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Garcia PS, Gribaldo S, Barras F. When iron and sulfur met on an anoxic planet and eventually made clusters essential for life. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119730. [PMID: 38631441 DOI: 10.1016/j.bbamcr.2024.119730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/11/2024] [Accepted: 04/04/2024] [Indexed: 04/19/2024]
Abstract
[FeS] clusters are co-factors that are essential for life and are synthesized by dedicated multiprotein cellular machineries. In this review, we present the current scenario for the emergence and the diversification of the [FeS] cluster biosynthesis machineries. In addition to well-known NIF, ISC and SUF machineries, two alternative minimal systems, SMS, and MIS, were recently identified. Taxonomic distribution and phylogeny analyses indicate that SMS and MIS were present in the Last Universal Common Ancestor (LUCA), well before the increase of oxygen on Earth. ISC, SUF and NIF systems emerged later in the history of life. The possible reasons for the emergence and diversification of these machineries are discussed.
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Affiliation(s)
- Pierre Simon Garcia
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Department of Microbiology, Unit Stress Adaptation and Metabolism in Enterobacteria, Paris, France; Institut Pasteur, Université Paris Cité, Department of Microbiology, Unit Evolutionary Biology of the Microbial Cell, Paris, France
| | - Simonetta Gribaldo
- Institut Pasteur, Université Paris Cité, Department of Microbiology, Unit Evolutionary Biology of the Microbial Cell, Paris, France
| | - Frédéric Barras
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Department of Microbiology, Unit Stress Adaptation and Metabolism in Enterobacteria, Paris, France.
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2
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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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3
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Stephens AC, Richardson AR. Recent developments in our understanding of the physiology and nitric oxide-resistance of Staphylococcus aureus. Adv Microb Physiol 2022; 81:111-135. [PMID: 36167441 DOI: 10.1016/bs.ampbs.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Staphylococcus aureus is an important human pathogen causing a wide range of disease presentations. It harbors a vast array of virulence factors and drug-resistance determinants. All of these factors are coordinately regulated by a hand full of key transcriptional regulators. The regulation and expression of these factors are tightly intertwined with the metabolic state of the cell. Furthermore, alterations in central metabolism are also key to the ability of S. aureus to resist clearance by the host innate immune response, including nitric oxide (NO·) production. Given the fact that central metabolism directly influences virulence, drug resistance and immune tolerance in S. aureus, a better understanding of the metabolic capabilities of this pathogen is critical. This work highlights some of the major findings within the last five years surrounding S. aureus central metabolism, both organic and inorganic. These are also put in the context of the unique NO·-resistance associated with this pathogen as well as their contributions to virulence. The more we understand the intersection between central metabolism and virulence capabilities in S. aureus, the better the chances of developing novel therapeutics so desperately needed to treat this pathogen.
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Affiliation(s)
- Amelia C Stephens
- Department of Microbiology & Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, United States
| | - Anthony R Richardson
- Department of Microbiology & Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, United States.
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4
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Tripathi A, Anand K, Das M, O'Niel RA, P S S, Thakur C, R L RR, Rajmani RS, Chandra N, Laxman S, Singh A. Mycobacterium tuberculosis requires SufT for Fe-S cluster maturation, metabolism, and survival in vivo. PLoS Pathog 2022; 18:e1010475. [PMID: 35427399 PMCID: PMC9045647 DOI: 10.1371/journal.ppat.1010475] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 04/27/2022] [Accepted: 03/25/2022] [Indexed: 11/18/2022] Open
Abstract
Iron-sulfur (Fe-S) cluster proteins carry out essential cellular functions in diverse organisms, including the human pathogen Mycobacterium tuberculosis (Mtb). The mechanisms underlying Fe-S cluster biogenesis are poorly defined in Mtb. Here, we show that Mtb SufT (Rv1466), a DUF59 domain-containing essential protein, is required for the Fe-S cluster maturation. Mtb SufT homodimerizes and interacts with Fe-S cluster biogenesis proteins; SufS and SufU. SufT also interacts with the 4Fe-4S cluster containing proteins; aconitase and SufR. Importantly, a hyperactive cysteine in the DUF59 domain mediates interaction of SufT with SufS, SufU, aconitase, and SufR. We efficiently repressed the expression of SufT to generate a SufT knock-down strain in Mtb (SufT-KD) using CRISPR interference. Depleting SufT reduces aconitase's enzymatic activity under standard growth conditions and in response to oxidative stress and iron limitation. The SufT-KD strain exhibited defective growth and an altered pool of tricarboxylic acid cycle intermediates, amino acids, and sulfur metabolites. Using Seahorse Extracellular Flux analyzer, we demonstrated that SufT depletion diminishes glycolytic rate and oxidative phosphorylation in Mtb. The SufT-KD strain showed defective survival upon exposure to oxidative stress and nitric oxide. Lastly, SufT depletion reduced the survival of Mtb in macrophages and attenuated the ability of Mtb to persist in mice. Altogether, SufT assists in Fe-S cluster maturation and couples this process to bioenergetics of Mtb for survival under low and high demand for Fe-S clusters.
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Affiliation(s)
- Ashutosh Tripathi
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | - Kushi Anand
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | - Mayashree Das
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | - Ruchika Annie O'Niel
- Institute for Stem Cell Science and Regenerative Medicine (inStem), Bangalore, India
| | - Sabarinath P S
- Institute for Stem Cell Science and Regenerative Medicine (inStem), Bangalore, India
| | - Chandrani Thakur
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Raghunatha Reddy R L
- Regional Horticultural Research and Extension Centre (RHREK), GKVK, Bengaluru, India
| | - Raju S Rajmani
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | - Nagasuma Chandra
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Sunil Laxman
- Institute for Stem Cell Science and Regenerative Medicine (inStem), Bangalore, India
| | - Amit Singh
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
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5
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Abstract
Building iron-sulfur (Fe-S) clusters and assembling Fe-S proteins are essential actions for life on Earth. The three processes that sustain life, photosynthesis, nitrogen fixation, and respiration, require Fe-S proteins. Genes coding for Fe-S proteins can be found in nearly every sequenced genome. Fe-S proteins have a wide variety of functions, and therefore, defective assembly of Fe-S proteins results in cell death or global metabolic defects. Compared to alternative essential cellular processes, there is less known about Fe-S cluster synthesis and Fe-S protein maturation. Moreover, new factors involved in Fe-S protein assembly continue to be discovered. These facts highlight the growing need to develop a deeper biological understanding of Fe-S cluster synthesis, holo-protein maturation, and Fe-S cluster repair. Here, we outline bacterial strategies used to assemble Fe-S proteins and the genetic regulation of these processes. We focus on recent and relevant findings and discuss future directions, including the proposal of using Fe-S protein assembly as an antipathogen target.
