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Sourice M, Oriol C, Aubert C, Mandin P, Py B. Genetic dissection of the bacterial Fe-S protein biogenesis machineries. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119746. [PMID: 38719030 DOI: 10.1016/j.bbamcr.2024.119746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 04/12/2024] [Accepted: 05/03/2024] [Indexed: 05/13/2024]
Abstract
Iron‑sulfur (Fe-S) clusters are one of the most ancient and versatile inorganic cofactors present in the three domains of life. Fe-S clusters are essential cofactors for the activity of a large variety of metalloproteins that play crucial physiological roles. Fe-S protein biogenesis is a complex process that starts with the acquisition of the elements (iron and sulfur atoms) and their assembly into an Fe-S cluster that is subsequently inserted into the target proteins. The Fe-S protein biogenesis is ensured by multiproteic systems conserved across all domains of life. Here, we provide an overview on how bacterial genetics approaches have permitted to reveal and dissect the Fe-S protein biogenesis process in vivo.
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Affiliation(s)
- Mathieu Sourice
- Laboratoire de Chimie Bactérienne (UMR7283), Institut de Microbiologie de la Méditerranée, Institut Microbiologie Bioénergies et Biotechnologie, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France
| | - Charlotte Oriol
- Laboratoire de Chimie Bactérienne (UMR7283), Institut de Microbiologie de la Méditerranée, Institut Microbiologie Bioénergies et Biotechnologie, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France
| | - Corinne Aubert
- Laboratoire de Chimie Bactérienne (UMR7283), Institut de Microbiologie de la Méditerranée, Institut Microbiologie Bioénergies et Biotechnologie, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France
| | - Pierre Mandin
- Laboratoire de Chimie Bactérienne (UMR7283), Institut de Microbiologie de la Méditerranée, Institut Microbiologie Bioénergies et Biotechnologie, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France
| | - Béatrice Py
- Laboratoire de Chimie Bactérienne (UMR7283), Institut de Microbiologie de la Méditerranée, Institut Microbiologie Bioénergies et Biotechnologie, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France.
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Mettert EL, Kiley PJ. Fe-S cluster homeostasis and beyond: The multifaceted roles of IscR. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119749. [PMID: 38763301 DOI: 10.1016/j.bbamcr.2024.119749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 03/29/2024] [Accepted: 05/08/2024] [Indexed: 05/21/2024]
Abstract
The role of IscR in regulating the transcription of genes involved in Fe-S cluster homeostasis has been well established for the model organism Escherichia coli K12. In this bacterium, IscR coordinates expression of the Isc and Suf Fe-S cluster assembly pathways to meet cellular Fe-S cluster demands shaped by a variety of environmental cues. However, since its initial discovery nearly 25 years ago, there has been growing evidence that IscR function extends well beyond Fe-S cluster homeostasis, not only in E. coli, but in bacteria of diverse lifestyles. Notably, pathogenic bacteria have exploited the ability of IscR to respond to changes in oxygen tension, oxidative and nitrosative stress, and iron availability to navigate their trajectory in their respective hosts as changes in these cues are frequently encountered during host infection. In this review, we highlight these broader roles of IscR in different cellular processes and, in particular, discuss the importance of IscR as a virulence factor for many bacterial pathogens.
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Affiliation(s)
- Erin L Mettert
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Patricia J Kiley
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA.
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Chekli Y, Stevick RJ, Kornobis E, Briolat V, Ghigo JM, Beloin C. Escherichia coli Aggregates Mediated by Native or Synthetic Adhesins Exhibit Both Core and Adhesin-Specific Transcriptional Responses. Microbiol Spectr 2023; 11:e0069023. [PMID: 37039668 PMCID: PMC10269875 DOI: 10.1128/spectrum.00690-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 03/20/2023] [Indexed: 04/12/2023] Open
Abstract
Bacteria can rapidly tune their physiology and metabolism to adapt to environmental fluctuations. In particular, they can adapt their lifestyle to the close proximity of other bacteria or the presence of different surfaces. However, whether these interactions trigger transcriptomic responses is poorly understood. We used a specific setup of E. coli strains expressing native or synthetic adhesins mediating bacterial aggregation to study the transcriptomic changes of aggregated compared to nonaggregated bacteria. Our results show that, following aggregation, bacteria exhibit a core response independent of the adhesin type, with differential expression of 56.9% of the coding genome, including genes involved in stress response and anaerobic lifestyle. Moreover, when aggregates were formed via a naturally expressed E. coli adhesin (antigen 43), the transcriptomic response of the bacteria was more exaggerated than that of aggregates formed via a synthetic adhesin. This suggests that the response to aggregation induced by native E. coli adhesins could have been finely tuned during bacterial evolution. Our study therefore provides insights into the effect of self-interaction in bacteria and allows a better understanding of why bacterial aggregates exhibit increased stress tolerance. IMPORTANCE The formation of bacterial aggregates has an important role in both clinical and ecological contexts. Although these structures have been previously shown to be more resistant to stressful conditions, the genetic basis of this stress tolerance associated with the aggregate lifestyle is poorly understood. Surface sensing mediated by different adhesins can result in various changes in bacterial physiology. However, whether adhesin-adhesin interactions, as well as the type of adhesin mediating aggregation, affect bacterial cell physiology is unknown. By sequencing the transcriptomes of aggregated and nonaggregated cells expressing native or synthetic adhesins, we characterized the effects of aggregation and adhesin type on E. coli physiology.
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Affiliation(s)
- Yankel Chekli
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Genetics of Biofilms Laboratory, Paris, France
| | - Rebecca J. Stevick
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Genetics of Biofilms Laboratory, Paris, France
| | - Etienne Kornobis
- Hub de Bioinformatique et Biostatistique-Département Biologie Computationnelle, Institut Pasteur, USR 3756 CNRS, Paris, France
- Plate-forme Technologique Biomics—Centre de Ressources et Recherches Technologiques, Institut Pasteur, Paris, France
| | - Valérie Briolat
- Hub de Bioinformatique et Biostatistique-Département Biologie Computationnelle, Institut Pasteur, USR 3756 CNRS, Paris, France
- Plate-forme Technologique Biomics—Centre de Ressources et Recherches Technologiques, Institut Pasteur, Paris, France
| | - Jean-Marc Ghigo
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Genetics of Biofilms Laboratory, Paris, France
| | - Christophe Beloin
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Genetics of Biofilms Laboratory, Paris, France
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A Diverged Transcriptional Network for Usage of Two Fe-S Cluster Biogenesis Machineries in the Delta-Proteobacterium Myxococcus xanthus. mBio 2023; 14:e0300122. [PMID: 36656032 PMCID: PMC9973013 DOI: 10.1128/mbio.03001-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Myxococcus xanthus possesses two Fe-S cluster biogenesis machineries, ISC (iron-sulfur cluster) and SUF (sulfur mobilization). Here, we show that in comparison to the phylogenetically distant Enterobacteria, which also have both machineries, M. xanthus evolved an independent transcriptional scheme to coordinately regulate the expression of these machineries. This transcriptional response is directed by RisR, which we show to belong to a phylogenetically distant and biochemically distinct subgroup of the Rrf2 transcription factor family, in comparison to IscR that regulates the isc and suf operons in Enterobacteria. We report that RisR harbors an Fe-S cluster and that holo-RisR acts as a repressor of both the isc and suf operons, in contrast to Escherichia coli, where holo-IscR represses the isc operon whereas apo-IscR activates the suf operon. In addition, we establish that the nature of the cluster and the DNA binding sites of RisR, in the isc and suf operons, diverge from those of IscR. We further show that in M. xanthus, the two machineries appear to be fully interchangeable in maintaining housekeeping levels of Fe-S cluster biogenesis and in synthesizing the Fe-S cluster for their common regulator, RisR. We also demonstrate that in response to oxidative stress and iron limitation, transcriptional upregulation of the M. xanthus isc and suf operons was mediated solely by RisR and that the contribution of the SUF machinery was greater than the ISC machinery. Altogether, these findings shed light on the diversity of homeostatic mechanisms exploited by bacteria to coordinately use two Fe-S cluster biogenesis machineries. IMPORTANCE Fe-S proteins are ubiquitous and control a wide variety of key biological processes; therefore, maintaining Fe-S cluster homeostasis is an essential task for all organisms. Here, we provide the first example of how a bacterium from the Deltaproteobacteria branch coordinates expression of two Fe-S cluster biogenesis machineries. The results revealed a new model of coordination, highlighting the unique and common features that have independently emerged in phylogenetically distant bacteria to maintain Fe-S cluster homeostasis in response to environmental changes. Regulation is orchestrated by a previously uncharacterized transcriptional regulator, RisR, belonging to the Rrf2 superfamily, whose members are known to sense diverse environmental stresses frequently encountered by bacteria. Understanding how M. xanthus maintains Fe-S cluster homeostasis via RisR regulation revealed a strategy reflective of the aerobic lifestyle of this organsim. This new knowledge also paves the way to improve production of Fe-S-dependent secondary metabolites using M. xanthus as a chassis.
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Debbarma S, Acharya A, Mangang YA, Monsang SJ, Choudhury TG, Parhi J, Pandey PK. Immune-biochemical response and immune gene expression profiling of Labeo rohita fingerlings fed with ethanolic tea leaf extracts and its survivability against Aeromonas hydrophila infection. FISH & SHELLFISH IMMUNOLOGY 2022; 130:520-529. [PMID: 36167295 DOI: 10.1016/j.fsi.2022.09.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 08/21/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
The present study was conducted to evaluate the immunostimulatory effect of tea leaf extract (Camellia sinensis) on Labeo rohita and its resistance against Aeromonas hydrophila infection. The ethanolic extract of green tea (GTEE) was found to be the most potent as compared to other solvent extract which was used for further study. It was used to evaluate immune-biochemical response of L. rohita fingerlings, fed with tea leaf extract (control- 0.0%, 0.2% (T1), 0.4% (T2), 0.8% (T3) and 1% (T4) of GTEE kg-1 feed). Different biochemical parameters like glucose, ALP, GPT, GOT, and immunological parameters like lysozyme activity, NBT, anti-protease activity, myeloperoxidase activity, plasma protein, and immune relevant genes (IL-10, C3, Lysozyme G type and iNOS) expressions were carried out. The immunological parameters such as lysozyme activity, NBT and myeloperoxidase activity showed significantly high value once fed with GTEE incorporated diets. Significant up-regulation of immune genes indicated the enhancement of immune response at molecular level. The biochemical parameters were found to be significantly decreasing, indicating that the extract had hepato-protective effect and can help to overcome stress. The fish, fed with GTEE incorporated diets, showed resistance against A. hydrophila when compared with the control group. 0.2% GTEE showed the highest post-challenged survival (76.67%). From the present study, it is concluded that GTEE @ 0.2% can be used as potent immunostimulant as a sustainable alternative prophylactic and therapeutic agent in aquaculture.
