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Karapetian M, Alimbarashvili E, Vishnepolsky B, Gabrielian A, Rosenthal A, Hurt DE, Tartakovsky M, Mchedlishvili M, Arsenadze D, Pirtskhalava M, Zaalishvili G. Evaluation of the synergistic potential and mechanisms of action for de novo designed cationic antimicrobial peptides. Heliyon 2024; 10:e27852. [PMID: 38560672 PMCID: PMC10979160 DOI: 10.1016/j.heliyon.2024.e27852] [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: 06/23/2023] [Revised: 03/01/2024] [Accepted: 03/07/2024] [Indexed: 04/04/2024] Open
Abstract
Antimicrobial peptides (AMPs) have emerged as promising candidates in combating antimicrobial resistance - a growing issue in healthcare. However, to develop AMPs into effective therapeutics, a thorough analysis and extensive investigations are essential. In this study, we employed an in silico approach to design cationic AMPs de novo, followed by their experimental testing. The antibacterial potential of de novo designed cationic AMPs, along with their synergistic properties in combination with conventional antibiotics was examined. Furthermore, the effects of bacterial inoculum density and metabolic state on the antibacterial activity of AMPs were evaluated. Finally, the impact of several potent AMPs on E. coli cell envelope and genomic DNA integrity was determined. Collectively, this comprehensive analysis provides insights into the unique characteristics of cationic AMPs.
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Affiliation(s)
- Margarita Karapetian
- Laboratory of Chromatin Biology, Institute of Cellular and Molecular Biology, Agricultural University of Georgia, 240 David Aghmashenebeli Alley, 0159, Tbilisi, Georgia
| | - Evgenia Alimbarashvili
- Laboratory of Chromatin Biology, Institute of Cellular and Molecular Biology, Agricultural University of Georgia, 240 David Aghmashenebeli Alley, 0159, Tbilisi, Georgia
- Ivane Beritashvili Center of Experimental Biomedicine, 0160, Tbilisi, Georgia
| | - Boris Vishnepolsky
- Ivane Beritashvili Center of Experimental Biomedicine, 0160, Tbilisi, Georgia
| | - Andrei Gabrielian
- Office of Cyber Infrastructure and Computational Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Alex Rosenthal
- Office of Cyber Infrastructure and Computational Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Darrell E. Hurt
- Office of Cyber Infrastructure and Computational Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Michael Tartakovsky
- Office of Cyber Infrastructure and Computational Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Mariam Mchedlishvili
- Laboratory of Chromatin Biology, Institute of Cellular and Molecular Biology, Agricultural University of Georgia, 240 David Aghmashenebeli Alley, 0159, Tbilisi, Georgia
| | - Davit Arsenadze
- Laboratory of Chromatin Biology, Institute of Cellular and Molecular Biology, Agricultural University of Georgia, 240 David Aghmashenebeli Alley, 0159, Tbilisi, Georgia
| | - Malak Pirtskhalava
- Ivane Beritashvili Center of Experimental Biomedicine, 0160, Tbilisi, Georgia
| | - Giorgi Zaalishvili
- Laboratory of Chromatin Biology, Institute of Cellular and Molecular Biology, Agricultural University of Georgia, 240 David Aghmashenebeli Alley, 0159, Tbilisi, Georgia
- Ivane Beritashvili Center of Experimental Biomedicine, 0160, Tbilisi, Georgia
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2
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Kuzminov A. Bacterial nucleoid is a riddle wrapped in a mystery inside an enigma. J Bacteriol 2024; 206:e0021123. [PMID: 38358278 PMCID: PMC10994824 DOI: 10.1128/jb.00211-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024] Open
Abstract
Bacterial chromosome, the nucleoid, is traditionally modeled as a rosette of DNA mega-loops, organized around proteinaceous central scaffold by nucleoid-associated proteins (NAPs), and mixed with the cytoplasm by transcription and translation. Electron microscopy of fixed cells confirms dispersal of the cloud-like nucleoid within the ribosome-filled cytoplasm. Here, I discuss evidence that the nucleoid in live cells forms DNA phase separate from riboprotein phase, the "riboid." I argue that the nucleoid-riboid interphase, where DNA interacts with NAPs, transcribing RNA polymerases, nascent transcripts, and ssRNA chaperones, forms the transcription zone. An active part of phase separation, transcription zone enforces segregation of the centrally positioned information phase (the nucleoid) from the surrounding action phase (the riboid), where translation happens, protein accumulates, and metabolism occurs. I speculate that HU NAP mostly tiles up the nucleoid periphery-facilitating DNA mobility but also supporting transcription in the interphase. Besides extruding plectonemically supercoiled DNA mega-loops, condensins could compact them into solenoids of uniform rings, while HU could support rigidity and rotation of these DNA rings. The two-phase cytoplasm arrangement allows the bacterial cell to organize the central dogma activities, where (from the cell center to its periphery) DNA replicates and segregates, DNA is transcribed, nascent mRNA is handed over to ribosomes, mRNA is translated into proteins, and finally, the used mRNA is recycled into nucleotides at the inner membrane. The resulting information-action conveyor, with one activity naturally leading to the next one, explains the efficiency of prokaryotic cell design-even though its main intracellular transportation mode is free diffusion.
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Affiliation(s)
- Andrei Kuzminov
- Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
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3
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Jian JY, Osheroff N. Telling Your Right Hand from Your Left: The Effects of DNA Supercoil Handedness on the Actions of Type II Topoisomerases. Int J Mol Sci 2023; 24:11199. [PMID: 37446377 PMCID: PMC10342825 DOI: 10.3390/ijms241311199] [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: 06/16/2023] [Revised: 07/05/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
Type II topoisomerases are essential enzymes that modulate the topological state of DNA supercoiling in all living organisms. These enzymes alter DNA topology by performing double-stranded passage reactions on over- or underwound DNA substrates. This strand passage reaction generates a transient covalent enzyme-cleaved DNA structure known as the cleavage complex. Al-though the cleavage complex is a requisite catalytic intermediate, it is also intrinsically dangerous to genomic stability in biological systems. The potential threat of type II topoisomerase function can also vary based on the nature of the supercoiled DNA substrate. During essential processes such as DNA replication and transcription, cleavage complex formation can be inherently more dangerous on overwound versus underwound DNA substrates. As such, it is important to understand the profound effects that DNA topology can have on the cellular functions of type II topoisomerases. This review will provide a broad assessment of how human and bacterial type II topoisomerases recognize and act on their substrates of various topological states.