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6
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Patel JS, Norambuena J, Al-Tameemi H, Ahn YM, Perryman AL, Wang X, Daher SS, Occi J, Russo R, Park S, Zimmerman M, Ho HP, Perlin DS, Dartois V, Ekins S, Kumar P, Connell N, Boyd JM, Freundlich JS. Bayesian Modeling and Intrabacterial Drug Metabolism Applied to Drug-Resistant Staphylococcus aureus. ACS Infect Dis 2021; 7:2508-2521. [PMID: 34342426 DOI: 10.1021/acsinfecdis.1c00265] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We present the application of Bayesian modeling to identify chemical tools and/or drug discovery entities pertinent to drug-resistant Staphylococcus aureus infections. The quinoline JSF-3151 was predicted by modeling and then empirically demonstrated to be active against in vitro cultured clinical methicillin- and vancomycin-resistant strains while also exhibiting efficacy in a mouse peritonitis model of methicillin-resistant S. aureus infection. We highlight the utility of an intrabacterial drug metabolism (IBDM) approach to probe the mechanism by which JSF-3151 is transformed within the bacteria. We also identify and then validate two mechanisms of resistance in S. aureus: one mechanism involves increased expression of a lipocalin protein, and the other arises from the loss of function of an azoreductase. The computational and experimental approaches, discovery of an antibacterial agent, and elucidated resistance mechanisms collectively hold promise to advance our understanding of therapeutic regimens for drug-resistant S. aureus.
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Affiliation(s)
- Jimmy S. Patel
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University − New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States
| | - Javiera Norambuena
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901, United States
| | - Hassan Al-Tameemi
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901, United States
| | - Yong-Mo Ahn
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University − New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States
| | - Alexander L. Perryman
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University − New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States
| | - Xin Wang
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University − New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States
| | - Samer S. Daher
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University − New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States
| | - James Occi
- Department of Medicine, Center for Emerging and Re-emerging Pathogens, Rutgers University − New Jersey Medical School, Newark, New Jersey 07103, United States
| | - Riccardo Russo
- Department of Medicine, Center for Emerging and Re-emerging Pathogens, Rutgers University − New Jersey Medical School, Newark, New Jersey 07103, United States
| | - Steven Park
- Public Health Research Institute, Rutgers University − New Jersey Medical School, 225 Warren St, Newark, New Jersey 07103, United States
| | - Matthew Zimmerman
- Public Health Research Institute, Rutgers University − New Jersey Medical School, 225 Warren St, Newark, New Jersey 07103, United States
| | - Hsin-Pin Ho
- Public Health Research Institute, Rutgers University − New Jersey Medical School, 225 Warren St, Newark, New Jersey 07103, United States
| | - David S. Perlin
- Public Health Research Institute, Rutgers University − New Jersey Medical School, 225 Warren St, Newark, New Jersey 07103, United States
| | - Véronique Dartois
- Public Health Research Institute, Rutgers University − New Jersey Medical School, 225 Warren St, Newark, New Jersey 07103, United States
| | - Sean Ekins
- Collaborations in Chemistry, 5616 Hilltop Needmore Road, Fuquay-Varina, North Carolina 27526, United States
| | - Pradeep Kumar
- Department of Medicine, Center for Emerging and Re-emerging Pathogens, Rutgers University − New Jersey Medical School, Newark, New Jersey 07103, United States
| | - Nancy Connell
- Department of Medicine, Center for Emerging and Re-emerging Pathogens, Rutgers University − New Jersey Medical School, Newark, New Jersey 07103, United States
| | - Jeffrey M. Boyd
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901, United States
| | - Joel S. Freundlich
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University − New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States
- Department of Medicine, Center for Emerging and Re-emerging Pathogens, Rutgers University − New Jersey Medical School, Newark, New Jersey 07103, United States
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7
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Turner ME, Huynh K, Carroll RK, Ahn SJ, Rice KC. Characterization of the Streptococcus mutans SMU.1703c-SMU.1702c Operon Reveals Its Role in Riboflavin Import and Response to Acid Stress. J Bacteriol 2020; 203:e00293-20. [PMID: 33077636 PMCID: PMC7950412 DOI: 10.1128/jb.00293-20] [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: 05/15/2020] [Accepted: 10/15/2020] [Indexed: 11/20/2022] Open
Abstract
Streptococcus mutans utilizes numerous metabolite transporters to obtain essential nutrients in the "feast or famine" environment of the human mouth. S. mutans and most other streptococci are considered auxotrophic for several essential vitamins including riboflavin (vitamin B2), which is used to generate key cofactors and to perform numerous cellular redox reactions. Despite the well-known contributions of this vitamin to central metabolism, little is known about how S. mutans obtains and metabolizes B2 The uncharacterized protein SMU.1703c displays high sequence homology to the riboflavin transporter RibU. Deletion of SMU.1703c hindered S. mutans growth in complex and defined medium in the absence of saturating levels of exogenous riboflavin, whereas deletion of cotranscribed SMU.1702c alone had no apparent effect on growth. Expression of SMU.1703c in a Bacillus subtilis riboflavin auxotroph functionally complemented growth in nonsaturating riboflavin conditions. S. mutans was also able to grow on flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN) in an SMU.1703c-dependent manner. Deletion of SMU.1703c and/or SMU.1702c impacted S. mutans acid stress tolerance, as all mutants showed improved growth at pH 5.5 compared to that of the wild type when medium was supplemented with saturating riboflavin. Cooccurrence of SMU.1703c and SMU.1702c, a hypothetical PAP2 family acid phosphatase gene, appears unique to the streptococci and may suggest a connection of SMU.1702c to the acquisition or metabolism of flavins within this genus. Identification of SMU.1703c as a RibU-like riboflavin transporter furthers our understanding of how S. mutans acquires essential micronutrients within the oral cavity and how this pathogen successfully competes within nutrient-starved oral biofilms.IMPORTANCE Dental caries form when acid produced by oral bacteria erodes tooth enamel. This process is driven by the fermentative metabolism of cariogenic bacteria, most notably Streptococcus mutans Nutrient acquisition is key in the competitive oral cavity, and many organisms have evolved various strategies to procure carbon sources or necessary biomolecules. B vitamins, such as riboflavin, which many oral streptococci must scavenge from the oral environment, are necessary for survival within the competitive oral cavity. However, the primary mechanism and proteins involved in this process remain uncharacterized. This study is important because it identifies a key step in S. mutans riboflavin acquisition and cofactor generation, which may enable the development of novel anticaries treatment strategies via selective targeting of metabolite transporters.
