Cancer Research UK Cancer Institute , Cambridge CB2 0RE, United Kingdom
| | - Markus Schwaiger
- Klinik und Poliklinik für Nuklearmedizin, Technische Universität München , München 81675, Germany
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11
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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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12
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Ghasemi S, Habibi Z, Notash B. Biotransformation of Active Methylene Compounds by Saccharomyces cerevisiae. Chem Nat Compd 2015. [DOI: 10.1007/s10600-015-1433-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Kim S, Hahn JS. Efficient production of 2,3-butanediol in Saccharomyces cerevisiae by eliminating ethanol and glycerol production and redox rebalancing. Metab Eng 2015; 31:94-101. [DOI: 10.1016/j.ymben.2015.07.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 06/24/2015] [Accepted: 07/17/2015] [Indexed: 12/18/2022]
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14
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Agarwal PK, Uppada V, Swaminathan AG, Noronha SB. Engineering of yeast pyruvate decarboxylase for enhanced selectivity towards carboligation. BIORESOURCE TECHNOLOGY 2015; 192:90-96. [PMID: 26022970 DOI: 10.1016/j.biortech.2015.05.060] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 05/16/2015] [Accepted: 05/18/2015] [Indexed: 06/04/2023]
Abstract
The aim of the study was to increase production of (R)-PAC by altering carboligation activity of Pdc in Saccharomyces cerevisiae. Pdc1 activity was modified by over-expression as well as changing the rate of decarboxylation and carboligation by site specific mutation in Pdc1. Over-expression of mutant Pdc1 resulted in 50 ± 2.5% increase in levels of (R)-PAC in wild-type and further 30-40% in pdc null background. The combination of mutant Pdc1 in pdc null background was successfully evaluated for production of (R)-PAC at industrial scale. This is the first report of enhancing (R)-PAC product in yeast by recombinant technology with capability of commercial production.
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Affiliation(s)
- Praveen Kumar Agarwal
- Department of Biosciences and Bioengineering, IIT Bombay, Powai 40076, Mumbai, India.
| | - Vanita Uppada
- Department of Biosciences and Bioengineering, IIT Bombay, Powai 40076, Mumbai, India.
| | | | - Santosh B Noronha
- Department of Chemical engineering, IIT Bombay, Powai 40076, Mumbai, India.
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15
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Vilela LDF, de Araujo VPG, Paredes RDS, Bon EPDS, Torres FAG, Neves BC, Eleutherio ECA. Enhanced xylose fermentation and ethanol production by engineered Saccharomyces cerevisiae strain. AMB Express 2015; 5:16. [PMID: 25852993 PMCID: PMC4385029 DOI: 10.1186/s13568-015-0102-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/09/2015] [Indexed: 11/10/2022] Open
Abstract
We have recently demonstrated that heterologous expression of a bacterial xylose isomerase gene (xylA) of Burkholderia cenocepacia enabled a laboratorial Saccharomyces cerevisiae strain to ferment xylose anaerobically, without xylitol accumulation. However, the recombinant yeast fermented xylose slowly. In this study, an evolutionary engineering strategy was applied to improve xylose fermentation by the xylA-expressing yeast strain, which involved sequential batch cultivation on xylose. The resulting yeast strain co-fermented glucose and xylose rapidly and almost simultaneously, exhibiting improved ethanol production and productivity. It was also observed that when cells were grown in a medium containing higher glucose concentrations before being transferred to fermentation medium, higher rates of xylose consumption and ethanol production were obtained, demonstrating that xylose utilization was not regulated by catabolic repression. Results obtained by qPCR demonstrate that the efficiency in xylose fermentation showed by the evolved strain is associated, to the increase in the expression of genes HXT2 and TAL1, which code for a low-affinity hexose transporter and transaldolase, respectively. The ethanol productivity obtained after the introduction of only one genetic modification and the submission to a one-stage process of evolutionary engineering was equivalent to those of strains submitted to extensive metabolic and evolutionary engineering, providing solid basis for future applications of this strategy in industrial strains.
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16
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Xiao Z, Lu JR. Generation of acetoin and its derivatives in foods. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:6487-97. [PMID: 25000216 DOI: 10.1021/jf5013902] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Acetoin is a common food flavor additive. This volatile compound widely exists in nature. Some microorganisms, higher plants, insects, and higher animals have the ability to synthesize acetoin using different enzymes and pathways under certain circumstances. As a very active molecule, acetoin acts as a precursor of dozens of compounds. Therefore, acetoin and its derivatives are frequently detected in the component analysis of a variety of foods using gas chromatography-mass spectrometry. Because of the increasing importance of these compounds, this paper reviews the origins and natural existence of these substances, physiological roles, the biological synthesis pathways, nonenzymatic spontaneous reactions, and the common determination methods in foods. This work is the first review on dietary natural acetoin.
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Affiliation(s)
- Zijun Xiao
- Centre for Bioengineering and Biotechnology, China University of Petroleum , Qingdao 266580, China
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17
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Jasim B, Jimtha John C, Shimil V, Jyothis M, Radhakrishnan E. Studies on the factors modulating indole-3-acetic acid production in endophytic bacterial isolates from Piper nigrum
and molecular analysis of ipdc
gene. J Appl Microbiol 2014; 117:786-99. [DOI: 10.1111/jam.12569] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Revised: 06/01/2014] [Accepted: 06/05/2014] [Indexed: 11/27/2022]
Affiliation(s)
- B. Jasim
- School of Biosciences; Mahatma Gandhi University; Kottayam India
| | - C. Jimtha John
- School of Biosciences; Mahatma Gandhi University; Kottayam India
| | - V. Shimil
- School of Biosciences; Mahatma Gandhi University; Kottayam India
| | - M. Jyothis
- School of Biosciences; Mahatma Gandhi University; Kottayam India
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Li S, Xu N, Liu L, Chen J. Engineering of carboligase activity reaction in Candida glabrata for acetoin production. Metab Eng 2013; 22:32-9. [PMID: 24365210 DOI: 10.1016/j.ymben.2013.12.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 11/12/2013] [Accepted: 12/14/2013] [Indexed: 01/25/2023]
Abstract
Utilization of Candida glabrata overproducing pyruvate is a promising strategy for high-level acetoin production. Based on the known regulatory and metabolic information, acetaldehyde and thiamine were fed to identify the key nodes of carboligase activity reaction (CAR) pathway and provide a direction for engineering C. glabrata. Accordingly, alcohol dehydrogenase, acetaldehyde dehydrogenase, pyruvate decarboxylase, and butanediol dehydrogenase were selected to be manipulated for strengthening the CAR pathway. Following the rational metabolic engineering, the engineered strain exhibited increased acetoin biosynthesis (2.24 g/L). In addition, through in silico simulation and redox balance analysis, NADH was identified as the key factor restricting higher acetoin production. Correspondingly, after introduction of NADH oxidase, the final acetoin production was further increased to 7.33 g/L. By combining the rational metabolic engineering and cofactor engineering, the acetoin-producing C. glabrata was improved stepwise, opening a novel pathway for rational development of microorganisms for bioproduction.