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Affiliation(s)
- Jeffrey Y. Jian
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA;
| | - Neil Osheroff
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA;
- Department of Medicine (Hematology/Oncology), Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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4
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Jian JY, McCarty KD, Byl J, Guengerich FP, Neuman K, Osheroff N. Basis for the discrimination of supercoil handedness during DNA cleavage by human and bacterial type II topoisomerases. Nucleic Acids Res 2023; 51:3888-3902. [PMID: 36999602 PMCID: PMC10164583 DOI: 10.1093/nar/gkad190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 02/24/2023] [Accepted: 03/23/2023] [Indexed: 04/01/2023] Open
Abstract
To perform double-stranded DNA passage, type II topoisomerases generate a covalent enzyme-cleaved DNA complex (i.e. cleavage complex). Although this complex is a requisite enzyme intermediate, it is also intrinsically dangerous to genomic stability. Consequently, cleavage complexes are the targets for several clinically relevant anticancer and antibacterial drugs. Human topoisomerase IIα and IIβ and bacterial gyrase maintain higher levels of cleavage complexes with negatively supercoiled over positively supercoiled DNA substrates. Conversely, bacterial topoisomerase IV is less able to distinguish DNA supercoil handedness. Despite the importance of supercoil geometry to the activities of type II topoisomerases, the basis for supercoil handedness recognition during DNA cleavage has not been characterized. Based on the results of benchtop and rapid-quench flow kinetics experiments, the forward rate of cleavage is the determining factor of how topoisomerase IIα/IIβ, gyrase and topoisomerase IV distinguish supercoil handedness in the absence or presence of anticancer/antibacterial drugs. In the presence of drugs, this ability can be enhanced by the formation of more stable cleavage complexes with negatively supercoiled DNA. Finally, rates of enzyme-mediated DNA ligation do not contribute to the recognition of DNA supercoil geometry during cleavage. Our results provide greater insight into how type II topoisomerases recognize their DNA substrates.
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Affiliation(s)
- Jeffrey Y Jian
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Kevin D McCarty
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Jo Ann W Byl
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Keir C Neuman
- Laboratory of Single Molecule Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20982, USA
| | - Neil Osheroff
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- Department of Medicine (Hematology/Oncology), Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- VA Tennessee Valley Healthcare System, Nashville, TN 37212, USA
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5
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Dorman CJ. Variable DNA topology is an epigenetic generator of physiological heterogeneity in bacterial populations. Mol Microbiol 2023; 119:19-28. [PMID: 36565252 PMCID: PMC10108321 DOI: 10.1111/mmi.15014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/25/2022] [Accepted: 12/06/2022] [Indexed: 12/25/2022]
Abstract
Transcription is a noisy and stochastic process that produces sibling-to-sibling variations in physiology across a population of genetically identical cells. This pattern of diversity reflects, in part, the burst-like nature of transcription. Transcription bursting has many causes and a failure to remove the supercoils that accumulate in DNA during transcription elongation is an important contributor. Positive supercoiling of the DNA ahead of the transcription elongation complex can result in RNA polymerase stalling if this DNA topological roadblock is not removed. The relaxation of these positive supercoils is performed by the ATP-dependent type II topoisomerases DNA gyrase and topoisomerase IV. Interference with the action of these topoisomerases involving, inter alia, topoisomerase poisons, fluctuations in the [ATP]/[ADP] ratio, and/or the intervention of nucleoid-associated proteins with GapR-like or YejK-like activities, may have consequences for the smooth operation of the transcriptional machinery. Antibiotic-tolerant (but not resistant) persister cells are among the phenotypic outliers that may emerge. However, interference with type II topoisomerase activity can have much broader consequences, making it an important epigenetic driver of physiological diversity in the bacterial population.
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Affiliation(s)
- Charles J Dorman
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin 2, Ireland
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6
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Mahaseth T, Kuzminov A. Catastrophic chromosome fragmentation probes the nucleoid structure and dynamics in Escherichia coli. Nucleic Acids Res 2022; 50:11013-11027. [PMID: 36243965 PMCID: PMC9638926 DOI: 10.1093/nar/gkac865] [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: 08/31/2022] [Revised: 09/14/2022] [Accepted: 09/26/2022] [Indexed: 11/17/2022] Open
Abstract
Escherichia coli cells treated with a combination of cyanide (CN) and hydrogen peroxide (HP) succumb to catastrophic chromosome fragmentation (CCF), detectable in pulsed-field gels as >100 double-strand breaks per genome equivalent. Here we show that CN + HP-induced double-strand breaks are independent of replication and occur uniformly over the chromosome,—therefore we used CCF to probe the nucleoid structure by measuring DNA release from precipitated nucleoids. CCF releases surprisingly little chromosomal DNA from the nucleoid suggesting that: (i) the nucleoid is a single DNA-protein complex with only limited stretches of protein-free DNA and (ii) CN + HP-induced breaks happen within these unsecured DNA stretches, rather than at DNA attachments to the central scaffold. Mutants lacking individual nucleoid-associated proteins (NAPs) release more DNA during CCF, consistent with NAPs anchoring chromosome to the central scaffold (Dps also reduces the number of double-strand breaks directly). Finally, significantly more broken DNA is released once ATP production is restored, with about two-thirds of this ATP-dependent DNA release being due to transcription, suggesting that transcription complexes act as pulleys to move DNA loops. In addition to NAPs, recombinational repair of double-strand breaks also inhibits DNA release by CCF, contributing to a dynamic and complex nucleoid structure.
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Affiliation(s)
- Tulip Mahaseth
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Andrei Kuzminov
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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7
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Yu C, Armengaud J, Blaustein RA, Chen K, Ye Z, Xu F, Gaillard JC, Qin Z, Fu Y, Hartmann EM, Shen C. Antibiotic tolerance and degradation capacity of the organic pollutant-degrading bacterium Rhodococcus biphenylivorans TG9 T. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127712. [PMID: 34865898 DOI: 10.1016/j.jhazmat.2021.127712] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 10/14/2021] [Accepted: 11/03/2021] [Indexed: 06/13/2023]
Abstract
Antibiotics are ubiquitous in soil due to natural ecological competition, as well as emerging contaminants due to anthropogenic inputs. Under environmental factors like antibiotic stress, some bacteria, including those that degrade environmental pollutants, can enter a dormant state as a survival strategy, thereby limiting their metabolic activity and function. Dormancy has a critical influence on the degradative activity of bacteria, dramatically decreasing the rate at which they transform organic pollutants. To better understand this phenomenon in environmental pollutant-degrading bacteria, we investigated dormancy transitions induced with norfloxacin in Rhodococcus biphenylivorans TG9T using next-generation proteomics, proteogenomics, and additional experiments. Our results suggest that exposure to norfloxacin inhibited DNA replication, which led to damage to the cell. Dormant cells then likely triggered DNA repair, particularly homologous recombination, for continued survival. The results also indicated that substrate transport (ATP-binding cassette transporter), ATP production, and the tricarboxylic acid (TCA) cycle were repressed during dormancy, and degradation of organic pollutants was down-regulated. Given the widespread phenomenon of dormancy among bacteria involved in pollutant removal systems, this study improves our understanding of possible implications of antibiotic survival strategies on biotransformation of mixtures containing antibiotics as well as other organics.