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Affiliation(s)
- Matthew E Turner
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Khanh Huynh
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, Ohio, USA
| | - Sang-Joon Ahn
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Kelly C Rice
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
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8
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Orsini SS, James KL, Reyes DJ, Couto‐Rodriguez RL, Gulko MK, Witte A, Carroll RK, Rice KC. Bacterial-like nitric oxide synthase in the haloalkaliphilic archaeon Natronomonas pharaonis. Microbiologyopen 2020; 9:e1124. [PMID: 33306280 PMCID: PMC7658456 DOI: 10.1002/mbo3.1124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 12/19/2022] Open
Abstract
Bacterial nitric oxide (NO) synthases (bNOS) play diverse and important roles in microbial physiology, stress resistance, and virulence. Although bacterial and mammalian NOS enzymes have been well-characterized, comparatively little is known about the prevalence and function of NOS enzymes in Archaea. Analysis of archaeal genomes revealed that highly conserved bNOS homologs were restricted to members of the Halobacteria. Of these, Natronomonas pharaonis NOS (npNOS) was chosen for further characterization. NO production was confirmed in heterologously expressed His-tagged npNOS by coupling nitrite production from N-hydroxy-L-arginine in an H2O2-supported reaction. Additionally, the nos gene was successfully targeted and disrupted to create a Nmn. pharaonis nos mutant by adapting an established Natrialba magadii transformation protocol. Genome re-sequencing of this mutant revealed an additional frameshift in a putative cation-acetate symporter gene, which could contribute to altered acetate metabolism in the nos mutant. Inactivation of Nmn. pharaonis nos was also associated with several phenotypes congruent with bacterial nos mutants (altered growth, increased oxygen consumption, increased pigment, increased UV susceptibility), suggesting that NOS function may be conserved between bacteria and archaea. These studies are the first to describe genetic inactivation and characterization of a Nmn. pharaonis gene and provides enhanced tools for probing its physiology.
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Affiliation(s)
- Silvia S. Orsini
- Department of Microbiology and Cell ScienceIFASUniversity of FloridaGainesvilleFLUSA
- Present address:
Pharma ServicesViral Vector ServicesThermo Fisher ScientificAlachuaFLUSA
| | - Kimberly L. James
- Department of Microbiology and Cell ScienceIFASUniversity of FloridaGainesvilleFLUSA
| | - Destiny J. Reyes
- Department of Microbiology and Cell ScienceIFASUniversity of FloridaGainesvilleFLUSA
- Present address:
Pharma ServicesViral Vector ServicesThermo Fisher ScientificAlachuaFLUSA
| | | | - Miriam K. Gulko
- Department OesterheltMax Planck Institut für BiochemieMartinsriedGermany
| | - Angela Witte
- Department of Microbiology, Immunobiology and GeneticsMPL LaboratoriesUniversity of ViennaViennaAustria
| | | | - Kelly C. Rice
- Department of Microbiology and Cell ScienceIFASUniversity of FloridaGainesvilleFLUSA
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9
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Al-Tameemi H, Beavers WN, Norambuena J, Skaar EP, Boyd JM. Staphylococcus aureus lacking a functional MntABC manganese import system has increased resistance to copper. Mol Microbiol 2020; 115:554-573. [PMID: 33034093 DOI: 10.1111/mmi.14623] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/28/2020] [Accepted: 10/04/2020] [Indexed: 12/17/2022]
Abstract
S. aureus USA300 isolates utilize the copBL and copAZ gene products to prevent Cu intoxication. We created and examined a ΔcopAZ ΔcopBL mutant strain (cop-). The cop- strain was sensitive to Cu and accumulated intracellular Cu. We screened a transposon (Tn) mutant library in the cop- background and isolated strains with Tn insertions in the mntABC operon that permitted growth in the presence of Cu. The mutations were in mntA and they were recessive. Under the growth conditions utilized, MntABC functioned in manganese (Mn) import. When cultured with Cu, strains containing a mntA::Tn accumulated less Cu than the parent strain. Mn(II) supplementation improved growth when cop- was cultured with Cu and this phenotype was dependent upon the presence of MntR, which is a repressor of mntABC transcription. A ΔmntR strain had an increased Cu load and decreased growth in the presence of Cu, which was abrogated by the introduction of mntA::Tn. Over-expression of mntABC increased cellular Cu load and sensitivity to Cu. The presence of a mntA::Tn mutation protected iron-sulfur (FeS) enzymes from inactivation by Cu. The data presented are consistent with a model wherein defective MntABC results in decreased cellular Cu accumulation and protection to FeS enzymes from Cu poisoning.
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Affiliation(s)
- Hassan Al-Tameemi
- Department of Biochemistry and Microbiology, Rutgers, the State University of New Jersey, New Brunswick, NJ, USA
| | - William N Beavers
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Javiera Norambuena
- Department of Biochemistry and Microbiology, Rutgers, the State University of New Jersey, New Brunswick, NJ, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jeffrey M Boyd
- Department of Biochemistry and Microbiology, Rutgers, the State University of New Jersey, New Brunswick, NJ, USA
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10
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Braymer JJ, Freibert SA, Rakwalska-Bange M, Lill R. Mechanistic concepts of iron-sulfur protein biogenesis in Biology. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118863. [PMID: 33007329 DOI: 10.1016/j.bbamcr.2020.118863] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 09/14/2020] [Accepted: 09/17/2020] [Indexed: 02/08/2023]
Abstract
Iron-sulfur (Fe/S) proteins are present in virtually all living organisms and are involved in numerous cellular processes such as respiration, photosynthesis, metabolic reactions, nitrogen fixation, radical biochemistry, protein synthesis, antiviral defense, and genome maintenance. Their versatile functions may go back to the proposed role of their Fe/S cofactors in the origin of life as efficient catalysts and electron carriers. More than two decades ago, it was discovered that the in vivo synthesis of cellular Fe/S clusters and their integration into polypeptide chains requires assistance by complex proteinaceous machineries, despite the fact that Fe/S proteins can be assembled chemically in vitro. In prokaryotes, three Fe/S protein biogenesis systems are known; ISC, SUF, and the more specialized NIF. The former two systems have been transferred by endosymbiosis from bacteria to mitochondria and plastids, respectively, of eukaryotes. In their cytosol, eukaryotes use the CIA machinery for the biogenesis of cytosolic and nuclear Fe/S proteins. Despite the structural diversity of the protein constituents of these four machineries, general mechanistic concepts underlie the complex process of Fe/S protein biogenesis. This review provides a comprehensive and comparative overview of the various known biogenesis systems in Biology, and summarizes their common or diverging molecular mechanisms, thereby illustrating both the conservation and diverse adaptions of these four machineries during evolution and under different lifestyles. Knowledge of these fundamental biochemical pathways is not only of basic scientific interest, but is important for the understanding of human 'Fe/S diseases' and can be used in biotechnology.
