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Joron K, Zamel J, Kalisman N, Lerner E. Evidence for a compact σ 70 conformation in vitro and in vivo. iScience 2024; 27:110140. [PMID: 38957792 PMCID: PMC11217687 DOI: 10.1016/j.isci.2024.110140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 03/28/2024] [Accepted: 05/27/2024] [Indexed: 07/04/2024] Open
Abstract
The initiation of transcription in Escherichia coli (E. coli) is facilitated by promoter specificity factors, also known as σ factors, which may bind a promoter only as part of a complex with RNA polymerase (RNAP). By performing in vitro cross-linking mass spectrometry (CL-MS) of apo-σ70, we reveal structural features suggesting a compact conformation compared to the known RNAP-bound extended conformation. Then, we validate the existence of the compact conformation using in vivo CL-MS by identifying cross-links similar to those found in vitro, which deviate from the extended conformation only during the stationary phase of bacterial growth. Conclusively, we provide information in support of a compact conformation of apo-σ70 that exists in live cells, which might represent a transcriptionally inactive form that can be activated upon binding to RNAP.
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Affiliation(s)
- Khalil Joron
- Department of Biological Chemistry, Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, Edmond J. Safra Campus, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Joanna Zamel
- Department of Biological Chemistry, Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, Edmond J. Safra Campus, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Nir Kalisman
- Department of Biological Chemistry, Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, Edmond J. Safra Campus, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- Center for Nanoscience and Nanotechnology, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Eitan Lerner
- Department of Biological Chemistry, Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, Edmond J. Safra Campus, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- Center for Nanoscience and Nanotechnology, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
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2
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Venkataraman P, Nagendra P, Ahlawat N, Brajesh RG, Saini S. Convergent genetic adaptation of Escherichia coli in minimal media leads to pleiotropic divergence. Front Mol Biosci 2024; 11:1286824. [PMID: 38660375 PMCID: PMC11039892 DOI: 10.3389/fmolb.2024.1286824] [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] [Received: 08/31/2023] [Accepted: 02/15/2024] [Indexed: 04/26/2024] Open
Abstract
Adaptation in an environment can either be beneficial, neutral or disadvantageous in another. To test the genetic basis of pleiotropic behaviour, we evolved six lines of E. coli independently in environments where glucose and galactose were the sole carbon sources, for 300 generations. All six lines in each environment exhibit convergent adaptation in the environment in which they were evolved. However, pleiotropic behaviour was observed in several environmental contexts, including other carbon environments. Genome sequencing reveals that mutations in global regulators rpoB and rpoC cause this pleiotropy. We report three new alleles of the rpoB gene, and one new allele of the rpoC gene. The novel rpoB alleles confer resistance to Rifampicin, and alter motility. Our results show how single nucleotide changes in the process of adaptation in minimal media can lead to wide-scale pleiotropy, resulting in changes in traits that are not under direct selection.
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Affiliation(s)
| | | | | | | | - Supreet Saini
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
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3
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Gracia J, Perumal D, Dhandapani P, Ragunathan P. Systematic identification and repurposing of FDA-approved drugs as antibacterial agents against Streptococcus pyogenes: In silico and in vitro studies. Int J Biol Macromol 2024; 257:128667. [PMID: 38101681 DOI: 10.1016/j.ijbiomac.2023.128667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 10/31/2023] [Accepted: 12/06/2023] [Indexed: 12/17/2023]
Abstract
Streptococcus pyogenes (Group A Streptococcus - GAS) is a human pathogen causing wide range of infections and toxin-mediated diseases in human beings of all age groups with fatality of 10-30 %. The limited success of antibiotics and the non-availability of vaccines makes GAS a global burden. The multi-subunit RNA polymerase (RNAP) is a validated bacterial therapeutic target as it is involved in transcription and can arrest growth. Of the five subunits of this enzyme complex, the β-subunit (RpoC) has attracted specific attention as a drug target, particularly in the switch region. Here we attempt to repurpose non-antimicrobial drugs to act as RpoC inhibitors against S. pyogenes. In this study, 1826 FDA approved drugs have been identified through high-throughput virtual screening. Free Energy Perturbation (FEP) based binding free energy calculations have been performed at the final step of the virtual screening funnel to ensure high accuracy in silico results. Three compounds identified have been tested for susceptibility of S. pyogenes MTCC 442 strain and two antibiotic-resistant clinical isolates of S. pyogenes using microdilution assay. Among the three, two drugs Amlodipine Besylate (Amd) and Ranitidine hydrochloride (Rnt) have shown inhibition against all the tested strains and its mechanism of interaction with RpoC has been studied. The docked complexes were analyzed to understand the binding mode of the drugs to the target. Classical Molecular Dynamics studies for RpoC-Rnt complex and the two stable conformations of RpoC-Amd complex was carried out. Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF), Radius of Gyration (RoG) and Solvent Accessible Surface Area (SASA) of the complexes were plotted and studied. The thermodynamic parameters of protein-drug were experimentally determined using Isothermal Titration Calorimetry (ITC). Infrared spectroscopic studies and Fluorescence quenching studies provided insights into the secondary structural changes in RpoC on binding to the drugs.
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Affiliation(s)
- Judith Gracia
- Centre for Advanced Studies in Crystallography and Biophysics, University of Madras, Guindy, India
| | - Damodharan Perumal
- Department of Microbiology, Dr. ALMPG IBMS, University of Madras, Taramani, India
| | - Prabu Dhandapani
- Department of Microbiology, Dr. ALMPG IBMS, University of Madras, Taramani, India
| | - Preethi Ragunathan
- Centre for Advanced Studies in Crystallography and Biophysics, University of Madras, Guindy, India.
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4
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Anwar AF, Cain CF, Garza MJ, Degen D, Ebright RH, Del Valle JR. Stabilizing Pseudouridimycin: Synthesis, RNA Polymerase Inhibitory Activity, and Antibacterial Activity of Dipeptide-Modified Analogues. ChemMedChem 2024; 19:e202300474. [PMID: 37751316 PMCID: PMC10843019 DOI: 10.1002/cmdc.202300474] [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: 09/01/2023] [Revised: 09/25/2023] [Accepted: 09/25/2023] [Indexed: 09/28/2023]
Abstract
Pseudouridimycin (PUM) is a microbially produced C-nucleoside dipeptide that selectively targets the nucleotide addition site of bacterial RNA polymerase (RNAP) and that has a lower rate of spontaneous resistance emergence relative to current drugs that target RNAP. Despite its promising biological profile, PUM undergoes relatively rapid decomposition in buffered aqueous solutions. Here, we describe the synthesis, RNAP-inhibitory activity, and antibacterial activity of chemically stabilized analogues of PUM. These analogues feature targeted modifications that mitigate guanidine-mediated hydroxamate bond scission. A subset of analogues in which the central hydroxamate is replaced with amide or hydrazide isosteres retain the antibacterial activity of the natural product.
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Affiliation(s)
- Avraz F Anwar
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Christopher F Cain
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Michael J Garza
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - David Degen
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ, 08854, USA
| | - Richard H Ebright
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ, 08854, USA
| | - Juan R Del Valle
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
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5
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Arseniev A, Panfilov M, Pobegalov G, Potyseva A, Pavlinova P, Yakunina M, Lee J, Borukhov S, Severinov K, Khodorkovskii M. Single-molecule studies reveal the off-pathway elemental pause state as a target of streptolydigin inhibition of RNA polymerase and its dramatic enhancement by Gre factors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.05.542125. [PMID: 37333075 PMCID: PMC10274647 DOI: 10.1101/2023.06.05.542125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Antibiotic streptolydigin (Stl) inhibits bacterial transcription by blocking the trigger loop folding in the active center of RNA polymerase (RNAP), which is essential for catalysis. We use acoustic force spectroscopy to characterize the dynamics of transcription elongation in ternary elongation complexes of RNAP (ECs) in the presence of Stl at a single-molecule level. We found that Stl induces long-lived stochastic pauses while the instantaneous velocity of transcription between the pauses is unaffected. Stl enhances the short-lived pauses associated with an off-pathway elemental paused state of the RNAP nucleotide addition cycle. Unexpectedly, we found that transcript cleavage factors GreA and GreB, which were thought to be Stl competitors, do not alleviate the streptolydigin-induced pausing; instead, they synergistically increase transcription inhibition by Stl. This is the first known instance of a transcriptional factor enhancing antibiotic activity. We propose a structural model of the EC-Gre-Stl complex that explains the observed Stl activities and provides insight into possible cooperative action of secondary channel factors and other antibiotics binding at the Stl-pocket. These results offer a new strategy for high-throughput screening for prospective antibacterial agents.
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Affiliation(s)
- Anatolii Arseniev
- Peter the Great St. Petersburg Polytechnic University, Saint Petersburg, Russia
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russian Federation
| | - Mikhail Panfilov
- Peter the Great St. Petersburg Polytechnic University, Saint Petersburg, Russia
| | - Georgii Pobegalov
- Peter the Great St. Petersburg Polytechnic University, Saint Petersburg, Russia
| | - Alina Potyseva
- Peter the Great St. Petersburg Polytechnic University, Saint Petersburg, Russia
| | - Polina Pavlinova
- Peter the Great St. Petersburg Polytechnic University, Saint Petersburg, Russia
| | - Maria Yakunina
- Peter the Great St. Petersburg Polytechnic University, Saint Petersburg, Russia
| | - Jookyung Lee
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ 08084-1489, USA
| | - Sergei Borukhov
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ 08084-1489, USA
| | - Konstantin Severinov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ, United States
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6
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Cheng A, Wan D, Ghatak A, Wang C, Feng D, Fondell JD, Ebright RH, Fan H. Identification and Structural Modeling of the RNA Polymerase Omega Subunits in Chlamydiae and Other Obligate Intracellular Bacteria. mBio 2023; 14:e0349922. [PMID: 36719197 PMCID: PMC9973325 DOI: 10.1128/mbio.03499-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 01/04/2023] [Indexed: 02/01/2023] Open
Abstract
Gene transcription in bacteria is carried out by the multisubunit RNA polymerase (RNAP), which is composed of a catalytic core enzyme and a promoter-recognizing σ factor. The core enzyme comprises two α subunits, one β subunit, one β' subunit, and one ω subunit. The ω subunit plays critical roles in the assembly of the core enzyme and other cellular functions, including the regulation of bacterial growth, the stress response, and biofilm formation. However, the identity of an ω subunit for the obligate intracellular bacterium Chlamydia has not previously been determined. Here, we report the identification of the hypothetical protein CTL0286 as the probable chlamydial ω subunit based on sequence, synteny, and AlphaFold and AlphaFold-Multimer three-dimensional-structure predictions. Our findings indicate that CTL0286 functions as the missing ω subunit of chlamydial RNAP. Our extended analysis also indicates that all obligate intracellular bacteria have ω orthologs. IMPORTANCE Chlamydiae are obligate intracellular bacteria that replicate only inside eukaryotic cells. Previously, it has not been possible to identify a candidate gene encoding the chlamydial RNA polymerase ω subunit, and it has been hypothesized that the chlamydial RNA polymerase ω subunit was lost in the evolutionary process through which Chlamydiae reduced their genome size and proteome sizes to adapt to an obligate intracellular lifestyle. Here, we report the identification of the chlamydial RNA polymerase ω subunit, based on conserved sequence, conserved synteny, AlphaFold-predicted conserved three-dimensional structure, and AlfaFold-Multimer-predicted conserved interactions. Our identification of the previously elusive chlamydial RNA polymerase ω subunit sets the stage for investigation of its roles in regulation of gene expression during chlamydial growth, development, and stress responses, and sets the stage for preparation and study of the intact chlamydial RNA polymerase and its interactions with inhibitors.