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Affiliation(s)
- Chungui Yu
- Zhejiang University, Department of Environmental Engineering, College of Environmental and Resource Sciences, Hangzhou 310058, Zhejiang, China
| | - Jean Armengaud
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, F-30200 Bagnols-sur-Cèze, France
| | - Ryan Andrew Blaustein
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL, USA
| | - Kezhen Chen
- Zhejiang University, Department of Environmental Engineering, College of Environmental and Resource Sciences, Hangzhou 310058, Zhejiang, China
| | - Zhe Ye
- Zhejiang University, Department of Environmental Engineering, College of Environmental and Resource Sciences, Hangzhou 310058, Zhejiang, China
| | - Fengjun Xu
- Zhejiang University, Department of Environmental Engineering, College of Environmental and Resource Sciences, Hangzhou 310058, Zhejiang, China
| | - Jean-Charles Gaillard
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, F-30200 Bagnols-sur-Cèze, France
| | - Zhihui Qin
- Zhejiang University, Department of Environmental Engineering, College of Environmental and Resource Sciences, Hangzhou 310058, Zhejiang, China
| | - Yulong Fu
- Zhejiang University, Department of Environmental Engineering, College of Environmental and Resource Sciences, Hangzhou 310058, Zhejiang, China
| | - Erica Marie Hartmann
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL, USA.
| | - Chaofeng Shen
- Zhejiang University, Department of Environmental Engineering, College of Environmental and Resource Sciences, Hangzhou 310058, Zhejiang, China.
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8
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Lsr2 and Its Novel Paralogue Mediate the Adjustment of Mycobacterium smegmatis to Unfavorable Environmental Conditions. mSphere 2021; 6:6/3/e00290-21. [PMID: 33980681 PMCID: PMC8125055 DOI: 10.1128/msphere.00290-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Nucleoid-associated proteins (NAPs) are the most abundant proteins involved in bacterial chromosome organization and global transcription regulation. The mycobacterial NAP family includes many diverse proteins; some are unique to actinobacteria, and many are crucial for survival under stress (e.g., HupB and Lsr2) and/or optimal growth conditions (e.g., mycobacterial integration host factor [mIHF]). Lsr2 is a nucleoid-associated protein (NAP) that has been found strictly in actinobacteria, including mycobacteria. It is a functional homolog of histone-like nucleoid-structuring protein (H-NS); it acts as a DNA-bridging protein that plays a role in chromosomal organization and transcriptional regulation. To date, the studies on Lsr2 have focused mainly on Mycobacterium tuberculosis. In this study, we analyze the role of Lsr2 as a transcription factor in Mycobacterium smegmatis, a saprophytic bacterium whose natural habitat (soil and water) substantially differs from those of the obligatory mycobacterial pathogens. Our chromatin immunoprecipitation-sequencing (ChIP-seq) data revealed that Lsr2 binds preferentially to AT-rich regions of the M. smegmatis chromosome. We found that Lsr2 acts mainly as a repressor, controlling gene expression either directly by binding promoter regions or indirectly through DNA loop formation and DNA coating. One of the Lsr2-repressed genes encodes polyketide synthase (MSMEG_4727), which is involved in the synthesis of lipooligosaccharides (LOSs). An M. smegmatis strain deprived of Lsr2 produces more LOSs, which is mirrored by changes in the smoothness of cells and their susceptibilities to antibiotics. Unlike M. tuberculosis, M. smegmatis additionally encodes a paralogue of Lsr2, MSMEG_1060, which is a novel member of the mycobacterial NAP family. The Lsr2 and MSMEG_1060 proteins exhibit different DNA binding specificities and chromosomal localizations. Our results suggest that these proteins help M. smegmatis cells cope with stress conditions, including hypoxia and exposure to antibiotics. Thus, the present work provides novel insight into the role of Lsr2 paralogues in the ability of a saprophytic mycobacterial species to adjust to environmental changes. IMPORTANCE Nucleoid-associated proteins (NAPs) are the most abundant proteins involved in bacterial chromosome organization and global transcription regulation. The mycobacterial NAP family includes many diverse proteins; some are unique to actinobacteria, and many are crucial for survival under stress (e.g., HupB and Lsr2) and/or optimal growth conditions (e.g., mycobacterial integration host factor [mIHF]). Here, we present a comprehensive study concerning two functional homologues of mycobacterial H-NS: Lsr2 and its paralogue from M. smegmatis, MSMEG_1060. We found that Lsr2 plays a role in transcriptional regulation, mainly by repressing gene expression via DNA loop formation and/or DNA-coating mechanisms. Intriguingly, the number of Lsr2-mediated genes was found to increase under hypoxia. Compared to Lsr2, MSMEG_1060 exhibits a different DNA binding specificity and chromosomal localization. Since tuberculosis remains a serious worldwide health problem, studies on stress response-mediating agents, such as Lsr2, may contribute to the development of novel antituberculosis drugs.
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Sutormin DA, Galivondzhyan AK, Polkhovskiy AV, Kamalyan SO, Severinov KV, Dubiley SA. Diversity and Functions of Type II Topoisomerases. Acta Naturae 2021; 13:59-75. [PMID: 33959387 PMCID: PMC8084294 DOI: 10.32607/actanaturae.11058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/09/2020] [Indexed: 11/29/2022] Open
Abstract
The DNA double helix provides a simple and elegant way to store and copy genetic information. However, the processes requiring the DNA helix strands separation, such as transcription and replication, induce a topological side-effect - supercoiling of the molecule. Topoisomerases comprise a specific group of enzymes that disentangle the topological challenges associated with DNA supercoiling. They relax DNA supercoils and resolve catenanes and knots. Here, we review the catalytic cycles, evolution, diversity, and functional roles of type II topoisomerases in organisms from all domains of life, as well as viruses and other mobile genetic elements.