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Affiliation(s)
- Joseph J Braymer
- Institut für Zytobiologie, Philipps-Universität Marburg, Robert-Koch-Str. 6, 35032 Marburg, Germany
| | - Sven A Freibert
- Institut für Zytobiologie, Philipps-Universität Marburg, Robert-Koch-Str. 6, 35032 Marburg, Germany
| | | | - Roland Lill
- Institut für Zytobiologie, Philipps-Universität Marburg, Robert-Koch-Str. 6, 35032 Marburg, Germany; SYNMIKRO Center for Synthetic Microbiology, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35043 Marburg, Germany.
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11
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Blahut M, Sanchez E, Fisher CE, Outten FW. Fe-S cluster biogenesis by the bacterial Suf pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118829. [PMID: 32822728 DOI: 10.1016/j.bbamcr.2020.118829] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/11/2020] [Accepted: 08/11/2020] [Indexed: 01/01/2023]
Abstract
Biogenesis of iron-sulfur (FeS) clusters in an essential process in living organisms due to the critical role of FeS cluster proteins in myriad cell functions. During biogenesis of FeS clusters, multi-protein complexes are used to drive the mobilization and protection of reactive sulfur and iron intermediates, regulate assembly of various FeS clusters on an ATPase-dependent, multi-protein scaffold, and target nascent clusters to their downstream protein targets. The evolutionarily ancient sulfur formation (Suf) pathway for FeS cluster assembly is found in bacteria and archaea. In Escherichia coli, the Suf pathway functions as an emergency pathway under conditions of iron limitation or oxidative stress. In other pathogenic bacteria, such as Mycobacterium tuberculosis and Enterococcus faecalis, the Suf pathway is the sole source for FeS clusters and therefore is a potential target for the development of novel antibacterial compounds. Here we summarize the considerable progress that has been made in characterizing the first step of mobilization and protection of reactive sulfur carried out by the SufS-SufE or SufS-SufU complex, FeS cluster assembly on SufBC2D scaffold complexes, and the downstream trafficking of nascent FeS clusters to A-type carrier (ATC) proteins. Cell Biology of Metals III edited by Roland Lill and Mick Petris.
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Affiliation(s)
- Matthew Blahut
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA
| | - Enis Sanchez
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA
| | - Claire E Fisher
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA
| | - F Wayne Outten
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA.
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Khemici V, Prados J, Petrignani B, Di Nolfi B, Bergé E, Manzano C, Giraud C, Linder P. The DEAD-box RNA helicase CshA is required for fatty acid homeostasis in Staphylococcus aureus. PLoS Genet 2020; 16:e1008779. [PMID: 32730248 PMCID: PMC7392221 DOI: 10.1371/journal.pgen.1008779] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 04/15/2020] [Indexed: 01/05/2023] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen that can grow in a wide array of conditions: on abiotic surfaces, on the skin, in the nose, in planktonic or biofilm forms and can cause many type of infections. Consequently, S. aureus must be able to adapt rapidly to these changing growth conditions, an ability largely driven at the posttranscriptional level. RNA helicases of the DEAD-box family play an important part in this process. In particular, CshA, which is part of the degradosome, is required for the rapid turnover of certain mRNAs and its deletion results in cold-sensitivity. To understand the molecular basis of this phenotype, we conducted a large genetic screen isolating 82 independent suppressors of cold growth. Full genome sequencing revealed the fatty acid synthesis pathway affected in many suppressor strains. Consistent with that result, sublethal doses of triclosan, a FASII inhibitor, can partially restore growth of a cshA mutant in the cold. Overexpression of the genes involved in branched-chain fatty acid synthesis was also able to suppress the cold-sensitivity. Using gas chromatography analysis of fatty acids, we observed an imbalance of straight and branched-chain fatty acids in the cshA mutant, compared to the wild-type. This imbalance is compensated in the suppressor strains. Thus, we reveal for the first time that the cold sensitive growth phenotype of a DEAD-box mutant can be explained, at least partially, by an improper membrane composition. The defect correlates with an accumulation of the pyruvate dehydrogenase complex mRNA, which is inefficiently degraded in absence of CshA. We propose that the resulting accumulation of acetyl-CoA fuels straight-chained fatty acid production at the expense of the branched ones. Strikingly, addition of acetate into the medium mimics the cshA deletion phenotype, resulting in cold sensitivity suppressed by the mutations found in our genetic screen or by sublethal doses of triclosan. DEAD-box RNA helicases are highly conserved proteins found in all domains of life. By acting on RNA secondary structures they determine the fate of RNA from transcription to degradation. Bacterial DEAD-box RNA helicases are not essential under laboratory conditions but are required for fitness and under stress conditions. Whereas many DEAD-box protein mutants display a cold sensitive phenotype, the underlying mechanisms have been studied only in few cases and found to be associated with ribosome biogenesis. We aimed here to elucidate the cold sensitivity of a cshA mutant in the Gram-positive opportunist pathogen Staphylococcus aureus. Our study revealed for the first time that part of the cold sensitivity is related to the inability of the bacterium to adapt the cytoplasmic membrane to lower temperatures. We propose that straight-chain fatty acid synthesis, reduced to sustain growth at lower temperature, is maintained due to inefficient turn-over of the pyruvate dehydrogenase mRNA, leading to elevated acetyl-CoA levels. This study allowed us to unravel at least in part the cold sensitive phenotype and to show that the pyruvate dehydrogenase activity plays an important function in the regulation of fatty acid composition of the membrane, a process that remains poorly understood in Gram-positive bacteria.