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Affiliation(s)
- Andrew Cheng
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Danny Wan
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
- Graduate Program in Physiology and Integrative Biology, Rutgers School of Graduate Studies, Piscataway, New Jersey, USA
| | - Arkaprabha Ghatak
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Chengyuan Wang
- Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Deyu Feng
- Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Joseph D. Fondell
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Richard H. Ebright
- Waksman Institute, Rutgers University, Piscataway, New Jersey, USA
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Huizhou Fan
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
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Stephanie F, Tambunan USF, Siahaan TJ. M. tuberculosis Transcription Machinery: A Review on the Mycobacterial RNA Polymerase and Drug Discovery Efforts. Life (Basel) 2022; 12:1774. [PMID: 36362929 PMCID: PMC9695777 DOI: 10.3390/life12111774] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 10/24/2022] [Accepted: 11/01/2022] [Indexed: 09/08/2023] Open
Abstract
Mycobacterium tuberculosis (MTB) is the main source of tuberculosis (TB), one of the oldest known diseases in the human population. Despite the drug discovery efforts of past decades, TB is still one of the leading causes of mortality and claimed more than 1.5 million lives worldwide in 2020. Due to the emergence of drug-resistant strains and patient non-compliance during treatments, there is a pressing need to find alternative therapeutic agents for TB. One of the important areas for developing new treatments is in the inhibition of the transcription step of gene expression; it is the first step to synthesize a copy of the genetic material in the form of mRNA. This further translates to functional protein synthesis, which is crucial for the bacteria living processes. MTB contains a bacterial DNA-dependent RNA polymerase (RNAP), which is the key enzyme for the transcription process. MTB RNAP has been targeted for designing and developing antitubercular agents because gene transcription is essential for the mycobacteria survival. Initiation, elongation, and termination are the three important sequential steps in the transcription process. Each step is complex and highly regulated, involving multiple transcription factors. This review is focused on the MTB transcription machinery, especially in the nature of MTB RNAP as the main enzyme that is regulated by transcription factors. The mechanism and conformational dynamics that occur during transcription are discussed and summarized. Finally, the current progress on MTB transcription inhibition and possible drug target in mycobacterial RNAP are also described to provide insight for future antitubercular drug design and development.
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Affiliation(s)
- Filia Stephanie
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok 16424, Indonesia
| | - Usman Sumo Friend Tambunan
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok 16424, Indonesia
| | - Teruna J. Siahaan
- Department of Pharmaceutical Chemistry, School of Pharmacy, The University of Kansas, Lawrence, KS 66045, USA
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How to Shut Down Transcription in Archaea during Virus Infection. Microorganisms 2022; 10:microorganisms10091824. [PMID: 36144426 PMCID: PMC9501531 DOI: 10.3390/microorganisms10091824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/09/2022] [Accepted: 09/10/2022] [Indexed: 11/16/2022] Open
Abstract
Multisubunit RNA polymerases (RNAPs) carry out transcription in all domains of life; during virus infection, RNAPs are targeted by transcription factors encoded by either the cell or the virus, resulting in the global repression of transcription with distinct outcomes for different host–virus combinations. These repressors serve as versatile molecular probes to study RNAP mechanisms, as well as aid the exploration of druggable sites for the development of new antibiotics. Here, we review the mechanisms and structural basis of RNAP inhibition by the viral repressor RIP and the crenarchaeal negative regulator TFS4, which follow distinct strategies. RIP operates by occluding the DNA-binding channel and mimicking the initiation factor TFB/TFIIB. RIP binds tightly to the clamp and locks it into one fixed position, thereby preventing conformational oscillations that are critical for RNAP function as it progresses through the transcription cycle. TFS4 engages with RNAP in a similar manner to transcript cleavage factors such as TFS/TFIIS through the NTP-entry channel; TFS4 interferes with the trigger loop and bridge helix within the active site by occlusion and allosteric mechanisms, respectively. The conformational changes in RNAP described above are universally conserved and are also seen in inactive dimers of eukaryotic RNAPI and several inhibited RNAP complexes of both bacterial and eukaryotic RNA polymerases, including inactive states that precede transcription termination. A comparison of target sites and inhibitory mechanisms reveals that proteinaceous repressors and RNAP-specific antibiotics use surprisingly common ways to inhibit RNAP function.
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Cohen Y, Hershberg R. Rapid adaptation often occurs through mutations to the most highly conserved positions of the RNA polymerase core enzyme. Genome Biol Evol 2022; 14:6649522. [PMID: 35876137 PMCID: PMC9459352 DOI: 10.1093/gbe/evac105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2022] [Indexed: 11/17/2022] Open
Abstract
Mutations to the genes encoding the RNA polymerase core enzyme (RNAPC) and additional housekeeping regulatory genes were found to be involved in adaptation, in the context of numerous evolutionary experiments, in which bacteria were exposed to diverse selective pressures. This provides a conundrum, as the housekeeping genes that were so often mutated in response to these diverse selective pressures tend to be among the genes that are most conserved in their sequences across the bacterial phylogeny. In order to further examine this apparent discrepancy, we characterized the precise positions of the RNAPC involved in adaptation to a large variety of selective pressures. We found that RNAPC lab adaptations tended to occur at positions displaying traits associated with higher selective constraint. Specifically, compared to other RNAPC positions, positions involved in adaptation tended to be more conserved in their sequences within bacteria, were more often located within defined protein domains, and were located closer to the complex’s active site. Higher sequence conservation was also found for resource exhaustion adaptations occurring within additional housekeeping genes. Combined, our results demonstrate that the positions that change most readily in response to well-defined selective pressures exerted in lab environments are often also those that evolve most slowly in nature.
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Affiliation(s)
- Yasmin Cohen
- Rachel & Menachem Mendelovitch Evolutionary Processes of Mutation & Natural Selection Research Laboratory, Department of Genetics and Developmental Biology, the Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Ruth Hershberg
- Rachel & Menachem Mendelovitch Evolutionary Processes of Mutation & Natural Selection Research Laboratory, Department of Genetics and Developmental Biology, the Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
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10
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Johnston CW, Badran AH. Natural and engineered precision antibiotics in the context of resistance. Curr Opin Chem Biol 2022; 69:102160. [PMID: 35660248 DOI: 10.1016/j.cbpa.2022.102160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 04/18/2022] [Accepted: 04/22/2022] [Indexed: 12/14/2022]
Abstract
Antibiotics are essential weapons in our fight against infectious disease, yet the consequences of broad-spectrum antibiotic use on microbiome stability and pathogen resistance are prompting investigations into more selective alternatives. Echoing the advent of precision medicine in oncology, precision antibiotics with focused activities are emerging as a means of addressing infections without damaging microbiomes or incentivizing resistance. Historically, antibiotic design principles have been gleaned from Nature, and reinvestigation of overlooked antibacterials is now providing scaffolds and targets for the design of pathogen-specific drugs. In this perspective, we summarize the biosynthetic and antibacterial mechanisms used to access these activities, and discuss how such strategies may be co-opted through engineering approaches to afford precision antibiotics.
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Affiliation(s)
- Chad W Johnston
- Department of Pharmacology & Chemical Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Ahmed H Badran
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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Kirsch SH, Haeckl FPJ, Müller R. Beyond the approved: target sites and inhibitors of bacterial RNA polymerase from bacteria and fungi. Nat Prod Rep 2022; 39:1226-1263. [PMID: 35507039 DOI: 10.1039/d1np00067e] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Covering: 2016 to 2022RNA polymerase (RNAP) is the central enzyme in bacterial gene expression representing an attractive and validated target for antibiotics. Two well-known and clinically approved classes of natural product RNAP inhibitors are the rifamycins and the fidaxomycins. Rifampicin (Rif), a semi-synthetic derivative of rifamycin, plays a crucial role as a first line antibiotic in the treatment of tuberculosis and a broad range of bacterial infections. However, more and more pathogens such as Mycobacterium tuberculosis develop resistance, not only against Rif and other RNAP inhibitors. To overcome this problem, novel RNAP inhibitors exhibiting different target sites are urgently needed. This review includes recent developments published between 2016 and today. Particular focus is placed on novel findings concerning already known bacterial RNAP inhibitors, the characterization and development of new compounds isolated from bacteria and fungi, and providing brief insights into promising new synthetic compounds.
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Affiliation(s)
- Susanne H Kirsch
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarland University Campus, 66123 Saarbrücken, Germany. .,German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 38124 Braunschweig, Germany
| | - F P Jake Haeckl
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarland University Campus, 66123 Saarbrücken, Germany. .,German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 38124 Braunschweig, Germany
| | - Rolf Müller
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarland University Campus, 66123 Saarbrücken, Germany. .,German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 38124 Braunschweig, Germany.,Department of Pharmacy, Saarland University, 66123 Saarbrücken, Germany
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12
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Xu Y, Yang L, Wang Y, Zhu Z, Yan J, Qin S, Chen L. Prophage-encoded gene VpaChn25_0734 amplifies ecological persistence of Vibrio parahaemolyticus CHN25. Curr Genet 2022; 68:267-287. [PMID: 35064802 PMCID: PMC8783578 DOI: 10.1007/s00294-022-01229-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/03/2021] [Accepted: 12/31/2021] [Indexed: 12/19/2022]
Abstract
Vibrio parahaemolyticus is a waterborne pathogen that can cause acute gastroenteritis, wound infection, and septicemia in humans. The molecular basis of its pathogenicity is not yet fully understood. Phages are found most abundantly in aquatic environments and play a critical role in horizontal gene transfer. Nevertheless, current literature on biological roles of prophage-encoded genes remaining in V. parahaemolyticus is rare. In this study, we characterized one such gene VpaChn25_0734 (543-bp) in V. parahaemolyticus CHN25 genome. A deletion mutant ΔVpaChn25_0734 (543-bp) was obtained by homologous recombination, and a revertant ΔVpaChn25_0734-com (543-bp) was also constructed. The ΔVpaChn25_0734 (543-bp) mutant was defective in growth and swimming mobility particularly at lower temperatures and/or pH 7.0–8.5. Cell surface hydrophobicity and biofilm formation were significantly decreased in the ΔVpaChn25_0734 (543-bp) mutant (p < 0.05). Based on the in vitro Caco-2 cell model, the deletion of VpaChn25_0734 (543-bp) gene significantly reduced the cytotoxicity of V. parahaemolyticus CHN25 to human intestinal epithelial cells (p < 0.05). Comparative secretomic and transcriptomic analyses revealed a slightly increased extracellular proteins, and thirteen significantly changed metabolic pathways in the ΔVpaChn25_0734 (543-bp) mutant, showing down-regulated carbon source transport and utilization, biofilm formation, and type II secretion system (p < 0.05), consistent with the observed defective phenotypes. Taken, the prophage-encoded gene VpaChn25_0734 (543-bp) enhanced V. parahaemolyticus CHN25 fitness for survival in the environment and the host. The results in this study facilitate better understanding of pathogenesis and genome evolution of V. parahaemolyticus, the leading sea foodborne pathogen worldwide.
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Affiliation(s)
- Yingwei Xu
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China
| | - Lianzhi Yang
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China
| | - Yaping Wang
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China
- Department of Internal Medicine, Virginia Commonwealth University/McGuire VA Medical Centre, Richmond, VA, USA
| | - Zhuoying Zhu
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China
| | - Jizhou Yan
- College of Fishers and Life Science, Shanghai Ocean University, Shanghai, 201306, China
| | - Si Qin
- Key Laboratory for Food Science and Biotechnology of Hunan Province, College of Food Science and Technology, Hunan Agricultural University, Changsha, 410128, China.
| | - Lanming Chen
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China.