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Affiliation(s)
- Shubo Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; The Laboratory of Food Microbial-Manufacturing Engineering, Jiangnan University, Wuxi 214122, China
| | - Nan Xu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; The Laboratory of Food Microbial-Manufacturing Engineering, Jiangnan University, Wuxi 214122, China
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; The Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; The Laboratory of Food Microbial-Manufacturing Engineering, Jiangnan University, Wuxi 214122, China.
| | - Jian Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; The Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
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19
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Andrews FH, McLeish MJ. Using site-saturation mutagenesis to explore mechanism and substrate specificity in thiamin diphosphate-dependent enzymes. FEBS J 2013; 280:6395-411. [DOI: 10.1111/febs.12459] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 07/23/2013] [Accepted: 07/26/2013] [Indexed: 12/25/2022]
Affiliation(s)
- Forest H. Andrews
- Department of Chemistry and Chemical Biology; Indiana University-Purdue University Indianapolis; IN USA
| | - Michael J. McLeish
- Department of Chemistry and Chemical Biology; Indiana University-Purdue University Indianapolis; IN USA
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20
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Kellett WF, Brunk E, Desai BJ, Fedorov AA, Almo SC, Gerlt JA, Rothlisberger U, Richards NGJ. Computational, structural, and kinetic evidence that Vibrio vulnificus FrsA is not a cofactor-independent pyruvate decarboxylase. Biochemistry 2013; 52:1842-4. [PMID: 23452154 PMCID: PMC3788570 DOI: 10.1021/bi400093y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The fermentation-respiration switch (FrsA) protein in Vibrio vulnificus was recently reported to catalyze the cofactor-independent decarboxylation of pyruvate. We now report quantum mechanical/molecular mechenical calculations that examine the energetics of C-C bond cleavage for a pyruvate molecule bound within the putative active site of FrsA. These calculations suggest that the barrier to C-C bond cleavage in the bound substrate is 28 kcal/mol, which is similar to that estimated for the uncatalyzed decarboxylation of pyruvate in water at 25 °C. In agreement with the theoretical predictions, no pyruvate decarboxylase activity was detected for recombinant FrsA protein that could be crystallized and structurally characterized. These results suggest that the functional annotation of FrsA as a cofactor-independent pyruvate decarboxylase is incorrect.
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Affiliation(s)
- Whitney F. Kellett
- Department of Chemistry, University of Florida, Gainesville, FL 32611, United States
| | - Elizabeth Brunk
- Laboratory of Computational Chemistry and Biochemistry, Ecole Polytechnique Fédérale Lausanne, CH-1015 Lausanne, Switzerland
| | - Bijoy J. Desai
- Departments of Biochemistry and Chemistry, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Alexander A. Fedorov
- Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, United States
| | - Steven C. Almo
- Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, United States
| | - John A. Gerlt
- Departments of Biochemistry and Chemistry, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Ursula Rothlisberger
- Laboratory of Computational Chemistry and Biochemistry, Ecole Polytechnique Fédérale Lausanne, CH-1015 Lausanne, Switzerland
| | - Nigel G. J. Richards
- Department of Chemistry, University of Florida, Gainesville, FL 32611, United States
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21
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Vogel C, Widmann M, Pohl M, Pleiss J. A standard numbering scheme for thiamine diphosphate-dependent decarboxylases. BMC BIOCHEMISTRY 2012; 13:24. [PMID: 23157214 PMCID: PMC3534367 DOI: 10.1186/1471-2091-13-24] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 11/08/2012] [Indexed: 01/05/2023]
Abstract
Background Standard numbering schemes for families of homologous proteins allow for the unambiguous identification of functionally and structurally relevant residues, to communicate results on mutations, and to systematically analyse sequence-function relationships in protein families. Standard numbering schemes have been successfully implemented for several protein families, including lactamases and antibodies, whereas a numbering scheme for the structural family of thiamine-diphosphate (ThDP) -dependent decarboxylases, a large subfamily of the class of ThDP-dependent enzymes encompassing pyruvate-, benzoylformate-, 2-oxo acid-, indolpyruvate- and phenylpyruvate decarboxylases, benzaldehyde lyase, acetohydroxyacid synthases and 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexadiene-1-carboxylate synthase (MenD) is still missing. Despite a high structural similarity between the members of the ThDP-dependent decarboxylases, their sequences are diverse and make a pairwise sequence comparison of protein family members difficult. Results We developed and validated a standard numbering scheme for the family of ThDP-dependent decarboxylases. A profile hidden Markov model (HMM) was created using a set of representative sequences from the family of ThDP-dependent decarboxylases. The pyruvate decarboxylase from S. cerevisiae (PDB: 2VK8) was chosen as a reference because it is a well characterized enzyme. The crystal structure with the PDB identifier 2VK8 encompasses the structure of the ScPDC mutant E477Q, the cofactors ThDP and Mg2+ as well as the substrate analogue (2S)-2-hydroxypropanoic acid. The absolute numbering of this reference sequence was transferred to all members of the ThDP-dependent decarboxylase protein family. Subsequently, the numbering scheme was integrated into the already established Thiamine-diphosphate dependent Enzyme Engineering Database (TEED) and was used to systematically analyze functionally and structurally relevant positions in the superfamily of ThDP-dependent decarboxylases. Conclusions The numbering scheme serves as a tool for the reliable sequence alignment of ThDP-dependent decarboxylases and the unambiguous identification and communication of corresponding positions. Thus, it is the basis for the systematic and automated analysis of sequence-encoded properties such as structural and functional relevance of amino acid positions, because the analysis of conserved positions, the identification of correlated mutations and the determination of subfamily specific amino acid distributions depend on reliable multisequence alignments and the unambiguous identification of the alignment columns. The method is reliable and robust and can easily be adapted to further protein families.
