1
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Bugg TDH. The chemical logic of enzymatic lignin degradation. Chem Commun (Camb) 2024; 60:804-814. [PMID: 38165282 PMCID: PMC10795516 DOI: 10.1039/d3cc05298b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 12/19/2023] [Indexed: 01/03/2024]
Abstract
Lignin is an aromatic heteropolymer, found in plant cell walls as 20-30% of lignocellulose. It represents the most abundant source of renewable aromatic carbon in the biosphere, hence, if it could be depolymerised efficiently, then it would be a highly valuable source of renewable aromatic chemicals. However, lignin presents a number of difficulties for biocatalytic or chemocatalytic breakdown. Research over the last 10 years has led to the identification of new bacterial enzymes for lignin degradation, and the use of metabolic engineering to generate useful bioproducts from microbial lignin degradation. The aim of this article is to discuss the chemical mechanisms used by lignin-degrading enzymes and microbes to break down lignin, and to describe current methods for generating aromatic bioproducts from lignin using enzymes and engineered microbes.
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Affiliation(s)
- Timothy D H Bugg
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK.
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2
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Thiol Reductases in Deinococcus Bacteria and Roles in Stress Tolerance. Antioxidants (Basel) 2022; 11:antiox11030561. [PMID: 35326211 PMCID: PMC8945050 DOI: 10.3390/antiox11030561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/11/2022] [Accepted: 03/13/2022] [Indexed: 12/10/2022] Open
Abstract
Deinococcus species possess remarkable tolerance to extreme environmental conditions that generate oxidative damage to macromolecules. Among enzymes fulfilling key functions in metabolism regulation and stress responses, thiol reductases (TRs) harbour catalytic cysteines modulating the redox status of Cys and Met in partner proteins. We present here a detailed description of Deinococcus TRs regarding gene occurrence, sequence features, and physiological functions that remain poorly characterised in this genus. Two NADPH-dependent thiol-based systems are present in Deinococcus. One involves thioredoxins, disulfide reductases providing electrons to protein partners involved notably in peroxide scavenging or in preserving protein redox status. The other is based on bacillithiol, a low-molecular-weight redox molecule, and bacilliredoxin, which together protect Cys residues against overoxidation. Deinococcus species possess various types of thiol peroxidases whose electron supply depends either on NADPH via thioredoxins or on NADH via lipoylated proteins. Recent data gained on deletion mutants confirmed the importance of TRs in Deinococcus tolerance to oxidative treatments, but additional investigations are needed to delineate the redox network in which they operate, and their precise physiological roles. The large palette of Deinococcus TR representatives very likely constitutes an asset for the maintenance of redox homeostasis in harsh stress conditions.
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3
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Rashid GMM, Bugg TDH. Enhanced biocatalytic degradation of lignin using combinations of lignin-degrading enzymes and accessory enzymes. Catal Sci Technol 2021. [DOI: 10.1039/d1cy00431j] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Combinations of lignin-oxidizing enzymes and accessory enzymes show enhanced activity for product formation from polymeric lignin.
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4
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Ren X, Zou L, Holmgren A. Targeting Bacterial Antioxidant Systems for Antibiotics Development. Curr Med Chem 2020; 27:1922-1939. [PMID: 31589114 DOI: 10.2174/0929867326666191007163654] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 09/18/2018] [Accepted: 12/13/2018] [Indexed: 12/15/2022]
Abstract
The emergence of multidrug-resistant bacteria has become an urgent issue in modern medicine which requires novel strategies to develop antibiotics. Recent studies have supported the hypothesis that antibiotic-induced bacterial cell death is mediated by Reactive Oxygen Species (ROS). The hypothesis also highlighted the importance of antioxidant systems, the defense mechanism which contributes to antibiotic resistance. Thioredoxin and glutathione systems are the two major thiol-dependent systems which not only provide antioxidant capacity but also participate in various biological events in bacteria, such as DNA synthesis and protein folding. The biological importance makes them promising targets for novel antibiotics development. Based on the idea, ebselen and auranofin, two bacterial thioredoxin reductase inhibitors, have been found to inhibit the growth of bacteria lacking the GSH efficiently. A recent study combining ebselen and silver exhibited a strong synergistic effect against Multidrug-Resistant (MDR) Gram-negative bacteria which possess both thioredoxin and glutathione systems. These drug-repurposing studies are promising for quick clinical usage due to their well-known profile.
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Affiliation(s)
- Xiaoyuan Ren
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Lili Zou
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden.,Translational Neuroscience & Neural Regeneration and Repair Institute/ Institute of Cell Therapy, The First Hospital of Yichang, Three Gorges University, 443000 Yichang, China
| | - Arne Holmgren
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
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5
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Zhang H, Wang Z, Huang J, Cao J, Zhou Y, Zhou J. A Novel Thioredoxin-Dependent Peroxiredoxin (TPx-Q) Plays an Important Role in Defense Against Oxidative Stress and Is a Possible Drug Target in Babesia microti. Front Vet Sci 2020; 7:76. [PMID: 32133382 PMCID: PMC7040034 DOI: 10.3389/fvets.2020.00076] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 01/29/2020] [Indexed: 01/03/2023] Open
Abstract
Thioredoxin peroxidases (TPxs) are ubiquitous cysteine-based peroxidases that reduce peroxides as part of antioxidant defenses and redox signaling and are essential for Babesia microti protection against adverse environment agents like reactive oxygen species (ROS) and reactive nitrogen species (RNS). To better systematically understand TPxs, we identified a novel 2-Cys peroxiredoxin-Q (BmTPx-Q) of B. microti. The full-length BmTPx-Q gene is 653 bp that consists of an intact open reading frame of 594 bp that encodes a 197-amino acid protein. The predicted protein has a molecular weight of 22.3 kDa and an isoelectric point of 9.18. Moreover, BmTPx-Q showed low identity at the amino acid level to other peroxiredoxins (Prxs) among the currently known subfamilies. The recombinant BmTPx-Q protein (rBmTPx-Q) was expressed in Escherichia coli and purified with beads. The native protein BmTPx-Q was detected using mouse anti-BmTPx-Q polyclonal serum with western blotting and indirect immunofluorescence assay (IFA). In addition, enzyme activity was observed using nicotinamide adenine dinucleotide phosphate (NADPH) as substrate and triggered the NADPH-dependent reduction of the Trx/TrxR system. It was also discovered that BmTPx-Q mainly exists as a monomer whether under its native or functional states. In addition, when incubated with Chloroquine diphosphate salt for 24 h in vitro, the expression of BmTPx-Q showed a marked downward trend with the increase of drug concentration. These results suggest that B. microti uses BmTPx-Q to reduce and detoxify hydrogen peroxides to survive and proliferate inside the host. Furthermore, BmTPx-Q showed the lowest identity with host enzymes and could be a potential drug target for the development of novel strategies to control B. microti infection.