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Mosaei H, Zenkin N. Two distinct pathways of RNA polymerase backtracking determine the requirement for the Trigger Loop during RNA hydrolysis. Nucleic Acids Res 2021; 49:8777-8784. [PMID: 34365509 PMCID: PMC8421135 DOI: 10.1093/nar/gkab675] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/20/2021] [Accepted: 07/25/2021] [Indexed: 12/30/2022] Open
Abstract
Transcribing RNA polymerase (RNAP) can fall into backtracking, phenomenon when the 3' end of the transcript disengages from the template DNA. Backtracking is caused by sequences of the nucleic acids or by misincorporation of erroneous nucleotides. To resume productive elongation backtracked complexes have to be resolved through hydrolysis of RNA. There is currently no consensus on the mechanism of catalysis of this reaction by Escherichia coli RNAP. Here we used Salinamide A, that we found inhibits RNAP catalytic domain Trigger Loop (TL), to show that the TL is required for RNA cleavage during proofreading of misincorporation events but plays little role during cleavage in sequence-dependent backtracked complexes. Results reveal that backtracking caused by misincorporation is distinct from sequence-dependent backtracking, resulting in different conformations of the 3' end of RNA within the active center. We show that the TL is required to transfer the 3' end of misincorporated transcript from cleavage-inefficient 'misincorporation site' into the cleavage-efficient 'backtracked site', where hydrolysis takes place via transcript-assisted catalysis and is largely independent of the TL. These findings resolve the controversy surrounding mechanism of RNA hydrolysis by E. coli RNA polymerase and indicate that the TL role in RNA cleavage has diverged among bacteria.
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Affiliation(s)
- Hamed Mosaei
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle Upon Tyne, NE2 4AX, UK
| | - Nikolay Zenkin
- To whom correspondence should be addressed. Tel: +44 0 1912083227; Fax: +44 0 1912083205;
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14
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Streptomyces Isolates from the Soil of an Ancient Irish Cure Site, Capable of Inhibiting Multi-Resistant Bacteria and Yeasts. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11114923] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Traditional Irish medicines are often intertwined with ritual and spirituality, making it difficult to substantiate the validity of their claims. In this manuscript, we use molecular and microscopic techniques to investigate some microorganisms that might be responsible for the reputed healing properties of an ancient Irish soil cure known as the Blessed clay from a site in Boho in the West Fermanagh Scarplands. We previously reported the isolation of an antibiotic producing bacteria from this soil. In this report, we characterize the antibiotic activity of a further six isolates of Streptomyces from this source. Two of these isolates inhibit the growth of multi-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, two inhibit the growth of the yeast Starmerella bombicola, and two have as yet undetermined activity. Genetic analysis of these Streptomyces reveals the potential to synthesize varieties of antibiotics similar to cypemycin, griseochelin, macrolactams, and candicidin. From these observations, we suggest that part of the medicinal reputation of the Blessed clay may lie in the diversity of antimicrobial producing Streptomyces isolated from this soil. These findings highlight the potential for antibiotic discovery in this area.
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15
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Fang C, Philips SJ, Wu X, Chen K, Shi J, Shen L, Xu J, Feng Y, O’Halloran TV, Zhang Y. CueR activates transcription through a DNA distortion mechanism. Nat Chem Biol 2021; 17:57-64. [PMID: 32989300 PMCID: PMC9904984 DOI: 10.1038/s41589-020-00653-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 08/14/2020] [Indexed: 01/16/2023]
Abstract
The MerR-family transcription factors (TFs) are a large group of bacterial proteins responding to cellular metal ions and multiple antibiotics by binding within central RNA polymerase-binding regions of a promoter. While most TFs alter transcription through protein-protein interactions, MerR TFs are capable of reshaping promoter DNA. To address the question of which mechanism prevails, we determined two cryo-EM structures of transcription activation complexes (TAC) comprising Escherichia coli CueR (a prototype MerR TF), RNAP holoenzyme and promoter DNA. The structures reveal that this TF promotes productive promoter-polymerase association without canonical protein-protein contacts seen between other activator proteins and RNAP. Instead, CueR realigns the key promoter elements in the transcription activation complex by clamp-like protein-DNA interactions: these induce four distinct kinks that ultimately position the -10 element for formation of the transcription bubble. These structural and biochemical results provide strong support for the DNA distortion paradigm of allosteric transcriptional control by MerR TFs.
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Affiliation(s)
- Chengli Fang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Steven J. Philips
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - Xiaoxian Wu
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kui Chen
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - Jing Shi
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Liqiang Shen
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Juncao Xu
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Feng
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.
| | - Thomas V. O’Halloran
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.,Department of Chemistry, Northwestern University, Evanston, IL 60208, USA.,The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA.,Corresponding author: (T.V.O.); (Y.F.); (Y.Z.)
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
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16
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Guo H, Yu X, Liu Z, Li J, Ye J, Zha Z. Deltamethrin transformation by Bacillus thuringiensis and the associated metabolic pathways. ENVIRONMENT INTERNATIONAL 2020; 145:106167. [PMID: 33035892 DOI: 10.1016/j.envint.2020.106167] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/08/2020] [Accepted: 09/25/2020] [Indexed: 05/22/2023]
Abstract
The biological toxicity of deltamethrin at molecular level has been investigated, whereas, the proteome responsive mechanisms of cells under deltamethrin stress at the phylogenetic level are not clear. The proteome expression, transformation-related pathway and regulatory network of Bacillus thuringiensis during the process of deltamethrin transformation were explored using proteomics and metabolomics approaches in the present study. The results showed that deltamethrin was effectively removed by B. thuringiensis within 48 h. The stress responses of B. thuringiensis were activated to resist deltamethrin stress, with significant differential expression of proteins that were primarily involved in the synthesis of DNA and shock proteins, endospore formation, carbon metabolism. The expression patterns of ribosomal proteins confirmed that the transcription and translation of DNA, and biosynthesis of heat shock proteins were inhibited as deltamethrin transformation. The synthesis of oxaloacetate and acetyl-CoA were also hindered, resulting in downregulated expression of carbohydrate metabolism, TCA cycle and energy metabolism. Meanwhile, endospore formation and germination were promoted to resist oxidative stress induced by deltamethrin. These findings imparted novel insight to elucidate underlying stress response mechanisms of the organism under target contaminants stress, and the interaction between deltamethrin transformation and cellular metabolism at the pathway and network levels.
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Affiliation(s)
- Huiying Guo
- Institute of Orthopedic Diseases and Department of Bone and Joint Surgery, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China
| | - Xiaolong Yu
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, China
| | - Ziyi Liu
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Jieruo Li
- Institute of Orthopedic Diseases and Department of Bone and Joint Surgery, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China
| | - Jinshao Ye
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China.
| | - Zhengang Zha
- Institute of Orthopedic Diseases and Department of Bone and Joint Surgery, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China.
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17
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Gross J, Avrani S, Katz S, Hilau S, Hershberg R. Culture Volume Influences the Dynamics of Adaptation under Long-Term Stationary Phase. Genome Biol Evol 2020; 12:2292-2301. [PMID: 33283867 DOI: 10.1093/gbe/evaa210] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2020] [Indexed: 12/20/2022] Open
Abstract
Escherichia coli and many other bacterial species, which are incapable of sporulation, can nevertheless survive within resource exhausted media by entering a state termed long-term stationary phase (LTSP). We have previously shown that E. coli populations adapt genetically under LTSP in an extremely convergent manner. Here, we examine how the dynamics of LTSP genetic adaptation are influenced by varying a single parameter of the experiment-culture volume. We find that culture volume affects survival under LTSP, with viable counts decreasing as volumes increase. Across all volumes, mutations accumulate with time, and the majority of mutations accumulated demonstrate signals of being adaptive. However, positive selection appears to affect mutation accumulation more strongly at higher, compared with lower volumes. Finally, we find that several similar genes are likely involved in adaptation across volumes. However, the specific mutations within these genes that contribute to adaptation can vary in a consistent manner. Combined, our results demonstrate how varying a single parameter of an evolutionary experiment can substantially influence the dynamics of observed adaptation.
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Affiliation(s)
- Jonathan Gross
- Rachel & Menachem Mendelovitch Evolutionary Processes of Mutation & Natural Selection Research Laboratory, Department of Genetics and Developmental Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Sarit Avrani
- The Department of Evolutionary and Environmental Biology and the Institute of Evolution, University of Haifa, Haifa 3498838, Israel
| | - Sophia Katz
- Rachel & Menachem Mendelovitch Evolutionary Processes of Mutation & Natural Selection Research Laboratory, Department of Genetics and Developmental Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Sabrin Hilau
- Rachel & Menachem Mendelovitch Evolutionary Processes of Mutation & Natural Selection Research Laboratory, Department of Genetics and Developmental Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Ruth Hershberg
- Rachel & Menachem Mendelovitch Evolutionary Processes of Mutation & Natural Selection Research Laboratory, Department of Genetics and Developmental Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
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18
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Diverse and unified mechanisms of transcription initiation in bacteria. Nat Rev Microbiol 2020; 19:95-109. [PMID: 33122819 DOI: 10.1038/s41579-020-00450-2] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2020] [Indexed: 12/21/2022]
Abstract
Transcription of DNA is a fundamental process in all cellular organisms. The enzyme responsible for transcription, RNA polymerase, is conserved in general architecture and catalytic function across the three domains of life. Diverse mechanisms are used among and within the different branches to regulate transcription initiation. Mechanistic studies of transcription initiation in bacteria are especially amenable because the promoter recognition and melting steps are much less complicated than in eukaryotes or archaea. Also, bacteria have critical roles in human health as pathogens and commensals, and the bacterial RNA polymerase is a proven target for antibiotics. Recent biophysical studies of RNA polymerases and their inhibition, as well as transcription initiation and transcription factors, have detailed the mechanisms of transcription initiation in phylogenetically diverse bacteria, inspiring this Review to examine unifying and diverse themes in this process.
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19
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Quigley J, Peoples A, Sarybaeva A, Hughes D, Ghiglieri M, Achorn C, Desrosiers A, Felix C, Liang L, Malveira S, Millett W, Nitti A, Tran B, Zullo A, Anklin C, Spoering A, Ling LL, Lewis K. Novel Antimicrobials from Uncultured Bacteria Acting against Mycobacterium tuberculosis. mBio 2020; 11:e01516-20. [PMID: 32753498 PMCID: PMC7407088 DOI: 10.1128/mbio.01516-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 07/06/2020] [Indexed: 12/13/2022] Open
Abstract
Mycobacterium tuberculosis, which causes tuberculosis (TB), is estimated to infect one-third of the world's population. The overall burden and the emergence of drug-resistant strains of Mycobacterium tuberculosis underscore the need for new therapeutic options against this important human pathogen. Our recent work demonstrated the success of natural product discovery in identifying novel compounds with efficacy against Mycobacterium tuberculosis Here, we improve on these methods by combining improved isolation and Mycobacterium tuberculosis selective screening to identify three new anti-TB compounds: streptomycobactin, kitamycobactin, and amycobactin. We were unable to obtain mutants resistant to streptomycobactin, and its target remains to be elucidated. We identify the target of kitamycobactin to be the mycobacterial ClpP1P2C1 protease and confirm that kitamycobactin is an analog of the previously identified compound lassomycin. Further, we identify the target of amycobactin to be the essential protein secretion pore SecY. We show further that amycobactin inhibits protein secretion via the SecY translocon. Importantly, this inhibition is bactericidal to nonreplicating Mycobacterium tuberculosis This is the first compound, to our knowledge, that targets the Sec protein secretion machinery in Mycobacterium tuberculosis This work underscores the ability of natural product discovery to deliver not only new compounds with activity against Mycobacterium tuberculosis but also compounds with novel targets.IMPORTANCE Decreasing discovery rates and increasing resistance have underscored the need for novel therapeutic options to treat Mycobacterium tuberculosis infection. Here, we screen extracts from previously uncultured soil microbes for specific activity against Mycobacterium tuberculosis, identifying three novel compounds. We further define the mechanism of action of one compound, amycobactin, and demonstrate that it inhibits protein secretion through the Sec translocation machinery.