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Affiliation(s)
- Constantin Vogel
- Institute of Technical Biochemistry, University of Stuttgart, Allmandring 31, Stuttgart, 70569, Germany
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22
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Ng CY, Jung MY, Lee J, Oh MK. Production of 2,3-butanediol in Saccharomyces cerevisiae by in silico aided metabolic engineering. Microb Cell Fact 2012; 11:68. [PMID: 22640729 PMCID: PMC3442981 DOI: 10.1186/1475-2859-11-68] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 05/04/2012] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND 2,3-Butanediol is a chemical compound of increasing interest due to its wide applications. It can be synthesized via mixed acid fermentation of pathogenic bacteria such as Enterobacter aerogenes and Klebsiella oxytoca. The non-pathogenic Saccharomyces cerevisiae possesses three different 2,3-butanediol biosynthetic pathways, but produces minute amount of 2,3-butanediol. Hence, we attempted to engineer S. cerevisiae strain to enhance 2,3-butanediol production. RESULTS We first identified gene deletion strategy by performing in silico genome-scale metabolic analysis. Based on the best in silico strategy, in which disruption of alcohol dehydrogenase (ADH) pathway is required, we then constructed gene deletion mutant strains and performed batch cultivation of the strains. Deletion of three ADH genes, ADH1, ADH3 and ADH5, increased 2,3-butanediol production by 55-fold under microaerobic condition. However, overproduction of glycerol was observed in this triple deletion strain. Additional rational design to reduce glycerol production by GPD2 deletion altered the carbon fluxes back to ethanol and significantly reduced 2,3-butanediol production. Deletion of ALD6 reduced acetate production in strains lacking major ADH isozymes, but it did not favor 2,3-butanediol production. Finally, we introduced 2,3-butanediol biosynthetic pathway from Bacillus subtilis and E. aerogenes to the engineered strain and successfully increased titer and yield. Highest 2,3-butanediol titer (2.29 . l-1) and yield (0.113 g . g-1) were achieved by Δadh1 Δadh3 Δadh5 strain under anaerobic condition. CONCLUSIONS With the aid of in silico metabolic engineering, we have successfully designed and constructed S. cerevisiae strains with improved 2,3-butanediol production.
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Affiliation(s)
- Chiam Yu Ng
- Department of Chemical & Biological Engineering, Korea University, Seoul 136-701, Republic of Korea
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23
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Balakrishnan A, Gao Y, Moorjani P, Nemeria NS, Tittmann K, Jordan F. Bifunctionality of the thiamin diphosphate cofactor: assignment of tautomeric/ionization states of the 4'-aminopyrimidine ring when various intermediates occupy the active sites during the catalysis of yeast pyruvate decarboxylase. J Am Chem Soc 2012; 134:3873-85. [PMID: 22300533 PMCID: PMC3295232 DOI: 10.1021/ja211139c] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Thiamin diphosphate (ThDP) dependent enzymes perform crucial C-C bond forming and breaking reactions in sugar and amino acid metabolism and in biosynthetic pathways via a sequence of ThDP-bound covalent intermediates. A member of this superfamily, yeast pyruvate decarboxylase (YPDC) carries out the nonoxidative decarboxylation of pyruvate and is mechanistically a simpler ThDP enzyme. YPDC variants created by substitution at the active center (D28A, E51X, and E477Q) and on the substrate activation pathway (E91D and C221E) display varying activity, suggesting that they stabilize different covalent intermediates. To test the role of both rings of ThDP in YPDC catalysis (the 4'-aminopyrimidine as acid-base, and thiazolium as electrophilic covalent catalyst), we applied a combination of steady state and time-resolved circular dichroism experiments (assessing the state of ionization and tautomerization of enzyme-bound ThDP-related intermediates), and chemical quench of enzymatic reaction mixtures followed by NMR characterization of the ThDP-bound intermediates released from YPDC (assessing occupancy of active centers by these intermediates and rate-limiting steps). Results suggest the following: (1) Pyruvate and analogs induce active site asymmetry in YPDC and variants. (2) The rare 1',4'-iminopyrimidine ThDP tautomer participates in formation of ThDP-bound intermediates. (3) Propionylphosphinate also binds at the regulatory site and its binding is reflected by catalytic events at the active site 20 Å away. (4) YPDC stabilizes an electrostatic model for the 4'-aminopyrimidinium ionization state, an important contribution of the protein to catalysis. The combination of tools used provides time-resolved details about individual events during ThDP catalysis; the methods are transferable to other ThDP superfamily members.
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Affiliation(s)
| | - Yuhong Gao
- Department of Chemistry, Rutgers University, Newark, NJ 07102, USA
| | - Prerna Moorjani
- Department of Chemistry, Rutgers University, Newark, NJ 07102, USA
| | | | - Kai Tittmann
- Albrecht-von-Haller Institute & Göttingen Center for Molecular Biosciences, Georg-August University Göttingen, D-37077 Göttingen, Germany
| | - Frank Jordan
- Department of Chemistry, Rutgers University, Newark, NJ 07102, USA
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24
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Substrate specificity in thiamin diphosphate-dependent decarboxylases. Bioorg Chem 2011; 43:26-36. [PMID: 22245019 DOI: 10.1016/j.bioorg.2011.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 12/19/2011] [Accepted: 12/20/2011] [Indexed: 11/20/2022]
Abstract
Thiamin diphosphate (ThDP) is the biologically active form of vitamin B(1), and ThDP-dependent enzymes are found in all forms of life. The catalytic mechanism of this family requires the formation of a common intermediate, the 2α-carbanion-enamine, regardless of whether the enzyme is involved in C-C bond formation or breakdown, or even formation of C-N, C-O and C-S bonds. This demands that the enzymes must screen substrates prior to, and/or after, formation of the common intermediate. This review is focused on the group for which the second step is the protonation of the 2α-carbanion, i.e., the ThDP-dependent decarboxylases. Based on kinetic data, sequence/structure alignments and mutagenesis studies the factors involved in substrate specificity have been identified.
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25
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WANG JIANYI, LI SHUHUA. THEORETICAL STUDY TOWARD UNDERSTANDING THE CATALYTIC MECHANISM OF PYRUVATE DEHYDROGENASE MULTIENZYME COMPLEX E1 COMPONENT. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2011. [DOI: 10.1142/s0219633606002386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Density functional calculations are employed to investigate the mechanisms of all elementary reaction steps involved in the catalytic reaction of pyruvate dehydrogenase multienzyme complex E1 (PDHc E1). We have obtained the free energy profiles for all reaction steps, and have demonstrated the importance of some key residues (Glu571, Glu522, His640 and a water molecule) near the active center in each individual step. Glu571 plays an essential role in the ylide formation, the addition of pyruvate, and the release of acetaldehyde. Glu522 helps to orientate the carboxyl of pyruvate in favor of the addition reaction of pyruvate. The protonation of the enamine is found to proceed through a concerted double proton transfer transition state involving His640 and a water molecule. All reaction steps are calculated to be thermodynamically favorable, except for the release of acetaldehyde which is slightly endothermic. The protonation of the enamine is a rate-limiting step with a barrier of 24.5 kcal/mol in the protein environment. Comparing the energetics of the catalytic reaction in PDHc E1 with that in PDC, we find that the relative orientation of some conserved residues and the conformation of the cofactor ThDP have a significant impact on the reaction rates of individual steps.