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Affiliation(s)
- D. A. Sutormin
- Institute of Gene Biology RAS, Moscow, 119334 Russia
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
| | - A. K. Galivondzhyan
- Lomonosov Moscow State University, Moscow, 119991 Russia
- Institute of Molecular Genetics RAS, Moscow, 123182 Russia
| | - A. V. Polkhovskiy
- Institute of Gene Biology RAS, Moscow, 119334 Russia
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
| | - S. O. Kamalyan
- Institute of Gene Biology RAS, Moscow, 119334 Russia
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
| | - K. V. Severinov
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
- Centre for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology RAS, Moscow, 119334 Russia
- Waksman Institute for Microbiology, Piscataway, New Jersey, 08854 USA
| | - S. A. Dubiley
- Institute of Gene Biology RAS, Moscow, 119334 Russia
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
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10
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Adamus-Białek W, Wawszczak M, Arabski M, Majchrzak M, Gulba M, Jarych D, Parniewski P, Głuszek S. Ciprofloxacin, amoxicillin, and aminoglycosides stimulate genetic and phenotypic changes in uropathogenic Escherichia coli strains. Virulence 2020; 10:260-276. [PMID: 30938219 PMCID: PMC6527016 DOI: 10.1080/21505594.2019.1596507] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Antibiotic therapy and its consequences in bacterial and human aspects are widely investigated. Despite this, the emergence of new multidrug resistant bacteria is still a current problem. The scope of our work included the observation of changes among uropathogenic Escherichia coli strains after the treatment with a subinhibitory concentration of different antibiotics. The sensitive strains with or without virulence factors were incubated with amoxicillin, ciprofloxacin, gentamycin, or tobramycin. After each passage, the E. coli derivatives were compared to their wild types based on their susceptibility profiles, virulence genes, biofilm formations and the fingerprint profiles of PCR products amplified with using the (N)(6)(CGG)(4) primer. It turned out that antibiotics caused significant changes in the repertoire of bacterial virulence and biofilm formation, corresponding to acquired cross-resistance. The genomic changes among the studied bacteria were reflected in the changed profiles of the CGG-PCR products. In conclusion, the inappropriate application of antibiotics may cause a rapid rise of Multidrug Resistant (MDR) strains and give bacteria a chance to modulate their own pathogenicity. This phenomenon has been easily observed among uropathogenic E. coli strains and it is one of the main reasons for recurrent infections of the urinary tract.
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Affiliation(s)
- Wioletta Adamus-Białek
- a Department of Surgery and Surgical Nursery with Laboratory of Genetics, Faculty of Medicine and Health Sciences , Jan Kochanowski University , Kielce , Poland
| | - Monika Wawszczak
- a Department of Surgery and Surgical Nursery with Laboratory of Genetics, Faculty of Medicine and Health Sciences , Jan Kochanowski University , Kielce , Poland
| | - Michał Arabski
- b Department of Biochemistry & Genetics , Jan Kochanowski University , Kielce , Poland
| | - Michał Majchrzak
- a Department of Surgery and Surgical Nursery with Laboratory of Genetics, Faculty of Medicine and Health Sciences , Jan Kochanowski University , Kielce , Poland
| | - Martyna Gulba
- a Department of Surgery and Surgical Nursery with Laboratory of Genetics, Faculty of Medicine and Health Sciences , Jan Kochanowski University , Kielce , Poland
| | - Dariusz Jarych
- c Institute of Medical Biology, Polish Academy of Sciences , Łódź , Poland
| | - Paweł Parniewski
- c Institute of Medical Biology, Polish Academy of Sciences , Łódź , Poland
| | - Stanisław Głuszek
- a Department of Surgery and Surgical Nursery with Laboratory of Genetics, Faculty of Medicine and Health Sciences , Jan Kochanowski University , Kielce , Poland
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11
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Gibson EG, Bax B, Chan PF, Osheroff N. Mechanistic and Structural Basis for the Actions of the Antibacterial Gepotidacin against Staphylococcus aureus Gyrase. ACS Infect Dis 2019; 5:570-581. [PMID: 30757898 DOI: 10.1021/acsinfecdis.8b00315] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gepotidacin is a first-in-class triazaacenaphthylene novel bacterial topoisomerase inhibitor (NBTI). The compound has successfully completed phase II trials for the treatment of acute bacterial skin/skin structure infections and for the treatment of uncomplicated urogenital gonorrhea. It also displays robust in vitro activity against a range of wild-type and fluoroquinolone-resistant bacteria. Due to the clinical promise of gepotidacin, a detailed understanding of its interactions with its antibacterial targets is essential. Thus, we characterized the mechanism of action of gepotidacin against Staphylococcus aureus gyrase. Gepotidacin was a potent inhibitor of gyrase-catalyzed DNA supercoiling (IC50 ≈ 0.047 μM) and relaxation of positively supercoiled substrates (IC50 ≈ 0.6 μM). Unlike fluoroquinolones, which induce primarily double-stranded DNA breaks, gepotidacin induced high levels of gyrase-mediated single-stranded breaks. No double-stranded breaks were observed even at high gepotidacin concentration, long cleavage times, or in the presence of ATP. Moreover, gepotidacin suppressed the formation of double-stranded breaks. Gepotidacin formed gyrase-DNA cleavage complexes that were stable for >4 h. In vitro competition suggests that gyrase binding by gepotidacin and fluoroquinolones are mutually exclusive. Finally, we determined crystal structures of gepotidacin with the S. aureus gyrase core fusion truncate with nicked (2.31 Å resolution) or intact (uncleaved) DNA (2.37 Å resolution). In both cases, a single gepotidacin molecule was bound midway between the two scissile DNA bonds and in a pocket between the two GyrA subunits. A comparison of the two structures demonstrates conformational flexibility within the central linker of gepotidacin, which may contribute to the activity of the compound.