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Affiliation(s)
- Jeffrey Quigley
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, Massachusetts, USA
| | - Aaron Peoples
- NovoBiotic Pharmaceuticals, LLC, Cambridge, Massachusetts, USA
| | - Asel Sarybaeva
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, Massachusetts, USA
| | - Dallas Hughes
- NovoBiotic Pharmaceuticals, LLC, Cambridge, Massachusetts, USA
| | - Meghan Ghiglieri
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, Massachusetts, USA
| | | | | | - Cintia Felix
- NovoBiotic Pharmaceuticals, LLC, Cambridge, Massachusetts, USA
| | - Libang Liang
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, Massachusetts, USA
| | - Stephanie Malveira
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, Massachusetts, USA
| | - William Millett
- NovoBiotic Pharmaceuticals, LLC, Cambridge, Massachusetts, USA
| | - Anthony Nitti
- NovoBiotic Pharmaceuticals, LLC, Cambridge, Massachusetts, USA
| | - Baldwin Tran
- NovoBiotic Pharmaceuticals, LLC, Cambridge, Massachusetts, USA
| | - Ashley Zullo
- NovoBiotic Pharmaceuticals, LLC, Cambridge, Massachusetts, USA
| | - Clemens Anklin
- Bruker Biospin Corporation, Billerica, Massachusetts, USA
| | - Amy Spoering
- NovoBiotic Pharmaceuticals, LLC, Cambridge, Massachusetts, USA
| | - Losee Lucy Ling
- NovoBiotic Pharmaceuticals, LLC, Cambridge, Massachusetts, USA
| | - Kim Lewis
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, Massachusetts, USA
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20
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Li W, Li L, Zhang C, Cai Y, Gao Q, Wang F, Cao Y, Lin J, Li J, Shang Z, Lin W. Investigations into the Antibacterial Mechanism of Action of Viridicatumtoxins. ACS Infect Dis 2020; 6:1759-1769. [PMID: 32437130 DOI: 10.1021/acsinfecdis.0c00031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Viridicatumtoxins are a rare class of tetracycline-like antibiotics that strongly inhibit drug-resistant Gram-positive bacteria. Although reported to exhibit in vitro inhibition activity to undecaprenyl pyrophosphate synthase (UPPS), an essential enzyme in bacterial cell wall synthesis, the biological targets and mechanism of action of viridicatumtoxins, especially the drug-target interactions, remain largely unknown. In this study, the structure of Enterococcus faecalis UPPS (EfaUPPS) was first determined, uncovering that EfaUPPS can form not only a typical functional dimer but also an unexpected atypical dimer. We then observed that viridicatumtoxins A (VirA) and B (VirB) are able to bind to UPPSs of E. faecalis, S. aureus, and E. coli in a direct and high-affinity manner as evidenced by in vitro enzyme inhibition assay, surface plasmon resonance (SPR) binding analysis, and in vivo growth inhibition assay, demonstrating that viridicatumtoxins exert antibacterial effects through UPPS binding. The key amino acid residues involved in the interactions with VirA and VirB in EfaUPPS binding pocket were revealed by molecular docking studies, and further validated by site-directed mutagenesis. A single mutation of EfaUPPS at D29A, N31A, and R42A can obviously increase their affinities to VirA, while a single mutation at W228A conferred significant resistance to VirA. Moreover, translation inhibition assay showed that VirA and VirB can weakly inhibit E. coli 70S ribosome. The weak inhibition of ribosome was proposed to be attributed to steric hindrance between viridicatumtoxin ring F and 70S ribosome helix 34 by molecular docking study. Our structural, biochemical, and computational investigations on the interactions of viridicatumtoxins with UPPS and 70S ribosome not only disclosed the potential biological targets of viridicatumtoxins, but also provided a theoretical basis for structural optimization to make new viridicatumtoxin derivatives with improved antimicrobial activities.
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Affiliation(s)
- Weijia Li
- Department of Microbiology and Immunology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Li Li
- School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Chao Zhang
- Department of Pharmacology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Yuanheng Cai
- Biochemistry and Cell Biology Department, Stony Brook University, Stony Brook, New York 11794, United States
| | - Qiyu Gao
- Department of Microbiology and Immunology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Fulin Wang
- Department of Microbiology and Immunology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Yu Cao
- Department of Microbiology and Immunology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Jinzhong Lin
- School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Jie Li
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Zhuo Shang
- Department of Microbiology and Immunology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Wei Lin
- Department of Microbiology and Immunology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 211198, China
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21
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Abstract
During transcription elongation at saturating nucleotide concentrations, RNA polymerase (RNAP) performs ∼50 nucleotide-addition cycles every second. The RNAP active center contains a structural element, termed the trigger loop (TL), that has been suggested, but not previously shown, to open to allow a nucleotide to enter and then to close to hold the nucleotide in each nucleotide-addition cycle. Here, using single-molecule fluorescence spectroscopy to monitor distances between a probe incorporated into the TL and a probe incorporated elsewhere in the transcription elongation complex, we show that TL closing and opening occur in solution, define time scales and functional roles of TL closing and opening, and, most crucially, demonstrate that one cycle of TL closing and opening occurs in each nucleotide-addition cycle. The RNA polymerase (RNAP) trigger loop (TL) is a mobile structural element of the RNAP active center that, based on crystal structures, has been proposed to cycle between an “unfolded”/“open” state that allows an NTP substrate to enter the active center and a “folded”/“closed” state that holds the NTP substrate in the active center. Here, by quantifying single-molecule fluorescence resonance energy transfer between a first fluorescent probe in the TL and a second fluorescent probe elsewhere in RNAP or in DNA, we detect and characterize TL closing and opening in solution. We show that the TL closes and opens on the millisecond timescale; we show that TL closing and opening provides a checkpoint for NTP complementarity, NTP ribo/deoxyribo identity, and NTP tri/di/monophosphate identity, and serves as a target for inhibitors; and we show that one cycle of TL closing and opening typically occurs in each nucleotide addition cycle in transcription elongation.
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22
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Prajapati RK, Rosenqvist P, Palmu K, Mäkinen JJ, Malinen AM, Virta P, Metsä-Ketelä M, Belogurov GA. Oxazinomycin arrests RNA polymerase at the polythymidine sequences. Nucleic Acids Res 2019; 47:10296-10312. [PMID: 31495891 PMCID: PMC6821320 DOI: 10.1093/nar/gkz782] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 08/13/2019] [Accepted: 08/31/2019] [Indexed: 02/06/2023] Open
Abstract
Oxazinomycin is a C-nucleoside antibiotic that is produced by Streptomyces hygroscopicus and closely resembles uridine. Here, we show that the oxazinomycin triphosphate is a good substrate for bacterial and eukaryotic RNA polymerases (RNAPs) and that a single incorporated oxazinomycin is rapidly extended by the next nucleotide. However, the incorporation of several successive oxazinomycins or a single oxazinomycin in a certain sequence context arrested a fraction of the transcribing RNAP. The addition of Gre RNA cleavage factors eliminated the transcriptional arrest at a single oxazinomycin and shortened the nascent RNAs arrested at the polythymidine sequences suggesting that the transcriptional arrest was caused by backtracking of RNAP along the DNA template. We further demonstrate that the ubiquitous C-nucleoside pseudouridine is also a good substrate for RNA polymerases in a triphosphorylated form but does not inhibit transcription of the polythymidine sequences. Our results collectively suggest that oxazinomycin functions as a Trojan horse substrate and its inhibitory effect is attributable to the oxygen atom in the position corresponding to carbon five of the uracil ring.
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Affiliation(s)
- Ranjit K Prajapati
- Department of Biochemistry, University of Turku, FIN-20014 Turku, Finland
| | - Petja Rosenqvist
- Department of Chemistry, University of Turku, FIN-20014 Turku, Finland
| | - Kaisa Palmu
- Department of Biochemistry, University of Turku, FIN-20014 Turku, Finland
| | - Janne J Mäkinen
- Department of Biochemistry, University of Turku, FIN-20014 Turku, Finland
| | - Anssi M Malinen
- Department of Biochemistry, University of Turku, FIN-20014 Turku, Finland
| | - Pasi Virta
- Department of Chemistry, University of Turku, FIN-20014 Turku, Finland
| | - Mikko Metsä-Ketelä
- Department of Biochemistry, University of Turku, FIN-20014 Turku, Finland
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23
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Belogurov GA, Artsimovitch I. The Mechanisms of Substrate Selection, Catalysis, and Translocation by the Elongating RNA Polymerase. J Mol Biol 2019; 431:3975-4006. [PMID: 31153902 DOI: 10.1016/j.jmb.2019.05.042] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/24/2019] [Accepted: 05/24/2019] [Indexed: 11/15/2022]
Abstract
Multi-subunit DNA-dependent RNA polymerases synthesize all classes of cellular RNAs, ranging from short regulatory transcripts to gigantic messenger RNAs. RNA polymerase has to make each RNA product in just one try, even if it takes millions of successive nucleotide addition steps. During each step, RNA polymerase selects a correct substrate, adds it to a growing chain, and moves one nucleotide forward before repeating the cycle. However, RNA synthesis is anything but monotonous: RNA polymerase frequently pauses upon encountering mechanical, chemical and torsional barriers, sometimes stepping back and cleaving off nucleotides from the growing RNA chain. A picture in which these intermittent dynamics enable processive, accurate, and controllable RNA synthesis is emerging from complementary structural, biochemical, computational, and single-molecule studies. Here, we summarize our current understanding of the mechanism and regulation of the on-pathway transcription elongation. We review the details of substrate selection, catalysis, proofreading, and translocation, focusing on rate-limiting steps, structural elements that modulate them, and accessory proteins that appear to control RNA polymerase translocation.
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Affiliation(s)
| | - Irina Artsimovitch
- Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, OH, USA.
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24
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Shi J, Feng Y. [New inhibitors targeting bacterial RNA polymerase]. Zhejiang Da Xue Xue Bao Yi Xue Ban 2019; 48:44-49. [PMID: 31102357 PMCID: PMC8800650 DOI: 10.3785/j.issn.1008-9292.2019.02.08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 09/05/2018] [Indexed: 06/09/2023]
Abstract
Rifamycins, a group of bacterial RNA polymerase inhibitors, are the firstline antimicrobial drugs to treat tuberculosis. In light of the emergence of rifamycinresistant bacteria, development of new RNA polymerase inhibitors that kill rifamycinresistant bacteria with high bioavailability is urgent. Structural analysis of bacterial RNA polymerase in complex with inhibitors by crystallography and cryo-EM indicates that RNA polymerase inhibitors function through five distinct molecular mechanisms:inhibition of the extension of short RNA; competition with substrates; inhibition of the conformational change of the'bridge helix'; inhibition of clamp opening;inhibition of clamp closure. This article reviews the research progress of these five groups of RNA polymerase inhibitors to provide references for the modification of existing RNA polymerase inhibitors and the discovery of new RNA polymerase inhibitors.
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Affiliation(s)
- Jing Shi
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Yu Feng
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou 310058, China
- Department of Pathology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China
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25
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Bauman KD, Li J, Murata K, Mantovani SM, Dahesh S, Nizet V, Luhavaya H, Moore BS. Refactoring the Cryptic Streptophenazine Biosynthetic Gene Cluster Unites Phenazine, Polyketide, and Nonribosomal Peptide Biochemistry. Cell Chem Biol 2019; 26:724-736.e7. [PMID: 30853419 PMCID: PMC6525064 DOI: 10.1016/j.chembiol.2019.02.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/02/2019] [Accepted: 01/31/2019] [Indexed: 11/28/2022]
Abstract
The disconnect between the genomic prediction of secondary metabolite biosynthetic potential and the observed laboratory production profile of microorganisms is well documented. While heterologous expression of biosynthetic gene clusters (BGCs) is often seen as a potential solution to bridge this gap, it is not immune to many challenges including impaired regulation, the inability to recruit essential building blocks, and transcriptional and/or translational silence of the biosynthetic genes. Here we report the discovery, cloning, refactoring, and heterologous expression of a cryptic hybrid phenazine-type BGC (spz) from the marine actinomycete Streptomyces sp. CNB-091. Overexpression of the engineered spz pathway resulted in increased production and chemical diversity of phenazine natural products belonging to the streptophenazine family, including bioactive members containing an unprecedented N-formylglycine attachment. An atypical discrete adenylation enzyme in the spz cluster is required to introduce the formylglycine moiety and represents a phylogenetically distinct class of adenylation proteins.