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Affiliation(s)
- JIANYI WANG
- School of Chemistry and Chemical Engineering, Institute of Theoretical and Computational Chemistry, Laboratory of Mesoscopic Chemistry, Nanjing University, Nanjing 210093, People's Republic of China
| | - SHUHUA LI
- School of Chemistry and Chemical Engineering, Institute of Theoretical and Computational Chemistry, Laboratory of Mesoscopic Chemistry, Nanjing University, Nanjing 210093, People's Republic of China
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26
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Shim DJ, Nemeria NS, Balakrishnan A, Patel H, Song J, Wang J, Jordan F, Farinas ET. Assignment of function to histidines 260 and 298 by engineering the E1 component of the Escherichia coli 2-oxoglutarate dehydrogenase complex; substitutions that lead to acceptance of substrates lacking the 5-carboxyl group. Biochemistry 2011; 50:7705-9. [PMID: 21809826 DOI: 10.1021/bi200936n] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The first component (E1o) of the Escherichia coli 2-oxoglutarate dehydrogenase complex (OGDHc) was engineered to accept substrates lacking the 5-carboxylate group by subjecting H260 and H298 to saturation mutagenesis. Apparently, H260 is required for substrate recognition, but H298 could be replaced with hydrophobic residues of similar molecular volume. To interrogate whether the second component would allow synthesis of acyl-coenzyme A derivatives, hybrid complexes consisting of recombinant components of OGDHc (o) and pyruvate dehydrogenase (p) enzymes were constructed, suggesting that a different component is the "gatekeeper" for specificity for these two multienzyme complexes in bacteria, E1p for pyruvate but E2o for 2-oxoglutarate.
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Affiliation(s)
- Da Jeong Shim
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, University Heights, Newark, New Jersey 07102, United States
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27
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Lee KJ, Jeong CS, An YJ, Lee HJ, Park SJ, Seok YJ, Kim P, Lee JH, Lee KH, Cha SS. FrsA functions as a cofactor-independent decarboxylase to control metabolic flux. Nat Chem Biol 2011; 7:434-6. [PMID: 21623357 DOI: 10.1038/nchembio.589] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Accepted: 04/07/2011] [Indexed: 01/09/2023]
Abstract
The interaction between fermentation-respiration switch (FrsA) protein and glucose-specific enzyme IIA(Glc) increases glucose fermentation under oxygen-limited conditions. We show that FrsA converts pyruvate to acetaldehyde and carbon dioxide in a cofactor-independent manner and that its pyruvate decarboxylation activity is enhanced by the dephosphorylated form of IIA(Glc) (d-IIA(Glc)). Crystal structures of FrsA and its complex with d-IIA(Glc) revealed residues required for catalysis as well as the structural basis for the activation by d-IIA(Glc).
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Affiliation(s)
- Kyung-Jo Lee
- Department of Environmental Science, Hankuk University of Foreign Studies, Yongin, Republic of Korea
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28
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Meyer D, Walter L, Kolter G, Pohl M, Müller M, Tittmann K. Conversion of Pyruvate Decarboxylase into an Enantioselective Carboligase with Biosynthetic Potential. J Am Chem Soc 2011; 133:3609-16. [PMID: 21341803 DOI: 10.1021/ja110236w] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Danilo Meyer
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences, Georg-August-University Göttingen, Ernst-Caspari-Haus, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany
- Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Strasse 3, D-06120 Halle/Saale, Germany
| | - Lydia Walter
- Institute of Pharmaceutical Sciences, Albert-Ludwigs-University Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Geraldine Kolter
- Institute of Biotechnology 2, Research Centre Jülich, 52425 Jülich, Germany
| | - Martina Pohl
- Institute of Biotechnology 2, Research Centre Jülich, 52425 Jülich, Germany
| | - Michael Müller
- Institute of Pharmaceutical Sciences, Albert-Ludwigs-University Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Kai Tittmann
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences, Georg-August-University Göttingen, Ernst-Caspari-Haus, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany
- Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Strasse 3, D-06120 Halle/Saale, Germany
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29
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Pei XY, Erixon KM, Luisi BF, Leeper FJ. Structural insights into the prereaction state of pyruvate decarboxylase from Zymomonas mobilis . Biochemistry 2010; 49:1727-36. [PMID: 20099870 PMCID: PMC2855724 DOI: 10.1021/bi901864j] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pyruvate decarboxylase (PDC) uses thiamine diphosphate as an essential cofactor to catalyze the formation of acetaldehyde on the pathway of ethanol synthesis. Here we report the crystallographic image of a prereaction intermediate of a bacterial pyruvate decarboxylase prepared by cocrystallizing the enzyme with pyruvate and a stable analogue of the cofactor's activated ylid form. A second crystal structure of PDC in complex with fluoride shows that the ion organizes a water molecule that occludes the pyruvate binding site, accounting for the inhibitory effect of the halide. Also reported is a structure of the cofactor-free apo form, which when compared to the structure of the holo form indicates how thiamine diphosphate organizes the active site pocket of pyruvate decarboxylase to support catalysis. Guided by the structural and enzymatic data, we propose roles for several key residues in the catalytic mechanism.