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Affiliation(s)
| | - Ben Bax
- Medicines Discovery Institute, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, United Kingdom
| | - Pan F. Chan
- Infectious Diseases Discovery, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Neil Osheroff
- VA Tennessee Valley Healthcare System, 1310 24th Avenue S., Nashville, Tennessee 37212, United States
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12
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El Harrad L, Bourais I, Mohammadi H, Amine A. Recent Advances in Electrochemical Biosensors Based on Enzyme Inhibition for Clinical and Pharmaceutical Applications. SENSORS (BASEL, SWITZERLAND) 2018; 18:E164. [PMID: 29315246 PMCID: PMC5795370 DOI: 10.3390/s18010164] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 01/02/2018] [Accepted: 01/07/2018] [Indexed: 12/22/2022]
Abstract
A large number of enzyme inhibitors are used as drugs to treat several diseases such as gout, diabetes, AIDS, depression, Parkinson's and Alzheimer's diseases. Electrochemical biosensors based on enzyme inhibition are useful devices for an easy, fast and environment friendly monitoring of inhibitors like drugs. In the last decades, electrochemical biosensors have shown great potentials in the detection of different drugs like neostigmine, ketoconazole, donepezil, allopurinol and many others. They attracted increasing attention due to the advantage of being high sensitive and accurate analytical tools, able to reach low detection limits and the possibility to be performed on real samples. This review will spotlight the research conducted in the past 10 years (2007-2017) on inhibition based enzymatic electrochemical biosensors for the analysis of different drugs. New assays based on novel bio-devices will be debated. Moreover, the exploration of the recent graphical approach in diagnosis of reversible and irreversible inhibition mechanism will be discussed. The accurate and the fast diagnosis of inhibition type will help researchers in further drug design improvements and the identification of new molecules that will serve as new enzyme targets.
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Affiliation(s)
- Loubna El Harrad
- Laboratory of Process Engineering & Environment, Faculty of Sciences and Technology, Hassan II University of Casablanca, Mohammadia B.P.146, Morocco.
| | - Ilhame Bourais
- Laboratory of Process Engineering & Environment, Faculty of Sciences and Technology, Hassan II University of Casablanca, Mohammadia B.P.146, Morocco.
| | - Hasna Mohammadi
- Laboratory of Process Engineering & Environment, Faculty of Sciences and Technology, Hassan II University of Casablanca, Mohammadia B.P.146, Morocco.
| | - Aziz Amine
- Laboratory of Process Engineering & Environment, Faculty of Sciences and Technology, Hassan II University of Casablanca, Mohammadia B.P.146, Morocco.
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Kuzminov A. When DNA Topology Turns Deadly - RNA Polymerases Dig in Their R-Loops to Stand Their Ground: New Positive and Negative (Super)Twists in the Replication-Transcription Conflict. Trends Genet 2017; 34:111-120. [PMID: 29179918 DOI: 10.1016/j.tig.2017.10.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 10/20/2017] [Accepted: 10/30/2017] [Indexed: 12/19/2022]
Abstract
Head-on replication-transcription conflict is especially bitter in bacterial chromosomes, explaining why actively transcribed genes are always co-oriented with replication. The mechanism of this conflict remains unclear, besides the anticipated accumulation of positive supercoils between head-on-conflicting polymerases. Unexpectedly, experiments in bacterial and human cells reveal that head-on replication-transcription conflict induces R-loops, indicating hypernegative supercoiling [(-)sc] in the region - precisely the opposite of that assumed. Further, as a result of these R-loops, both replication and transcription in the affected region permanently stall, so the failure of R-loop removal in RNase H-deficient bacteria becomes lethal. How hyper(-)sc emerges in the middle of a positively supercoiled chromosomal domain is a mystery that requires rethinking of topoisomerase action around polymerases.
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Affiliation(s)
- Andrei Kuzminov
- Department of Microbiology, University of Illinois at Urbana-Champaign, B103 CLSL, 601 South Goodwin Avenue, Urbana, IL 61801-3709, USA.
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14
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Ashley RE, Dittmore A, McPherson SA, Turnbough CL, Neuman KC, Osheroff N. Activities of gyrase and topoisomerase IV on positively supercoiled DNA. Nucleic Acids Res 2017; 45:9611-9624. [PMID: 28934496 PMCID: PMC5766186 DOI: 10.1093/nar/gkx649] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 07/14/2017] [Indexed: 11/12/2022] Open
Abstract
Although bacterial gyrase and topoisomerase IV have critical interactions with positively supercoiled DNA, little is known about the actions of these enzymes on overwound substrates. Therefore, the abilities of Bacillus anthracis and Escherichia coli gyrase and topoisomerase IV to relax and cleave positively supercoiled DNA were analyzed. Gyrase removed positive supercoils ∼10-fold more rapidly and more processively than it introduced negative supercoils into relaxed DNA. In time-resolved single-molecule measurements, gyrase relaxed overwound DNA with burst rates of ∼100 supercoils per second (average burst size was 6.2 supercoils). Efficient positive supercoil removal required the GyrA-box, which is necessary for DNA wrapping. Topoisomerase IV also was able to distinguish DNA geometry during strand passage and relaxed positively supercoiled substrates ∼3-fold faster than negatively supercoiled molecules. Gyrase maintained lower levels of cleavage complexes with positively supercoiled (compared with negatively supercoiled) DNA, whereas topoisomerase IV generated similar levels with both substrates. Results indicate that gyrase is better suited than topoisomerase IV to safely remove positive supercoils that accumulate ahead of replication forks. They also suggest that the wrapping mechanism of gyrase may have evolved to promote rapid removal of positive supercoils, rather than induction of negative supercoils.
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Affiliation(s)
- Rachel E Ashley
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | - Andrew Dittmore
- Laboratory of Single Molecule Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20982, USA
| | - Sylvia A McPherson
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Charles L Turnbough
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Keir C Neuman
- Laboratory of Single Molecule Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20982, USA
| | - Neil Osheroff
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA.,VA Tennessee Valley Healthcare System, Nashville, TN 37212, USA.,Department of Medicine (Hematology/Oncology), Vanderbilt University School of Medicine, Nashville, TN 37232-6307, USA
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15
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Ashley RE, Blower TR, Berger JM, Osheroff N. Recognition of DNA Supercoil Geometry by Mycobacterium tuberculosis Gyrase. Biochemistry 2017; 56:5440-5448. [PMID: 28921956 PMCID: PMC5637011 DOI: 10.1021/acs.biochem.7b00681] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
![]()
Mycobacterium
tuberculosis encodes only a single
type II topoisomerase, gyrase. As a result, this enzyme likely carries
out the cellular functions normally performed by canonical gyrase
and topoisomerase IV, both in front of and behind the replication
fork. In addition, it is the sole target for quinolone antibacterials
in this species. Because quinolone-induced DNA strand breaks generated
on positively supercoiled DNA ahead of replication forks and transcription
complexes are most likely to result in permanent genomic damage, the
actions of M. tuberculosis gyrase on positively supercoiled
DNA were investigated. Results indicate that the enzyme acts rapidly
on overwound DNA and removes positive supercoils much faster than
it introduces negative supercoils into relaxed DNA. Canonical gyrase
and topoisomerase IV distinguish supercoil handedness differently
during the DNA cleavage reaction: while gyrase maintains lower levels
of cleavage complexes on overwound DNA, topoisomerase IV maintains
similar levels of cleavage complexes on both over- and underwound
substrates. M. tuberculosis gyrase maintained lower
levels of cleavage complexes on positively supercoiled DNA in the
absence and presence of quinolone-based drugs. By retaining this important
feature of canonical gyrase, the dual function M. tuberculosis type II enzyme remains a safe enzyme to act in front of replication
forks and transcription complexes. Finally, the N-terminal gate region
of the enzyme appears to be necessary to distinguish supercoil handedness
during DNA cleavage, suggesting that the capture of the transport
segment may influence how gyrase maintains cleavage complexes on substrates
with different topological states.