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Affiliation(s)
- Katherine D Bauman
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA, USA
| | - Jie Li
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA, USA
| | - Kazuya Murata
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA, USA
| | - Simone M Mantovani
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA, USA
| | - Samira Dahesh
- Department of Pediatrics, University of California at San Diego, La Jolla, CA, USA
| | - Victor Nizet
- Department of Pediatrics, University of California at San Diego, La Jolla, CA, USA; Collaborative to Halt Antibiotic Resistant Microbes, University of California at San Diego, La Jolla, CA, USA; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA, USA
| | - Hanna Luhavaya
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA, USA.
| | - Bradley S Moore
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA, USA; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA, USA.
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26
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Bacteriophage gene products as potential antimicrobials against tuberculosis. Biochem Soc Trans 2019; 47:847-860. [PMID: 31085613 DOI: 10.1042/bst20180506] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 04/02/2019] [Accepted: 04/08/2019] [Indexed: 01/20/2023]
Abstract
Tuberculosis (TB) is recognised as one of the most pressing global health threats among infectious diseases. Bacteriophages are adapted for killing of their host, and they were exploited in antibacterial therapy already before the discovery of antibiotics. Antibiotics as broadly active drugs overshadowed phage therapy for a long time. However, owing to the rapid spread of antibiotic resistance and the increasing complexity of treatment of drug-resistant TB, mycobacteriophages are being studied for their antimicrobial potential. Besides phage therapy, which is the administration of live phages to infected patients, the development of drugs of phage origin is gaining interest. This path of medical research might provide us with a new pool of previously undiscovered inhibition mechanisms and molecular interactions which are also of interest in basic research of cellular processes, such as transcription. The current state of research on mycobacteriophage-derived anti-TB treatment is reviewed in comparison with inhibitors from other phages, and with focus on transcription as the host target process.
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27
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An Introduction to the Structure and Function of the Catalytic Core Enzyme of Escherichia coli RNA Polymerase. EcoSal Plus 2019; 8. [PMID: 30109846 DOI: 10.1128/ecosalplus.esp-0004-2018] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
RNA polymerase (RNAP) is the essential enzyme responsible for transcribing genetic information stored in DNA to RNA. Understanding the structure and function of RNAP is important for those who study basic principles in gene expression, such as the mechanism of transcription and its regulation, as well as translational sciences such as antibiotic development. With over a half-century of investigations, there is a wealth of information available on the structure and function of Escherichia coli RNAP. This review introduces the structural features of E. coli RNAP, organized by subunit, giving information on the function, location, and conservation of these features to early stage investigators who have just started their research of E. coli RNAP.
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28
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Li L, Fang C, Zhuang N, Wang T, Zhang Y. Structural basis for transcription initiation by bacterial ECF σ factors. Nat Commun 2019; 10:1153. [PMID: 30858373 PMCID: PMC6411747 DOI: 10.1038/s41467-019-09096-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/01/2019] [Indexed: 01/07/2023] Open
Abstract
Bacterial RNA polymerase employs extra-cytoplasmic function (ECF) σ factors to regulate context-specific gene expression programs. Despite being the most abundant and divergent σ factor class, the structural basis of ECF σ factor-mediated transcription initiation remains unknown. Here, we determine a crystal structure of Mycobacterium tuberculosis (Mtb) RNAP holoenzyme comprising an RNAP core enzyme and the ECF σ factor σH (σH-RNAP) at 2.7 Å, and solve another crystal structure of a transcription initiation complex of Mtb σH-RNAP (σH-RPo) comprising promoter DNA and an RNA primer at 2.8 Å. The two structures together reveal the interactions between σH and RNAP that are essential for σH-RNAP holoenzyme assembly as well as the interactions between σH-RNAP and promoter DNA responsible for stringent promoter recognition and for promoter unwinding. Our study establishes that ECF σ factors and primary σ factors employ distinct mechanisms for promoter recognition and for promoter unwinding.
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Affiliation(s)
- Lingting Li
- 0000000119573309grid.9227.eKey Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032 China ,0000 0004 1797 8419grid.410726.6University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Chengli Fang
- 0000000119573309grid.9227.eKey Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032 China ,0000 0004 1797 8419grid.410726.6University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Ningning Zhuang
- 0000000119573309grid.9227.eKey Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032 China
| | - Tiantian Wang
- 0000000119573309grid.9227.eKey Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032 China ,0000 0004 1797 8419grid.410726.6University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Yu Zhang
- 0000000119573309grid.9227.eKey Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032 China
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29
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An updated structural classification of replicative DNA polymerases. Biochem Soc Trans 2019; 47:239-249. [PMID: 30647142 DOI: 10.1042/bst20180579] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 11/30/2018] [Accepted: 12/07/2018] [Indexed: 12/13/2022]
Abstract
Replicative DNA polymerases are nano-machines essential to life, which have evolved the ability to copy the genome with high fidelity and high processivity. In contrast with cellular transcriptases and ribosome machines, which evolved by accretion of complexity from a conserved catalytic core, no replicative DNA polymerase is universally conserved. Strikingly, four different families of DNA polymerases have evolved to perform DNA replication in the three domains of life. In Bacteria, the genome is replicated by DNA polymerases belonging to the A- and C-families. In Eukarya, genomic DNA is copied mainly by three distinct replicative DNA polymerases, Polα, Polδ, and Polε, which all belong to the B-family. Matters are more complicated in Archaea, which contain an unusual D-family DNA polymerase (PolD) in addition to PolB, a B-family replicative DNA polymerase that is homologous to the eukaryotic ones. PolD is a heterodimeric DNA polymerase present in all Archaea discovered so far, except Crenarchaea. While PolD is an essential replicative DNA polymerase, it is often underrepresented in the literature when the diversity of DNA polymerases is discussed. Recent structural studies have shown that the structures of both polymerase and proofreading active sites of PolD differ from other structurally characterized DNA polymerases, thereby extending the repertoire of folds known to perform DNA replication. This review aims to provide an updated structural classification of all replicative DNAPs and discuss their evolutionary relationships, both regarding the DNA polymerase and proofreading active sites.
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30
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Mechanisms of antibiotics inhibiting bacterial RNA polymerase. Biochem Soc Trans 2019; 47:339-350. [PMID: 30647141 DOI: 10.1042/bst20180499] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 12/18/2018] [Accepted: 12/20/2018] [Indexed: 12/21/2022]
Abstract
Transcription, the first phase of gene expression, is performed by the multi-subunit RNA polymerase (RNAP). Bacterial RNAP is a validated target for clinical antibiotics. Many natural and synthetic compounds are now known to target RNAP, inhibiting various stages of the transcription cycle. However, very few RNAP inhibitors are used clinically. A detailed knowledge of inhibitors and their mechanisms of action (MOA) is vital for the future development of efficacious antibiotics. Moreover, inhibitors of RNAP are often useful tools with which to dissect RNAP function. Here, we review the MOA of antimicrobial transcription inhibitors.
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31
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Structural mechanism of transcription inhibition by lasso peptides microcin J25 and capistruin. Proc Natl Acad Sci U S A 2019; 116:1273-1278. [PMID: 30626643 PMCID: PMC6347699 DOI: 10.1073/pnas.1817352116] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Many bacteria produce antimicrobial peptides for survival under stressful conditions. Some of these antimicrobial peptides are lasso peptides, which have a unique lasso-like topology and have generated great interest as a result of their stability in harsh conditions and amenability to functional engineering. In this study, we determined crystal structures of two lasso peptides, microcin J25 and capistruin, bound to their natural enzymatic target, the bacterial RNA polymerase (RNAP). The structures define peptide inhibitor–RNAP interactions that are important for inhibition and provide detailed insight into how the peptides inhibit RNAP function. This work provides a structural basis to guide the design of more potent lasso peptide antimicrobial approaches. We report crystal structures of the antibacterial lasso peptides microcin J25 (MccJ25) and capistruin (Cap) bound to their natural enzymatic target, the bacterial RNA polymerase (RNAP). Both peptides bind within the RNAP secondary channel, through which NTP substrates enter the RNAP active site, and sterically block trigger-loop folding, which is essential for efficient catalysis by the RNAP. MccJ25 binds deep within the secondary channel in a manner expected to interfere with NTP substrate binding, explaining the partial competitive mechanism of inhibition with respect to NTPs found previously [Mukhopadhyay J, Sineva E, Knight J, Levy RM, Ebright RH (2004) Mol Cell 14:739–751]. The Cap binding determinant on RNAP overlaps, but is not identical to, that of MccJ25. Cap binds further from the RNAP active site and does not sterically interfere with NTP binding, and we show that Cap inhibition is partially noncompetitive with respect to NTPs. This work lays the groundwork for structure determination of other lasso peptides that target the bacterial RNAP and provides a structural foundation to guide lasso peptide antimicrobial engineering approaches.
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32
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Discovery, properties, and biosynthesis of pseudouridimycin, an antibacterial nucleoside-analog inhibitor of bacterial RNA polymerase. J Ind Microbiol Biotechnol 2018; 46:335-343. [PMID: 30465105 DOI: 10.1007/s10295-018-2109-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 11/08/2018] [Indexed: 12/21/2022]
Abstract
Pseudouridimycin (PUM) is a novel pseudouridine-containing peptidyl-nucleoside antibiotic that inhibits bacterial RNA polymerase (RNAP) through a binding site and mechanism different from those of clinically approved RNAP inhibitors of the rifamycin and lipiarmycin (fidaxomicin) classes. PUM was discovered by screening microbial fermentation extracts for RNAP inhibitors. In this review, we describe the discovery and characterization of PUM. We also describe the RNAP-inhibitory and antibacterial properties of PUM. Finally, we review available information on the gene cluster and pathway for PUM biosynthesis and on the potential for discovering additional novel pseudouridine-containing nucleoside antibiotics by searching bacterial genome and metagenome sequences for sequences similar to pumJ, the pseudouridine-synthase gene of the PUM biosynthesis gene cluster.
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33
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Mosaei H, Molodtsov V, Kepplinger B, Harbottle J, Moon CW, Jeeves RE, Ceccaroni L, Shin Y, Morton-Laing S, Marrs ECL, Wills C, Clegg W, Yuzenkova Y, Perry JD, Bacon J, Errington J, Allenby NEE, Hall MJ, Murakami KS, Zenkin N. Mode of Action of Kanglemycin A, an Ansamycin Natural Product that Is Active against Rifampicin-Resistant Mycobacterium tuberculosis. Mol Cell 2018; 72:263-274.e5. [PMID: 30244835 PMCID: PMC6202310 DOI: 10.1016/j.molcel.2018.08.028] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/19/2018] [Accepted: 08/17/2018] [Indexed: 01/07/2023]
Abstract
Antibiotic-resistant bacterial pathogens pose an urgent healthcare threat, prompting a demand for new medicines. We report the mode of action of the natural ansamycin antibiotic kanglemycin A (KglA). KglA binds bacterial RNA polymerase at the rifampicin-binding pocket but maintains potency against RNA polymerases containing rifampicin-resistant mutations. KglA has antibiotic activity against rifampicin-resistant Gram-positive bacteria and multidrug-resistant Mycobacterium tuberculosis (MDR-M. tuberculosis). The X-ray crystal structures of KglA with the Escherichia coli RNA polymerase holoenzyme and Thermus thermophilus RNA polymerase-promoter complex reveal an altered-compared with rifampicin-conformation of KglA within the rifampicin-binding pocket. Unique deoxysugar and succinate ansa bridge substituents make additional contacts with a separate, hydrophobic pocket of RNA polymerase and preclude the formation of initial dinucleotides, respectively. Previous ansa-chain modifications in the rifamycin series have proven unsuccessful. Thus, KglA represents a key starting point for the development of a new class of ansa-chain derivatized ansamycins to tackle rifampicin resistance.