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Affiliation(s)
- Sourabh Debbarma
- College of Fisheries, CAU, Lembucherra, Agartala, Tripura, 799210, India
| | - Arpit Acharya
- College of Fisheries, CAU, Lembucherra, Agartala, Tripura, 799210, India
| | | | | | | | - Janmejay Parhi
- College of Fisheries, CAU, Lembucherra, Agartala, Tripura, 799210, India
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Gupta A, Imlay JA. Escherichia coli induces DNA repair enzymes to protect itself from low-grade hydrogen peroxide stress. Mol Microbiol 2021; 117:754-769. [PMID: 34942039 DOI: 10.1111/mmi.14870] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/18/2021] [Accepted: 12/18/2021] [Indexed: 11/30/2022]
Abstract
E. coli responds to hydrogen peroxide (H2 O2 ) by inducing defenses that protect H2 O2 -sensitive enzymes. DNA is believed to be another important target of oxidation, and E. coli contains enzymes that can repair oxidative lesions in vitro. However, those enzymes are not known to be induced by H2 O2 , and experiments have indicated that they are not necessary for the cell to withstand natural (low-micromolar) concentrations. In this study we used H2 O2 -scavenging mutants to impose controlled doses of H2 O2 for extended time. Transcriptomic analysis revealed that in the presence of 1 µM cytoplasmic H2 O2 , the OxyR transcription factor induced xthA, encoding exonuclease III. The xthA mutants survived a conventional 15-minute exposure to even 100 times this level of H2 O2 . However, when these mutants were exposed to 1 µM H2 O2 for hours, they accumulated DNA lesions, failed to propagate, and eventually died. Although endonuclease III (nth) was not induced, nth mutants struggled to grow. Low-grade H2 O2 stress also activated the SOS regulon, and when this induction was blocked, cell replication stopped. Collectively, these data indicate that physiological levels of H2 O2 are a real threat to DNA, and the engagement of the base-excision-repair and SOS systems is necessary to enable propagation during protracted stress.
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Affiliation(s)
- Anshika Gupta
- Department of Microbiology, University of Illinois, 601 S. Goodwin Ave, Urbana, IL, 61801, USA
| | - James A Imlay
- Department of Microbiology, University of Illinois, 601 S. Goodwin Ave, Urbana, IL, 61801, USA
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Kim Y, Roe JH, Park JH, Cho YJ, Lee KL. Regulation of iron homeostasis by peroxide-sensitive CatR, a Fur-family regulator in Streptomyces coelicolor. J Microbiol 2021; 59:1083-1091. [PMID: 34865197 DOI: 10.1007/s12275-021-1457-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/08/2021] [Accepted: 10/20/2021] [Indexed: 11/30/2022]
Abstract
CatR, a peroxide-sensing transcriptional repressor of Fur family, can de-repress the transcription of the catA gene encoding catalase upon peroxide stress in Streptomyces coelicolor. Since CatR-regulated genes other than catA and its own gene catR have not been identified in detail, the understanding of the role of CatR regulon is very limited. In this study, we performed transcriptomic analysis to identify genes influenced by both ΔcatR mutation and hydrogen peroxide treatment. Through ChIP-qPCR and other analyses, a new consensus sequence was found in CatR-responsive promoter region of catR gene and catA operon for direct regulation. In addition, vtlA (SCO2027) and SCO4983 were identified as new members of the CatR regulon. Expression levels of iron uptake genes were reduced by hydrogen peroxide and a DmdR1 binding sequence was identified in promoters of these genes. The increase in free iron by hydrogen peroxide was thought to suppress the iron import system by DmdR1. A putative exporter protein VtlA regulated by CatR appeared to reduce intracellular iron to prevent oxidative stress. The name vtlA (VIT1-like transporter) was proposed for iron homeostasis related gene SCO2027.
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Affiliation(s)
- Yeonbum Kim
- Department of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jung-Hye Roe
- Department of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Joo-Hong Park
- Department of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Yong-Joon Cho
- Department of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea. .,The Research Institute of Basic Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
| | - Kang-Lok Lee
- Department of Biology Education, IALS, Gyeongsang National University, Jinju, 52828, Republic of Korea.
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Ling N, Ou D, Shen Y, Zhang D, Wang Y, Tong L, Ding Y, Wang J, Yang X, Zhang J, Wu Q, Ye Y. Proteomics analysis mediated by quorum sensing luxS involved in oxidative stress in Cronobacter malonaticus. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Das M, Dewan A, Shee S, Singh A. The Multifaceted Bacterial Cysteine Desulfurases: From Metabolism to Pathogenesis. Antioxidants (Basel) 2021; 10:antiox10070997. [PMID: 34201508 PMCID: PMC8300815 DOI: 10.3390/antiox10070997] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/01/2021] [Accepted: 05/06/2021] [Indexed: 12/02/2022] Open
Abstract
Living cells have developed a relay system to efficiently transfer sulfur (S) from cysteine to various thio-cofactors (iron-sulfur (Fe-S) clusters, thiamine, molybdopterin, lipoic acid, and biotin) and thiolated tRNA. The presence of such a transit route involves multiple protein components that allow the flux of S to be precisely regulated as a function of environmental cues to avoid the unnecessary accumulation of toxic concentrations of soluble sulfide (S2−). The first enzyme in this relay system is cysteine desulfurase (CSD). CSD catalyzes the release of sulfane S from L-cysteine by converting it to L-alanine by forming an enzyme-linked persulfide intermediate on its conserved cysteine residue. The persulfide S is then transferred to diverse acceptor proteins for its incorporation into the thio-cofactors. The thio-cofactor binding-proteins participate in essential and diverse cellular processes, including DNA repair, respiration, intermediary metabolism, gene regulation, and redox sensing. Additionally, CSD modulates pathogenesis, antibiotic susceptibility, metabolism, and survival of several pathogenic microbes within their hosts. In this review, we aim to comprehensively illustrate the impact of CSD on bacterial core metabolic processes and its requirement to combat redox stresses and antibiotics. Targeting CSD in human pathogens can be a potential therapy for better treatment outcomes.
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Sen A, Imlay JA. How Microbes Defend Themselves From Incoming Hydrogen Peroxide. Front Immunol 2021; 12:667343. [PMID: 33995399 PMCID: PMC8115020 DOI: 10.3389/fimmu.2021.667343] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 03/19/2021] [Indexed: 12/02/2022] Open
Abstract
Microbes rely upon iron as a cofactor for many enzymes in their central metabolic processes. The reactive oxygen species (ROS) superoxide and hydrogen peroxide react rapidly with iron, and inside cells they can generate both enzyme and DNA damage. ROS are formed in some bacterial habitats by abiotic processes. The vulnerability of bacteria to ROS is also apparently exploited by ROS-generating host defense systems and bacterial competitors. Phagocyte-derived O 2 - can toxify captured bacteria by damaging unidentified biomolecules on the cell surface; it is unclear whether phagocytic H2O2, which can penetrate into the cell interior, also plays a role in suppressing bacterial invasion. Both pathogenic and free-living microbes activate defensive strategies to defend themselves against incoming H2O2. Most bacteria sense the H2O2via OxyR or PerR transcription factors, whereas yeast uses the Grx3/Yap1 system. In general these regulators induce enzymes that reduce cytoplasmic H2O2 concentrations, decrease the intracellular iron pools, and repair the H2O2-mediated damage. However, individual organisms have tailored these transcription factors and their regulons to suit their particular environmental niches. Some bacteria even contain both OxyR and PerR, raising the question as to why they need both systems. In lab experiments these regulators can also respond to nitric oxide and disulfide stress, although it is unclear whether the responses are physiologically relevant. The next step is to extend these studies to natural environments, so that we can better understand the circumstances in which these systems act. In particular, it is important to probe the role they may play in enabling host infection by microbial pathogens.
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Affiliation(s)
| | - James A. Imlay
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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Röder J, Felgner P, Hensel M. Comprehensive Single Cell Analyses of the Nutritional Environment of Intracellular Salmonella enterica. Front Cell Infect Microbiol 2021; 11:624650. [PMID: 33834004 PMCID: PMC8021861 DOI: 10.3389/fcimb.2021.624650] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 01/25/2021] [Indexed: 12/11/2022] Open
Abstract
The facultative intracellular pathogen Salmonella enterica Typhimurium (STM) resides in a specific membrane-bound compartment termed the Salmonella-containing vacuole (SCV). STM is able to obtain all nutrients required for rapid proliferation, although being separated from direct access to host cell metabolites. The formation of specific tubular membrane compartments, called Salmonella-induced filaments (SIFs) are known to provides bacterial nutrition by giving STM access to endocytosed material and enabling proliferation. Additionally, STM expresses a range of nutrient uptake system for growth in nutrient limited environments to overcome the nutrition depletion inside the host. By utilizing dual fluorescence reporters, we shed light on the nutritional environment of intracellular STM in various host cells and distinct intracellular niches. We showed that STM uses nutrients of the host cell and adapts uniquely to the different nutrient conditions. In addition, we provide further evidence for improved nutrient supply by SIF formation or presence in the cytosol of epithelial cells, and the correlation of nutrient supply to bacterial proliferation.
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Affiliation(s)
- Jennifer Röder
- Abteilung Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | - Pascal Felgner
- Abteilung Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | - Michael Hensel
- Abteilung Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
- CellNanOs – Center of Cellular Nanoanalytics, Fachbereich Biologie/Chemie, Universität Osnabrück, Osnabrück, Germany
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Gerstel A, Zamarreño Beas J, Duverger Y, Bouveret E, Barras F, Py B. Oxidative stress antagonizes fluoroquinolone drug sensitivity via the SoxR-SUF Fe-S cluster homeostatic axis. PLoS Genet 2020; 16:e1009198. [PMID: 33137124 PMCID: PMC7671543 DOI: 10.1371/journal.pgen.1009198] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 11/17/2020] [Accepted: 10/15/2020] [Indexed: 11/18/2022] Open
Abstract
The level of antibiotic resistance exhibited by bacteria can vary as a function of environmental conditions. Here, we report that phenazine-methosulfate (PMS), a redox-cycling compound (RCC) enhances resistance to fluoroquinolone (FQ) norfloxacin. Genetic analysis showed that E. coli adapts to PMS stress by making Fe-S clusters with the SUF machinery instead of the ISC one. Based upon phenotypic analysis of soxR, acrA, and micF mutants, we showed that PMS antagonizes fluoroquinolone toxicity by SoxR-mediated up-regulation of the AcrAB drug efflux pump. Subsequently, we showed that despite the fact that SoxR could receive its cluster from either ISC or SUF, only SUF is able to sustain efficient SoxR maturation under exposure to prolonged PMS period or high PMS concentrations. This study furthers the idea that Fe-S cluster homeostasis acts as a sensor of environmental conditions, and because its broad influence on cell metabolism, modifies the antibiotic resistance profile of E. coli. Our study investigates how phenazine compounds, which are widely present in the environment, impact antibiotic resistance of the Gram-negative bacteria Escherichia coli. The paucity of new antibacterial molecules fuels concern in the wake of increased antibiotic resistance among pathogens. Equally worrying is the realization that environmental conditions can have a drastic influence on the efficiency of antibacterial compounds. Here we report that phenazine, a member of the redox-cycling molecule family, is antagonistic to norfloxacin, a well-known and routinely used fluoroquinolone antibiotic. We show that the mechanism E. coli is using for synthesizing Fe-S clusters controls the phenazine/fluoroquinolone antagonism. Indeed, upon exposure to phenazine, E. coli switches from making Fe-S clusters with the ISC Fe-S biogenesis system to making them with SUF, a consequence of which is the activation of the SoxR transcriptional activator, up-regulation of the AcrAB efflux pump, and efflux of fluoroquinolone out of the cell. This study illustrates the major influence that environmental conditions play in setting antibiotic level resistance and further highlights the major contribution of Fe-S cluster homeostasis in antibiotic susceptibility.