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Affiliation(s)
- Vanessa Khemici
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Julien Prados
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Bianca Petrignani
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Benjamin Di Nolfi
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Elodie Bergé
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Caroline Manzano
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Caroline Giraud
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Patrick Linder
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- * E-mail:
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Turner ME, Huynh K, Carney OV, Gross D, Carroll RK, Ahn SJ, Rice KC. Genomic instability of TnSMU2 contributes to Streptococcus mutans biofilm development and competence in a cidB mutant. Microbiologyopen 2019; 8:e934. [PMID: 31599128 PMCID: PMC6925190 DOI: 10.1002/mbo3.934] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/20/2019] [Accepted: 08/21/2019] [Indexed: 02/06/2023] Open
Abstract
Streptococcus mutans is a key pathogenic bacterium in the oral cavity and a primary contributor to dental caries. The S. mutans Cid/Lrg system likely contributes to tolerating stresses encountered in this environment as cid and/or lrg mutants exhibit altered oxidative stress sensitivity, genetic competence, and biofilm phenotypes. It was recently noted that the cidB mutant had two stable colony morphologies: a “rough” phenotype (similar to wild type) and a “smooth” phenotype. In our previously published work, the cidB rough mutant exhibited increased sensitivity to oxidative stress, and RNAseq identified widespread transcriptomic changes in central carbon metabolism and oxidative stress response genes. In this current report, we conducted Illumina‐based genome resequencing of wild type, cidB rough, and cidB smooth mutants and compared their resistance to oxidative and acid stress, biofilm formation, and competence phenotypes. Both cidB mutants exhibited comparable aerobic growth inhibition on agar plates, during planktonic growth, and in the presence of 1 mM hydrogen peroxide. The cidB smooth mutant displayed a significant competence defect in BHI, which was rescuable by synthetic CSP. Both cidB mutants also displayed reduced XIP‐mediated competence, although this reduction was more pronounced in the cidB smooth mutant. Anaerobic biofilms of the cidB smooth mutant displayed increased propidium iodide staining, but corresponding biofilm CFU data suggest this phenotype is due to cell damage and not increased cell death. The cidB rough anaerobic biofilms showed altered structure relative to wild type (reduced biomass and average thickness) which correlated with decreased CFU counts. Sequencing data revealed that the cidB smooth mutant has a unique “loss of read coverage” of ~78 kb of DNA, corresponding to the genomic island TnSMU2 and genes flanking its 3′ end. It is therefore likely that the unique biofilm and competence phenotypes of the cidB smooth mutant are related to its genomic changes in this region.
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Affiliation(s)
- Matthew E Turner
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Khanh Huynh
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - O'neshia V Carney
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Dennis Gross
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, OH, USA
| | - Sang-Joon Ahn
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Kelly C Rice
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
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The ClpCP Complex Modulates Respiratory Metabolism in Staphylococcus aureus and Is Regulated in a SrrAB-Dependent Manner. J Bacteriol 2019; 201:JB.00188-19. [PMID: 31109995 DOI: 10.1128/jb.00188-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 05/17/2019] [Indexed: 01/13/2023] Open
Abstract
The staphylococcal respiratory regulator (SrrAB) modulates energy metabolism in Staphylococcus aureus Studies have suggested that regulated protein catabolism facilitates energy homeostasis. Regulated proteolysis in S. aureus is achieved through protein complexes composed of a peptidase (ClpQ or ClpP) in association with an AAA+ family ATPase (typically, ClpC or ClpX). In the present report, we tested the hypothesis that SrrAB regulates a Clp complex to facilitate energy homeostasis in S. aureus Strains deficient in one or more Clp complexes were attenuated for growth in the presence of puromycin, which causes enrichment of misfolded proteins. A ΔsrrAB strain had increased sensitivity to puromycin. Epistasis experiments suggested that the puromycin sensitivity phenotype of the ΔsrrAB strain was a result of decreased ClpC activity. Consistent with this, transcriptional activity of clpC was decreased in the ΔsrrAB mutant, and overexpression of clpC suppressed the puromycin sensitivity of the ΔsrrAB strain. We also found that ClpC positively influenced respiration and that it did so upon association with ClpP. In contrast, ClpC limited fermentative growth, while ClpP was required for optimal fermentative growth. Metabolomics studies demonstrated that intracellular metabolic profiles of the ΔclpC and ΔsrrAB mutants were distinct from those of the wild-type strain, supporting the notion that both ClpC and SrrAB affect central metabolism. We propose a model wherein SrrAB regulates energy homeostasis, in part, via modulation of regulated proteolysis.IMPORTANCE Oxygen is used as a substrate to derive energy by the bacterial pathogen Staphylococcus aureus during infection; however, S. aureus can also grow fermentatively in the absence of oxygen. To successfully cause infection, S. aureus must tailor its metabolism to take advantage of respiratory activity. Different proteins are required for growth in the presence or absence of oxygen; therefore, when cells transition between these conditions, several proteins would be expected to become unnecessary. In this report, we show that regulated proteolysis is used to modulate energy metabolism in S. aureus We report that the ClpCP protein complex is involved in specifically modulating aerobic respiratory growth but is dispensable for fermentative growth.
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Abstract
Staphylococcus aureus is clearly the most pathogenic member of the Staphylococcaceae. This is in large part due to the acquisition of an impressive arsenal of virulence factors that are coordinately regulated by a series of dedicated transcription factors. What is becoming more and more appreciated in the field is the influence of the metabolic state of S. aureus on the activity of these virulence regulators and their roles in modulating metabolic gene expression. Here I highlight recent advances in S. aureus metabolism as it pertains to virulence. Specifically, mechanisms of nutrient acquisition are outlined including carbohydrate and non-carbohydrate carbon/energy sources as well as micronutrient (Fe, Mn, Zn and S) acquisition. Additionally, energy producing strategies (respiration versus fermentation) are discussed and put in the context of pathogenesis. Finally, transcriptional regulators that coordinate metabolic gene expression are outlined, particularly those that affect the activities of major virulence factor regulators. This chapter essentially connects many recent observations that link the metabolism of S. aureus to its overall pathogenesis and hints that the mere presence of a plethora of virulence factors may not entirely explain the extraordinary pathogenic potential of S. aureus.