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Affiliation(s)
- Hamed Mosaei
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Vadim Molodtsov
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Bernhard Kepplinger
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK,Demuris Limited, Newcastle Biomedicine Bio-Incubators, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - John Harbottle
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Christopher William Moon
- TB Research Group, National Infection Service, Public Health England, Manor Farm Road, Porton, Salisbury SP4 0JG, UK
| | - Rose Elizabeth Jeeves
- TB Research Group, National Infection Service, Public Health England, Manor Farm Road, Porton, Salisbury SP4 0JG, UK
| | - Lucia Ceccaroni
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Yeonoh Shin
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Stephanie Morton-Laing
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | | | - Corinne Wills
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - William Clegg
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Yulia Yuzenkova
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - John David Perry
- Microbiology Department, Freeman Hospital, Newcastle upon Tyne NE7 7DN, UK
| | - Joanna Bacon
- TB Research Group, National Infection Service, Public Health England, Manor Farm Road, Porton, Salisbury SP4 0JG, UK
| | - Jeff Errington
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK,Demuris Limited, Newcastle Biomedicine Bio-Incubators, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | | | - Michael John Hall
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Katsuhiko S. Murakami
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA,Corresponding author
| | - Nikolay Zenkin
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK,Corresponding author
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34
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Duchi D, Mazumder A, Malinen AM, Ebright RH, Kapanidis AN. The RNA polymerase clamp interconverts dynamically among three states and is stabilized in a partly closed state by ppGpp. Nucleic Acids Res 2018; 46:7284-7295. [PMID: 29878276 PMCID: PMC6101503 DOI: 10.1093/nar/gky482] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 05/09/2018] [Accepted: 05/16/2018] [Indexed: 02/06/2023] Open
Abstract
RNA polymerase (RNAP) contains a mobile structural module, the 'clamp,' that forms one wall of the RNAP active-center cleft and that has been linked to crucial aspects of the transcription cycle, including promoter melting, transcription elongation complex stability, transcription pausing, and transcription termination. Using single-molecule FRET on surface-immobilized RNAP molecules, we show that the clamp in RNAP holoenzyme populates three distinct conformational states and interconvert between these states on the 0.1-1 s time-scale. Similar studies confirm that the RNAP clamp is closed in open complex (RPO) and in initial transcribing complexes (RPITC), including paused initial transcribing complexes, and show that, in these complexes, the clamp does not exhibit dynamic behaviour. We also show that, the stringent-response alarmone ppGpp, which reprograms transcription during amino acid starvation stress, selectively stabilizes the partly-closed-clamp state and prevents clamp opening; these results raise the possibility that ppGpp controls promoter opening by modulating clamp dynamics.
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Affiliation(s)
- Diego Duchi
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK
| | - Abhishek Mazumder
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK
- Waksman Institute of Microbiology and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Anssi M Malinen
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK
| | - Richard H Ebright
- Waksman Institute of Microbiology and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Achillefs N Kapanidis
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK
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35
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Giordano D, Costantini M, Coppola D, Lauritano C, Núñez Pons L, Ruocco N, di Prisco G, Ianora A, Verde C. Biotechnological Applications of Bioactive Peptides From Marine Sources. Adv Microb Physiol 2018; 73:171-220. [PMID: 30262109 DOI: 10.1016/bs.ampbs.2018.05.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
This review is an overview on marine bioactive peptides with promising activities for the development of alternative drugs to fight human pathologies. In particular, we focus on potentially prolific producers of peptides in microorganisms, including sponge-associated bacteria and marine photoautotrophs such as microalgae and cyanobacteria. Microorganisms are still poorly explored for drug discovery, even if they are highly metabolically plastic and potentially amenable to culturing. This offers the possibility of obtaining a continuous source of bioactive compounds to satisfy the challenging demands of pharmaceutical industries. This review targets peptides because of the variety of potent biological activities demonstrated by these molecules, including antiviral, antimicrobial, antifungal, antioxidant, anticoagulant, antihypertensive, anticancer, antidiabetic, antiobesity, and calcium-binding bioactivities. Several of these peptides have already gained recognition as effective drug agents in recent years. We also focus on cutting-edge omic approaches for the discovery of novel compounds for pharmacological applications. With rapid depletion of natural resources, omic technologies may be the solution to efficiently produce a vast variety of novel peptides with unique pharmacological potential.
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Affiliation(s)
- Daniela Giordano
- Institute of Biosciences and BioResources (IBBR), CNR, Napoli, Italy; Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Maria Costantini
- Institute of Biosciences and BioResources (IBBR), CNR, Napoli, Italy; Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Daniela Coppola
- Institute of Biosciences and BioResources (IBBR), CNR, Napoli, Italy
| | - Chiara Lauritano
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Laura Núñez Pons
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Nadia Ruocco
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy; Department of Biology, University of Napoli Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cinthia, Napoli, Italy; Bio-Organic Chemistry Unit, Institute of Biomolecular Chemistry-CNR, Napoli, Italy
| | - Guido di Prisco
- Institute of Biosciences and BioResources (IBBR), CNR, Napoli, Italy
| | - Adrianna Ianora
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Cinzia Verde
- Institute of Biosciences and BioResources (IBBR), CNR, Napoli, Italy; Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy; Dipartimento di Biologia, Università Roma 3, Roma, Italy.
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36
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Lin W, Das K, Degen D, Mazumder A, Duchi D, Wang D, Ebright YW, Ebright RY, Sineva E, Gigliotti M, Srivastava A, Mandal S, Jiang Y, Liu Y, Yin R, Zhang Z, Eng ET, Thomas D, Donadio S, Zhang H, Zhang C, Kapanidis AN, Ebright RH. Structural Basis of Transcription Inhibition by Fidaxomicin (Lipiarmycin A3). Mol Cell 2018; 70:60-71.e15. [PMID: 29606590 PMCID: PMC6205224 DOI: 10.1016/j.molcel.2018.02.026] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 02/14/2018] [Accepted: 02/23/2018] [Indexed: 12/16/2022]
Abstract
Fidaxomicin is an antibacterial drug in clinical use for treatment of Clostridium difficile diarrhea. The active ingredient of fidaxomicin, lipiarmycin A3 (Lpm), functions by inhibiting bacterial RNA polymerase (RNAP). Here we report a cryo-EM structure of Mycobacterium tuberculosis RNAP holoenzyme in complex with Lpm at 3.5-Å resolution. The structure shows that Lpm binds at the base of the RNAP "clamp." The structure exhibits an open conformation of the RNAP clamp, suggesting that Lpm traps an open-clamp state. Single-molecule fluorescence resonance energy transfer experiments confirm that Lpm traps an open-clamp state and define effects of Lpm on clamp dynamics. We suggest that Lpm inhibits transcription by trapping an open-clamp state, preventing simultaneous interaction with promoter -10 and -35 elements. The results account for the absence of cross-resistance between Lpm and other RNAP inhibitors, account for structure-activity relationships of Lpm derivatives, and enable structure-based design of improved Lpm derivatives.
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Affiliation(s)
- Wei Lin
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Kalyan Das
- Rega Institute and Department of Microbiology and Immunology, KU Leuven, 3000 Leuven, Belgium.
| | - David Degen
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Abhishek Mazumder
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Diego Duchi
- Department of Physics, University of Oxford, Oxford OX1 3PU, UK
| | - Dongye Wang
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Yon W Ebright
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Richard Y Ebright
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Elena Sineva
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Matthew Gigliotti
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Aashish Srivastava
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Sukhendu Mandal
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Yi Jiang
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Yu Liu
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Ruiheng Yin
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Zhening Zhang
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York NY 10027, USA
| | - Edward T Eng
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York NY 10027, USA
| | - Dennis Thomas
- Center for Integrative Proteomics, Rutgers University, Piscataway, NJ 08854, USA
| | | | - Haibo Zhang
- South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Changsheng Zhang
- South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | | | - Richard H Ebright
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA.
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37
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Abstract
Covering: 2006 to 2017Actinomycetes have been, for decades, one of the most important sources for the discovery of new antibiotics with an important number of drugs and analogs successfully introduced in the market and still used today in clinical practice. The intensive antibacterial discovery effort that generated the large number of highly potent broad-spectrum antibiotics, has seen a dramatic decline in the large pharma industry in the last two decades resulting in a lack of new classes of antibiotics with novel mechanisms of action reaching the clinic. Whereas the decline in the number of new chemical scaffolds and the rediscovery problem of old known molecules has become a hurdle for industrial natural products discovery programs, new actinomycetes compounds and leads have continued to be discovered and developed to the preclinical stages. Actinomycetes are still one of the most important sources of chemical diversity and a reservoir to mine for novel structures that is requiring the integration of diverse disciplines. These can range from novel strategies to isolate species previously not cultivated, innovative whole cell screening approaches and on-site analytical detection and dereplication tools for novel compounds, to in silico biosynthetic predictions from whole gene sequences and novel engineered heterologous expression, that have inspired the isolation of new NPs and shown their potential application in the discovery of novel antibiotics. This review will address the discovery of antibiotics from actinomycetes from two different perspectives including: (1) an update of the most important antibiotics that have only reached the clinical development in the recent years despite their early discovery, and (2) an overview of the most recent classes of antibiotics described from 2006 to 2017 in the framework of the different strategies employed to untap novel compounds previously overlooked with traditional approaches.
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Affiliation(s)
- Olga Genilloud
- Fundación MEDINA, Avda Conocimiento 34, 18016 Granada, Spain.
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38
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Broad-Host-Range Expression Reveals Native and Host Regulatory Elements That Influence Heterologous Antibiotic Production in Gram-Negative Bacteria. mBio 2017; 8:mBio.01291-17. [PMID: 28874475 PMCID: PMC5587914 DOI: 10.1128/mbio.01291-17] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Heterologous expression has become a powerful tool for studying microbial biosynthetic gene clusters (BGCs). Here, we extend the transformation-associated recombination cloning and heterologous expression platform for microbial BGCs to include Gram-negative proteobacterial expression hosts. Using a broad-host-range expression platform, we test the implicit assumption that biosynthetic pathways are more successfully expressed in more closely related heterologous hosts. Cloning and expression of the violacein BGC from Pseudoalteromonas luteoviolacea 2ta16 revealed robust production in two proteobacterial hosts, Pseudomonas putida KT2440 and Agrobacterium tumefaciens LBA4404, but very little production of the antibiotic in various laboratory strains of Escherichia coli, despite their closer phylogenetic relationship. We identified a nonclustered LuxR-type quorum-sensing receptor from P. luteoviolacea 2ta16, PviR, that increases pathway transcription and violacein production in E. coli by ∼60-fold independently of acyl-homoserine lactone autoinducers. Although E. coli harbors the most similar homolog of PviR identified from all of the hosts tested, overexpression of various E. coli transcription factors did not result in a statistically significant increase in violacein production, while overexpression of two A. tumefaciens PviR homologs significantly increased production. Thus, this work not only introduces a new genetic platform for the heterologous expression of microbial BGCs, it also challenges the assumption that host phylogeny is an accurate predictor of host compatibility.IMPORTANCE Although Gram-positive heterologous hosts such as Streptomyces have been developed and optimized to support diverse secondary metabolic reactions, there has been comparatively less work on Gram-negative hosts, some of which grow faster and are easier to work with. This work presents a new genetic platform for direct cloning and broad-host-range heterologous expression of BGCs in Gram-negative proteobacterial expression hosts, and we leverage this platform to uncover regulatory elements that influence violacein expression from Pseudoalteromonas Although it is often assumed that BGCs will be more successfully expressed in more closely related hosts, our work suggests that this may not be a general rule of thumb, as heterologous production of natural products can be influenced by specific host regulatory and/or biosynthetic elements, and the identity and effectiveness of those elements are difficult to predict. We argue for the use of a diverse set of heterologous hosts, which may also provide insights into the BGC biosynthetic mechanism and the biological function of BGCs.