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Affiliation(s)
- Houshuang Zhang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Zhonghua Wang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Jingwei Huang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Jie Cao
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yongzhi Zhou
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Jinlin Zhou
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
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6
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Riediger M, Kadowaki T, Nagayama R, Georg J, Hihara Y, Hess WR. Biocomputational Analyses and Experimental Validation Identify the Regulon Controlled by the Redox-Responsive Transcription Factor RpaB. iScience 2019; 15:316-331. [PMID: 31103851 PMCID: PMC6525291 DOI: 10.1016/j.isci.2019.04.033] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 04/05/2019] [Accepted: 04/24/2019] [Indexed: 11/24/2022] Open
Abstract
Oxygenic photosynthesis requires the coordination of environmental stimuli with the regulation of transcription. The transcription factor RpaB is conserved from the simplest unicellular cyanobacteria to complex eukaryotic algae, representing more than 1 billion years of evolution. To predict the RpaB-controlled regulon in the cyanobacterium Synechocystis, we analyzed the positional distribution of binding sites together with high-resolution mapping data of transcriptional start sites (TSSs). We describe more than 150 target promoters whose activity responds to fluctuating light conditions. Binding sites close to the TSS mediate repression, whereas sites centered ∼50 nt upstream mediate activation. Using complementary experimental approaches, we found that RpaB controls genes involved in photoprotection, cyclic electron flow and state transitions, photorespiration, and nirA and isiA for which we suggest cross-regulation with the transcription factors NtcA or FurA. The deep integration of RpaB with diverse photosynthetic gene functions makes it one of the most important and versatile transcriptional regulators. RpaB controls a complex regulon, widely beyond the photosynthetic machinery The expression of the RNA regulators IsrR, PsrR1, and others depends on RpaB RpaB exhibits cross-regulations with other transcription factors, NtcA and Fur RpaB is a crucial transcriptional regulator in a photosynthetic microorganism
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Affiliation(s)
- Matthias Riediger
- Genetics & Experimental Bioinformatics, Institute of Biology III, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Taro Kadowaki
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Ryuta Nagayama
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Jens Georg
- Genetics & Experimental Bioinformatics, Institute of Biology III, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Yukako Hihara
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan.
| | - Wolfgang R Hess
- Genetics & Experimental Bioinformatics, Institute of Biology III, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany; Freiburg Institute for Advanced Studies, University of Freiburg, Albertstr. 19, 79104 Freiburg, Germany.
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7
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Mehta K, Jaiswal D, Nayak M, Prasannan CB, Wangikar PP, Srivastava S. Elevated carbon dioxide levels lead to proteome-wide alterations for optimal growth of a fast-growing cyanobacterium, Synechococcus elongatus PCC 11801. Sci Rep 2019; 9:6257. [PMID: 31000743 PMCID: PMC6472392 DOI: 10.1038/s41598-019-42576-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 03/29/2019] [Indexed: 12/21/2022] Open
Abstract
The environmental considerations attributing to the escalation of carbon dioxide emissions have raised alarmingly. Consequently, the concept of sequestration and biological conversion of CO2 by photosynthetic microorganisms is gaining enormous recognition. In this study, in an attempt to discern the synergistic CO2 tolerance mechanisms, metabolic responses to increasing CO2 concentrations were determined for Synechococcus elongatus PCC 11801, a fast-growing, novel freshwater strain, using quantitative proteomics. The protein expression data revealed that the organism responded to elevated CO2 by not only regulating the cellular transporters involved in carbon-nitrogen uptake and assimilation but also by inducing photosynthesis, carbon fixation and glycolysis. Several components of photosynthetic machinery like photosystem reaction centers, phycobilisomes, cytochromes, etc. showed a marked up-regulation with a concomitant downshift in proteins involved in photoprotection and redox maintenance. Additionally, enzymes belonging to the TCA cycle and oxidative pentose phosphate pathway exhibited a decline in their expression, further highlighting that the demand for reduced cofactors was fulfilled primarily through photosynthesis. The present study brings the first-ever comprehensive assessment of intricate molecular changes in this novel strain while shifting from carbon-limited to carbon-sufficient conditions and may pave the path for future host and pathway engineering for production of sustainable fuels through efficient CO2 capture.