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Bezar IF, Mashruwala AA, Boyd JM, Stock AM. Drug-like Fragments Inhibit agr-Mediated Virulence Expression in Staphylococcus aureus. Sci Rep 2019; 9:6786. [PMID: 31043623 PMCID: PMC6494831 DOI: 10.1038/s41598-019-42853-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 04/01/2019] [Indexed: 11/23/2022] Open
Abstract
In response to the increasingly problematic emergence of antibiotic resistance, novel strategies for combating pathogenic bacteria are being investigated. Targeting the agr quorum sensing system, which regulates expression of virulence in Staphylococcus aureus, is one potentially useful approach for combating drug-resistant pathogens that has not yet been fully explored. A previously published study of a fragment screen resulted in the identification of five compound fragments that interact with the DNA-binding domain of the response regulator AgrA from S. aureus. We have analyzed the ability of these compounds to affect agr-mediated virulence gene expression in cultured S. aureus cells. Three of the compounds demonstrated the ability to reduce agr-driven transcription at the P2 and P3 promoters of the agr operon and increase biofilm formation, and two of these compounds also showed the ability to reduce levels of secreted toxins. The finding that the compounds tested were able to reduce agr activity suggests that they could be useful tools for probing the effects of agr inhibition. Furthermore, the characteristics of compound fragments make them good starting materials for the development of compound libraries to iteratively improve the inhibitors.
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Affiliation(s)
- Ian F Bezar
- Department of Biochemistry and Molecular Biology, Center for Advanced Biotechnology and Medicine, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, 08854, USA
- Graduate School of Biomedical Sciences at Robert Wood Johnson Medical School, Piscataway, New Jersey, 08854, USA
| | - Ameya A Mashruwala
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, 08901, USA
- Graduate School-New Brunswick, Rutgers University, New Brunswick, New Jersey, 08901, USA
- Department of Molecular Biology, Princeton University, Princeton, 08544, New Jersey, USA
| | - Jeffrey M Boyd
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, 08901, USA
| | - Ann M Stock
- Department of Biochemistry and Molecular Biology, Center for Advanced Biotechnology and Medicine, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, 08854, USA.
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Vo AT, Fleischman NM, Marquez MD, Camire EJ, Esonwune SU, Grossman JD, Gay KA, Cosman JA, Perlstein DL. Defining the domains of Cia2 required for its essential function in vivo and in vitro. Metallomics 2018; 9:1645-1654. [PMID: 29057997 DOI: 10.1039/c7mt00181a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The cytosolic iron-sulfur cluster assembly (CIA) system biosynthesizes iron-sulfur (FeS) cluster cofactors for cytosolic and nuclear proteins. The yeast Cia2 protein is the central component of the targeting complex which identifies apo-protein targets in the final step of the pathway. Herein, we determine that Cia2 contains five conserved motifs distributed between an intrinsically disordered N-terminal domain and a C-terminal domain of unknown function 59 (DUF59). The disordered domain is dispensible for binding the other subunits of the targeting complex, Met18 and Cia1, and the apo-target Rad3 in vitro. While in vivo assays reveal that the C-terminal domain is sufficient to support viability, several phenotypic assays indicate that deletion of the N-terminal domain negatively impacts CIA function. We additionally establish that Glu208, located within a conserved motif found only in eukaryotic DUF59 proteins, is important for the Cia1-Cia2 interaction in vitro. In vivo, E208A-Cia2 results in a diminished activity of the cytosolic iron sulfur cluster protein, Leu1 but only modest effects on hydroxyurea or methylmethane sulfonate sensitivity. Finally, we demonstrate that neither of the two highly conserved motifs of the DUF59 domain are vital for any of Cia2's interactions in vitro yet mutation of the DPE motif in the DUF59 domain results in a nonfunctional allele in vivo. Our observation that four of the five highly conserved motifs of Cia2 are dispensable for targeting complex formation and apo-target binding suggests that Cia2 is not simply a protein-protein interaction mediator but it likely possesses an additional, currently cryptic, function during the final cluster insertion step of CIA.
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Affiliation(s)
- Amanda T Vo
- Department of Chemistry, Boston University, Boston, MA, USA.
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Laczkovich I, Teoh WP, Flury S, Grayczyk JP, Zorzoli A, Alonzo F. Increased flexibility in the use of exogenous lipoic acid by Staphylococcus aureus. Mol Microbiol 2018; 109:150-168. [PMID: 29660187 DOI: 10.1111/mmi.13970] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2018] [Indexed: 02/06/2023]
Abstract
Lipoic acid is a cofactor required for intermediary metabolism that is either synthesized de novo or acquired from environmental sources. The bacterial pathogen Staphylococcus aureus encodes enzymes required for de novo biosynthesis, but also encodes two ligases, LplA1 and LplA2, that are sufficient for lipoic acid salvage during infection. S. aureus also encodes two H proteins, GcvH of the glycine cleavage system and the homologous GcvH-L encoded in an operon with LplA2. GcvH is a recognized conduit for lipoyl transfer to α-ketoacid dehydrogenase E2 subunits, while the function of GcvH-L remains unclear. The potential to produce two ligases and two H proteins is an unusual characteristic of S. aureus that is unlike most other Gram positive Firmicutes and might allude to an expanded pathway of lipoic acid acquisition in this microorganism. Here, we demonstrate that LplA1 and LplA2 facilitate lipoic acid salvage by differentially targeting lipoyl domain-containing proteins; LplA1 targets H proteins and LplA2 targets α-ketoacid dehydrogenase E2 subunits. Furthermore, GcvH and GcvH-L both facilitate lipoyl relay to E2 subunits. Altogether, these studies identify an expanded mode of lipoic acid salvage used by S. aureus and more broadly underscore the importance of bacterial adaptations when faced with nutritional limitation.