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Lee Y, Phat C, Hong SC. Structural diversity of marine cyclic peptides and their molecular mechanisms for anticancer, antibacterial, antifungal, and other clinical applications. Peptides 2017; 95:94-105. [PMID: 28610952 DOI: 10.1016/j.peptides.2017.06.002] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 06/06/2017] [Accepted: 06/06/2017] [Indexed: 01/28/2023]
Abstract
Many cyclic peptides and analogues derived from marine sources are known to possess biological properties, including anticancer, antitumor, antibacterial, antifungal, antiparasitic, anti-inflammation, anti-proliferative, anti-hypertensive, cytotoxic, and antibiotic properties. These compounds demonstrate different activities and modes of action according to their structure such as cyclic oligopeptide, cyclic lipopeptide, cyclic glycopeptide and cyclic depsipeptide. The recent advances in application of the above-mentioned cyclic peptides were reported in dolastatins, soblidotin, didemnin B, aplidine, salinosporamide A, kahalalide F and bryostatin 1 and they are currently in clinical trials. These cyclic peptides are possible novel drugs discovered and developed from marine origin. Literature data concerning the potential properties of marine cyclic peptides were reviewed here, and the structural diversity and biological activities of marine cyclic peptides are discussed in relation to the molecular mechanisms of these marine cyclic peptides.
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Affiliation(s)
- Yeji Lee
- College of Medicine, Korea University, Seoul, Republic of Korea
| | - Chanvorleak Phat
- School of Food Science and Technology, Chung-Ang University, Anseong-Si, Gyeonggi-Do, Republic of Korea
| | - Soon-Cheol Hong
- College of Medicine, Korea University, Seoul, Republic of Korea.
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Maffioli SI, Zhang Y, Degen D, Carzaniga T, Del Gatto G, Serina S, Monciardini P, Mazzetti C, Guglierame P, Candiani G, Chiriac AI, Facchetti G, Kaltofen P, Sahl HG, Dehò G, Donadio S, Ebright RH. Antibacterial Nucleoside-Analog Inhibitor of Bacterial RNA Polymerase. Cell 2017. [PMID: 28622509 DOI: 10.1016/j.cell.2017.05.042] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Drug-resistant bacterial pathogens pose an urgent public-health crisis. Here, we report the discovery, from microbial-extract screening, of a nucleoside-analog inhibitor that inhibits bacterial RNA polymerase (RNAP) and exhibits antibacterial activity against drug-resistant bacterial pathogens: pseudouridimycin (PUM). PUM is a natural product comprising a formamidinylated, N-hydroxylated Gly-Gln dipeptide conjugated to 6'-amino-pseudouridine. PUM potently and selectively inhibits bacterial RNAP in vitro, inhibits bacterial growth in culture, and clears infection in a mouse model of Streptococcus pyogenes peritonitis. PUM inhibits RNAP through a binding site on RNAP (the NTP addition site) and mechanism (competition with UTP for occupancy of the NTP addition site) that differ from those of the RNAP inhibitor and current antibacterial drug rifampin (Rif). PUM exhibits additive antibacterial activity when co-administered with Rif, exhibits no cross-resistance with Rif, and exhibits a spontaneous resistance rate an order-of-magnitude lower than that of Rif. PUM is a highly promising lead for antibacterial therapy.
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Affiliation(s)
- Sonia I Maffioli
- NAICONS Srl, 20139 Milan, Italy; Vicuron Pharmaceuticals, 21040 Gerenzano, Italy
| | - Yu Zhang
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - David Degen
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Thomas Carzaniga
- Department of Bioscience, University of Milan, 20122 Milan, Italy
| | | | - Stefania Serina
- NAICONS Srl, 20139 Milan, Italy; Vicuron Pharmaceuticals, 21040 Gerenzano, Italy
| | - Paolo Monciardini
- NAICONS Srl, 20139 Milan, Italy; Vicuron Pharmaceuticals, 21040 Gerenzano, Italy
| | | | | | | | - Alina Iulia Chiriac
- Institute of Medical Microbiology, Immunology, and Parasitology, University of Bonn, D-53012 Bonn, Germany
| | | | | | - Hans-Georg Sahl
- Institute of Medical Microbiology, Immunology, and Parasitology, University of Bonn, D-53012 Bonn, Germany
| | - Gianni Dehò
- Department of Bioscience, University of Milan, 20122 Milan, Italy
| | - Stefano Donadio
- NAICONS Srl, 20139 Milan, Italy; Vicuron Pharmaceuticals, 21040 Gerenzano, Italy.
| | - Richard H Ebright
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA.
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Oyama LB, Crochet JA, Edwards JE, Girdwood SE, Cookson AR, Fernandez-Fuentes N, Hilpert K, Golyshin PN, Golyshina OV, Privé F, Hess M, Mantovani HC, Creevey CJ, Huws SA. Buwchitin: A Ruminal Peptide with Antimicrobial Potential against Enterococcus faecalis. Front Chem 2017; 5:51. [PMID: 28748180 PMCID: PMC5506224 DOI: 10.3389/fchem.2017.00051] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/27/2017] [Indexed: 11/14/2022] Open
Abstract
Antimicrobial peptides (AMPs) are gaining popularity as alternatives for treatment of bacterial infections and recent advances in omics technologies provide new platforms for AMP discovery. We sought to determine the antibacterial activity of a novel antimicrobial peptide, buwchitin, against Enterococcus faecalis. Buwchitin was identified from a rumen bacterial metagenome library, cloned, expressed and purified. The antimicrobial activity of the recombinant peptide was assessed using a broth microdilution susceptibility assay to determine the peptide's killing kinetics against selected bacterial strains. The killing mechanism of buwchitin was investigated further by monitoring its ability to cause membrane depolarization (diSC3(5) method) and morphological changes in E. faecalis cells. Transmission electron micrographs of buwchitin treated E. faecalis cells showed intact outer membranes with blebbing, but no major damaging effects and cell morphology changes. Buwchitin had negligible cytotoxicity against defibrinated sheep erythrocytes. Although no significant membrane leakage and depolarization was observed, buwchitin at minimum inhibitory concentration (MIC) was bacteriostatic against E. faecalis cells and inhibited growth in vitro by 70% when compared to untreated cells. These findings suggest that buwchitin, a rumen derived peptide, has potential for antimicrobial activity against E. faecalis.
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Affiliation(s)
- Linda B Oyama
- Institute of Biological Environmental and Rural Sciences, Aberystwyth UniversityAberystwyth, United Kingdom
| | - Jean-Adrien Crochet
- Institute of Biological Environmental and Rural Sciences, Aberystwyth UniversityAberystwyth, United Kingdom
| | - Joan E Edwards
- Institute of Biological Environmental and Rural Sciences, Aberystwyth UniversityAberystwyth, United Kingdom
| | - Susan E Girdwood
- Institute of Biological Environmental and Rural Sciences, Aberystwyth UniversityAberystwyth, United Kingdom
| | - Alan R Cookson
- Institute of Biological Environmental and Rural Sciences, Aberystwyth UniversityAberystwyth, United Kingdom
| | - Narcis Fernandez-Fuentes
- Institute of Biological Environmental and Rural Sciences, Aberystwyth UniversityAberystwyth, United Kingdom
| | - Kai Hilpert
- Institute of Infection and Immunity, St George's University of LondonLondon, United Kingdom
| | - Peter N Golyshin
- School of Biological Sciences, Bangor UniversityBangor, United Kingdom
| | - Olga V Golyshina
- School of Biological Sciences, Bangor UniversityBangor, United Kingdom
| | - Florence Privé
- Institute of Biological Environmental and Rural Sciences, Aberystwyth UniversityAberystwyth, United Kingdom
| | - Matthias Hess
- College of Agricultural and Environmental Sciences, University of California, DavisDavis, CA, United States
| | | | - Christopher J Creevey
- Institute of Biological Environmental and Rural Sciences, Aberystwyth UniversityAberystwyth, United Kingdom
| | - Sharon A Huws
- Medical Biology Centre, School of Biological Sciences, Queen's University BelfastBelfast, United Kingdom
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Walker SS, Degen D, Nickbarg E, Carr D, Soriano A, Mandal M, Painter RE, Sheth P, Xiao L, Sher X, Murgolo N, Su J, Olsen DB, Ebright RH, Young K. Affinity Selection-Mass Spectrometry Identifies a Novel Antibacterial RNA Polymerase Inhibitor. ACS Chem Biol 2017; 12:1346-1352. [PMID: 28323406 DOI: 10.1021/acschembio.6b01133] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The growing prevalence of drug resistant bacteria is a significant global threat to human health. The antibacterial drug rifampin, which functions by inhibiting bacterial RNA polymerase (RNAP), is an important part of the antibacterial armamentarium. Here, in order to identify novel inhibitors of bacterial RNAP, we used affinity-selection mass spectrometry to screen a chemical library for compounds that bind to Escherichia coli RNAP. We identified a novel small molecule, MRL-436, that binds to RNAP, inhibits RNAP, and exhibits antibacterial activity. MRL-436 binds to RNAP through a binding site that differs from the rifampin binding site, inhibits rifampin-resistant RNAP derivatives, and exhibits antibacterial activity against rifampin-resistant strains. Isolation of mutants resistant to the antibacterial activity of MRL-436 yields a missense mutation in codon 622 of the rpoC gene encoding the RNAP β' subunit or a null mutation in the rpoZ gene encoding the RNAP ω subunit, confirming that RNAP is the functional cellular target for the antibacterial activity of MRL-436, and indicating that RNAP β' subunit residue 622 and the RNAP ω subunit are required for the antibacterial activity of MRL-436. Similarity between the resistance determinant for MRL-436 and the resistance determinant for the cellular alarmone ppGpp suggests a possible similarity in binding site and/or induced conformational state for MRL-436 and ppGpp.
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Affiliation(s)
- Scott S. Walker
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - David Degen
- Department
of Chemistry and Waksman Institute, Rutgers University, Piscataway, New Jersey 08854, United States
| | | | - Donna Carr
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Aileen Soriano
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Mihir Mandal
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | | | - Payal Sheth
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Li Xiao
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Xinwei Sher
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
| | | | - Jing Su
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - David B. Olsen
- Merck & Co., Inc., Upper Gwynedd, Pennsylvania 19454, United States
| | - Richard H. Ebright
- Department
of Chemistry and Waksman Institute, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Katherine Young
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
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43
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Schinke C, Martins T, Queiroz SCN, Melo IS, Reyes FGR. Antibacterial Compounds from Marine Bacteria, 2010-2015. JOURNAL OF NATURAL PRODUCTS 2017; 80:1215-1228. [PMID: 28362500 DOI: 10.1021/acs.jnatprod.6b00235] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This review summarizes the reports on antibacterial compounds that have been obtained from marine-derived bacteria during the period 2010-2015. Over 50 active compounds were isolated during this period, most of which (69%) were obtained from Actinobacteria. Several compounds were already known, such as etamycin A (11) and nosiheptide (65), and new experiments with them showed some previously undetected antibacterial activities, highlighting the fact that known natural products may be an important source of new antibacterial leads. New broad-spectrum antibacterial compounds were reported with activity against antibiotic resistant Gram-positive and Gram-negative bacteria. Anthracimycin (33), kocurin (66), gageotetrins A-C (72-74), and gageomacrolactins 1-3 (86-88) are examples of compounds that display promising properties and could be leads to new antibiotics. A number of microbes produced mixtures of metabolites sharing similar chemical scaffolds, and structure-activity relationships are discussed.