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Affiliation(s)
- Kanika Mehta
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Damini Jaiswal
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Monalisha Nayak
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Charulata B Prasannan
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.,DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Pramod P Wangikar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.,DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.,Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Sanjeeva Srivastava
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India. .,DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India. .,Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
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8
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Liu X, Qiu W, Rao B, Cao Y, Fang X, Yang J, Jiang G, Zhong Z, Zhu J. Bacterioferritin comigratory protein is important in hydrogen peroxide resistance, nodulation, and nitrogen fixation in Azorhizobium caulinodans. Arch Microbiol 2019; 201:823-831. [PMID: 30953092 DOI: 10.1007/s00203-019-01654-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/16/2019] [Accepted: 03/22/2019] [Indexed: 12/01/2022]
Abstract
Reactive oxygen species are not only harmful for rhizobia but also required for the establishment of symbiotic interactions between rhizobia and their legume hosts. In this work, we first investigated the preliminary role of the bacterioferritin comigratory protein (BCP), a member of the peroxiredoxin family, in the nitrogen-fixing bacterium Azorhizobium caulinodans. Our data revealed that the bcp-deficient strain of A. caulinodans displayed an increased sensitivity to inorganic hydrogen peroxide (H2O2) but not to two organic peroxides in a growth-phase-dependent manner. Meanwhile, BCP was found to be involved in catalase activity under relatively low H2O2 conditions. Furthermore, nodulation and N2 fixation were significantly impaired by mutation of the bcp gene in A. caulinodans. Our work initially documented the importance of BCP in the bacterial defence against H2O2 in the free-living stage of rhizobia and during their symbiotic interactions with legumes. Molecular signalling in vivo is required to decipher the holistic functions of BCP in A. caulinodans as well as in other rhizobia.
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Affiliation(s)
- Xiaomeng Liu
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, People's Republic of China
| | - Wei Qiu
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, People's Republic of China
| | - Bei Rao
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, People's Republic of China
| | - Yajun Cao
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, People's Republic of China
| | - Xingxing Fang
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, People's Republic of China
| | - Juan Yang
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, People's Republic of China
| | - Gaofei Jiang
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, National Engineering Research Center for Organic-based Fertilizers, Postdoctoral Station of Agricultural Resources and Environment, Nanjing Agricultural University, 210095, Nanjing, People's Republic of China.
| | - Zengtao Zhong
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, People's Republic of China.
| | - Jun Zhu
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, People's Republic of China
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9
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Superoxide Dismutase and Pseudocatalase Increase Tolerance to Hg(II) in Thermus thermophilus HB27 by Maintaining the Reduced Bacillithiol Pool. mBio 2019; 10:mBio.00183-19. [PMID: 30940703 PMCID: PMC6445937 DOI: 10.1128/mbio.00183-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thermus thermophilus is a deep-branching thermophilic aerobe. It is a member of the Deinococcus-Thermus phylum that, together with the Aquificae, constitute the earliest branching aerobic bacterial lineages; therefore, this organism serves as a model for early diverged bacteria (R. K. Hartmann, J. Wolters, B. Kröger, S. Schultze, et al., Syst Appl Microbiol 11:243–249, 1989, https://doi.org/10.1016/S0723-2020(89)80020-7) whose natural heated habitat may contain mercury of geological origins (G. G. Geesey, T. Barkay, and S. King, Sci Total Environ 569-570:321–331, 2016, https://doi.org/10.1016/j.scitotenv.2016.06.080). T. thermophilus likely arose shortly after the oxidation of the biosphere 2.4 billion years ago. Studying T. thermophilus physiology provides clues about the origin and evolution of mechanisms for mercury and oxidative stress responses, the latter being critical for the survival and function of all extant aerobes. Mercury (Hg) is a widely distributed, toxic heavy metal with no known cellular role. Mercury toxicity has been linked to the production of reactive oxygen species (ROS), but Hg does not directly perform redox chemistry with oxygen. How exposure to the ionic form, Hg(II), generates ROS is unknown. Exposure of Thermus thermophilus to Hg(II) triggered ROS accumulation and increased transcription and activity of superoxide dismutase (Sod) and pseudocatalase (Pcat); however, Hg(II) inactivated Sod and Pcat. Strains lacking Sod or Pcat had increased oxidized bacillithiol (BSH) levels and were more sensitive to Hg(II) than the wild type. The ΔbshA Δsod and ΔbshA Δpcat double mutant strains were as sensitive to Hg(II) as the ΔbshA strain that lacks bacillithiol, suggesting that the increased sensitivity to Hg(II) in the Δsod and Δpcat mutant strains is due to a decrease of reduced BSH. Treatment of T. thermophilus with Hg(II) decreased aconitase activity and increased the intracellular concentration of free Fe, and these phenotypes were exacerbated in Δsod and Δpcat mutant strains. Treatment with Hg(II) also increased DNA damage. We conclude that sequestration of the redox buffering thiol BSH by Hg(II), in conjunction with direct inactivation of ROS-scavenging enzymes, impairs the ability of T. thermophilus to effectively metabolize ROS generated as a normal consequence of growth in aerobic environments.
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10
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Cho C, Lee GW, Hong SH, Kaur S, Jung KW, Jung JH, Lim S, Chung BY, Lee SS. Novel functions of peroxiredoxin Q from Deinococcus radiodurans R1 as a peroxidase and a molecular chaperone. FEBS Lett 2018; 593:219-229. [PMID: 30488429 PMCID: PMC6590489 DOI: 10.1002/1873-3468.13302] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 11/14/2018] [Accepted: 11/15/2018] [Indexed: 12/02/2022]
Abstract
Deinococcus radiodurans R1 is extremely resistant to ionizing radiation and oxidative stress. In this study, we characterized DR0846, a candidate peroxiredoxin in D. radiodurans. DR0846 is a peroxiredoxin Q containing two conserved cysteine residues. DR0846 exists mainly in monomeric form with an intramolecular disulfide bond between the two cysteine residues. We found that DR0846 functions as a molecular chaperone as well as a peroxidase. A mutational analysis indicates that the two cysteine residues are essential for enzymatic activity. A double‐deletion mutant lacking DR0846 and catalase DR1998 exhibits decreased oxidative and heat shock stress tolerance with respect to the single mutants or the wild‐type cells. These results suggest that DR0846 contributes to resistance against oxidative and heat stresses in D. radiodurans.