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Affiliation(s)
| | - Tim R Blower
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine , Baltimore, Maryland 21205-2185, United States
| | - James M Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine , Baltimore, Maryland 21205-2185, United States
| | - Neil Osheroff
- VA Tennessee Valley Healthcare System , Nashville, Tennessee 37212, United States
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16
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The role of parC, parE, and qnrB Genes in Ciprofloxacin-Resistant Escherichia coli Isolates from Urinary Tract Infections. ARCHIVES OF PEDIATRIC INFECTIOUS DISEASES 2017. [DOI: 10.5812/pedinfect.41504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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17
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El Sayyed H, Le Chat L, Lebailly E, Vickridge E, Pages C, Cornet F, Cosentino Lagomarsino M, Espéli O. Mapping Topoisomerase IV Binding and Activity Sites on the E. coli Genome. PLoS Genet 2016; 12:e1006025. [PMID: 27171414 PMCID: PMC4865107 DOI: 10.1371/journal.pgen.1006025] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 04/11/2016] [Indexed: 11/27/2022] Open
Abstract
Catenation links between sister chromatids are formed progressively during DNA replication and are involved in the establishment of sister chromatid cohesion. Topo IV is a bacterial type II topoisomerase involved in the removal of catenation links both behind replication forks and after replication during the final separation of sister chromosomes. We have investigated the global DNA-binding and catalytic activity of Topo IV in E. coli using genomic and molecular biology approaches. ChIP-seq revealed that Topo IV interaction with the E. coli chromosome is controlled by DNA replication. During replication, Topo IV has access to most of the genome but only selects a few hundred specific sites for its activity. Local chromatin and gene expression context influence site selection. Moreover strong DNA-binding and catalytic activities are found at the chromosome dimer resolution site, dif, located opposite the origin of replication. We reveal a physical and functional interaction between Topo IV and the XerCD recombinases acting at the dif site. This interaction is modulated by MatP, a protein involved in the organization of the Ter macrodomain. These results show that Topo IV, XerCD/dif and MatP are part of a network dedicated to the final step of chromosome management during the cell cycle. DNA topoisomerases are ubiquitous enzymes that solve the topological problems associated with replication, transcription and recombination. Type II Topoisomerases play a major role in the management of newly replicated DNA. They contribute to the condensation and segregation of chromosomes to the future daughter cells and are essential for the optimal transmission of genetic information. In most bacteria, including the model organism Escherichia coli, these tasks are performed by two enzymes, DNA gyrase and DNA Topoisomerase IV (Topo IV). The distribution of the roles between these enzymes during the cell cycle is not yet completely understood. In the present study we use genomic and molecular biology methods to decipher the regulation of Topo IV during the cell cycle. Here we present data that strongly suggest the interaction of Topo IV with the chromosome is controlled by DNA replication and chromatin factors responsible for its loading to specific regions of the chromosome. In addition, our observations reveal, that by sharing several key factors, the DNA management processes ensuring accuracy of the late steps of chromosome segregation are all interconnected.
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Affiliation(s)
- Hafez El Sayyed
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, UMR-CNRS 7241, Paris, France
- Université Paris–Saclay, Gif-sur-Yvette, France
| | - Ludovic Le Chat
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, UMR-CNRS 7241, Paris, France
| | - Elise Lebailly
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), CNRS-Université Toulouse III, Toulouse, France
| | - Elise Vickridge
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, UMR-CNRS 7241, Paris, France
- Université Paris–Saclay, Gif-sur-Yvette, France
| | - Carine Pages
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), CNRS-Université Toulouse III, Toulouse, France
| | - Francois Cornet
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), CNRS-Université Toulouse III, Toulouse, France
| | | | - Olivier Espéli
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, UMR-CNRS 7241, Paris, France
- * E-mail:
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18
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The Localization and Action of Topoisomerase IV in Escherichia coli Chromosome Segregation Is Coordinated by the SMC Complex, MukBEF. Cell Rep 2015; 13:2587-2596. [PMID: 26686641 PMCID: PMC5061553 DOI: 10.1016/j.celrep.2015.11.034] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 10/23/2015] [Accepted: 11/10/2015] [Indexed: 01/15/2023] Open
Abstract
The type II topoisomerase TopoIV, which has an essential role in Escherichia coli chromosome decatenation, interacts with MukBEF, an SMC (structural maintenance of chromosomes) complex that acts in chromosome segregation. We have characterized the intracellular dynamics of individual TopoIV molecules and the consequences of their interaction with MukBEF clusters by using photoactivated-localization microscopy. We show that ∼15 TopoIV molecules per cell are associated with MukBEF clusters that are preferentially localized to the replication origin region (ori), close to the long axis of the cell. A replication-dependent increase in the fraction of immobile molecules, together with a proposed catalytic cycle of ∼1.8 s, is consistent with the majority of active TopoIV molecules catalyzing decatenation, with a minority maintaining steady-state DNA supercoiling. Finally, we show that the MukB-ParC interaction is crucial for timely decatenation and segregation of newly replicated ori DNA. Individual molecules of topoisomerase IV (TopoIV) were tracked in live E. coli cells TopoIV was monitored in cellular space and in time throughout the cell cycle The interaction of TopoIV and MukBEF directs TopoIV to its sites of action The TopoIV-MukBEF interaction promotes timely segregation of newly replicated DNA
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19
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Abstract
This review provides a brief review of the current understanding of the structure-function relationship of the Escherichia coli nucleoid developed after the overview by Pettijohn focusing on the physical properties of nucleoids. Isolation of nucleoids requires suppression of DNA expansion by various procedures. The ability to control the expansion of nucleoids in vitro has led to purification of nucleoids for chemical and physical analyses and for high-resolution imaging. Isolated E. coli genomes display a number of individually intertwined supercoiled loops emanating from a central core. Metabolic processes of the DNA double helix lead to three types of topological constraints that all cells must resolve to survive: linking number, catenates, and knots. The major species of nucleoid core protein share functional properties with eukaryotic histones forming chromatin; even the structures are different from histones. Eukaryotic histones play dynamic roles in the remodeling of eukaryotic chromatin, thereby controlling the access of RNA polymerase and transcription factors to promoters. The E. coli genome is tightly packed into the nucleoid, but, at each cell division, the genome must be faithfully replicated, divided, and segregated. Nucleoid activities such as transcription, replication, recombination, and repair are all affected by the structural properties and the special conformations of nucleoid. While it is apparent that much has been learned about the nucleoid, it is also evident that the fundamental interactions organizing the structure of DNA in the nucleoid still need to be clearly defined.