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Affiliation(s)
- Xue-Yuan Pei
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QA, UK
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30
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31
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Jordan F, Arjunan P, Kale S, Nemeria NS, Furey W. Multiple roles of mobile active center loops in the E1 component of the Escherichia coli pyruvate dehydrogenase complex - Linkage of protein dynamics to catalysis. JOURNAL OF MOLECULAR CATALYSIS. B, ENZYMATIC 2009; 61:14-22. [PMID: 20160956 PMCID: PMC2759092 DOI: 10.1016/j.molcatb.2009.04.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The region encompassing residues 401-413 on the E1 component of the pyruvate dehydrogenase multienzyme complex from Escherichia coli comprises a loop (the inner loop) which was not seen in the X-ray structure in the presence of thiamin diphosphate, the required cofactor for the enzyme. This loop is seen in the presence of a stable analogue of the pre-decarboxylation intermediate, the covalent adduct between the substrate analogue methyl acetylphosphonate and thiamin diphosphate, C2α-phosphonolactylthiamin diphosphate. It has been shown that the residue H407 and several other residues on this loop are required to reduce the mobility of the loop so electron density corresponding to it can be seen once the pre-decarboxylation intermediate is formed. Concomitantly, the loop encompassing residues 541-557 (the outer loop) appears to work in tandem with the inner loop and there is a hydrogen bond between the two loops ensuring their correlated motion. The inner loop was shown to: a) sequester the active center from carboligase side reactions; b) assist the interaction between the E1 and the E2 components, thereby affecting the overall reaction rate of the entire multienzyme complex; c) control substrate access to the active center. Using viscosity effects on kinetics it was shown that formation of the pre-decarboxylation intermediate is specifically affected by loop movement. A cysteine-less variant was created for the E1 component, onto which cysteines were substituted at selected loop positions. Introducing an electron spin resonance spin label and an (19)F NMR label onto these engineered cysteines, the loop mobility was examined: a) both methods suggested that in the absence of ligand, the loop exists in two conformations; b) line-shape analysis of the NMR signal at different temperatures, enabled estimation of the rate constant for loop movement, and this rate constant was found to be of the same order of magnitude as the turnover number for the enzyme under the same conditions. Furthermore, this analysis gave important insights into rate-limiting thermal loop dynamics. Overall, the results suggest that the dynamic properties correlate with catalytic events on the E1 component of the pyruvate dehydrogenase complex.
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Affiliation(s)
- Frank Jordan
- Department of Chemistry, Rutgers University, Newark, New Jersey 07102
| | - Palaniappa Arjunan
- Biocrystallography Laboratory, Veterans Affairs Medical Center, Pittsburgh, Pennsylvania 15240
| | - Sachin Kale
- Department of Chemistry, Rutgers University, Newark, New Jersey 07102
| | | | - William Furey
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
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32
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König S, Spinka M, Kutter S. Allosteric activation of pyruvate decarboxylases. A never-ending story? ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.molcatb.2009.02.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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33
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Kutter S, Weiss MS, Wille G, Golbik R, Spinka M, König S. Covalently bound substrate at the regulatory site of yeast pyruvate decarboxylases triggers allosteric enzyme activation. J Biol Chem 2009; 284:12136-44. [PMID: 19246454 PMCID: PMC2673282 DOI: 10.1074/jbc.m806228200] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Revised: 02/17/2009] [Indexed: 11/06/2022] Open
Abstract
The mechanism by which the enzyme pyruvate decarboxylase from two yeast species is activated allosterically has been elucidated. A total of seven three-dimensional structures of the enzyme, of enzyme variants, or of enzyme complexes from two yeast species, three of them reported here for the first time, provide detailed atomic resolution snapshots along the activation coordinate. The prime event is the covalent binding of the substrate pyruvate to the side chain of cysteine 221, thus forming a thiohemiketal. This reaction causes the shift of a neighboring amino acid, which eventually leads to the rigidification of two otherwise flexible loops, one of which provides two histidine residues necessary to complete the enzymatically competent active site architecture. The structural data are complemented and supported by kinetic investigations and binding studies, providing a consistent picture of the structural changes occurring upon enzyme activation.
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Affiliation(s)
- Steffen Kutter
- Institute for Biochemistry and Biotechnology, Faculty of Biological Sciences, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120 Halle (Saale), Germany
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34
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Kluger R, Tittmann K. Thiamin diphosphate catalysis: enzymic and nonenzymic covalent intermediates. Chem Rev 2008; 108:1797-833. [PMID: 18491870 DOI: 10.1021/cr068444m] [Citation(s) in RCA: 216] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ronald Kluger
- Davenport Laboratories, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6 Canada.
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Saturation mutagenesis of putative catalytic residues of benzoylformate decarboxylase provides a challenge to the accepted mechanism. Proc Natl Acad Sci U S A 2008; 105:5733-8. [PMID: 18398009 DOI: 10.1073/pnas.0709657105] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Benzoylformate decarboxylase from Pseudomonas putida (PpBFDC) is a thiamin diphosphate-dependent enzyme that carries out the nonoxidative decarboxylation of aromatic 2-keto acids. The x-ray structure of PpBFDC suggested that Ser-26, His-70, and His-281 would play important roles in its catalytic mechanism, and the S26A, H70A, and H281A variants all exhibited greatly impaired catalytic activity. Based on stopped-flow studies with the alanine mutants, it was proposed that the histidine residues acted as acid-base catalysts, whereas Ser-26 was involved in substrate binding and played a significant, albeit less well defined, role in catalysis. While developing a saturation mutagenesis protocol to examine residues involved in PpBFDC substrate specificity, we tested the procedure on His-281. To our surprise, we found that His-281, which is thought to be necessary for protonation of the carbanion/enamine intermediate, could be replaced by phenyl alanine with only a 5-fold decrease in k(cat). Even more surprising were our subsequent observations (i) that His-70 could be replaced by threonine or leucine with approximately a 30-fold decrease in k(cat)/K(m) compared with a 4,000-fold decrease for the H70A variant and (ii) that Ser-26, which forms hydrogen bonds with the substrate carboxylate, could be replaced by threonine, leucine, or methionine without significant loss of activity. These results call into question the assigned roles for Ser-26, His-70, and His-281. Further, they demonstrate the danger in assigning catalytic function based solely on results with alanine mutants and show that saturation mutagenesis is a valuable tool in assessing the role and relative importance of putative catalytic residues.