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Affiliation(s)
- Chuloh Cho
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Korea
| | | | - Sung H Hong
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Korea
| | - Shubhpreet Kaur
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Korea
| | - Kwang-Woo Jung
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Korea
| | - Jong-Hyun Jung
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Korea.,Department of Radiation Biotechnology and Applied Radioisotope, Korea University of Science and Technology, Daejeon, Korea
| | - Sangyong Lim
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Korea.,Department of Radiation Biotechnology and Applied Radioisotope, Korea University of Science and Technology, Daejeon, Korea
| | - Byung Yeoup Chung
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Korea
| | - Seung Sik Lee
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Korea.,Department of Radiation Biotechnology and Applied Radioisotope, Korea University of Science and Technology, Daejeon, Korea
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11
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Su T, Si M, Zhao Y, Liu Y, Yao S, Che C, Chen C. A thioredoxin-dependent peroxiredoxin Q from Corynebacterium glutamicum plays an important role in defense against oxidative stress. PLoS One 2018; 13:e0192674. [PMID: 29438446 PMCID: PMC5811025 DOI: 10.1371/journal.pone.0192674] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 01/29/2018] [Indexed: 02/07/2023] Open
Abstract
Peroxiredoxin Q (PrxQ) that belonged to the cysteine-based peroxidases has long been identified in numerous bacteria, but the information on the physiological and biochemical functions of PrxQ remain largely lacking in Corynebacterium glutamicum. To better systematically understand PrxQ, we reported that PrxQ from model and important industrial organism C. glutamicum, encoded by the gene ncgl2403 annotated as a putative PrxQ, played important roles in adverse stress resistance. The lack of C. glutamicum prxQ gene resulted in enhanced cell sensitivity, increased ROS accumulation, and elevated protein carbonylation levels under adverse stress conditions. Accordingly, PrxQ-mediated resistance to adverse stresses mainly relied on the degradation of ROS. The physiological roles of PrxQ in resistance to adverse stresses were corroborated by its induced expression under adverse stresses, regulated directly by the stress-responsive ECF-sigma factor SigH. Through catalytical kinetic activity, heterodimer formation, and bacterial two-hybrid analysis, we proved that C. glutamicum PrxQ catalytically eliminated peroxides by exclusively receiving electrons from thioredoxin (Trx)/thioredoxin reductase (TrxR) system and had a broad range of oxidizing substrates, but a better efficiency for peroxynitrite and cumene hydroperoxide (CHP). Site-directed mutagenesis confirmed that the conserved Cys49 and Cys54 are the peroxide oxidation site and the resolving Cys residue, respectively. It was also discovered that C. glutamicum PrxQ mainly existed in monomer whether under its native state or functional state. Based on these results, a catalytic model of PrxQ is being proposed. Moreover, our result that C. glutamicum PrxQ can prevent the damaging effects of adverse stresses by acting as thioredoxin-dependent monomeric peroxidase could be further applied to improve the survival ability and robustness of the important bacterium during fermentation process.
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Affiliation(s)
- Tao Su
- College of Life Sciences, Qufu Normal University, Qufu, Shandong, China
| | - Meiru Si
- College of Life Sciences, Qufu Normal University, Qufu, Shandong, China
| | - Yunfeng Zhao
- College of Life Sciences, Qufu Normal University, Qufu, Shandong, China
| | - Yan Liu
- School of Geography And Tourism, Qufu Normal University, Rizhao, Shandong, China
| | - Shumin Yao
- College of Life Sciences, Qufu Normal University, Qufu, Shandong, China
| | - Chengchuan Che
- College of Life Sciences, Qufu Normal University, Qufu, Shandong, China
| | - Can Chen
- College of Life Science and Agronomy, Zhoukou Normal University, Zhoukou, Henan, China
- * E-mail:
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12
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Nitrosative stress defences of the enterohepatic pathogenic bacterium Helicobacter pullorum. Sci Rep 2017; 7:9909. [PMID: 28855660 PMCID: PMC5577044 DOI: 10.1038/s41598-017-10375-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 08/07/2017] [Indexed: 01/28/2023] Open
Abstract
Helicobacter pullorum is an avian bacterium that causes gastroenteritis, intestinal bowel and hepatobiliary diseases in humans. Although H. pullorum has been shown to activate the mammalian innate immunity with release of nitric oxide (NO), the proteins that afford protection against NO and reactive nitrogen species (RNS) remain unknown. Here several protein candidates of H. pullorum, namely a truncated (TrHb) and a single domain haemoglobin (SdHb), and three peroxiredoxin-like proteins (Prx1, Prx2 and Prx3) were investigated. We report that the two haemoglobin genes are induced by RNS, and that SdHb confers resistance to nitrosative stress both in vitro and in macrophages. For peroxiredoxins, the prx2 and prx3 expression is enhanced by peroxynitrite and hydrogen peroxide, respectively. Mutation of prx1 does not alter the resistance to these stresses, while the single ∆prx2 and double ∆prx1∆prx2 mutants have decreased viability. To corroborate the physiological data, the biochemical analysis of the five recombinant enzymes was done, namely by stopped-flow spectrophotometry. It is shown that H. pullorum SdHb reacts with NO much more quickly than TrHb, and that the three Prxs react promptly with peroxynitrite, Prx3 displaying the highest reactivity. Altogether, the results unveil SdHb and Prx3 as major protective systems of H. pullorum against nitrosative stress.