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Affiliation(s)
- Irina Laczkovich
- Department of Microbiology and Immunology, Loyola University Chicago - Stritch School of Medicine, 2160 S. First Avenue, Maywood, IL, 60153, USA
| | - Wei Ping Teoh
- Department of Microbiology and Immunology, Loyola University Chicago - Stritch School of Medicine, 2160 S. First Avenue, Maywood, IL, 60153, USA
| | - Sarah Flury
- Department of Microbiology and Immunology, Loyola University Chicago - Stritch School of Medicine, 2160 S. First Avenue, Maywood, IL, 60153, USA
| | - James P Grayczyk
- Department of Microbiology and Immunology, Loyola University Chicago - Stritch School of Medicine, 2160 S. First Avenue, Maywood, IL, 60153, USA
| | - Azul Zorzoli
- Department of Microbiology and Immunology, Loyola University Chicago - Stritch School of Medicine, 2160 S. First Avenue, Maywood, IL, 60153, USA
| | - Francis Alonzo
- Department of Microbiology and Immunology, Loyola University Chicago - Stritch School of Medicine, 2160 S. First Avenue, Maywood, IL, 60153, USA
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SaeRS Is Responsive to Cellular Respiratory Status and Regulates Fermentative Biofilm Formation in Staphylococcus aureus. Infect Immun 2017; 85:IAI.00157-17. [PMID: 28507069 DOI: 10.1128/iai.00157-17] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 05/08/2017] [Indexed: 01/12/2023] Open
Abstract
Biofilms are multicellular communities of microorganisms living as a quorum rather than as individual cells. The bacterial human pathogen Staphylococcus aureus uses oxygen as a terminal electron acceptor during respiration. Infected human tissues are hypoxic or anoxic. We recently reported that impaired respiration elicits a programmed cell lysis (PCL) phenomenon in S. aureus leading to the release of cellular polymers that are utilized to form biofilms. PCL is dependent upon the AtlA murein hydrolase and is regulated, in part, by the SrrAB two-component regulatory system (TCRS). In the current study, we report that the SaeRS TCRS also governs fermentative biofilm formation by positively influencing AtlA activity. The SaeRS-modulated factor fibronectin-binding protein A (FnBPA) also contributed to the fermentative biofilm formation phenotype. SaeRS-dependent biofilm formation occurred in response to changes in cellular respiratory status. Genetic evidence presented suggests that a high cellular titer of phosphorylated SaeR is required for biofilm formation. Epistasis analyses found that SaeRS and SrrAB influence biofilm formation independently of one another. Analyses using a mouse model of orthopedic implant-associated biofilm formation found that both SaeRS and SrrAB govern host colonization. Of these two TCRSs, SrrAB was the dominant system driving biofilm formation in vivo We propose a model wherein impaired cellular respiration stimulates SaeRS via an as yet undefined signal molecule(s), resulting in increasing expression of AtlA and FnBPA and biofilm formation.
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Mashruwala AA, Boyd JM. Investigating the role(s) of SufT and the domain of unknown function 59 (DUF59) in the maturation of iron-sulfur proteins. Curr Genet 2017; 64:9-16. [PMID: 28589301 DOI: 10.1007/s00294-017-0716-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Revised: 05/24/2017] [Accepted: 05/26/2017] [Indexed: 01/07/2023]
Abstract
Comprehending biology at the molecular and systems levels is predicated upon understanding the functions of proteins. Proteins are typically composed of one or more functional moieties termed domains. Members of Bacteria, Eukarya, and Archaea utilize proteins containing a domain of unknown function (DUF) 59. Proteins requiring iron-sulfur (FeS) clusters containing cofactors are necessary for nearly all organisms making the assembly of functional FeS proteins essential. Recently, studies in eukaryotic and bacterial organisms have shown that proteins containing a DUF59, or those composed solely of DUF59, function in FeS protein maturation and/or intracellular Fe homeostasis. Herein, we review the current literature, discuss potential roles for DUF59, and address future studies that will help advance the field.
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Affiliation(s)
- Ameya A Mashruwala
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, 76 Lipman Dr., New Brunswick, NJ, 08901, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Jeffrey M Boyd
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, 76 Lipman Dr., New Brunswick, NJ, 08901, USA.
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The Suf Iron-Sulfur Cluster Biosynthetic System Is Essential in Staphylococcus aureus, and Decreased Suf Function Results in Global Metabolic Defects and Reduced Survival in Human Neutrophils. Infect Immun 2017; 85:IAI.00100-17. [PMID: 28320837 DOI: 10.1128/iai.00100-17] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/16/2017] [Indexed: 01/30/2023] Open
Abstract
Staphylococcus aureus remains a causative agent for morbidity and mortality worldwide. This is in part a result of antimicrobial resistance, highlighting the need to uncover novel antibiotic targets and to discover new therapeutic agents. In the present study, we explored the possibility that iron-sulfur (Fe-S) cluster synthesis is a viable antimicrobial target. RNA interference studies established that Suf (sulfur mobilization)-dependent Fe-S cluster synthesis is essential in S. aureus We found that sufCDSUB were cotranscribed and that suf transcription was positively influenced by sigma factor B. We characterized an S. aureus strain that contained a transposon inserted in the intergenic space between sufC and sufD (sufD*), resulting in decreased transcription of sufSUB Consistent with the transcriptional data, the sufD* strain had multiple phenotypes associated with impaired Fe-S protein maturation. They included decreased activities of Fe-S cluster-dependent enzymes, decreased growth in media lacking metabolites that require Fe-S proteins for synthesis, and decreased flux through the tricarboxylic acid (TCA) cycle. Decreased Fe-S cluster synthesis resulted in sensitivity to reactive oxygen and reactive nitrogen species, as well as increased DNA damage and impaired DNA repair. The sufD* strain also exhibited perturbed intracellular nonchelated Fe pools. Importantly, the sufD* strain did not exhibit altered exoprotein production or altered biofilm formation, but it was attenuated for survival upon challenge by human polymorphonuclear leukocytes. The results presented are consistent with the hypothesis that Fe-S cluster synthesis is a viable target for antimicrobial development.