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Affiliation(s)
- Audrey Gerstel
- Laboratoire de Chimie Bactérienne, Aix-Marseille Université-CNRS UMR7283, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Jordi Zamarreño Beas
- Laboratoire de Chimie Bactérienne, Aix-Marseille Université-CNRS UMR7283, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Yohann Duverger
- Laboratoire de Chimie Bactérienne, Aix-Marseille Université-CNRS UMR7283, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Emmanuelle Bouveret
- SAMe Unit, Département de Microbiologie, Institut Pasteur, CNRS UMR IMM 2001, Paris, France
| | - Frédéric Barras
- Laboratoire de Chimie Bactérienne, Aix-Marseille Université-CNRS UMR7283, Institut de Microbiologie de la Méditerranée, Marseille, France
- SAMe Unit, Département de Microbiologie, Institut Pasteur, CNRS UMR IMM 2001, Paris, France
- * E-mail: (FB); (BP)
| | - Béatrice Py
- Laboratoire de Chimie Bactérienne, Aix-Marseille Université-CNRS UMR7283, Institut de Microbiologie de la Méditerranée, Marseille, France
- * E-mail: (FB); (BP)
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During Oxidative Stress the Clp Proteins of Escherichia coli Ensure that Iron Pools Remain Sufficient To Reactivate Oxidized Metalloenzymes. J Bacteriol 2020; 202:JB.00235-20. [PMID: 32601069 DOI: 10.1128/jb.00235-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 06/20/2020] [Indexed: 11/20/2022] Open
Abstract
Hydrogen peroxide (H2O2) is formed in natural environments by both biotic and abiotic processes. It easily enters the cytoplasms of microorganisms, where it can disrupt growth by inactivating iron-dependent enzymes. It also reacts with the intracellular iron pool, generating hydroxyl radicals that can lethally damage DNA. Therefore, virtually all bacteria possess H2O2-responsive transcription factors that control defensive regulons. These typically include catalases and peroxidases that scavenge H2O2 Another common component is the miniferritin Dps, which sequesters loose iron and thereby suppresses hydroxyl-radical formation. In this study, we determined that Escherichia coli also induces the ClpS and ClpA proteins of the ClpSAP protease complex. Mutants that lack this protease, plus its partner, ClpXP protease, cannot grow when H2O2 levels rise. The growth defect was traced to the inactivity of dehydratases in the pathway of branched-chain amino acid synthesis. These enzymes rely on a solvent-exposed [4Fe-4S] cluster that H2O2 degrades. In a typical cell the cluster is continuously repaired, but in the clpSA clpX mutant the repair process is defective. We determined that this disability is due to an excessively small iron pool, apparently due to the oversequestration of iron by Dps. Dps was previously identified as a substrate of both the ClpSAP and ClpXP proteases, and in their absence its levels are unusually high. The implication is that the stress response to H2O2 has evolved to strike a careful balance, diminishing iron pools enough to protect the DNA but keeping them substantial enough that critical iron-dependent enzymes can be repaired.IMPORTANCE Hydrogen peroxide mediates the toxicity of phagocytes, lactic acid bacteria, redox-cycling antibiotics, and photochemistry. The underlying mechanisms all involve its reaction with iron atoms, whether in enzymes or on the surface of DNA. Accordingly, when bacteria perceive toxic H2O2, they activate defensive tactics that are focused on iron metabolism. In this study, we identify a conundrum: DNA is best protected by the removal of iron from the cytoplasm, but this action impairs the ability of the cell to reactivate its iron-dependent enzymes. The actions of the Clp proteins appear to hedge against the oversequestration of iron by the miniferritin Dps. This buffering effect is important, because E. coli seeks not just to survive H2O2 but to grow in its presence.
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Engl C, Jovanovic G, Brackston RD, Kotta-Loizou I, Buck M. The route to transcription initiation determines the mode of transcriptional bursting in E. coli. Nat Commun 2020; 11:2422. [PMID: 32415118 PMCID: PMC7229158 DOI: 10.1038/s41467-020-16367-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 04/24/2020] [Indexed: 11/20/2022] Open
Abstract
Transcription is fundamentally noisy, leading to significant heterogeneity across bacterial populations. Noise is often attributed to burstiness, but the underlying mechanisms and their dependence on the mode of promotor regulation remain unclear. Here, we measure E. coli single cell mRNA levels for two stress responses that depend on bacterial sigma factors with different mode of transcription initiation (σ70 and σ54). By fitting a stochastic model to the observed mRNA distributions, we show that the transition from low to high expression of the σ70-controlled stress response is regulated via the burst size, while that of the σ54-controlled stress response is regulated via the burst frequency. Therefore, transcription initiation involving σ54 differs from other bacterial systems, and yields bursting kinetics characteristic of eukaryotic systems. Transcription noise in bacteria is often attributed to burstiness, but the mechanisms are unclear. Here, the authors show that the transition from low to high expression can be regulated via burst size or burst frequency, depending on the mode of transcription initiation determined by different sigma factors.
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Affiliation(s)
- Christoph Engl
- School of Biological & Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK.
| | - Goran Jovanovic
- Faculty of Medicine, Department of Medicine, Imperial College London, London, SW7 2AZ, UK.,Faculty of Natural Sciences, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK.,Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11042, Belgrade, Serbia
| | - Rowan D Brackston
- Faculty of Natural Sciences, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Ioly Kotta-Loizou
- Faculty of Natural Sciences, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Martin Buck
- Faculty of Natural Sciences, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK.
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15
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Gao F. Iron-Sulfur Cluster Biogenesis and Iron Homeostasis in Cyanobacteria. Front Microbiol 2020; 11:165. [PMID: 32184761 PMCID: PMC7058544 DOI: 10.3389/fmicb.2020.00165] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Accepted: 01/23/2020] [Indexed: 01/23/2023] Open
Abstract
Iron–sulfur (Fe–S) clusters are ancient and ubiquitous cofactors and are involved in many important biological processes. Unlike the non-photosynthetic bacteria, cyanobacteria have developed the sulfur utilization factor (SUF) mechanism as their main assembly pathway for Fe–S clusters, supplemented by the iron–sulfur cluster and nitrogen-fixing mechanisms. The SUF system consists of cysteine desulfurase SufS, SufE that can enhance SufS activity, SufBC2D scaffold complex, carrier protein SufA, and regulatory repressor SufR. The S source for the Fe–S cluster assembly mainly originates from L-cysteine, but the Fe donor remains elusive. This minireview mainly focuses on the biogenesis pathway of the Fe–S clusters in cyanobacteria and its relationship with iron homeostasis. Future challenges of studying Fe–S clusters in cyanobacteria are also discussed.
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Affiliation(s)
- Fudan Gao
- College of Life Sciences, Shanghai Normal University, Shanghai, China
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16
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Nie X, Remes B, Klug G. Multiple Sense and Antisense Promoters Contribute to the Regulated Expression of the isc-suf Operon for Iron-Sulfur Cluster Assembly in Rhodobacter. Microorganisms 2019; 7:microorganisms7120671. [PMID: 31835540 PMCID: PMC6956336 DOI: 10.3390/microorganisms7120671] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/02/2019] [Accepted: 12/04/2019] [Indexed: 11/16/2022] Open
Abstract
A multitude of biological functions relies on iron-sulfur clusters. The formation of photosynthetic complexes goes along with an additional demand for iron-sulfur clusters for bacteriochlorophyll synthesis and photosynthetic electron transport. However, photooxidative stress leads to the destruction of iron-sulfur clusters, and the released iron promotes the formation of further reactive oxygen species. A balanced regulation of iron-sulfur cluster synthesis is required to guarantee the supply of this cofactor, on the one hand, but also to limit stress, on the other hand. The phototrophic alpha-proteobacterium Rhodobacter sphaeroides harbors a large operon for iron-sulfur cluster assembly comprising the iscRS and suf genes. IscR (iron-sulfur cluster regulator) is an iron-dependent regulator of isc-suf genes and other genes with a role in iron metabolism. We applied reporter gene fusions to identify promoters of the isc-suf operon and studied their activity alone or in combination under different conditions. Gel-retardation assays showed the binding of regulatory proteins to individual promoters. Our results demonstrated that several promoters in a sense and antisense direction influenced isc-suf expression and the binding of the IscR, Irr, and OxyR regulatory proteins to individual promoters. These findings demonstrated a complex regulatory network of several promoters and regulatory proteins that helped to adjust iron-sulfur cluster assembly to changing conditions in Rhodobacter sphaeroides.
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17
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Garcia PS, Gribaldo S, Py B, Barras F. The SUF system: an ABC ATPase-dependent protein complex with a role in Fe-S cluster biogenesis. Res Microbiol 2019; 170:426-434. [PMID: 31419582 DOI: 10.1016/j.resmic.2019.08.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 07/30/2019] [Accepted: 08/07/2019] [Indexed: 12/13/2022]
Abstract
Iron-sulfur (Fe-S) clusters are considered one of the most ancient and versatile inorganic cofactors present in the three domains of life. Fe-S clusters can act as redox sensors or catalysts and are found to be used by a large number of functional and structurally diverse proteins. Here, we cover current knowledge of the SUF multiprotein machinery that synthesizes and inserts Fe-S clusters into proteins. Specific focus is put on the ABC ATPase SufC, which contributes to building Fe-S clusters, and appeared early on during evolution.
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Affiliation(s)
- Pierre Simon Garcia
- Department of Microbiology, Stress Adaptation and Metabolism in Enterobacteria Unit, ERL CNRS 6002, Institut Pasteur, 25-28 Rue du Dr Roux, 75015, Paris, France; Department of Microbiology, Evolutionary Biology of the Microbial Cell Unit, Institut Pasteur, 25-28 Rue du Dr Roux, 75015, Paris, France
| | - Simonetta Gribaldo
- Department of Microbiology, Evolutionary Biology of the Microbial Cell Unit, Institut Pasteur, 25-28 Rue du Dr Roux, 75015, Paris, France
| | - Béatrice Py
- Laboratoire de Chimie Bactérienne, UMR7243 Aix-Marseille Université CNRS, 31 Chemin Joseph Aiguier, 13009, Marseille, France.
| | - Frédéric Barras
- Department of Microbiology, Stress Adaptation and Metabolism in Enterobacteria Unit, ERL CNRS 6002, Institut Pasteur, 25-28 Rue du Dr Roux, 75015, Paris, France.
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18
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Hou J, Chen Z, Gao J, Xie Y, Li L, Qin S, Wang Q, Mao D, Luo Y. Simultaneous removal of antibiotics and antibiotic resistance genes from pharmaceutical wastewater using the combinations of up-flow anaerobic sludge bed, anoxic-oxic tank, and advanced oxidation technologies. WATER RESEARCH 2019; 159:511-520. [PMID: 31129481 DOI: 10.1016/j.watres.2019.05.034] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/24/2019] [Accepted: 05/11/2019] [Indexed: 06/09/2023]
Abstract
Pharmaceutical wastewater often contains high levels of antibiotic residues and serves as an important reservoir for antibiotic resistance genes (ARGs). However, the current pharmaceutical wastewater treatment plants (PWWTPs) were not sufficiently effective in removing antibiotics and ARGs. Here, we designed a lab-scale simulation reactor, including up-flow anaerobic sludge bed (UASB), anoxic-oxic tank (A/O), and four separate advanced oxidation processes (AOPs) i.e., UV, Ozonation, Fenton, and Fenton/UV, to simultaneously remove 18 antibiotics and 10 ARGs from a real pharmaceutical wastewater. The results showed that all antibiotics were fully eliminated through the reactor during 180 d-operation. Among all treatment units, UASB provided the greatest contribution (85.8 ± 16.1%) for the removal of 18 antibiotics. The mass balance results manifested that degradation was a predominant mechanism for the removal of tetracyclines, sulfamethoxazole, and ampicillin (62.5-80.9%), while sorption to sludge (73.9%) was predominant for enrofloxacin removal in UASB. Meanwhile, the substantial decrease of ARG absolute abundance (log reduction by 0.1-3.1 fold) through the whole reactor was observed although the existence of the partial enrichment (1.2-3.8 log units) from the influent to the A/O unit. Fenton/UV combination was the most effective AOP for the removal of ARGs. Finally, the optimum operating conditions for the removal of ARGs using Fenton was also proposed considering the relatively lower cost and high ARG elimination. Overall, this study provides feasible suggestions for the design of real PWWTPs for simultaneous removal of antibiotics and ARGs.