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13
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Lee S, Jeong H, Lee JH, Chung JM, Kim R, Yun HJ, Won J, Jung HS. Characterisation of conformational and functional features of alkyl hydroperoxide reductase E-like protein. Biochem Biophys Res Commun 2017; 489:217-222. [PMID: 28551405 DOI: 10.1016/j.bbrc.2017.05.135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 05/23/2017] [Indexed: 11/25/2022]
Abstract
Alkyl hydroperoxide reductase E (AhpE) is a member of the peroxidase family of enzymes that catalyse the reduction of peroxides, however its structural and functional roles are still unclear in details. In this study, we used the Thermococcus kodakarensis AhpE-like protein as a model to investigate structure-function relationships including the molecular properties of DNA binding activity. Multiple sequence alignment, structural comparison and biochemical analyses revealed that TkAhpE includes conserved peroxidase residues in the active site, and exhibits peroxidase activity with structure-dependent holdase chaperone function. Following electrophoretic mobility shift assays and electron microscopy analysis demonstrated distinctive binding features of TkAhpE to the DNA showing that their dimeric conformer can bind to the double-stranded DNA, but not to the single-stranded DNA, indicating its striking molecular features to double-stranded DNA-specific interactions. Based on our results, we provided that TkAhpE is a multifunctional peroxidase displaying structure-dependent molecular chaperone and DNA binding activities.
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Affiliation(s)
- Sangmin Lee
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon-si, Gangwon-do, 24341, Republic of Korea.
| | - Hyeongseop Jeong
- Center for Electron Microscopy Research, Korea Basic Science Institute 161, Yeongudanji-ro, Ochang-eup, Chengwon-gu, Chengju-si, Chungchengbuk-do, 28119, Republic of Korea
| | - Ju Huck Lee
- Korean Collection for Type Cultures, Korea Research Institute of Bioscience and Biotechnology, 181 Ipsin-gil, Jeongeup-si, Jeollabuk-do 56212, Republic of Korea
| | - Jeong Min Chung
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon-si, Gangwon-do, 24341, Republic of Korea
| | - Rumi Kim
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon-si, Gangwon-do, 24341, Republic of Korea
| | - Hyung Joong Yun
- Advanced Nano Surface Research Group, Korea Basic Science Institute, 169-148 Gwahak-ro, Daejeon, 34133, Republic of Korea
| | - Jonghan Won
- Advanced Nano Surface Research Group, Korea Basic Science Institute, 169-148 Gwahak-ro, Daejeon, 34133, Republic of Korea
| | - Hyun Suk Jung
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon-si, Gangwon-do, 24341, Republic of Korea.
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Tailor V, Ballal A. Novel molecular insights into the function and the antioxidative stress response of a Peroxiredoxin Q protein from cyanobacteria. Free Radic Biol Med 2017; 106:278-287. [PMID: 28159708 DOI: 10.1016/j.freeradbiomed.2017.01.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 01/18/2017] [Accepted: 01/20/2017] [Indexed: 12/11/2022]
Abstract
The Peroxiredoxin Q (PrxQ) proteins are thiol-based peroxidases that are important for maintaining redox homeostasis in several organisms. Activity of PrxQs is mediated by two cysteines, peroxidatic (Cp) and resolving (Cr), in association with a reducing partner. A PrxQ, Alr3183, from the cyanobacterium, Anabaena PCC 7120, was characterized in this study. Alr3183, which required thioredoxin A (TrxA) for peroxidase activity, was an intramolecular disulfide bond-containing monomeric protein. However, Alr3183 lacking Cp (Alr3183C46S) or Cr (Alr3183C51S) formed intermolecular disulfide linkages and was dimeric. Alr3183C46S was completely inactive, while Alr3183C51S required higher concentration of TrxA for peroxidase activity. Surface plasmon resonance analysis showed that unlike Alr3183 or Alr3183C46S, Alr3183C51S bound rather poorly to TrxA. Also, compared to the oxidized protein, the DTT-treated (reduced) Alr3183 displayed decreased interaction with TrxA. In vivo, Alr3183 was found to be induced in response to γ-radiation. On exposure to H2O2, Anabaena strain over-expressing Alr3183 showed reduced formation of ROS, intact photosynthetic pigments and consequently better survival than the wild-type, whereas overproduction of Alr3183C46S did not provide any protection. Significantly, this study (1) reveals the importance of Cr for interaction with thioredoxins and (2) demonstrates that over-expression of PrxQs can protect cyanobacteria from oxidative stresses.
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Affiliation(s)
- Vijay Tailor
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushakti Nagar, Mumbai 400094, India.
| | - Anand Ballal
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushakti Nagar, Mumbai 400094, India.
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15
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Reyes AM, Vazquez DS, Zeida A, Hugo M, Piñeyro MD, De Armas MI, Estrin D, Radi R, Santos J, Trujillo M. PrxQ B from Mycobacterium tuberculosis is a monomeric, thioredoxin-dependent and highly efficient fatty acid hydroperoxide reductase. Free Radic Biol Med 2016; 101:249-260. [PMID: 27751911 DOI: 10.1016/j.freeradbiomed.2016.10.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 09/16/2016] [Accepted: 10/06/2016] [Indexed: 12/23/2022]
Abstract
Mycobacterium tuberculosis (M. tuberculosis) is the intracellular bacterium responsible for tuberculosis disease (TD). Inside the phagosomes of activated macrophages, M. tuberculosis is exposed to cytotoxic hydroperoxides such as hydrogen peroxide, fatty acid hydroperoxides and peroxynitrite. Thus, the characterization of the bacterial antioxidant systems could facilitate novel drug developments. In this work, we characterized the product of the gene Rv1608c from M. tuberculosis, which according to sequence homology had been annotated as a putative peroxiredoxin of the peroxiredoxin Q subfamily (PrxQ B from M. tuberculosis or MtPrxQ B). The protein has been reported to be essential for M. tuberculosis growth in cholesterol-rich medium. We demonstrated the M. tuberculosis thioredoxin B/C-dependent peroxidase activity of MtPrxQ B, which acted as a two-cysteine peroxiredoxin that could function, although less efficiently, using a one-cysteine mechanism. Through steady-state and competition kinetic analysis, we proved that the net forward rate constant of MtPrxQ B reaction was 3 orders of magnitude faster for fatty acid hydroperoxides than for hydrogen peroxide (3×106vs 6×103M-1s-1, respectively), while the rate constant of peroxynitrite reduction was (0.6-1.4) ×106M-1s-1 at pH 7.4. The enzyme lacked activity towards cholesterol hydroperoxides solubilized in sodium deoxycholate. Both thioredoxin B and C rapidly reduced the oxidized form of MtPrxQ B, with rates constants of 0.5×106 and 1×106M-1s-1, respectively. Our data indicated that MtPrxQ B is monomeric in solution both under reduced and oxidized states. In spite of the similar hydrodynamic behavior the reduced and oxidized forms of the protein showed important structural differences that were reflected in the protein circular dichroism spectra.