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Affiliation(s)
- Claudia Schinke
- Department of Food Science, School of Food Engineering, University of Campinas , Campinas-SP, CEP 13083-862, Brazil
| | - Thamires Martins
- Department of Food Science, School of Food Engineering, University of Campinas , Campinas-SP, CEP 13083-862, Brazil
| | - Sonia C N Queiroz
- Brazilian Agricultural Research Corporation , Rodovia SP-340 km 127.5, Jaguariúna-SP, CEP 13820-000, Brazil
| | - Itamar S Melo
- Brazilian Agricultural Research Corporation , Rodovia SP-340 km 127.5, Jaguariúna-SP, CEP 13820-000, Brazil
| | - Felix G R Reyes
- Department of Food Science, School of Food Engineering, University of Campinas , Campinas-SP, CEP 13083-862, Brazil
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Abstract
Oxidative cyclizations are important transformations that occur widely during natural product biosynthesis. The transformations from acyclic precursors to cyclized products can afford morphed scaffolds, structural rigidity, and biological activities. Some of the most dramatic structural alterations in natural product biosynthesis occur through oxidative cyclization. In this Review, we examine the different strategies used by nature to create new intra(inter)molecular bonds via redox chemistry. This Review will cover both oxidation- and reduction-enabled cyclization mechanisms, with an emphasis on the former. Radical cyclizations catalyzed by P450, nonheme iron, α-KG-dependent oxygenases, and radical SAM enzymes are discussed to illustrate the use of molecular oxygen and S-adenosylmethionine to forge new bonds at unactivated sites via one-electron manifolds. Nonradical cyclizations catalyzed by flavin-dependent monooxygenases and NAD(P)H-dependent reductases are covered to show the use of two-electron manifolds in initiating cyclization reactions. The oxidative installations of epoxides and halogens into acyclic scaffolds to drive subsequent cyclizations are separately discussed as examples of "disappearing" reactive handles. Last, oxidative rearrangement of rings systems, including contractions and expansions, will be covered.
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Affiliation(s)
- Man-Cheng Tang
- Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, 420 Westwood Plaza, Los Angeles, CA 90095, USA
| | - Yi Zou
- Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, 420 Westwood Plaza, Los Angeles, CA 90095, USA
| | - Kenji Watanabe
- Department of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Christopher T. Walsh
- Stanford University Chemistry, Engineering, and Medicine for Human Health (ChEM-H), Stanford University, 443 Via Ortega, Stanford, CA 94305
| | - Yi Tang
- Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, 420 Westwood Plaza, Los Angeles, CA 90095, USA
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45
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Peptides, Peptidomimetics, and Polypeptides from Marine Sources: A Wealth of Natural Sources for Pharmaceutical Applications. Mar Drugs 2017; 15:md15040124. [PMID: 28441741 PMCID: PMC5408270 DOI: 10.3390/md15040124] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 04/11/2017] [Accepted: 04/18/2017] [Indexed: 01/07/2023] Open
Abstract
Nature provides a variety of peptides that are expressed in most living species. Evolutionary pressure and natural selection have created and optimized these peptides to bind to receptors with high affinity. Hence, natural resources provide an abundant chemical space to be explored in peptide-based drug discovery. Marine peptides can be extracted by simple solvent extraction techniques. The advancement of analytical techniques has made it possible to obtain pure peptides from natural resources. Extracted peptides have been evaluated as possible therapeutic agents for a wide range of diseases, including antibacterial, antifungal, antidiabetic and anticancer activity as well as cardiovascular and neurotoxin activity. Although marine resources provide thousands of possible peptides, only a few peptides derived from marine sources have reached the pharmaceutical market. This review focuses on some of the peptides derived from marine sources in the past ten years and gives a brief review of those that are currently in clinical trials or on the market.
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46
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Lin W, Mandal S, Degen D, Liu Y, Ebright YW, Li S, Feng Y, Zhang Y, Mandal S, Jiang Y, Liu S, Gigliotti M, Talaue M, Connell N, Das K, Arnold E, Ebright RH. Structural Basis of Mycobacterium tuberculosis Transcription and Transcription Inhibition. Mol Cell 2017; 66:169-179.e8. [PMID: 28392175 DOI: 10.1016/j.molcel.2017.03.001] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 02/15/2017] [Accepted: 02/28/2017] [Indexed: 01/22/2023]
Abstract
Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis, which kills 1.8 million annually. Mtb RNA polymerase (RNAP) is the target of the first-line antituberculosis drug rifampin (Rif). We report crystal structures of Mtb RNAP, alone and in complex with Rif, at 3.8-4.4 Å resolution. The results identify an Mtb-specific structural module of Mtb RNAP and establish that Rif functions by a steric-occlusion mechanism that prevents extension of RNA. We also report non-Rif-related compounds-Nα-aroyl-N-aryl-phenylalaninamides (AAPs)-that potently and selectively inhibit Mtb RNAP and Mtb growth, and we report crystal structures of Mtb RNAP in complex with AAPs. AAPs bind to a different site on Mtb RNAP than Rif, exhibit no cross-resistance with Rif, function additively when co-administered with Rif, and suppress resistance emergence when co-administered with Rif.
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Affiliation(s)
- Wei Lin
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Soma Mandal
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - David Degen
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Yu Liu
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Yon W Ebright
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Shengjian Li
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Yu Feng
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Yu Zhang
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Sukhendu Mandal
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Yi Jiang
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Shuang Liu
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Matthew Gigliotti
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Meliza Talaue
- Center for Biodefense and Department of Medicine, New Jersey Medical School, Rutgers University, Newark, NJ 07101, USA
| | - Nancy Connell
- Center for Biodefense and Department of Medicine, New Jersey Medical School, Rutgers University, Newark, NJ 07101, USA
| | - Kalyan Das
- Center for Advanced Biotechnology and Medicine and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Eddy Arnold
- Center for Advanced Biotechnology and Medicine and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Richard H Ebright
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA.
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Molodtsov V, Scharf NT, Stefan MA, Garcia GA, Murakami KS. Structural basis for rifamycin resistance of bacterial RNA polymerase by the three most clinically important RpoB mutations found in Mycobacterium tuberculosis. Mol Microbiol 2017; 103:1034-1045. [PMID: 28009073 DOI: 10.1111/mmi.13606] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2016] [Indexed: 12/01/2022]
Abstract
Since 1967, Rifampin (RMP, a Rifamycin) has been used as a first line antibiotic treatment for tuberculosis (TB), and it remains the cornerstone of current short-term TB treatment. Increased occurrence of Rifamycin-resistant (RIFR ) TB, ∼41% of which results from the RpoB S531L mutation in RNA polymerase (RNAP), has become a growing problem worldwide. In this study, we determined the X-ray crystal structures of the Escherichia coli RNAPs containing the most clinically important S531L mutation and two other frequently observed RIFR mutants, RpoB D516V and RpoB H526Y. The structures reveal that the S531L mutation imparts subtle if any structural or functional impact on RNAP in the absence of RIF. However, upon RMP binding, the S531L mutant exhibits a disordering of the RIF binding interface, which effectively reduces the RMP affinity. In contrast, the H526Y mutation reshapes the RIF binding pocket, generating significant steric conflicts that essentially prevent any RIF binding. While the D516V mutant does not exhibit any such gross structural changes, certainly the electrostatic surface of the RIF binding pocket is dramatically changed, likely resulting in the decreased affinity for RIFs. Analysis of interactions of RMP with three common RIFR mutant RNAPs suggests that modifications to RMP may recover its efficacy against RIFR TB.
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Affiliation(s)
- Vadim Molodtsov
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Nathan T Scharf
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church St, Ann Arbor, MI, 48109-1065, USA
| | - Maxwell A Stefan
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church St, Ann Arbor, MI, 48109-1065, USA
| | - George A Garcia
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church St, Ann Arbor, MI, 48109-1065, USA
| | - Katsuhiko S Murakami
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
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48
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New antibiotics from Nature’s chemical inventory. Bioorg Med Chem 2016; 24:6227-6252. [DOI: 10.1016/j.bmc.2016.09.014] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 09/07/2016] [Indexed: 01/07/2023]
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49
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Lee J, Borukhov S. Bacterial RNA Polymerase-DNA Interaction-The Driving Force of Gene Expression and the Target for Drug Action. Front Mol Biosci 2016; 3:73. [PMID: 27882317 PMCID: PMC5101437 DOI: 10.3389/fmolb.2016.00073] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 10/24/2016] [Indexed: 11/17/2022] Open
Abstract
DNA-dependent multisubunit RNA polymerase (RNAP) is the key enzyme of gene expression and a target of regulation in all kingdoms of life. It is a complex multifunctional molecular machine which, unlike other DNA-binding proteins, engages in extensive and dynamic interactions (both specific and nonspecific) with DNA, and maintains them over a distance. These interactions are controlled by DNA sequences, DNA topology, and a host of regulatory factors. Here, we summarize key recent structural and biochemical studies that elucidate the fine details of RNAP-DNA interactions during initiation. The findings of these studies help unravel the molecular mechanisms of promoter recognition and open complex formation, initiation of transcript synthesis and promoter escape. We also discuss most current advances in the studies of drugs that specifically target RNAP-DNA interactions during transcription initiation and elongation.
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Affiliation(s)
- Jookyung Lee
- Department of Cell Biology, Rowan University School of Osteopathic Medicine Stratford, NJ, USA
| | - Sergei Borukhov
- Department of Cell Biology, Rowan University School of Osteopathic Medicine Stratford, NJ, USA
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50
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Castro-Falcón G, Hahn D, Reimer D, Hughes CC. Thiol Probes To Detect Electrophilic Natural Products Based on Their Mechanism of Action. ACS Chem Biol 2016; 11:2328-36. [PMID: 27294329 DOI: 10.1021/acschembio.5b00924] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
New methods are urgently needed to find novel natural products as structural leads for the development of new drugs against emerging diseases such as cancer and multiresistant bacterial infections. Here we introduce a reactivity-guided drug discovery approach for electrophilic natural products, a therapeutically relevant class of natural products that covalently modify their cellular targets, in crude extracts. Using carefully designed halogenated aromatic reagents, the process furnishes derivatives that are UV-active and highly conspicuous via mass spectrometry by virtue of an isotopically unique bromine or chlorine tag. In addition to the identification of high-value metabolites, the process facilitates the difficult task of structure elucidation by providing derivatives that are primed for X-ray crystallographic analysis. We show that a cysteine probe efficiently and chemoselectively labels enone-, β-lactam-, and β-lactone-based electrophilic natural products (parthenolide, andrographolide, wortmannin, penicillin G, salinosporamide), while a thiophenol probe preferentially labels epoxide-based electrophilic natural products (triptolide, epoxomicin, eponemycin, cyclomarin, salinamide). Using the optimized method, we were able to detect and isolate the epoxide-bearing natural product tirandalydigin from Salinispora and thereby link an orphan gene cluster to its gene product.
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Affiliation(s)
- Gabriel Castro-Falcón
- Center for Marine Biotechnology
and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, United States
| | - Dongyup Hahn
- Center for Marine Biotechnology
and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, United States
| | - Daniela Reimer
- Center for Marine Biotechnology
and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, United States
| | - Chambers C. Hughes
- Center for Marine Biotechnology
and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, United States
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