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Affiliation(s)
- Jie Hou
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300071, China
| | - Zeyou Chen
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300071, China
| | - Ju Gao
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300071, China
| | - Yonglei Xie
- School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin, 300384, China
| | - Linyun Li
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300071, China
| | - Songyan Qin
- School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin, 300384, China
| | - Qing Wang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300071, China
| | - Daqing Mao
- School of Medicine, Nankai University, Tianjin, 300071, China.
| | - Yi Luo
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300071, China.
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19
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Sevilla E, Bes MT, González A, Peleato ML, Fillat MF. Redox-Based Transcriptional Regulation in Prokaryotes: Revisiting Model Mechanisms. Antioxid Redox Signal 2019; 30:1651-1696. [PMID: 30073850 DOI: 10.1089/ars.2017.7442] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
SIGNIFICANCE The successful adaptation of microorganisms to ever-changing environments depends, to a great extent, on their ability to maintain redox homeostasis. To effectively maintain the redox balance, cells have developed a variety of strategies mainly coordinated by a battery of transcriptional regulators through diverse mechanisms. Recent Advances: This comprehensive review focuses on the main mechanisms used by major redox-responsive regulators in prokaryotes and their relationship with the different redox signals received by the cell. An overview of the corresponding regulons is also provided. CRITICAL ISSUES Some regulators are difficult to classify since they may contain several sensing domains and respond to more than one signal. We propose a classification of redox-sensing regulators into three major groups. The first group contains one-component or direct regulators, whose sensing and regulatory domains are in the same protein. The second group comprises the classical two-component systems involving a sensor kinase that transduces the redox signal to its DNA-binding partner. The third group encompasses a heterogeneous group of flavin-based photosensors whose mechanisms are not always fully understood and are often involved in more complex regulatory networks. FUTURE DIRECTIONS Redox-responsive transcriptional regulation is an intricate process as identical signals may be sensed and transduced by different transcription factors, which often interplay with other DNA-binding proteins with or without regulatory activity. Although there is much information about some key regulators, many others remain to be fully characterized due to the instability of their clusters under oxygen. Understanding the mechanisms and the regulatory networks operated by these regulators is essential for the development of future applications in biotechnology and medicine.
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Affiliation(s)
- Emma Sevilla
- 1 Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain.,2 Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Universidad de Zaragoza, Zaragoza, Spain.,3 Grupo de Bioquímica, Biofísica y Biología Computacional (BIFI, UNIZAR), Unidad Asociada al CSIC, Zaragoza, Spain
| | - María Teresa Bes
- 1 Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain.,2 Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Universidad de Zaragoza, Zaragoza, Spain.,3 Grupo de Bioquímica, Biofísica y Biología Computacional (BIFI, UNIZAR), Unidad Asociada al CSIC, Zaragoza, Spain
| | - Andrés González
- 2 Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Universidad de Zaragoza, Zaragoza, Spain.,3 Grupo de Bioquímica, Biofísica y Biología Computacional (BIFI, UNIZAR), Unidad Asociada al CSIC, Zaragoza, Spain.,4 Instituto de Investigación Sanitaria Aragón (IIS Aragón), Zaragoza, Spain
| | - María Luisa Peleato
- 1 Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain.,2 Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Universidad de Zaragoza, Zaragoza, Spain.,3 Grupo de Bioquímica, Biofísica y Biología Computacional (BIFI, UNIZAR), Unidad Asociada al CSIC, Zaragoza, Spain
| | - María F Fillat
- 1 Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain.,2 Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Universidad de Zaragoza, Zaragoza, Spain.,3 Grupo de Bioquímica, Biofísica y Biología Computacional (BIFI, UNIZAR), Unidad Asociada al CSIC, Zaragoza, Spain
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20
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Duprey A, Taib N, Leonard S, Garin T, Flandrois JP, Nasser W, Brochier-Armanet C, Reverchon S. The phytopathogenic nature of Dickeya aquatica 174/2 and the dynamic early evolution of Dickeya pathogenicity. Environ Microbiol 2019; 21:2809-2835. [PMID: 30969462 DOI: 10.1111/1462-2920.14627] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/04/2019] [Accepted: 04/08/2019] [Indexed: 12/13/2022]
Abstract
Dickeya is a genus of phytopathogenic enterobacterales causing soft rot in a variety of plants (e.g. potato, chicory, maize). Among the species affiliated to this genus, Dickeya aquatica, described in 2014, remained particularly mysterious because it had no known host. Furthermore, while D. aquatica was proposed to represent a deep-branching species among Dickeya genus, its precise phylogenetic position remained elusive. Here, we report the complete genome sequence of the D. aquatica type strain 174/2. We demonstrate the affinity of D. aquatica strain 174/2 for acidic fruits such as tomato and cucumber and show that exposure of this bacterium to acidic pH induces twitching motility. An in-depth phylogenomic analysis of all available Dickeya proteomes pinpoints D. aquatica as the second deepest branching lineage within this genus and reclassifies two lineages that likely correspond to new genomospecies (gs.): Dickeya gs. poaceaephila (Dickeya sp NCPPB 569) and Dickeya gs. undicola (Dickeya sp 2B12), together with a new putative genus, tentatively named Prodigiosinella. Finally, from comparative analyses of Dickeya proteomes, we infer the complex evolutionary history of this genus, paving the way to study the adaptive patterns and processes of Dickeya to different environmental niches and hosts. In particular, we hypothesize that the lack of xylanases and xylose degradation pathways in D. aquatica could reflect adaptation to aquatic charophyte hosts which, in contrast to land plants, do not contain xyloglucans.
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Affiliation(s)
- Alexandre Duprey
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation et Pathogénie, 10 Rue Raphaël Dubois, 69622, Villeurbanne, France
| | - Najwa Taib
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Évolutive, 43 bd du 11 novembre 1918, 69622, Villeurbanne, France
| | - Simon Leonard
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation et Pathogénie, 10 Rue Raphaël Dubois, 69622, Villeurbanne, France
| | - Tiffany Garin
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Évolutive, 43 bd du 11 novembre 1918, 69622, Villeurbanne, France
| | - Jean-Pierre Flandrois
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Évolutive, 43 bd du 11 novembre 1918, 69622, Villeurbanne, France
| | - William Nasser
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation et Pathogénie, 10 Rue Raphaël Dubois, 69622, Villeurbanne, France
| | - Céline Brochier-Armanet
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Évolutive, 43 bd du 11 novembre 1918, 69622, Villeurbanne, France
| | - Sylvie Reverchon
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation et Pathogénie, 10 Rue Raphaël Dubois, 69622, Villeurbanne, France
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21
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Zupok A, Iobbi-Nivol C, Méjean V, Leimkühler S. The regulation of Moco biosynthesis and molybdoenzyme gene expression by molybdenum and iron in bacteria. Metallomics 2019; 11:1602-1624. [DOI: 10.1039/c9mt00186g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The regulation of the operons involved in Moco biosynthesis is dependent on the availability of Fe–S clusters in the cell.
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Affiliation(s)
- Arkadiusz Zupok
- University of Potsdam
- Institute of Biochemistry and Biology
- Molecular Enzymology
- Potsdam-Golm
- Germany
| | - Chantal Iobbi-Nivol
- Aix-Marseille Université
- Institut de Microbiologie de la Méditerranée
- Laboratoire de Bioénergétique et Ingénierie des Protéines
- Centre National de la Recherche Scientifique
- Marseille
| | - Vincent Méjean
- Aix-Marseille Université
- Institut de Microbiologie de la Méditerranée
- Laboratoire de Bioénergétique et Ingénierie des Protéines
- Centre National de la Recherche Scientifique
- Marseille
| | - Silke Leimkühler
- University of Potsdam
- Institute of Biochemistry and Biology
- Molecular Enzymology
- Potsdam-Golm
- Germany
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22
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Imlay JA. Where in the world do bacteria experience oxidative stress? Environ Microbiol 2018; 21:521-530. [PMID: 30307099 DOI: 10.1111/1462-2920.14445] [Citation(s) in RCA: 155] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 10/02/2018] [Accepted: 10/07/2018] [Indexed: 11/26/2022]
Abstract
Reactive oxygen species - superoxide, hydrogen peroxide and hydroxyl radicals - have long been suspected of constraining bacterial growth in important microbial habitats and indeed of shaping microbial communities. Over recent decades, studies of paradigmatic organisms such as Escherichia coli, Salmonella typhimurium, Bacillus subtilis and Saccharomyces cerevisiae have pinpointed the biomolecules that oxidants can damage and the strategies by which microbes minimize their injuries. What is lacking is a good sense of the circumstances under which oxidative stress actually occurs. In this MiniReview several potential natural sources of oxidative stress are considered: endogenous ROS formation, chemical oxidation of reduced species at oxic-anoxic interfaces, H2 O2 production by lactic acid bacteria, the oxidative burst of phagocytes and the redox-cycling of secreted small molecules. While all of these phenomena can be reproduced and verified in the lab, the actual quantification of stress in natural habitats remains lacking - and, therefore, we have a fundamental hole in our understanding of the role that oxidative stress actually plays in the biosphere.
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Affiliation(s)
- James A Imlay
- Department of Microbiology, University of Illinois, 601 S. Goodwin Ave, Urbana, IL, 61801, USA
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23
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Guyet A, Dade-Robertson M, Wipat A, Casement J, Smith W, Mitrani H, Zhang M. Mild hydrostatic pressure triggers oxidative responses in Escherichia coli. PLoS One 2018; 13:e0200660. [PMID: 30016375 PMCID: PMC6049941 DOI: 10.1371/journal.pone.0200660] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 06/30/2018] [Indexed: 11/24/2022] Open
Abstract
Hydrostatic pressure is an important physical stimulus which can cause various responses in bacterial cells. The survival and cellular processes of Escherichia coli under hydrostatic pressures between 10 MPa and 110 MPa have been studied. However, understanding bacterial responses to moderately elevated pressure of up to 10 MPa is useful for a range of different applications including for example in smart and responsive materials. In this study, the genetic responses of E. coli K-12 MG1655 to 1 MPa pressure was examined using transcriptomic analysis by RNA-Seq. The results show that 101 genes were differentially expressed under 1 MPa pressure in E. coli cells, with 85 of them up-regulated. The analysis suggested that some genes were over expressed to adapt the increase of oxygen levels in our system, and several functional categories are involved including oxidative stress responses, Fe-S cluster assembly and iron acquisition. Two differentially expressed genes azuC and entC were further investigated using RT-qPCR, and GFP reported strains of those two genes were created, AG1319 (PazuCazuC-msfgfp) and AG1321 (PentCentC-msfgfp). A linear response of azuC expression was observed between 0 MPa to 1 MPa by monitoring the fluorescence signal of strain AG1319 (PazuCazuC-msfgfp). This study is the first report to demonstrate the genetic response of bacterial cells under 1 MPa hydrostatic pressure, and provides preliminary data for creating pressure sensing bacterial strains for a wide range of applications.