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36
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Spaepen S, Versées W, Gocke D, Pohl M, Steyaert J, Vanderleyden J. Characterization of phenylpyruvate decarboxylase, involved in auxin production of Azospirillum brasilense. J Bacteriol 2007; 189:7626-33. [PMID: 17766418 PMCID: PMC2168738 DOI: 10.1128/jb.00830-07] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Azospirillum brasilense belongs to the plant growth-promoting rhizobacteria with direct growth promotion through the production of the phytohormone indole-3-acetic acid (IAA). A key gene in the production of IAA, annotated as indole-3-pyruvate decarboxylase (ipdC), has been isolated from A. brasilense, and its regulation was reported previously (A. Vande Broek, P. Gysegom, O. Ona, N. Hendrickx, E. Prinsen, J. Van Impe, and J. Vanderleyden, Mol. Plant-Microbe Interact. 18:311-323, 2005). An ipdC-knockout mutant was found to produce only 10% (wt/vol) of the wild-type IAA production level. In this study, the encoded enzyme is characterized via a biochemical and phylogenetic analysis. Therefore, the recombinant enzyme was expressed and purified via heterologous overexpression in Escherichia coli and subsequent affinity chromatography. The molecular mass of the holoenzyme was determined by size-exclusion chromatography, suggesting a tetrameric structure, which is typical for 2-keto acid decarboxylases. The enzyme shows the highest kcat value for phenylpyruvate. Comparing values for the specificity constant kcat/Km, indole-3-pyruvate is converted 10-fold less efficiently, while no activity could be detected with benzoylformate. The enzyme shows pronounced substrate activation with indole-3-pyruvate and some other aromatic substrates, while for phenylpyruvate it appears to obey classical Michaelis-Menten kinetics. Based on these data, we propose a reclassification of the ipdC gene product of A. brasilense as a phenylpyruvate decarboxylase (EC 4.1.1.43).
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Affiliation(s)
- Stijn Spaepen
- Centre of Microbial and Plant Genetics, K.U. Leuven, Kasteelpark Arenberg 20, 3001 Heverlee, Belgium
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Wang J, Dong H, Li S, He H. Theoretical study toward understanding the catalytic mechanism of pyruvate decarboxylase. J Phys Chem B 2007; 109:18664-72. [PMID: 16853401 DOI: 10.1021/jp052802s] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Density functional calculations are employed to explore the mechanisms of all elementary reaction steps involved in the catalytic cycle of pyruvate decarboxylase (PDC). Different models are constructed for mimicking the involvement of some key residues in a certain step. The effect of the protein framework on the potential energy profiles of active site models is approximately modeled by fixing some freedoms, based on the crystal structure of the PDC enzyme from Saccharomyces cerevisiae (ScPDC). Our calculations confirm that Glu51 is the most important residue in the formation of the ylide and the release of acetaldehyde via the proton relay between Glu51, N1', and the 4'-amino group of thiamine diphosphate. The presence of Glu477 and Asp28 residues makes the decarboxylation of lactylthiamin diphosphate (LThDP) an endothermic process with a significant free energy barrier. The protonation of the alpha-carbanion to form 2-(1-hydroxyethyl)-thiamin diphosphate is found to go through a concerted double proton transfer transition state involving both Asp28 and His115 residues. The final step, acetaldehyde release, is likely to proceed through a concerted transition state involving carbon-carbon bond-breaking and the deprotonation of the alpha-hydroxyl group. The decarboxylation of LThDP and the protonation of the alpha-carbanion are two rate-limiting steps, relative to the facile occurrence of the ylide formation and acetaldehyde release. The catalytic roles of residues Glu51, Glu477, Asp28, and Gly417 in the active site of ScPDC in individual steps elucidated from the present study are in good agreement with those derived from site-directed mutagenesis.
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Affiliation(s)
- Jianyi Wang
- Laboratory of Mesoscopic Chemistry, Institute of Theoretical and Computational Chemistry, Department of Chemistry, Nanjing University, Nanjing 210093, People's Republic of China
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38
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Baykal A, Chakraborty S, Dodoo A, Jordan F. Synthesis with good enantiomeric excess of both enantiomers of alpha-ketols and acetolactates by two thiamin diphosphate-dependent decarboxylases. Bioorg Chem 2006; 34:380-93. [PMID: 17083961 PMCID: PMC1702321 DOI: 10.1016/j.bioorg.2006.09.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Revised: 09/07/2006] [Accepted: 09/08/2006] [Indexed: 10/24/2022]
Abstract
In addition to the decarboxylation of 2-oxo acids, thiamin diphosphate (ThDP)-dependent decarboxylases/dehydrogenases can also carry out so-called carboligation reactions, where the central ThDP-bound enamine intermediate reacts with electrophilic substrates. For example, the enzyme yeast pyruvate decarboxylase (YPDC, from Saccharomyces cerevisiae) or the E1 subunit of the Escherichia coli pyruvate dehydrogenase complex (PDHc-E1) can produce acetoin and acetolactate, resulting from the reaction of the central thiamin diphosphate-bound enamine with acetaldehyde and pyruvate, respectively. Earlier, we had shown that some active center variants indeed prefer such a carboligase pathway to the usual one [Sergienko, Jordan, Biochemistry 40 (2001) 7369-7381; Nemeria et al., J. Biol. Chem. 280 (2005) 21,473-21,482]. Herein is reported detailed analysis of the stereoselectivity for forming the carboligase products acetoin, acetolactate, and phenylacetylcarbinol by the E477Q and D28A YPDC, and the E636A and E636Q PDHc-E1 active-center variants. Both pyruvate and beta-hydroxypyruvate were used as substrates and the enantiomeric excess was analyzed by a combination of NMR, circular dichroism and chiral-column gas chromatographic methods. Remarkably, the two enzymes produced a high enantiomeric excess of the opposite enantiomer of both acetoin-derived and acetolactate-derived products, strongly suggesting that the facial selectivity for the electrophile in the carboligation is different in the two enzymes. The different stereoselectivities exhibited by the two enzymes could be utilized in the chiral synthesis of important intermediates.
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Affiliation(s)
- Ahmet Baykal
- Department of Chemistry, Rutgers the State University, Newark, NJ 07102, USA
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39
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Vinogradov M, Kaplun A, Vyazmensky M, Engel S, Golbik R, Tittmann K, Uhlemann K, Meshalkina L, Barak Z, Hübner G, Chipman DM. Monitoring the acetohydroxy acid synthase reaction and related carboligations by circular dichroism spectroscopy. Anal Biochem 2005; 342:126-33. [PMID: 15958189 DOI: 10.1016/j.ab.2005.03.049] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 03/27/2005] [Accepted: 03/28/2005] [Indexed: 11/22/2022]
Abstract
Acetohydroxy acid synthase (AHAS) and related enzymes catalyze the production of chiral compounds [(S)-acetolactate, (S)-acetohydroxybutyrate, or (R)-phenylacetylcarbinol] from achiral substrates (pyruvate, 2-ketobutyrate, or benzaldehyde). The common methods for the determination of AHAS activity have shortcomings. The colorimetric method for detection of acyloins formed from the products is tedious and does not allow time-resolved measurements. The continuous assay for consumption of pyruvate based on its absorbance at 333 nm, though convenient, is limited by the extremely small extinction coefficient of pyruvate, which results in a low signal-to-noise ratio and sensitivity to interfering absorbing compounds. Here, we report the use of circular dichroism spectroscopy for monitoring AHAS activity. This method, which exploits the optical activity of reaction products, displays a high signal-to-noise ratio and is easy to perform both in time-resolved and in commercial modes. In addition to AHAS, we examined the determination of activity of glyoxylate carboligase. This enzyme catalyzes the condensation of two molecules of glyoxylate to chiral tartronic acid semialdehyde. The use of circular dichroism also identifies the product of glyoxylate carboligase as being in the (R) configuration.