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Mashruwala AA, Guchte AVD, Boyd JM. Impaired respiration elicits SrrAB-dependent programmed cell lysis and biofilm formation in Staphylococcus aureus. eLife 2017; 6. [PMID: 28221135 PMCID: PMC5380435 DOI: 10.7554/elife.23845] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 02/20/2017] [Indexed: 01/25/2023] Open
Abstract
Biofilms are communities of microorganisms attached to a surface or each other. Biofilm-associated cells are the etiologic agents of recurrent Staphylococcus aureus infections. Infected human tissues are hypoxic or anoxic. S. aureus increases biofilm formation in response to hypoxia, but how this occurs is unknown. In the current study we report that oxygen influences biofilm formation in its capacity as a terminal electron acceptor for cellular respiration. Genetic, physiological, or chemical inhibition of respiratory processes elicited increased biofilm formation. Impaired respiration led to increased cell lysis via divergent regulation of two processes: increased expression of the AtlA murein hydrolase and decreased expression of wall-teichoic acids. The AltA-dependent release of cytosolic DNA contributed to increased biofilm formation. Further, cell lysis and biofilm formation were governed by the SrrAB two-component regulatory system. Data presented support a model wherein SrrAB-dependent biofilm formation occurs in response to the accumulation of reduced menaquinone. DOI:http://dx.doi.org/10.7554/eLife.23845.001 Millions of bacteria live on the human body. Generally these bacteria co-exist with us peacefully, but sometimes certain bacteria may enter the body and cause infections, such as gum disease or a bone infection called osteomyelitis. Many of these infections are thought to occur when the bacteria become able to form complex communities called biofilms. Bacteria living in a biofilm cooperate and make lifestyle choices as a community, so in this way, they behave like a single organism containing many cells. A sticky glue-like material called the matrix holds the bacteria in a biofilm together. This matrix protects the bacteria in the biofilm from both the human immune system and antibiotics, allowing infections to develop and making them difficult to treat. Previous research has shown that the supply and level of oxygen in infected tissues decreases as an infection gets worse. One bacterium that typically lives peacefully on our bodies, called Staphylococcus aureus, can sometimes cause serious biofilm-associated infections. S. aureus forms biofilms more readily when oxygen is in short supply, but it was not known how these biofilms form. Understanding how S. aureus forms biofilms could help scientists develop better treatments for bacterial infections. Most bacterial cells have a cell wall to provide them with structural support. Mashruwala et al. found that, when oxygen levels are low, S. aureus decreases the production of a type of sugar that makes up the cell wall. At the same time, the bacteria produce more of an enzyme that breaks down cell walls. Together, these processes cause some of the bacteria cells to break open. The contents of these broken cells, including their DNA, help form the matrix that will hold together and protect the other bacterial cells in the biofilm. The experiments also identified a protein called SrrAB that switches on the process that ruptures the cells when oxygen is low. The findings of Mashruwala et al. show how bacteria grown in the laboratory form biofilms when they are starved of oxygen. The next steps following on from this work are to find out whether the same thing happens when bacteria infect animals and whether drugs that block the rupturing of bacterial cells could be used to treat infections. DOI:http://dx.doi.org/10.7554/eLife.23845.002
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Affiliation(s)
- Ameya A Mashruwala
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, United States
| | - Adriana van de Guchte
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, United States
| | - Jeffrey M Boyd
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, United States
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Mashruwala AA, Boyd JM. The Staphylococcus aureus SrrAB Regulatory System Modulates Hydrogen Peroxide Resistance Factors, Which Imparts Protection to Aconitase during Aerobic Growth. PLoS One 2017; 12:e0170283. [PMID: 28099473 PMCID: PMC5242492 DOI: 10.1371/journal.pone.0170283] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 01/03/2017] [Indexed: 01/09/2023] Open
Abstract
The SrrAB two-component regulatory system (TCRS) positively influences the transcription of genes involved in aerobic respiration in response to changes in respiratory flux. Hydrogen peroxide (H2O2) can arise as a byproduct of spontaneous interactions between dioxygen and components of respiratory pathways. H2O2 damages cellular factors including protein associated iron-sulfur cluster prosthetic groups. We found that a Staphylococcus aureus strain lacking the SrrAB two-component regulatory system (TCRS) is sensitive to H2O2 intoxication. We tested the hypothesis that SrrAB manages the mutually inclusive expression of genes required for aerobic respiration and H2O2 resistance. Consistent with our hypothesis, a ΔsrrAB strain had decreased transcription of genes encoding for H2O2 resistance factors (kat, ahpC, dps). SrrAB was not required for the inducing the transcription of these genes in cells challenged with H2O2. Purified SrrA bound to the promoter region for dps suggesting that SrrA directly influences dps transcription. The H2O2 sensitivity of the ΔsrrAB strain was alleviated by iron chelation or deletion of the gene encoding for the peroxide regulon repressor (PerR). The positive influence of SrrAB upon H2O2 metabolism bestowed protection upon the solvent accessible iron-sulfur (FeS) cluster of aconitase from H2O2 poisoning. SrrAB also positively influenced transcription of scdA (ytfE), which encodes for a FeS cluster repair protein. Finally, we found that SrrAB positively influences H2O2 resistance only during periods of high dioxygen-dependent respiratory activity. SrrAB did not influence H2O2 resistance when cellular respiration was diminished as a result of decreased dioxygen availability, and negatively influenced it in the absence of respiration (fermentative growth). We propose a model whereby SrrAB-dependent regulatory patterns facilitate the adaptation of cells to changes in dioxygen concentrations, and thereby aids in the prevention of H2O2 intoxication during respiratory growth upon dixoygen.
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Affiliation(s)
- Ameya A. Mashruwala
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Jeffrey M. Boyd
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, United States of America
- * E-mail:
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Choby JE, Mike LA, Mashruwala AA, Dutter BF, Dunman PM, Sulikowski GA, Boyd JM, Skaar EP. A Small-Molecule Inhibitor of Iron-Sulfur Cluster Assembly Uncovers a Link between Virulence Regulation and Metabolism in Staphylococcus aureus. Cell Chem Biol 2016; 23:1351-1361. [PMID: 27773628 DOI: 10.1016/j.chembiol.2016.09.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 09/01/2016] [Accepted: 09/30/2016] [Indexed: 11/28/2022]
Abstract
The rising problem of antimicrobial resistance in Staphylococcus aureus necessitates the discovery of novel therapeutic targets for small-molecule intervention. A major obstacle of drug discovery is identifying the target of molecules selected from high-throughput phenotypic assays. Here, we show that the toxicity of a small molecule termed '882 is dependent on the constitutive activity of the S. aureus virulence regulator SaeRS, uncovering a link between virulence factor production and energy generation. A series of genetic, physiological, and biochemical analyses reveal that '882 inhibits iron-sulfur (Fe-S) cluster assembly most likely through inhibition of the Suf complex, which synthesizes Fe-S clusters. In support of this, '882 supplementation results in decreased activity of the Fe-S cluster-dependent enzyme aconitase. Further information regarding the effects of '882 has deepened our understanding of virulence regulation and demonstrates the potential for small-molecule modulation of Fe-S cluster assembly in S. aureus and other pathogens.
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Affiliation(s)
- Jacob E Choby
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Graduate Program in Microbiology & Immunology, Vanderbilt University, Nashville, TN 37232, USA
| | - Laura A Mike
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Ameya A Mashruwala
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA
| | - Brendan F Dutter
- Department of Chemistry, Vanderbilt Institute for Chemical Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Paul M Dunman
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Gary A Sulikowski
- Department of Chemistry, Vanderbilt Institute for Chemical Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Jeffrey M Boyd
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Eric P Skaar
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Veterans Affairs Tennessee Valley Healthcare Services, Nashville, TN 37232, USA.
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