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Affiliation(s)
- Aurelie Guyet
- The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Martyn Dade-Robertson
- School of Computing, Newcastle University, Newcastle upon Tyne, United Kingdom
- School of Architecture Planning and Landscape, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Anil Wipat
- School of Computing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - John Casement
- Bioinformatics Support Unit, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Wendy Smith
- School of Computing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Helen Mitrani
- School of Engineering, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Meng Zhang
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
- * E-mail:
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24
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Willemse D, Weber B, Masino L, Warren RM, Adinolfi S, Pastore A, Williams MJ. Rv1460, a SufR homologue, is a repressor of the suf operon in Mycobacterium tuberculosis. PLoS One 2018; 13:e0200145. [PMID: 29979728 PMCID: PMC6034842 DOI: 10.1371/journal.pone.0200145] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 06/20/2018] [Indexed: 11/19/2022] Open
Abstract
Iron–sulphur (Fe-S) clusters are ubiquitous co-factors which require multi-protein systems for their synthesis. In Mycobacterium tuberculosis, the Rv1460-Rv1461-Rv1462-Rv1463-csd-Rv1465-Rv1466 operon (suf operon) encodes the primary Fe-S cluster biogenesis system. The first gene in this operon, Rv1460, shares homology with the cyanobacterial SufR, which functions as a transcriptional repressor of the sufBCDS operon. Rv1460’s function in M. tuberculosis has however not been determined. In this study, we demonstrate that M. tuberculosis mutants lacking a functional Rv1460 protein are impaired for growth under standard culture conditions. Elevated expression of Rv1460 and Rv1461 was observed in the mutant, implicating Rv1460 in the regulation of the suf operon. Binding of an Fe-S cluster to purified recombinant Rv1460 was confirmed by UV-visible spectroscopy and circular dichroism. Furthermore, three conserved cysteine residues, C203, C216 and C244, proposed to provide ligands for the coordination of an Fe-S cluster, were shown to be required for the function of Rv1460 in M. tuberculosis. Rv1460 therefore seems to be functionally analogous to cyanobacterial SufR.
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Affiliation(s)
- Danicke Willemse
- DST-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Brandon Weber
- Electron Microscope Unit, University of Cape Town, Cape Town, South Africa
| | - Laura Masino
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Robin M. Warren
- DST-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Salvatore Adinolfi
- Pharmaceutical Science and Technology, University of Turin, Turin, Italy
| | - Annalisa Pastore
- Department of Basic and Clinical Neuroscience, Maurice Wohl Institute, King's College London, London, United Kingdom
| | - Monique J. Williams
- DST-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
- * E-mail:
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25
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Adaptation to the coupling of glycolysis to toxic methylglyoxal production in tpiA deletion strains of Escherichia coli requires synchronized and counterintuitive genetic changes. Metab Eng 2018; 48:82-93. [PMID: 29842925 DOI: 10.1016/j.ymben.2018.05.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 05/03/2018] [Accepted: 05/23/2018] [Indexed: 11/21/2022]
Abstract
Methylglyoxal is a highly toxic metabolite that can be produced in all living organisms. Methylglyoxal was artificially elevated by removal of the tpiA gene from a growth optimized Escherichia coli strain. The initial response to elevated methylglyoxal and its toxicity was characterized, and detoxification mechanisms were studied using adaptive laboratory evolution. We found that: 1) Multi-omics analysis revealed biological consequences of methylglyoxal toxicity, which included attack on macromolecules including DNA and RNA and perturbation of nucleotide levels; 2) Counter-intuitive cross-talk between carbon starvation and inorganic phosphate signalling was revealed in the tpiA deletion strain that required mutations in inorganic phosphate signalling mechanisms to alleviate; and 3) The split flux through lower glycolysis depleted glycolytic intermediates requiring a host of synchronized and coordinated mutations in non-intuitive network locations in order to re-adjust the metabolic flux map to achieve optimal growth. Such mutations included a systematic inactivation of the Phosphotransferase System (PTS) and alterations in cell wall biosynthesis enzyme activity. This study demonstrated that deletion of major metabolic genes followed by ALE was a productive approach to gain novel insight into the systems biology underlying optimal phenotypic states.
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26
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Michael-Kordatou I, Karaolia P, Fatta-Kassinos D. The role of operating parameters and oxidative damage mechanisms of advanced chemical oxidation processes in the combat against antibiotic-resistant bacteria and resistance genes present in urban wastewater. WATER RESEARCH 2018; 129:208-230. [PMID: 29153875 DOI: 10.1016/j.watres.2017.10.007] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/04/2017] [Accepted: 10/04/2017] [Indexed: 05/26/2023]
Abstract
An upsurge in the study of antibiotic resistance in the environment has been observed in the last decade. Nowadays, it is becoming increasingly clear that urban wastewater is a key source of antibiotic resistance determinants, i.e. antibiotic-resistant bacteria and antibiotic resistance genes (ARB&ARGs). Urban wastewater reuse has arisen as an important component of water resources management in the European Union and worldwide to address prolonged water scarcity issues. Especially, biological wastewater treatment processes (i.e. conventional activated sludge), which are widely applied in urban wastewater treatment plants, have been shown to provide an ideal environment for the evolution and spread of antibiotic resistance. The ability of advanced chemical oxidation processes (AOPs), e.g. light-driven oxidation in the presence of H2O2, ozonation, homogeneous and heterogeneous photocatalysis, to inactivate ARB and remove ARGs in wastewater effluents has not been yet evaluated through a systematic and integrated approach. Consequently, this review seeks to provide an extensive and critical appraisal on the assessment of the efficiency of these processes in inactivating ARB and removing ARGs in wastewater effluents, based on recent available scientific literature. It tries to elucidate how the key operating conditions may affect the process efficiency, while pinpointing potential areas for further research and major knowledge gaps which need to be addressed. Also, this review aims at shedding light on the main oxidative damage pathways involved in the inactivation of ARB and removal of ARGs by these processes. In general, the lack and/or heterogeneity of the available scientific data, as well as the different methodological approaches applied in the various studies, make difficult the accurate evaluation of the efficiency of the processes applied. Besides the operating conditions, the variable behavior observed by the various examined genetic constituents of the microbial community, may be directed by the process distinct oxidative damage mechanisms in place during the application of each treatment technology. For example, it was shown in various studies that the majority of cellular damage by advanced chemical oxidation may be on cell wall and membrane structures of the targeted bacteria, leaving the internal components of the cells relatively intact/able to repair damage. As a result, further in-depth mechanistic studies are required, to establish the optimum operating conditions under which oxidative mechanisms target internal cell components such as genetic material and ribosomal structures more intensively, thus conferring permanent damage and/or death and preventing potential post-treatment re-growth.
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Affiliation(s)
- I Michael-Kordatou
- Nireas-International Water Research Centre, University of Cyprus, P.O. Box 20537, CY-1678, Nicosia, Cyprus
| | - P Karaolia
- Nireas-International Water Research Centre, University of Cyprus, P.O. Box 20537, CY-1678, Nicosia, Cyprus; Department of Civil and Environmental Engineering University of Cyprus, P.O. Box 20537, CY-1678, Nicosia, Cyprus
| | - D Fatta-Kassinos
- Nireas-International Water Research Centre, University of Cyprus, P.O. Box 20537, CY-1678, Nicosia, Cyprus; Department of Civil and Environmental Engineering University of Cyprus, P.O. Box 20537, CY-1678, Nicosia, Cyprus.
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27
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Cherak SJ, Turner RJ. Assembly pathway of a bacterial complex iron sulfur molybdoenzyme. Biomol Concepts 2018; 8:155-167. [PMID: 28688222 DOI: 10.1515/bmc-2017-0011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 05/10/2017] [Indexed: 11/15/2022] Open
Abstract
Protein folding and assembly into macromolecule complexes within the living cell are complex processes requiring intimate coordination. The biogenesis of complex iron sulfur molybdoenzymes (CISM) requires use of a system specific chaperone - a redox enzyme maturation protein (REMP) - to help mediate final folding and assembly. The CISM dimethyl sulfoxide (DMSO) reductase is a bacterial oxidoreductase that utilizes DMSO as a final electron acceptor for anaerobic respiration. The REMP DmsD strongly interacts with DMSO reductase to facilitate folding, cofactor-insertion, subunit assembly and targeting of the multi-subunit enzyme prior to membrane translocation and final assembly and maturation into a bioenergetic catalytic unit. In this article, we discuss the biogenesis of DMSO reductase as an example of the participant network for bacterial CISM maturation pathways.
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28
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Pérard J, Ollagnier de Choudens S. Iron-sulfur clusters biogenesis by the SUF machinery: close to the molecular mechanism understanding. J Biol Inorg Chem 2017; 23:581-596. [PMID: 29280002 PMCID: PMC6006206 DOI: 10.1007/s00775-017-1527-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 12/11/2017] [Indexed: 11/30/2022]
Abstract
Iron–sulfur clusters (Fe–S) are amongst the most ancient and versatile inorganic cofactors in nature which are used by proteins for fundamental biological processes. Multiprotein machineries (NIF, ISC, SUF) exist for Fe–S cluster biogenesis which are mainly conserved from bacteria to human. SUF system (sufABCDSE operon) plays a general role in many bacteria under conditions of iron limitation or oxidative stress. In this mini-review, we will summarize the current understanding of the molecular mechanism of Fe–S biogenesis by SUF. The advances in our understanding of the molecular aspects of SUF originate from biochemical, biophysical and recent structural studies. Combined with recent in vivo experiments, the understanding of the Fe–S biogenesis mechanism considerably moved forward.
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Affiliation(s)
- J Pérard
- Laboratoire de Chimie et Biologie des Métaux, Biocat, Université Grenoble Alpes, Grenoble, France.,Laboratoire de Chimie et Biologie des Métaux, CNRS, BioCat, UMR 5249, Grenoble, France.,CEA-Grenoble, DRF/BIG/CBM, Grenoble, France
| | - Sandrine Ollagnier de Choudens
- Laboratoire de Chimie et Biologie des Métaux, Biocat, Université Grenoble Alpes, Grenoble, France. .,Laboratoire de Chimie et Biologie des Métaux, CNRS, BioCat, UMR 5249, Grenoble, France. .,CEA-Grenoble, DRF/BIG/CBM, Grenoble, France.
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29
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Escherichia coli cytochrome c peroxidase is a respiratory oxidase that enables the use of hydrogen peroxide as a terminal electron acceptor. Proc Natl Acad Sci U S A 2017; 114:E6922-E6931. [PMID: 28696311 DOI: 10.1073/pnas.1701587114] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Microbial cytochrome c peroxidases (Ccp) have been studied for 75 years, but their physiological roles are unclear. Ccps are located in the periplasms of bacteria and the mitochondrial intermembrane spaces of fungi. In this study, Ccp is demonstrated to be a significant degrader of hydrogen peroxide in anoxic Escherichia coli Intriguingly, ccp transcription requires both the presence of H2O2 and the absence of O2 Experiments show that Ccp lacks enough activity to shield the cytoplasm from exogenous H2O2 However, it receives electrons from the quinone pool, and its flux rate approximates flow to other anaerobic electron acceptors. Indeed, Ccp enabled E. coli to grow on a nonfermentable carbon source when H2O2 was supplied. Salmonella behaved similarly. This role rationalizes ccp repression in oxic environments. We speculate that micromolar H2O2 is created both biologically and abiotically at natural oxic/anoxic interfaces. The OxyR response appears to exploit this H2O2 as a terminal oxidant while simultaneously defending the cell against its toxicity.