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20
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Weng X, Xiao J. Spatial organization of transcription in bacterial cells. Trends Genet 2014; 30:287-97. [PMID: 24862529 DOI: 10.1016/j.tig.2014.04.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 04/28/2014] [Accepted: 04/29/2014] [Indexed: 11/27/2022]
Abstract
Prokaryotic transcription has been extensively studied over the past half a century. However, there often exists a gap between the structural, mechanistic description of transcription obtained from in vitro biochemical studies, and the cellular, phenomenological observations from in vivo genetic studies. It is now accepted that a living bacterial cell is a complex entity; the heterogeneous cellular environment is drastically different from the homogenous, well-mixed situation in vitro. Where molecules are inside a cell may be important for their function; hence, the spatial organization of different molecular components may provide a new means of transcription regulation in vivo, possibly bridging this gap. In this review, we survey current evidence for the spatial organization of four major components of transcription [genes, transcription factors, RNA polymerase (RNAP) and RNAs] and critically analyze their biological significance.
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Affiliation(s)
- Xiaoli Weng
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jie Xiao
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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21
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Jin DJ, Cagliero C, Zhou YN. Role of RNA polymerase and transcription in the organization of the bacterial nucleoid. Chem Rev 2013; 113:8662-82. [PMID: 23941620 PMCID: PMC3830623 DOI: 10.1021/cr4001429] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Ding Jun Jin
- Transcription Control Section, Gene Regulation and Chromosome Biology Laboratory National Cancer Institute, NIH, P.O. Box B, Frederick, MD 21702
| | - Cedric Cagliero
- Transcription Control Section, Gene Regulation and Chromosome Biology Laboratory National Cancer Institute, NIH, P.O. Box B, Frederick, MD 21702
| | - Yan Ning Zhou
- Transcription Control Section, Gene Regulation and Chromosome Biology Laboratory National Cancer Institute, NIH, P.O. Box B, Frederick, MD 21702
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22
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Wang X, Montero Llopis P, Rudner DZ. Organization and segregation of bacterial chromosomes. Nat Rev Genet 2013; 14:191-203. [PMID: 23400100 DOI: 10.1038/nrg3375] [Citation(s) in RCA: 209] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The bacterial chromosome must be compacted more than 1,000-fold to fit into the compartment in which it resides. How it is condensed, organized and ultimately segregated has been a puzzle for over half a century. Recent advances in live-cell imaging and genome-scale analyses have led to new insights into these problems. We argue that the key feature of compaction is the orderly folding of DNA along adjacent segments and that this organization provides easy and efficient access for protein-DNA transactions and has a central role in driving segregation. Similar principles and common proteins are used in eukaryotes to condense and to resolve sister chromatids at metaphase.
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Affiliation(s)
- Xindan Wang
- Harvard Medical School, Department of Microbiology and Immunobiology, HIM 1025, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA
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23
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Toueille M, Mirabella B, Guérin P, Bouthier de la Tour C, Boisnard S, Nguyen HH, Blanchard L, Servant P, de Groot A, Sommer S, Armengaud J. A comparative proteomic approach to better define Deinococcus nucleoid specificities. J Proteomics 2012; 75:2588-600. [DOI: 10.1016/j.jprot.2012.03.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 02/23/2012] [Accepted: 03/01/2012] [Indexed: 10/28/2022]
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24
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Timsit Y. Local sensing of global DNA topology: from crossover geometry to type II topoisomerase processivity. Nucleic Acids Res 2011; 39:8665-76. [PMID: 21764774 PMCID: PMC3203592 DOI: 10.1093/nar/gkr556] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Type II topoisomerases are ubiquitous enzymes that control the topology and higher order structures of DNA. Type IIA enzymes have the remarkable property to sense locally the global DNA topology. Although many theoretical models have been proposed, the molecular mechanism of chiral discrimination is still unclear. While experimental studies have established that topoisomerases IIA discriminate topology on the basis of crossover geometry, a recent single-molecule experiment has shown that the enzyme has a different processivity on supercoiled DNA of opposite sign. Understanding how cross-over geometry influences enzyme processivity is, therefore, the key to elucidate the mechanism of chiral discrimination. Analysing this question from the DNA side reveals first, that the different stability of chiral DNA cross-overs provides a way to locally sense the global DNA topology. Second, it shows that these enzymes have evolved to recognize the G- and T-segments stably assembled into a right-handed cross-over. Third, it demonstrates how binding right-handed cross-overs across their large angle imposes a different topological link between the topoIIA rings and the plectonemes of opposite sign thus directly affecting the enzyme freedom of motion and processivity. In bridging geometry and kinetic data, this study brings a simple solution for type IIA topoisomerase chiral discrimination.
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Affiliation(s)
- Youri Timsit
- Information Génomique et Structurale, CNRS - UPR2589, Institut de Microbiologie de la Méditerranée, Aix-Marseille University, Parc Scientifique de Luminy, Marseille, France
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25
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Sissi C, Palumbo M. In front of and behind the replication fork: bacterial type IIA topoisomerases. Cell Mol Life Sci 2010; 67:2001-24. [PMID: 20165898 PMCID: PMC11115839 DOI: 10.1007/s00018-010-0299-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 01/26/2010] [Accepted: 02/01/2010] [Indexed: 01/03/2023]
Abstract
Topoisomerases are vital enzymes specialized in controlling DNA topology, in particular supercoiling and decatenation, to properly handle nucleic acid packing and cell dynamics. The type IIA enzymes act by cleaving both strands of a double helix and having another strand from the same or another molecule cross the DNA gate before a re-sealing event completes the catalytic cycle. Here, we will consider the two types of IIA prokaryotic topoisomerases, DNA Gyrase and Topoisomerase IV, as crucial regulators of bacterial cell cycle progression. Their synergistic action allows control of chromosome packing and grants occurrence of functional transcription and replication processes. In addition to displaying a fascinating molecular mechanism of action, which transduces chemical energy into mechanical energy by means of large conformational changes, these enzymes represent attractive pharmacological targets for antibacterial chemotherapy.