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Affiliation(s)
- Michael Vinogradov
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 84105, Israel
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40
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41
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Kneen MM, Pogozheva ID, Kenyon GL, McLeish MJ. Exploring the active site of benzaldehyde lyase by modeling and mutagenesis. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1753:263-71. [PMID: 16226928 DOI: 10.1016/j.bbapap.2005.08.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Revised: 08/15/2005] [Accepted: 08/24/2005] [Indexed: 10/25/2022]
Abstract
Benzaldehyde lyase (BAL) is a thiamin diphosphate-dependent enzyme, which catalyzes the breakdown of (R)-benzoin to benzaldehyde. In essence, this is the reverse of the carboligation reaction catalyzed by benzoylformate decarboxylase (BFD). Here, we describe the first steps towards understanding the factors influencing BFD to form a CC bond under conditions wherein BAL will cleave the same bond. What are the similarities and differences between these two enzymes that result in the different catalytic activities? The X-ray structures of BFD and pyruvate decarboxylase (PDC) were used as templates for modeling benzaldehyde lyase. The model shows that a glutamine residue, Gln113, replaces the active site histidines of BFD and PDC. Replacement of the Gln113 by alanine or histidine reduced the value of k(cat) for lyase activity by more than 200-fold. The residues in BFD interacting with the phenyl ring of benzoylformate have similarly positioned counterparts in BAL but Ser26, the residue known to interact with the carboxylate group of benzoylformate, has been replaced by an alanine (Ala28). The BAL A28S variant exhibited 7% of WT activity in the BAL assay but, in the most intriguing result, this variant was able to catalyze the decarboxylation of benzoylformate. Conversely, the BFD S26A variant was unable to cleave benzoin.
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Affiliation(s)
- Malea M Kneen
- College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
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42
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Jordan F, Nemeria NS. Experimental observation of thiamin diphosphate-bound intermediates on enzymes and mechanistic information derived from these observations. Bioorg Chem 2005; 33:190-215. [PMID: 15888311 PMCID: PMC4189838 DOI: 10.1016/j.bioorg.2005.02.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2004] [Revised: 02/08/2005] [Accepted: 02/10/2005] [Indexed: 11/27/2022]
Abstract
Thiamin diphosphate (ThDP), the vitamin B1 coenzyme, is an excellent representative of coenzymes, which carry out electrophilic catalysis by forming a covalent complex with their substrates. The function of ThDP is to greatly increase the acidity of two carbon acids by stabilizing their conjugate bases, the ylide/C2-carbanion of the thiazolium ring and the C2alpha-carbanion (or enamine) once the substrate binds to ThDP. In recent years, several ThDP-bound intermediates on such pathways have been characterized by both solution and solid-state (X-ray) methods. Prominent among these advances are X-ray crystallographic results identifying both oxidative and non-oxidative intermediates, rapid chemical quench followed by NMR detection of a several intermediates which are stable under acidic conditions, and circular dichroism detection of the 1',4'-imino tautomer of ThDP in some of the intermediates. Some of these methods also enable the investigator to determine the rate-limiting step in the complex series of steps.
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Affiliation(s)
- Frank Jordan
- Department of Chemistry, Rutgers University, Newark, NJ 07102, USA
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43
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Nemeria N, Tittmann K, Joseph E, Zhou L, Vazquez-Coll MB, Arjunan P, Hübner G, Furey W, Jordan F. Glutamate 636 of the Escherichia coli pyruvate dehydrogenase-E1 participates in active center communication and behaves as an engineered acetolactate synthase with unusual stereoselectivity. J Biol Chem 2005; 280:21473-82. [PMID: 15802265 DOI: 10.1074/jbc.m502691200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The residue Glu636 is located near the thiamine diphosphate (ThDP) binding site of the Escherichia coli pyruvate dehydrogenase complex E1 subunit (PDHc-E1), and to probe its function two variants, E636A and E636Q were created with specific activities of 2.5 and 26% compared with parental PDHc-E1. According to both fluorescence binding and kinetic assays, the E636A variant behaved according to half-of-the-sites mechanism with respect to ThDP. In contrast, with the E636Q variant a K(d,ThDP) = 4.34 microM and K(m,ThDP) = 11 microM were obtained with behavior more reminiscent of the parental enzyme. The CD spectra of both variants gave evidence for formation of the 1',4'-iminopyrimidine tautomer on binding of phosphonolactylthiamine diphosphate, a stable analog of the substrate-ThDP covalent complex. Rapid formation of optically active (R)-acetolactate by both variants, but not by the parental enzyme, was observed by CD and NMR spectroscopy. The acetolactate configuration produced by the Glu636 variants is opposite that produced by the enzyme acetolactate synthase and the Asp28-substituted variants of yeast pyruvate decarboxylase, suggesting that the active centers of the two sets of enzymes exhibit different facial selectivity (re or si) vis à vis pyruvate. The tryptic peptide map (mass spectral analysis) revealed that the Glu636 substitution changed the mobility of a loop comprising amino acid residues from the ThDP binding fold. Apparently, the residue Glu636 has important functions both in active center communication and in protecting the active center from undesirable "carboligase" side reactions.
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Affiliation(s)
- Natalia Nemeria
- Department of Chemistry, Rutgers University, Newark, New Jersey 07102, USA.