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30
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Sawyer A, Bai Y, Lu Y, Hemschemeier A, Happe T. Compartmentalisation of [FeFe]-hydrogenase maturation in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:1134-1143. [PMID: 28295776 DOI: 10.1111/tpj.13535] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/01/2017] [Accepted: 03/06/2017] [Indexed: 06/06/2023]
Abstract
Molecular hydrogen (H2 ) can be produced in green microalgae by [FeFe]-hydrogenases as a direct product of photosynthesis. The Chlamydomonas reinhardtii hydrogenase HYDA1 contains a catalytic site comprising a classic [4Fe4S] cluster linked to a unique 2Fe sub-cluster. From in vitro studies it appears that the [4Fe4S] cluster is incorporated first by the housekeeping FeS cluster assembly machinery, followed by the 2Fe sub-cluster, whose biosynthesis requires the specific maturases HYDEF and HYDG. To investigate the maturation process in vivo, we expressed HYDA1 from the C. reinhardtii chloroplast and nuclear genomes (with and without a chloroplast transit peptide) in a hydrogenase-deficient mutant strain, and examined the cellular enzymatic hydrogenase activity, as well as in vivo H2 production. The transformants expressing HYDA1 from the chloroplast genome displayed levels of H2 production comparable to the wild type, as did the transformants expressing full-length HYDA1 from the nuclear genome. In contrast, cells equipped with cytoplasm-targeted HYDA1 produced inactive enzyme, which could only be activated in vitro after reconstitution of the [4Fe4S] cluster. This indicates that the HYDA1 FeS cluster can only be built by the chloroplastic FeS cluster assembly machinery. Further, the expression of a bacterial hydrogenase gene, CPI, from the C. reinhardtii chloroplast genome resulted in H2 -producing strains, demonstrating that a hydrogenase with a very different structure can fulfil the role of HYDA1 in vivo and that overexpression of foreign hydrogenases in C. reinhardtii is possible. All chloroplast transformants were stable and no toxic effects were seen from HYDA1 or CPI expression.
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Affiliation(s)
- Anne Sawyer
- AG Photobiotechnologie, Lehrstuhl für Biochemie der Pflanzen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, 44801, Bochum, Germany
| | - Yu Bai
- AG Photobiotechnologie, Lehrstuhl für Biochemie der Pflanzen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, 44801, Bochum, Germany
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Yinghua Lu
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Anja Hemschemeier
- AG Photobiotechnologie, Lehrstuhl für Biochemie der Pflanzen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, 44801, Bochum, Germany
| | - Thomas Happe
- AG Photobiotechnologie, Lehrstuhl für Biochemie der Pflanzen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, 44801, Bochum, Germany
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31
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Abstract
Iron-sulfur (Fe-S) clusters are fundamental to numerous biological processes in most organisms, but these protein cofactors can be prone to damage by various oxidants (e.g., O2, reactive oxygen species, and reactive nitrogen species) and toxic levels of certain metals (e.g., cobalt and copper). Furthermore, their synthesis can also be directly influenced by the level of available iron in the environment. Consequently, the cellular need for Fe-S cluster biogenesis varies with fluctuating growth conditions. To accommodate changes in Fe-S demand, microorganisms employ diverse regulatory strategies to tailor Fe-S cluster biogenesis according to their surroundings. Here, we review the mechanisms that regulate Fe-S cluster formation in bacteria, primarily focusing on control of the Isc and Suf Fe-S cluster biogenesis systems in the model bacterium Escherichia coli.
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Affiliation(s)
- Erin L Mettert
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin-Madison, ,
| | - Patricia J Kiley
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin-Madison, ,
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32
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Arbel-Goren R, Tal A, Parasar B, Dym A, Costantino N, Muñoz-García J, Court DL, Stavans J. Transcript degradation and noise of small RNA-controlled genes in a switch activated network in Escherichia coli. Nucleic Acids Res 2016; 44:6707-20. [PMID: 27085802 PMCID: PMC5001584 DOI: 10.1093/nar/gkw273] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 04/05/2016] [Indexed: 12/20/2022] Open
Abstract
Post-transcriptional regulatory processes may change transcript levels and affect cell-to-cell variability or noise. We study small-RNA downregulation to elucidate its effects on noise in the iron homeostasis network of Escherichia coli. In this network, the small-RNA RyhB undergoes stoichiometric degradation with the transcripts of target genes in response to iron stress. Using single-molecule fluorescence in situ hybridization, we measured transcript numbers of the RyhB-regulated genes sodB and fumA in individual cells as a function of iron deprivation. We observed a monotonic increase of noise with iron stress but no evidence of theoretically predicted, enhanced stoichiometric fluctuations in transcript numbers, nor of bistable behavior in transcript distributions. Direct detection of RyhB in individual cells shows that its noise is much smaller than that of these two targets, when RyhB production is significant. A generalized two-state model of bursty transcription that neglects RyhB fluctuations describes quantitatively the dependence of noise and transcript distributions on iron deprivation, enabling extraction of in vivo RyhB-mediated transcript degradation rates. The transcripts’ threshold-linear behavior indicates that the effective in vivo interaction strength between RyhB and its two target transcripts is comparable. Strikingly, the bacterial cell response exhibits Fur-dependent, switch-like activation instead of a graded response to iron deprivation.
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Affiliation(s)
- Rinat Arbel-Goren
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Asaf Tal
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Bibudha Parasar
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alvah Dym
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Nina Costantino
- Gene Regulation and Chromosome Biology Laboratory, National Cancer Institute, Frederick, MD 21702-1201, USA
| | - Javier Muñoz-García
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel Departamento de Matemáticas and GISC, Universidad Carlos III de Madrid, Av. de la Universidad 30, 28911 Leganés, Madrid, Spain
| | - Donald L Court
- Gene Regulation and Chromosome Biology Laboratory, National Cancer Institute, Frederick, MD 21702-1201, USA
| | - Joel Stavans
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
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33
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Zhu D, Li R, Liu F, Xu H, Li B, Yuan Y, Saris P, Qiao M. Mu insertion in feuD
triggers the increase in nisin immunity in Lactococcus lactis
subsp. lactis
N8. J Appl Microbiol 2016; 120:402-12. [DOI: 10.1111/jam.13015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 10/21/2015] [Accepted: 11/20/2015] [Indexed: 11/29/2022]
Affiliation(s)
- D. Zhu
- Key Laboratory of Molecular Microbiology and Technology; Ministry of Education; Nankai University; Tianjin China
| | - R. Li
- School of Life Sciences and Technology; ShanghaiTech University; Shanghai China
| | - F. Liu
- Key Laboratory of Molecular Microbiology and Technology; Ministry of Education; Nankai University; Tianjin China
| | - H. Xu
- Key Laboratory of Molecular Microbiology and Technology; Ministry of Education; Nankai University; Tianjin China
| | - B. Li
- Key Laboratory of Systems Bioengineering; Ministry of Education; Department of Pharmaceutical Engineering; Tianjin University; Tianjin China
| | - Y. Yuan
- Key Laboratory of Systems Bioengineering; Ministry of Education; Department of Pharmaceutical Engineering; Tianjin University; Tianjin China
| | - P.E.J. Saris
- Department of Food and Environmental Sciences; University of Helsinki; Helsinki Finland
| | - M. Qiao
- Key Laboratory of Molecular Microbiology and Technology; Ministry of Education; Nankai University; Tianjin China
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34
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Friedrich T, Dekovic DK, Burschel S. Assembly of the Escherichia coli NADH:ubiquinone oxidoreductase (respiratory complex I). BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:214-23. [PMID: 26682761 DOI: 10.1016/j.bbabio.2015.12.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 12/03/2015] [Accepted: 12/07/2015] [Indexed: 12/13/2022]
Abstract
Energy-converting NADH:ubiquinone oxidoreductase, respiratory complex I, couples the electron transfer from NADH to ubiquinone with the translocation of four protons across the membrane. The Escherichia coli complex I is made up of 13 different subunits encoded by the so-called nuo-genes. The electron transfer is catalyzed by nine cofactors, a flavin mononucleotide and eight iron-sulfur (Fe/S)-clusters. The individual subunits and the cofactors have to be assembled together in a coordinated way to guarantee the biogenesis of the active holoenzyme. Only little is known about the assembly of the bacterial complex compared to the mitochondrial one. Due to the presence of so many Fe/S-clusters the assembly of complex I is intimately connected with the systems responsible for the biogenesis of these clusters. In addition, a few other proteins have been reported to be required for an effective assembly of the complex in other bacteria. The proposed role of known bacterial assembly factors is discussed and the information from other bacterial species is used in this review to draw an as complete as possible model of bacterial complex I assembly. In addition, the supramolecular organization of the complex in E. coli is briefly described. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Prof. Conrad Mullineaux.
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Affiliation(s)
- Thorsten Friedrich
- Albert-Ludwigs-Universität Freiburg, Institut für Biochemie, 79104 Freiburg i. Br., Germany; Spemann Graduate School of Biology and Medicine, Albertstr. 19A, 79104 Freiburg i. Br., Germany.
| | - Doris Kreuzer Dekovic
- Albert-Ludwigs-Universität Freiburg, Institut für Biochemie, 79104 Freiburg i. Br., Germany; Spemann Graduate School of Biology and Medicine, Albertstr. 19A, 79104 Freiburg i. Br., Germany
| | - Sabrina Burschel
- Albert-Ludwigs-Universität Freiburg, Institut für Biochemie, 79104 Freiburg i. Br., Germany
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Abstract
The ancestors of Escherichia coli and Salmonella ultimately evolved to thrive in air-saturated liquids, in which oxygen levels reach 210 μM at 37°C. However, in 1976 Brown and colleagues reported that some sensitivity persists: growth defects still become apparent when hyperoxia is imposed on cultures of E. coli. This residual vulnerability was important in that it raised the prospect that normal levels of oxygen might also injure bacteria, albeit at reduced rates that are not overtly toxic. The intent of this article is both to describe the threat that molecular oxygen poses for bacteria and to detail what we currently understand about the strategies by which E. coli and Salmonella defend themselves against it. E. coli mutants that lack either superoxide dismutases or catalases and peroxidases exhibit a variety of growth defects. These phenotypes constitute the best evidence that aerobic cells continually generate intracellular superoxide and hydrogen peroxide at potentially lethal doses. Superoxide has reduction potentials that allow it to serve in vitro as either a weak univalent reductant or a stronger univalent oxidant. The addition of micromolar hydrogen peroxide to lab media will immediately block the growth of most cells, and protracted exposure will result in the loss of viability. The need for inducible antioxidant systems seems especially obvious for enteric bacteria, which move quickly from the anaerobic gut to fully aerobic surface waters or even to ROS-perfused phagolysosomes. E. coli and Salmonella have provided two paradigmatic models of oxidative-stress responses: the SoxRS and OxyR systems.
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36
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Abstract
This review describes the two main systems, namely the Isc (iron-sulfur cluster) and Suf (sulfur assimilation) systems, utilized by Escherichia coli and Salmonella for the biosynthesis of iron-sulfur (Fe-S) clusters, as well as other proteins presumably participating in this process. In the case of Fe-S cluster biosynthesis, it is assumed that the sulfur atoms from the cysteine desulfurase end up at cysteine residues of the scaffold protein, presumably waiting for iron atoms for cluster assembly. The review discusses the various potential iron donor proteins. For in vitro experiments, in general, ferrous salts are used during the assembly of Fe-S clusters, even though this approach is unlikely to reflect the physiological conditions. The fact that sulfur atoms can be directly transferred from cysteine desulfurases to scaffold proteins supports a mechanism in which the latter bind sulfur atoms first and iron atoms afterwards. In E. coli, fdx gene inactivation results in a reduced growth rate and reduced Fe-S enzyme activities. Interestingly, the SufE structure resembles that of IscU, strengthening the notion that the two proteins share the property of acting as acceptors of sulfur atoms provided by cysteine desulfurases. Several other factors have been suggested to participate in cluster assembly and repair in E. coli and Salmonella. Most of them were identified by their abilities to act as extragenic and/or multicopy suppressors of mutations in Fe-S cluster metabolism, while others possess biochemical properties that are consistent with a role in Fe-S cluster biogenesis.