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Affiliation(s)
- Aníbal M Reyes
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; Center for Free Radical and Biomedical Research, Universidad de la República, Montevideo, Uruguay
| | - Diego S Vazquez
- Instituto de Química y Físicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Universidad de Buenos Aires and CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Ari Zeida
- Departamento de Química Inorgánica, Analítica y Química-Física and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Martín Hugo
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; Center for Free Radical and Biomedical Research, Universidad de la República, Montevideo, Uruguay
| | - M Dolores Piñeyro
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; Unidad de Biología Molecular-Institut Pasteur Montevideo, Montevideo, Uruguay
| | - María Inés De Armas
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; Center for Free Radical and Biomedical Research, Universidad de la República, Montevideo, Uruguay
| | - Darío Estrin
- Departamento de Química Inorgánica, Analítica y Química-Física and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Rafael Radi
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; Center for Free Radical and Biomedical Research, Universidad de la República, Montevideo, Uruguay
| | - Javier Santos
- Instituto de Química y Físicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Universidad de Buenos Aires and CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Madia Trujillo
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; Center for Free Radical and Biomedical Research, Universidad de la República, Montevideo, Uruguay.
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16
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Lee S, Chung JM, Yun HJ, Won J, Jung HS. New insight into multifunctional role of peroxiredoxin family protein: Determination of DNA protection properties of bacterioferritin comigratory protein under hyperthermal and oxidative stresses. Biochem Biophys Res Commun 2016; 469:1028-33. [DOI: 10.1016/j.bbrc.2015.12.099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 12/22/2015] [Indexed: 10/22/2022]
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17
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18
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Wallock-Richards D, Doherty CJ, Doherty L, Clarke DJ, Place M, Govan JRW, Campopiano DJ. Garlic revisited: antimicrobial activity of allicin-containing garlic extracts against Burkholderia cepacia complex. PLoS One 2014; 9:e112726. [PMID: 25438250 PMCID: PMC4249831 DOI: 10.1371/journal.pone.0112726] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 10/14/2014] [Indexed: 12/30/2022] Open
Abstract
The antimicrobial activities of garlic and other plant alliums are primarily based on allicin, a thiosulphinate present in crushed garlic bulbs. We set out to determine if pure allicin and aqueous garlic extracts (AGE) exhibit antimicrobial properties against the Burkholderia cepacia complex (Bcc), the major bacterial phytopathogen for alliums and an intrinsically multiresistant and life-threatening human pathogen. We prepared an AGE from commercial garlic bulbs and used HPLC to quantify the amount of allicin therein using an aqueous allicin standard (AAS). Initially we determined the minimum inhibitory concentrations (MICs) of the AGE against 38 Bcc isolates; these MICs ranged from 0.5 to 3% (v/v). The antimicrobial activity of pure allicin (AAS) was confirmed by MIC and minimum bactericidal concentration (MBC) assays against a smaller panel of five Bcc isolates; these included three representative strains of the most clinically important species, B. cenocepacia. Time kill assays, in the presence of ten times MIC, showed that the bactericidal activity of AGE and AAS against B. cenocepacia C6433 correlated with the concentration of allicin. We also used protein mass spectrometry analysis to begin to investigate the possible molecular mechanisms of allicin with a recombinant form of a thiol-dependent peroxiredoxin (BCP, Prx) from B. cenocepacia. This revealed that AAS and AGE modifies an essential BCP catalytic cysteine residue and suggests a role for allicin as a general electrophilic reagent that targets protein thiols. To our knowledge, we report the first evidence that allicin and allicin-containing garlic extracts possess inhibitory and bactericidal activities against the Bcc. Present therapeutic options against these life-threatening pathogens are limited; thus, allicin-containing compounds merit investigation as adjuncts to existing antibiotics.
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Affiliation(s)
- Daynea Wallock-Richards
- EastChem School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, United Kingdom
| | - Catherine J. Doherty
- University of Edinburgh Medical School, Little France Crescent, Edinburgh, United Kingdom
| | - Lynsey Doherty
- University of Edinburgh Medical School, Little France Crescent, Edinburgh, United Kingdom
| | - David J. Clarke
- EastChem School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, United Kingdom
| | - Marc Place
- University of Edinburgh Medical School, Little France Crescent, Edinburgh, United Kingdom
| | - John R. W. Govan
- University of Edinburgh Medical School, Little France Crescent, Edinburgh, United Kingdom
- * E-mail: (JRWG); (D. Campopiano)
| | - Dominic J. Campopiano
- EastChem School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, United Kingdom
- * E-mail: (JRWG); (D. Campopiano)
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19
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Lim JG, Bang YJ, Choi SH. Characterization of the Vibrio vulnificus 1-Cys peroxiredoxin Prx3 and regulation of its expression by the Fe-S cluster regulator IscR in response to oxidative stress and iron starvation. J Biol Chem 2014; 289:36263-74. [PMID: 25398878 DOI: 10.1074/jbc.m114.611020] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Peroxiredoxins (Prxs) are ubiquitous antioxidant enzymes that reduce toxic peroxides. A new Vibrio vulnificus Prx, named Prx3, was identified and characterized in this study. Biochemical and mutational analyses revealed that Prx3 reduces H2O2, utilizing glutaredoxin 3 (Grx3) and glutathione (GSH) as reductants, and requires only N-terminal peroxidatic cysteine for its catalysis. These results, combined with the monomeric size of Prx3 observed under non-reducing conditions, suggested that Prx3 is a Grx3/GSH-dependent 1-Cys Prx and oxidized without forming intermolecular disulfide bonds. The prx3 mutation impaired growth in the medium containing peroxides and reduced virulence in mice, indicating that Prx3 is essential for survival under oxidative stress and pathogenesis of V. vulnificus. The Fe-S cluster regulator IscR activates prx3 by direct binding to a specific binding sequence centered at -44 from the transcription start site. The binding sequence was homologous to the Type 2 IscR-binding sequence, most likely recognized by the Fe-S clusterless apo-IscR in Escherichia coli. The iscR3CA mutant, chromosomally encoding the apo-locked IscR, exhibited 3-fold higher levels of activation of prx3 than the wild type and accumulated more IscR3CA protein in cells. The IscR-dependent activation of prx3 by aerobic growth and iron starvation was also associated with the increase in cellular levels of IscR protein. Taken together, the results suggested that IscR senses iron starvation as well as reactive oxygen species and shifts to the apo-form, which leads to the increase of cellular IscR and in turn prx3 expression, contributing to the survival and virulence of V. vulnificus during pathogenesis.