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Affiliation(s)
- Claudia Sissi
- Department of Pharmaceutical Sciences, University of Padova, Via Marzolo 5, 35131, Padua, Italy.
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26
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Abstract
Emerging models of the bacterial nucleoid show that nucleoid-associated proteins (NAPs) and transcription contribute in combination to the dynamic nature of nucleoid structure. NAPs and other DNA-binding proteins that display gene-silencing and anti-silencing activities are emerging as key antagonistic regulators of nucleoid structure. Furthermore, it is becoming clear that the boundary between NAPs and conventional transcriptional regulators is quite blurred and that NAPs facilitate the evolution of novel gene regulatory circuits. Here, NAP biology is considered from the standpoints of both gene regulation and nucleoid structure.
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Abstract
Bacteria and archaea possess several different SMC-like proteins, which perform essential functions in a variety of chromosome dynamics, such as chromosome compaction, segregation, and DNA repair. SMC-like proteins localize to distinct sites within the cells at different time points in the cell cycle, or are recruited to sites of DNA breaks and damage. The bacterial SMC (MukB) complex appears to perform a condensin-like function, while SbcC and RecN act early during DNA repair, but apparently at different sites within the cells. Thus, bacterial SMC-like proteins have dynamic functions in chromosome segregation and maintenance of genetic stability.
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28
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Tamayo M, Santiso R, Gosalvez J, Bou G, Fernández JL. Rapid assessment of the effect of ciprofloxacin on chromosomal DNA from Escherichia coli using an in situ DNA fragmentation assay. BMC Microbiol 2009; 9:69. [PMID: 19364397 PMCID: PMC2670838 DOI: 10.1186/1471-2180-9-69] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Accepted: 04/13/2009] [Indexed: 12/29/2022] Open
Abstract
Background Fluoroquinolones are extensively used antibiotics that induce DNA double-strand breaks (DSBs) by trapping DNA gyrase and topoisomerase IV on DNA. This effect is usually evaluated using biochemical or molecular procedures, but these are not effective at the single-cell level. We assessed ciprofloxacin (CIP)-induced chromosomal DNA breakage in single-cell Escherichia coli by direct visualization of the DNA fragments that diffused from the nucleoid obtained after bacterial lysis in an agarose microgel on a slide. Results Exposing the E. coli strain TG1 to CIP starting at a minimum inhibitory concentration (MIC) of 0.012 μg/ml and at increasing doses for 40 min increased the DNA fragmentation progressively. DNA damage started to be detectable at the MIC dose. At a dose of 1 μg/ml of CIP, DNA damage was visualized clearly immediately after processing, and the DNA fragmentation increased progressively with the antibiotic incubation time. The level of DNA damage was much higher when the bacteria were taken from liquid LB broth than from solid LB agar. CIP treatment produced a progressively slower rate of DNA damage in bacteria in the stationary phase than in the exponentially growing phase. Removing the antibiotic after the 40 min incubation resulted in progressive DSB repair activity with time. The magnitude of DNA repair was inversely related to CIP dose and was noticeable after incubation with CIP at 0.1 μg/ml but scarce after 10 μg/ml. The repair activity was not strictly related to viability. Four E. coli strains with identified mechanisms of reduced sensitivity to CIP were assessed using this procedure and produced DNA fragmentation levels that were inversely related to MIC dose, except those with very high MIC dose. Conclusion This procedure for determining DNA fragmentation is a simple and rapid test for studying and evaluating the effect of quinolones.
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Affiliation(s)
- María Tamayo
- INIBIC-Complejo Hospitalario Universitario A Coruña, Unidad de Genética, A Coruña, Spain.
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29
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Construction of a functional network for common DNA damage responses in Escherichia coli. Genomics 2009; 93:514-24. [PMID: 19232389 DOI: 10.1016/j.ygeno.2009.01.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 01/15/2009] [Accepted: 01/31/2009] [Indexed: 11/24/2022]
Abstract
In this study, we aim to identify a common, general mode of toxic action in Escherichia coli when experiencing DNA damage, irrespective of the agents used. We conducted or collected 69 microarray data from seven different DNA damaging agents. In a quantitative manner, we constructed a probable DNA damage stress network, entitled the 'Functional Linked Network (FLN)', which consists of 399 significantly perturbed genes and the 1283 interactions among them. The SOS response related genes (LexA modules) were found to be dominantly activated by DNA damage, irrespective of the agents. Several minor, plausible modules were also implicated in this network, and appear to be related with the metabolic inhibition response to DNA damage or mediate the induction of SOS response. This systems and comparison approach across a variety of genotoxic agents may serve as a starting point to specify some of the unknown and common features of DNA damage responses in bacteria.
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30
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McArthur M, Bibb M. In vivo DNase I sensitivity of the Streptomyces coelicolor chromosome correlates with gene expression: implications for bacterial chromosome structure. Nucleic Acids Res 2006; 34:5395-401. [PMID: 17012277 PMCID: PMC1636467 DOI: 10.1093/nar/gkl649] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
For a bacterium, Streptomyces coelicolor A3(2) contains a relatively large genome (8.7 Mb) with a complex and adaptive pattern of gene regulation. We discovered a correlation between the physical structure of the S.coelicolor genome and the transcriptional activity of the genes therein. Twelve genes were surveyed throughout 72 h of growth for both in vivo sensitivity to DNase I digestion and levels of transcription. DNase I-sensitivity correlated positively with transcript levels, implying that it was predictive of gene expression, and indicating increased accessibility of transcribed DNA. The genome was fractionated based on the sensitivity to DNase I digestion, with the low molecular weight (frequently cut) fraction highly enriched for actively transcribed sequences when compared to the infrequently cut fraction, which was representative of the entire genome. This approach will allow comparison of nucleoid proteins, and any modifications thereof, associated with transcriptionally active and inactive regions of the bacterial genome.
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Affiliation(s)
- Michael McArthur
- To whom correspondence should be addressed. Tel: +44 1603 450757; Fax: +44 1603 450778;
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