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37
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Chhabra S, Spiro S. Inefficient translation of nsrR constrains behaviour of the NsrR regulon in Escherichia coli. Microbiology (Reading) 2015; 161:2029-2038. [DOI: 10.1099/mic.0.000151] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- Shivani Chhabra
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Stephen Spiro
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
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38
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What a difference a cluster makes: The multifaceted roles of IscR in gene regulation and DNA recognition. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1101-12. [PMID: 25641558 DOI: 10.1016/j.bbapap.2015.01.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 01/21/2015] [Indexed: 11/22/2022]
Abstract
Iron-sulfur clusters are essential cofactors in a myriad of metabolic pathways. Therefore, their biogenesis is tightly regulated across a variety of organisms and environmental conditions. In Gram-negative bacteria, two pathways - ISC and SUF - concur for maintaining intracellular iron-sulfur cluster balance. Recently, the mechanism of iron-sulfur cluster biosynthesis regulation by IscR, an iron-sulfur cluster-containing regulator encoded by the isc operon, was found to be conserved in some Gram-positive bacteria. Belonging to the Rrf2 family of transcriptional regulators, IscR displays a single helix-turn-helix DNA-binding domain but is able to recognize two distinct DNA sequence motifs, switching its specificity upon cluster ligation. This review provides an overview of gene regulation by iron-sulfur cluster-containing sensors, in the light of the recent structural characterization of cluster-less free and DNA-bound IscR, which provided insights into the molecular mechanism of nucleotide sequence recognition and discrimination of this unique transcription factor. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.
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Roche B, Huguenot A, Barras F, Py B. The iron-binding CyaY and IscX proteins assist the ISC-catalyzed Fe-S biogenesis in Escherichia coli. Mol Microbiol 2015; 95:605-23. [PMID: 25430730 DOI: 10.1111/mmi.12888] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2014] [Indexed: 01/18/2023]
Abstract
In eukaryotes, frataxin deficiency (FXN) causes severe phenotypes including loss of iron-sulfur (Fe-S) cluster protein activity, accumulation of mitochondrial iron and leads to the neurodegenerative disease Friedreich's ataxia. In contrast, in prokaryotes, deficiency in the FXN homolog, CyaY, was reported not to cause any significant phenotype, questioning both its importance and its actual contribution to Fe-S cluster biogenesis. Because FXN is conserved between eukaryotes and prokaryotes, this surprising discrepancy prompted us to reinvestigate the role of CyaY in Escherichia coli. We report that CyaY (i) potentiates E. coli fitness, (ii) belongs to the ISC pathway catalyzing the maturation of Fe-S cluster-containing proteins and (iii) requires iron-rich conditions for its contribution to be significant. A genetic interaction was discovered between cyaY and iscX, the last gene of the isc operon. Deletion of both genes showed an additive effect on Fe-S cluster protein maturation, which led, among others, to increased resistance to aminoglycosides and increased sensitivity to lambda phage infection. Together, these in vivo results establish the importance of CyaY as a member of the ISC-mediated Fe-S cluster biogenesis pathway in E. coli, like it does in eukaryotes, and validate IscX as a new bona fide Fe-S cluster biogenesis factor.
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Affiliation(s)
- Béatrice Roche
- Laboratoire de Chimie Bactérienne, UMR 7283, Aix-Marseille Université-CNRS, Institut de Microbiologie de la Méditerranée, 31 Chemin Joseph Aiguier, 13009, Marseille, France
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40
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IscR plays a role in oxidative stress resistance and pathogenicity of a plant pathogen, Xanthomonas campestris. Microbiol Res 2015; 170:139-46. [DOI: 10.1016/j.micres.2014.08.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 08/01/2014] [Accepted: 08/11/2014] [Indexed: 12/20/2022]
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41
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Voigt B, Schroeter R, Schweder T, Jürgen B, Albrecht D, van Dijl JM, Maurer KH, Hecker M. A proteomic view of cell physiology of the industrial workhorse Bacillus licheniformis. J Biotechnol 2014; 191:139-49. [DOI: 10.1016/j.jbiotec.2014.06.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 05/26/2014] [Accepted: 06/03/2014] [Indexed: 11/16/2022]
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42
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Outten FW. Recent advances in the Suf Fe-S cluster biogenesis pathway: Beyond the Proteobacteria. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:1464-9. [PMID: 25447545 DOI: 10.1016/j.bbamcr.2014.11.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 10/31/2014] [Accepted: 11/03/2014] [Indexed: 01/21/2023]
Abstract
Fe-S clusters play critical roles in cellular function throughout all three kingdoms of life. Consequently, Fe-S cluster biogenesis systems are present in most organisms. The Suf (sulfur formation) system is the most ancient of the three characterized Fe-S cluster biogenesis pathways, which also include the Isc and Nif systems. Much of the first work on the Suf system took place in Gram-negative Proteobacteria used as model organisms. These early studies led to a wealth of biochemical, genetic, and physiological information on Suf function. From those studies we have learned that SufB functions as an Fe-S scaffold in conjunction with SufC (and in some cases SufD). SufS and SufE together mobilize sulfur for cluster assembly and SufA traffics the complete Fe-S cluster from SufB to target apo-proteins. However, recent progress on the Suf system in other organisms has opened up new avenues of research and new hypotheses about Suf function. This review focuses primarily on the most recent discoveries about the Suf pathway and where those new models may lead the field. This article is part of a Special Issue entitled: Fe/S proteins: Analysis, structure, function, biogenesis and diseases.
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Affiliation(s)
- F Wayne Outten
- University of South Carolina, Department of Chemistry and Biochemistry, 631 Sumter Street, Columbia, SC 29208, USA.
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Coordinate regulation of the Suf and Isc Fe-S cluster biogenesis pathways by IscR is essential for viability of Escherichia coli. J Bacteriol 2014; 196:4315-23. [PMID: 25266384 DOI: 10.1128/jb.01975-14] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Fe-S cluster biogenesis is essential for the viability of most organisms. In Escherichia coli, this process requires either the housekeeping Isc or the stress-induced Suf pathway. The global regulator IscR coordinates cluster synthesis by repressing transcription of the isc operon by [2Fe-2S]-IscR and activating expression of the suf operon. We show that either [2Fe-2S]-IscR or apo-IscR can activate suf, making expression sensitive to mainly IscR levels and not the cluster state, unlike isc expression. We also demonstrate that in the absence of isc, IscR-dependent suf activation is essential since strains lacking both the Isc pathway and IscR were not viable unless Suf was expressed ectopically. Similarly, removal of the IscR binding site in the sufA promoter also led to a requirement for isc. Furthermore, suf expression was increased in a Δisc mutant, presumably due to increased IscR levels in this mutant. This was surprising because the iron-dependent repressor Fur, whose higher-affinity binding at the sufA promoter should occlude IscR binding, showed only partial repression. In addition, Fur derepression was not sufficient for viability in the absence of IscR and the Isc pathway, highlighting the importance of direct IscR activation. Finally, a mutant lacking Fur and the Isc pathway increased suf expression to the highest observed levels and nearly restored [2Fe-2S]-IscR activity, providing a mechanism for regulating IscR activity under stress conditions. Together, these findings have enhanced our understanding of the homeostatic mechanism by which cells use one regulator, IscR, to differentially control Fe-S cluster biogenesis pathways to ensure viability.
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Boyd ES, Thomas KM, Dai Y, Boyd JM, Outten FW. Interplay between oxygen and Fe-S cluster biogenesis: insights from the Suf pathway. Biochemistry 2014; 53:5834-47. [PMID: 25153801 PMCID: PMC4172210 DOI: 10.1021/bi500488r] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
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Iron–sulfur (Fe–S)
cluster metalloproteins conduct
essential functions in nearly all contemporary forms of life. The
nearly ubiquitous presence of Fe–S clusters and the fundamental
requirement for Fe–S clusters in both aerobic and anaerobic
Archaea, Bacteria, and Eukarya suggest that these clusters were likely
integrated into central metabolic pathways early in the evolution
of life prior to the widespread oxidation of Earth’s atmosphere.
Intriguingly, Fe–S cluster-dependent metabolism is sensitive
to disruption by oxygen because of the decreased bioavailability of
ferric iron as well as direct oxidation of sulfur trafficking intermediates
and Fe–S clusters by reactive oxygen species. This fact, coupled
with the ubiquity of Fe–S clusters in aerobic organisms, suggests
that organisms evolved with mechanisms that facilitate the biogenesis
and use of these essential cofactors in the presence of oxygen, which
gradually began to accumulate around 2.5 billion years ago as oxygenic
photosynthesis proliferated and reduced minerals that buffered against
oxidation were depleted. This review highlights the most ancient of
the Fe–S cluster biogenesis pathways, the Suf system, which
likely was present in early anaerobic forms of life. Herein, we use
the evolution of the Suf pathway to assess the relationships between
the biochemical functions and physiological roles of Suf proteins,
with an emphasis on the selective pressure of oxygen toxicity. Our
analysis suggests that diversification into oxygen-containing environments
disrupted iron and sulfur metabolism and was a main driving force
in the acquisition of accessory Suf proteins (such as SufD, SufE,
and SufS) by the core SufB–SufC scaffold complex. This analysis
provides a new framework for the study of Fe–S cluster biogenesis
pathways and Fe–S cluster-containing metalloenzymes and their
complicated patterns of divergence in response to oxygen.
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Affiliation(s)
- Eric S Boyd
- Department of Microbiology and Immunology, Montana State University , 109 Lewis Hall, Bozeman, Montana 59717, United States
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45
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Tan G, Cheng Z, Pang Y, Landry AP, Li J, Lu J, Ding H. Copper binding in IscA inhibits iron-sulphur cluster assembly in Escherichia coli. Mol Microbiol 2014; 93:629-44. [PMID: 24946160 DOI: 10.1111/mmi.12676] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2014] [Indexed: 11/28/2022]
Abstract
Among the iron-sulphur cluster assembly proteins encoded by gene cluster iscSUA-hscBA-fdx in Escherichia coli, IscA has a unique and strong iron binding activity and can provide iron for iron-sulphur cluster assembly in proteins in vitro. Deletion of IscA and its paralogue SufA results in an E. coli mutant that fails to assemble [4Fe-4S] clusters in proteins under aerobic conditions, suggesting that IscA has a crucial role for iron-sulphur cluster biogenesis. Here we report that among the iron-sulphur cluster assembly proteins, IscA also has a strong and specific binding activity for Cu(I) in vivo and in vitro. The Cu(I) centre in IscA is stable and resistant to oxidation under aerobic conditions. Mutation of the conserved cysteine residues that are essential for the iron binding in IscA abolishes the copper binding activity, indicating that copper and iron may share the same binding site in the protein. Additional studies reveal that copper can compete with iron for the metal binding site in IscA and effectively inhibits the IscA-mediated [4Fe-4S] cluster assembly in E. coli cells. The results suggest that copper may not only attack the [4Fe-4S] clusters in dehydratases, but also block the [4Fe-4S] cluster assembly in proteins by targeting IscA in cells.