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Affiliation(s)
- Jong Gyu Lim
- From the National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, South Korea
| | - Ye-Ji Bang
- From the National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, South Korea
| | - Sang Ho Choi
- From the National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, South Korea
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20
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Couturier J, Prosper P, Winger AM, Hecker A, Hirasawa M, Knaff DB, Gans P, Jacquot JP, Navaza A, Haouz A, Rouhier N. In the absence of thioredoxins, what are the reductants for peroxiredoxins in Thermotoga maritima? Antioxid Redox Signal 2013; 18:1613-22. [PMID: 22866991 PMCID: PMC3613187 DOI: 10.1089/ars.2012.4739] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Three peroxiredoxins (Prxs) were identified in Thermotoga maritima, which possesses neither glutathione nor typical thioredoxins: one of the Prx6 class; one 2-Cys PrxBCP; and a unique hybrid protein containing an N-terminal 1-Cys PrxBCP domain fused to a flavin mononucleotide-containing nitroreductase (Ntr) domain. No peroxidase activity was detected for Prx6, whereas both bacterioferritin comigratory proteins (BCPs) were regenerated by a NADH/thioredoxin reductase/glutaredoxin (Grx)-like system, constituting a unique peroxide removal system. Only two of the three Grx-like proteins were able to support peroxidase activity. The inability of TmGrx1 to regenerate oxidized 2-Cys PrxBCP probably results from the thermodynamically unfavorable difference in their disulfide/dithiol E(m) values, -150 and -315 mV, respectively. Mutagenesis of the Prx-Ntr fusion, combined with kinetic and structural analyses, indicated that electrons are not transferred between its two domains. However, their separate activities could function in a complementary manner, with peroxide originating from the chromate reductase activity of the Ntr domain reduced by the Prx domain.
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Affiliation(s)
- Jérémy Couturier
- Unité Mixte de Recherches 1136 INRA-Lorraine Université, Interactions Arbres-Microorganismes, IFR 110, Faculté des Sciences, Vandoeuvre Cedex, France
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21
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Mallikarjun V, Clarke DJ, Campbell CJ. Cellular redox potential and the biomolecular electrochemical series: a systems hypothesis. Free Radic Biol Med 2012; 53:280-8. [PMID: 22609360 DOI: 10.1016/j.freeradbiomed.2012.04.034] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Revised: 04/26/2012] [Accepted: 04/28/2012] [Indexed: 01/21/2023]
Abstract
The role of cellular redox potential in the regulation of protein activity is becoming increasingly appreciated and characterized. In this paper we put forward a new hypothesis relating to redox regulation of cellular physiology. We have exemplified our hypothesis using apoptosis since its redox phenomenology is well established, but believe that it is equally applicable to several other pathways. Our hypothesis is that since multiple proteins in the apoptosis pathway are thought to be regulated via oxidation/reduction reactions and since cellular redox potentials have been shown to become progressively more oxidative during apoptosis, that the proteins could be arranged in an electrochemical series where the protein's standard potential correlates with its position in the pathway. Since the most stable oxidation state of the protein is determined by its standard potential and the redox potential of its environment (in a way predictable by the Nernst equation), a quantitative model of the redox regulation of the pathway could be developed. We have outlined our hypothesis, illustrating it using a pathway map which assembles a selection of the literature on apoptosis into a readable graphical format. We have also outlined experimental approaches suitable for testing our hypothesis.
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22
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Mishra S, Imlay J. Why do bacteria use so many enzymes to scavenge hydrogen peroxide? Arch Biochem Biophys 2012; 525:145-60. [PMID: 22609271 DOI: 10.1016/j.abb.2012.04.014] [Citation(s) in RCA: 258] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/13/2012] [Accepted: 04/14/2012] [Indexed: 12/16/2022]
Abstract
Hydrogen peroxide (H(2)O(2)) is continuously formed by the autoxidation of redox enzymes in aerobic cells, and it also enters from the environment, where it can be generated both by chemical processes and by the deliberate actions of competing organisms. Because H(2)O(2) is acutely toxic, bacteria elaborate scavenging enzymes to keep its intracellular concentration at nanomolar levels. Mutants that lack such enzymes grow poorly, suffer from high rates of mutagenesis, or even die. In order to understand how bacteria cope with oxidative stress, it is important to identify the key enzymes involved in H(2)O(2) degradation. Catalases and NADH peroxidase (Ahp) are primary scavengers in many bacteria, and their activities and physiological impacts have been unambiguously demonstrated through phenotypic analysis and through direct measurements of H(2)O(2) clearance in vivo. Yet a wide variety of additional enzymes have been proposed to serve similar roles: thiol peroxidase, bacterioferritin comigratory protein, glutathione peroxidase, cytochrome c peroxidase, and rubrerythrins. Each of these enzymes can degrade H(2)O(2) in vitro, but their contributions in vivo remain unclear. In this review we examine the genetic, genomic, regulatory, and biochemical evidence that each of these is a bonafide scavenger of H(2)O(2) in the cell. We also consider possible reasons that bacteria might require multiple enzymes to catalyze this process, including differences in substrate specificity, compartmentalization, cofactor requirements, kinetic optima, and enzyme stability. It is hoped that the resolution of these issues will lead to an understanding of stress resistance that is more accurate and perceptive.