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44
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Kim J, Beak DG, Kim YT, Choi JD, Yoon MY. Effects of deletions at the C-terminus of tobacco acetohydroxyacid synthase on the enzyme activity and cofactor binding. Biochem J 2004; 384:59-68. [PMID: 15521822 PMCID: PMC1134088 DOI: 10.1042/bj20040427] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2004] [Revised: 06/17/2004] [Accepted: 07/22/2004] [Indexed: 11/17/2022]
Abstract
AHAS (acetohydroxyacid synthase) catalyses the first committed step in the biosynthesis of branched-chain amino acids, such as valine, leucine and isoleucine. Owing to the unique presence of these biosynthetic pathways in plants and micro-organisms, AHAS has been widely investigated as an attractive target of several classes of herbicides. Recently, the crystal structure of the catalytic subunit of yeast AHAS has been resolved at 2.8 A (1 A=0.1 nm), showing that the active site is located at the dimer interface and is near the herbicide-binding site. In this structure, the existence of two disordered regions, a 'mobile loop' and a C-terminal 'lid', is worth notice. Although these regions contain the residues that are known to be important in substrate specificity and in herbicide resistance, they are poorly folded into any distinct secondary structure and are not within contact distance of the cofactors. In the present study, we have tried to demonstrate the role of these regions of tobacco AHAS by constructing variants with serial deletions, based on the structure of yeast AHAS. In contrast with the wild-type AHAS, the truncated mutant which removes the C-terminal lid, Delta630, and the internal deletion mutant without the mobile loop, Delta567-582, impaired the binding affinity for ThDP (thiamine diphosphate), and showed different elution profiles representing a monomeric form in gel-filtration chromatography. Our results suggest that these regions are involved in the binding/stabilization of the active dimer and ThDP binding.
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Affiliation(s)
- Joungmok Kim
- *Department of Chemistry, College of Natural Science, Hanyang University, Seoul 133-791, South Korea
| | - Dong-Gil Beak
- *Department of Chemistry, College of Natural Science, Hanyang University, Seoul 133-791, South Korea
| | - Young-Tae Kim
- †Department of Microbiology, Pukyung National University, Busan 608-737, South Korea
| | - Jung-Do Choi
- ‡School of Life Science and Research Institute for Genetic Engineering, Chungbuk National University, Cheongju 361-763, South Korea
| | - Moon-Young Yoon
- *Department of Chemistry, College of Natural Science, Hanyang University, Seoul 133-791, South Korea
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Lingen B, Grötzinger J, Kolter D, Kula MR, Pohl M. Improving the carboligase activity of benzoylformate decarboxylase from Pseudomonas putida by a combination of directed evolution and site-directed mutagenesis. Protein Eng Des Sel 2002; 15:585-93. [PMID: 12200541 DOI: 10.1093/protein/15.7.585] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Benzoylformate decarboxylase (BFD) from Pseudomonas putida was subjected to directed molecular evolution to generate mutants with increased carboligase activity which is a side reaction of the enzyme. After a single round of random mutagenesis mutants were isolated which exhibited a 5-fold increased carboligase activity in aqueous buffer compared to the wild-type enzyme with a high enantiomeric excess of the product (S)-2-hydroxy-1-phenyl-propanone. From the same library, mutants with enhanced carboligase activity in water-miscible organic solvents have been isolated. The selected mutants have been characterized by sequencing, revealing that all mutants carry a mutation at Leu476, which is close to the active site but does not directly interact with the active center. BFD-L476Q has a 5-fold higher carboligase activity than the wild-type enzyme. L476 was subjected to saturation mutagenesis yielding eight different mutants with up to 5-fold increased carboligase activity. Surprisingly, all L476 mutants catalyze the formation of 2-hydroxy-1-phenyl-propanone with significantly higher enantioselectivity than the wild-type enzyme although enantioselectivity was not a selection parameter. Leu476 potentially plays the role of a gatekeeper of the active site of BFD, possibly by controlling the release of the product. The biocatalyst could be significantly improved for its side reaction, the C-C bond formation and for application under conditions that are not optimized in nature.
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Affiliation(s)
- B Lingen
- Institut für Enzymtechnologie der Heinrich-Heine-Universität Düsseldorf, im Forschungszentrum Jülich, D-52426 Jülich, Germany.
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Jordan F, Zhang Z, Sergienko E. Spectroscopic evidence for participation of the 1',4'-imino tautomer of thiamin diphosphate in catalysis by yeast pyruvate decarboxylase. Bioorg Chem 2002; 30:188-98. [PMID: 12406703 DOI: 10.1006/bioo.2002.1249] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The 1',4'-iminopyrimidine tautomeric form of the coenzyme thiamin diphosphate (ThDP), implicated in catalysis on the basis of the conformation of enzyme-bound ThDP, has been observed by both ultraviolet absorption and circular dichroism spectroscopy. On yeast pyruvate decarboxylase, the unusual tautomer is observed in an active center variant in which catalysis in the post-decarboxylation regime of the reaction is compromised. In a model system consisting of N1-methyl-4-aminopyrimidinium or N1-methyl-N4-n-butylpyrimidinium salts, on treatment with either NaOH in water, or DBU in DMSO there is an intermediate formed with lambda(max) near 310 nm, and this intermediate reverts back to the starting salt on acidification. Proton NMR chemical shifts are consistent with the intermediate representing the 1-methyl-4-imino tautomer. On the enzyme, the intermediate could be observed by rapid-scan stopped flow with UV detection when reacting holoenzyme of the E477Q active center variant with pyruvate, and by circular dichroism even in the absence of pyruvate. This represents the first direct observation of the imino tautomeric form of ThDP both on the enzyme and in models, although some years ago, this laboratory had already reported some pertinent acid-base properties for its formation [Jordan, F., and Mariam, Y. H. (1978) J. Am. Chem. Soc.100, 2534-2541]. The work also represents the first instance in which a rare tautomer implicated in catalysis is identified and suggests that such tautomeric catalysis may be more common in biology than hitherto recognized.
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Affiliation(s)
- Frank Jordan
- Department of Chemistry, Rutgers, the State University of New Jersey, Newark, 07102, USA.
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47
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Pang SS, Duggleby RG, Guddat LW. Crystal structure of yeast acetohydroxyacid synthase: a target for herbicidal inhibitors. J Mol Biol 2002; 317:249-62. [PMID: 11902841 DOI: 10.1006/jmbi.2001.5419] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Acetohydroxyacid synthase (AHAS; EC 4.1.3.18) catalyzes the first step in branched-chain amino acid biosynthesis. The enzyme requires thiamin diphosphate and FAD for activity, but the latter is unexpected, because the reaction involves no oxidation or reduction. Due to its presence in plants, AHAS is a target for sulfonylurea and imidazolinone herbicides. Here, the crystal structure to 2.6 A resolution of the catalytic subunit of yeast AHAS is reported. The active site is located at the dimer interface and is near the proposed herbicide-binding site. The conformation of FAD and its position in the active site are defined. The structure of AHAS provides a starting point for the rational design of new herbicides.
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Affiliation(s)
- Siew Siew Pang
- Centre for Protein Structure Function and Engineering, Department of Biochemistry and Molecular Biology, School of Molecular and Microbial Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
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Current awareness on yeast. Yeast 2001; 18:1357-64. [PMID: 11571760 DOI: 10.1002/yea.690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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