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Affiliation(s)
- Guoqiang Tan
- Laboratory of Molecular Medicine, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China; Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
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46
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Riboldi GP, Bierhals CG, de Mattos EP, Frazzon APG, d‘Azevedo PA, Frazzon J. Oxidative stress enhances the expression of sulfur assimilation genes: preliminary insights on the Enterococcus faecalis iron-sulfur cluster machinery regulation. Mem Inst Oswaldo Cruz 2014; 109:408-13. [PMID: 24936909 PMCID: PMC4155840 DOI: 10.1590/0074-0276140006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 03/27/2014] [Indexed: 11/21/2022] Open
Abstract
The Firmicutes bacteria participate extensively in virulence and pathological processes. Enterococcus faecalis is a commensal microorganism; however, it is also a pathogenic bacterium mainly associated with nosocomial infections in immunocompromised patients. Iron-sulfur [Fe-S] clusters are inorganic prosthetic groups involved in diverse biological processes, whose in vivo formation requires several specific protein machineries. Escherichia coli is one of the most frequently studied microorganisms regarding [Fe-S] cluster biogenesis and encodes the iron-sulfur cluster and sulfur assimilation systems. In Firmicutes species, a unique operon composed of the sufCDSUB genes is responsible for [Fe-S] cluster biogenesis. The aim of this study was to investigate the potential of the E. faecalis sufCDSUB system in the [Fe-S] cluster assembly using oxidative stress and iron depletion as adverse growth conditions. Quantitative real-time polymerase chain reaction demonstrated, for the first time, that Gram-positive bacteria possess an OxyR component responsive to oxidative stress conditions, as fully described for E. coli models. Likewise, strong expression of the sufCDSUB genes was observed in low concentrations of hydrogen peroxide, indicating that the lowest concentration of oxygen free radicals inside cells, known to be highly damaging to [Fe-S] clusters, is sufficient to trigger the transcriptional machinery for prompt replacement of [Fe-S] clusters.
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Affiliation(s)
- Gustavo Pelicioli Riboldi
- Laboratório de Cocos Gram-positivos e Microbiologia Molecular,
Departamento de Microbiologia, Universidade Federal de Ciências da Saúde de Porto
Alegre, Porto Alegre, RS, Brasil
| | | | | | | | - Pedro Alves d‘Azevedo
- Laboratório de Cocos Gram-positivos e Microbiologia Molecular,
Departamento de Microbiologia, Universidade Federal de Ciências da Saúde de Porto
Alegre, Porto Alegre, RS, Brasil
| | - Jeverson Frazzon
- Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do
Rio Grande do Sul, Porto Alegre, RS, Brasil
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47
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Santos-Garcia D, Latorre A, Moya A, Gibbs G, Hartung V, Dettner K, Kuechler SM, Silva FJ. Small but powerful, the primary endosymbiont of moss bugs, Candidatus Evansia muelleri, holds a reduced genome with large biosynthetic capabilities. Genome Biol Evol 2014; 6:1875-93. [PMID: 25115011 PMCID: PMC4122945 DOI: 10.1093/gbe/evu149] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Moss bugs (Coleorrhyncha: Peloridiidae) are members of the order Hemiptera, and like many hemipterans, they have symbiotic associations with intracellular bacteria to fulfill nutritional requirements resulting from their unbalanced diet. The primary endosymbiont of the moss bugs, Candidatus Evansia muelleri, is phylogenetically related to Candidatus Carsonella ruddii and Candidatus Portiera aleyrodidarum, primary endosymbionts of psyllids and whiteflies, respectively. In this work, we report the genome of Candidatus Evansia muelleri Xc1 from Xenophyes cascus, which is the only obligate endosymbiont present in the association. This endosymbiont possesses an extremely reduced genome similar to Carsonella and Portiera. It has crossed the borderline to be considered as an autonomous cell, requiring the support of the insect host for some housekeeping cell functions. Interestingly, in spite of its small genome size, Evansia maintains enriched amino acid (complete or partial pathways for ten essential and six nonessential amino acids) and sulfur metabolisms, probably related to the poor diet of the insect, based on bryophytes, which contains very low levels of nitrogenous and sulfur compounds. Several facts, including the congruence of host (moss bugs, whiteflies, and psyllids) and endosymbiont phylogenies and the retention of the same ribosomal RNA operon during genome reduction in Evansia, Portiera, and Carsonella, suggest the existence of an ancient endosymbiotic Halomonadaceae clade associated with Hemiptera. Three possible scenarios for the origin of these three primary endosymbiont genera are proposed and discussed.
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Affiliation(s)
- Diego Santos-Garcia
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain
| | - Amparo Latorre
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain
- Unidad Mixta de Investigación en Genómica y Salud (FISABIO-Salud Pública and Universitat de València), Spain
| | - Andrés Moya
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain
- Unidad Mixta de Investigación en Genómica y Salud (FISABIO-Salud Pública and Universitat de València), Spain
| | - George Gibbs
- School of Biological Science, Victoria University, Wellington, New Zealand
| | - Viktor Hartung
- Museum für Naturkunde, Leibniz-Institute for Research on Evolution and Biodiversity, Berlin, Germany
| | - Konrad Dettner
- Department of Animal Ecology II, University of Bayreuth, Germany
| | - Stefan Martin Kuechler
- Department of Animal Ecology II, University of Bayreuth, Germany
- *Corresponding author: E-mail: ;
| | - Francisco J. Silva
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain
- Unidad Mixta de Investigación en Genómica y Salud (FISABIO-Salud Pública and Universitat de València), Spain
- *Corresponding author: E-mail: ;
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48
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Gama-Castro S, Rinaldi F, López-Fuentes A, Balderas-Martínez YI, Clematide S, Ellendorff TR, Santos-Zavaleta A, Marques-Madeira H, Collado-Vides J. Assisted curation of regulatory interactions and growth conditions of OxyR in E. coli K-12. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2014; 2014:bau049. [PMID: 24903516 PMCID: PMC4207228 DOI: 10.1093/database/bau049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Given the current explosion of data within original publications generated in the field of genomics, a recognized bottleneck is the transfer of such knowledge into comprehensive databases. We have for years organized knowledge on transcriptional regulation reported in the original literature of Escherichia coli K-12 into RegulonDB (http://regulondb.ccg.unam.mx), our database that is currently supported by >5000 papers. Here, we report a first step towards the automatic biocuration of growth conditions in this corpus. Using the OntoGene text-mining system (http://www.ontogene.org), we extracted and manually validated regulatory interactions and growth conditions in a new approach based on filters that enable the curator to select informative sentences from preprocessed full papers. Based on a set of 48 papers dealing with oxidative stress by OxyR, we were able to retrieve 100% of the OxyR regulatory interactions present in RegulonDB, including the transcription factors and their effect on target genes. Our strategy was designed to extract, as we did, their growth conditions. This result provides a proof of concept for a more direct and efficient curation process, and enables us to define the strategy of the subsequent steps to be implemented for a semi-automatic curation of original literature dealing with regulation of gene expression in bacteria. This project will enhance the efficiency and quality of the curation of knowledge present in the literature of gene regulation, and contribute to a significant increase in the encoding of the regulatory network of E. coli. RegulonDB Database URL:http://regulondb.ccg.unam.mx OntoGene URL:http://www.ontogene.org
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Affiliation(s)
- Socorro Gama-Castro
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100 and Institute of Computational Linguistics, University of Zurich, Binzmuhlestrasse 14, Zurich 8050, Switzerland
| | - Fabio Rinaldi
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100 and Institute of Computational Linguistics, University of Zurich, Binzmuhlestrasse 14, Zurich 8050, Switzerland
| | - Alejandra López-Fuentes
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100 and Institute of Computational Linguistics, University of Zurich, Binzmuhlestrasse 14, Zurich 8050, Switzerland
| | - Yalbi Itzel Balderas-Martínez
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100 and Institute of Computational Linguistics, University of Zurich, Binzmuhlestrasse 14, Zurich 8050, Switzerland
| | - Simon Clematide
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100 and Institute of Computational Linguistics, University of Zurich, Binzmuhlestrasse 14, Zurich 8050, Switzerland
| | - Tilia Renate Ellendorff
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100 and Institute of Computational Linguistics, University of Zurich, Binzmuhlestrasse 14, Zurich 8050, Switzerland
| | - Alberto Santos-Zavaleta
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100 and Institute of Computational Linguistics, University of Zurich, Binzmuhlestrasse 14, Zurich 8050, Switzerland
| | - Hernani Marques-Madeira
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100 and Institute of Computational Linguistics, University of Zurich, Binzmuhlestrasse 14, Zurich 8050, Switzerland
| | - Julio Collado-Vides
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100 and Institute of Computational Linguistics, University of Zurich, Binzmuhlestrasse 14, Zurich 8050, Switzerland
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49
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Global identification of genes affecting iron-sulfur cluster biogenesis and iron homeostasis. J Bacteriol 2014; 196:1238-49. [PMID: 24415728 DOI: 10.1128/jb.01160-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Iron-sulfur (Fe-S) clusters are ubiquitous cofactors that are crucial for many physiological processes in all organisms. In Escherichia coli, assembly of Fe-S clusters depends on the activity of the iron-sulfur cluster (ISC) assembly and sulfur mobilization (SUF) apparatus. However, the underlying molecular mechanisms and the mechanisms that control Fe-S cluster biogenesis and iron homeostasis are still poorly defined. In this study, we performed a global screen to identify the factors affecting Fe-S cluster biogenesis and iron homeostasis using the Keio collection, which is a library of 3,815 single-gene E. coli knockout mutants. The approach was based on radiolabeling of the cells with [2-(14)C]dihydrouracil, which entirely depends on the activity of an Fe-S enzyme, dihydropyrimidine dehydrogenase. We identified 49 genes affecting Fe-S cluster biogenesis and/or iron homeostasis, including 23 genes important only under microaerobic/anaerobic conditions. This study defines key proteins associated with Fe-S cluster biogenesis and iron homeostasis, which will aid further understanding of the cellular mechanisms that coordinate the processes. In addition, we applied the [2-(14)C]dihydrouracil-labeling method to analyze the role of amino acid residues of an Fe-S cluster assembly scaffold (IscU) as a model of the Fe-S cluster assembly apparatus. The analysis showed that Cys37, Cys63, His105, and Cys106 are essential for the function of IscU in vivo, demonstrating the potential of the method to investigate in vivo function of proteins involved in Fe-S cluster assembly.
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50
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Bhubhanil S, Niamyim P, Sukchawalit R, Mongkolsuk S. Cysteine desulphurase-encoding gene sufS2 is required for the repressor function of RirA and oxidative resistance in Agrobacterium tumefaciens. MICROBIOLOGY-SGM 2013; 160:79-90. [PMID: 24194559 DOI: 10.1099/mic.0.068643-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Agrobacterium tumefaciens genome contains a cluster of genes that are predicted to encode Fe-S cluster assembly proteins, and this cluster is known as the sufS2BCDS1XA operon. sufS2 is the first gene in the operon, and it was inactivated to determine its physiological function. The sufS2 mutant exhibited a small colony phenotype, grew slower than the wild-type strain and was more sensitive to various oxidants including peroxide, organic hydroperoxide and superoxide. The sufS2 gene was negatively regulated by iron response regulator (Irr) and rhizobial iron regulator (RirA) under low and high iron conditions, respectively, and was inducible in response to oxidative stress. The oxidant-induced expression of sufS2 was controlled by Irr, RirA and an additional but not yet identified mechanism. sufS2 was required for RirA activity in the repression of a sufS2 promoter-lacZ fusion. RirA may use Fe-S as its cofactor. sufS2 disruption may cause a defect in the Fe-S supply and could thereby affect the RirA activity. The three conserved cysteine residues (C91, C99 and C105) in RirA were predicted to coordinate with the Fe-S cluster and were shown to be essential for RirA repression of the sufS2-lacZ fusion. These results suggested that sufS2 is important for the survival of A. tumefaciens.
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Affiliation(s)
- Sakkarin Bhubhanil
- Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand.,Applied Biological Sciences, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand
| | - Phettree Niamyim
- Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand.,Applied Biological Sciences, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand
| | - Rojana Sukchawalit
- Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.,Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand.,Applied Biological Sciences, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand
| | - Skorn Mongkolsuk
- Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.,Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.,Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand
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