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Affiliation(s)
- Surabhi Mishra
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
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23
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Reeves SA, Parsonage D, Nelson KJ, Poole LB. Kinetic and thermodynamic features reveal that Escherichia coli BCP is an unusually versatile peroxiredoxin. Biochemistry 2011; 50:8970-81. [PMID: 21910476 DOI: 10.1021/bi200935d] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In Escherichia coli, bacterioferritin comigratory protein (BCP) is a peroxiredoxin (Prx) that catalyzes the reduction of H(2)O(2) and organic hydroperoxides. This protein, along with plant PrxQ, is a founding member of one of the least studied subfamilies of Prxs. Recent structural data have suggested that proteins in the BCP/PrxQ group can exist as monomers or dimers; we report here that, by analytical ultracentrifugation, both oxidized and reduced E. coli BCP behave as monomers in solution at concentrations as high as 200 μM. Unexpectedly, thioredoxin (Trx1)-dependent peroxidase assays conducted by stopped-flow spectroscopy demonstrated that V(max,app) increases with increasing Trx1 concentrations, indicating a nonsaturable interaction (K(m) > 100 μM). At a physiologically reasonable Trx1 concentration of 10 μM, the apparent K(m) value for H(2)O(2) is ~80 μM, and overall, the V(max)/K(m) for H(2)O(2), which remains constant at the various Trx1 concentrations (consistent with a ping-pong mechanism), is ~1.3 × 10(4) M(-1) s(-1). Our kinetic analyses demonstrated that BCP can utilize a variety of reducing substrates, including Trx1, Trx2, Grx1, and Grx3. BCP exhibited a high redox potential of -145.9 ± 3.2 mV, the highest to date observed for a Prx. Moreover, BCP exhibited a broad peroxide specificity, with comparable rates for H(2)O(2) and cumene hydroperoxide. We determined a pK(a) of ~5.8 for the peroxidatic cysteine (Cys45) using both spectroscopic and activity titration data. These findings support an important role for BCP in interacting with multiple substrates and remaining active under highly oxidizing cellular conditions, potentially serving as a defense enzyme of last resort.
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Affiliation(s)
- Stacy A Reeves
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, USA
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24
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Abstract
Peroxiredoxins are cysteine-dependent peroxidases that react with hydrogen peroxide, larger hydroperoxide substrates, and peroxynitrite. Protocols are provided to measure Prx activity with peroxide by (1) a coupled reaction with NADPH, thioredoxin reductase, and thioredoxin, (2) the direct monitoring of thioredoxin oxidation, (3) competition with horseradish peroxidase, and (4) peroxide consumption using the FOX assay.
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Affiliation(s)
- Kimberly J. Nelson
- Dept. of Biochemistry, Wake Forest University School of Medicine Winston-Salem, NC 27157
| | - Derek Parsonage
- Dept. of Biochemistry, Wake Forest University School of Medicine Winston-Salem, NC 27157
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25
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Koerdt A, Orell A, Pham TK, Mukherjee J, Wlodkowski A, Karunakaran E, Biggs CA, Wright PC, Albers SV. Macromolecular fingerprinting of sulfolobus species in biofilm: a transcriptomic and proteomic approach combined with spectroscopic analysis. J Proteome Res 2011; 10:4105-19. [PMID: 21761944 PMCID: PMC3166137 DOI: 10.1021/pr2003006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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Microorganisms in nature often live in surface-associated sessile communities, encased in a self-produced matrix, referred to as biofilms. Biofilms have been well studied in bacteria but in a limited way for archaea. We have recently characterized biofilm formation in three closely related hyperthermophilic crenarchaeotes: Sulfolobus acidocaldarius, S. solfataricus, and S. tokodaii. These strains form different communities ranging from simple carpet structures in S. solfataricus to high density tower-like structures in S. acidocaldarius under static condition. Here, we combine spectroscopic, proteomic, and transcriptomic analyses to describe physiological and regulatory features associated with biofilms. Spectroscopic analysis reveals that in comparison to planktonic life-style, biofilm life-style has distinctive influence on the physiology of each Sulfolobus spp. Proteomic and transcriptomic data show that biofilm-forming life-style is strain specific (eg ca. 15% of the S. acidocaldarius genes were differently expressed, S. solfataricus and S. tokodaii had ∼3.4 and ∼1%, respectively). The -omic data showed that regulated ORFs were widely distributed in basic cellular functions, including surface modifications. Several regulated genes are common to biofilm-forming cells in all three species. One of the most striking common response genes include putative Lrs14-like transcriptional regulators, indicating their possible roles as a key regulatory factor in biofilm development. S. acidocaldarius, S. solfataricus, and S. tokodaii strains were grown independently as biofilms. Comparison between planktonic and biofilm cell popupations of all three strains was performed by spectroscopic analysis (FTIR and XPS), iTRAQ proteomics, and RNA microarrays. To highlight common features in biofilm formation among the Sulfolobus strains, the data is presented as a comparative analysis. One of the most striking common response genes include putative Lrs14-like transcriptional regulators, suggesting their roles as key regulatory factor in biofilm development.
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Affiliation(s)
- Andrea Koerdt
- Molecular Biology of Archaea, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse, 35043 Marburg, Germany
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