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Bakker AT, Kotsogianni I, Avalos M, Punt JM, Liu B, Piermarini D, Gagestein B, Slingerland CJ, Zhang L, Willemse JJ, Ghimire LB, van den Berg RJHBN, Janssen APA, Ottenhoff THM, van Boeckel CAA, van Wezel GP, Ghilarov D, Martin NI, van der Stelt M. Discovery of isoquinoline sulfonamides as allosteric gyrase inhibitors with activity against fluoroquinolone-resistant bacteria. Nat Chem 2024:10.1038/s41557-024-01516-x. [PMID: 38898213 DOI: 10.1038/s41557-024-01516-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 03/22/2024] [Indexed: 06/21/2024]
Abstract
Bacteria have evolved resistance to nearly all known antibacterials, emphasizing the need to identify antibiotics that operate via novel mechanisms. Here we report a class of allosteric inhibitors of DNA gyrase with antibacterial activity against fluoroquinolone-resistant clinical isolates of Escherichia coli. Screening of a small-molecule library revealed an initial isoquinoline sulfonamide hit, which was optimized via medicinal chemistry efforts to afford the more potent antibacterial LEI-800. Target identification studies, including whole-genome sequencing of in vitro selected mutants with resistance to isoquinoline sulfonamides, unanimously pointed to the DNA gyrase complex, an essential bacterial topoisomerase and an established antibacterial target. Using single-particle cryogenic electron microscopy, we determined the structure of the gyrase-LEI-800-DNA complex. The compound occupies an allosteric, hydrophobic pocket in the GyrA subunit and has a mode of action that is distinct from the clinically used fluoroquinolones or any other gyrase inhibitor reported to date. LEI-800 provides a chemotype suitable for development to counter the increasingly widespread bacterial resistance to fluoroquinolones.
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Affiliation(s)
- Alexander T Bakker
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Ioli Kotsogianni
- Biological Chemistry Group, Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Mariana Avalos
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Jeroen M Punt
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Bing Liu
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Diana Piermarini
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Berend Gagestein
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Cornelis J Slingerland
- Biological Chemistry Group, Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Le Zhang
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Joost J Willemse
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Leela B Ghimire
- Department of Molecular Microbiology, John Innes Centre, Norwich, UK
| | | | - Antonius P A Janssen
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Tom H M Ottenhoff
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, the Netherlands
| | - Constant A A van Boeckel
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Gilles P van Wezel
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Dmitry Ghilarov
- Department of Molecular Microbiology, John Innes Centre, Norwich, UK.
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology, Leiden University, Leiden, the Netherlands.
| | - Mario van der Stelt
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands.
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Piplani P, Kumar A, Kulshreshtha A, Vohra T, Piplani V. Recent Development of DNA Gyrase Inhibitors: An Update. Mini Rev Med Chem 2024; 24:1001-1030. [PMID: 37909434 DOI: 10.2174/0113895575264264230921080718] [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: 06/15/2023] [Revised: 08/15/2023] [Accepted: 08/16/2023] [Indexed: 11/03/2023]
Abstract
Antibiotic or antimicrobial resistance is an urgent global public health threat that occurs when bacterial or fungal infections do not respond to the drug regimen designed to treat these infections. As a result, these microbes are not evaded and continue to grow. Antibiotic resistance against natural and already-known antibiotics like Ciprofloxacin and Novobiocin can be overcome by developing an agent that can act in different ways. The success of agents like Zodiflodacin and Zenoxacin in clinical trials against DNA gyrase inhibitors that act on different sites of DNA gyrase has resulted in further exploration of this target. However, due to the emergence of bacterial resistance against these targets, there is a great need to design agents that can overcome this resistance and act with greater efficacy. This review provides information on the synthetic and natural DNA gyrase inhibitors that have been developed recently and their promising potential for combating antimicrobial resistance. The review also presents information on molecules that are in clinical trials and their current status. It also analysed the SAR studies and mechanisms of action of enlisted agents.
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Affiliation(s)
- Poonam Piplani
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160017, India
| | - Ajay Kumar
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160017, India
| | - Akanksha Kulshreshtha
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160017, India
| | - Tamanna Vohra
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160017, India
| | - Vritti Piplani
- Bhojia Dental College and Hospital, Baddi, 173205, India
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Jin Q, Fan Y, He T, Peng J, Liu J, Wang J. Fluorescence Polarization Assay Based on a New Recognition Motif QepA for the One-Step Detection of Fluoroquinolones in Eggs. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:19749-19759. [PMID: 38029390 DOI: 10.1021/acs.jafc.3c03526] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
A recognition motif is vital in determining the specificity and sensitivity of the fluorescence polarization assay (FPA) for detecting chemical contaminants in food. Four candidates (Gyrase, GyrBA, TopIV, and QepA) were prepared for this study. The applicability of QepA was confirmed through DNA cleavage assay, inhibition effects, and mechanism investigations using molecular docking, compared to other counterparts. Finally, a novel FPA based on QepA and a CIP-FITC tracer for the detection of fluoroquinolones (FQs) in eggs was developed. The limits of detection (LODs) for eight fluoroquinolones ranged from 2.2 to 5.1 ng g-1, with enrofloxacin, danofloxacin, and difloxacin meeting the maximum residue limits (MRLs). The spiked recoveries ranged from 65.8 to 103.6% with coefficients of variation (CVs) of 5.4-12.8%. Therefore, a new recognition motif for FQs that did not belong to conventional antibodies was identified, and QepA-based FPA could be a potential tool for rapid, homogeneous, and sensitive monitoring of the residue of FQs in eggs.
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Affiliation(s)
- Qiushi Jin
- College of Veterinary Medicine, Hebei Agricultural University, Baoding 071000, Hebei, China
| | - Yuhang Fan
- College of Veterinary Medicine, Hebei Agricultural University, Baoding 071000, Hebei, China
| | - Tong He
- College of Veterinary Medicine, Hebei Agricultural University, Baoding 071000, Hebei, China
| | - Junling Peng
- College of Veterinary Medicine, Hebei Agricultural University, Baoding 071000, Hebei, China
| | - Jing Liu
- College of Veterinary Medicine, Hebei Agricultural University, Baoding 071000, Hebei, China
| | - Jianping Wang
- College of Veterinary Medicine, Hebei Agricultural University, Baoding 071000, Hebei, China
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Maliszewski D, Demirel R, Wróbel A, Baradyn M, Ratkiewicz A, Drozdowska D. s-Triazine Derivatives Functionalized with Alkylating 2-Chloroethylamine Fragments as Promising Antimicrobial Agents: Inhibition of Bacterial DNA Gyrases, Molecular Docking Studies, and Antibacterial and Antifungal Activity. Pharmaceuticals (Basel) 2023; 16:1248. [PMID: 37765056 PMCID: PMC10650753 DOI: 10.3390/ph16091248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/17/2023] [Accepted: 09/01/2023] [Indexed: 09/29/2023] Open
Abstract
The spectrum of biological properties of s-triazine derivatives is broad and includes anti-microbial, anti-cancer, and anti-neurodegenerative activities, among others. The s-triazine molecule, due to the possibility of substituting three substituents, offers many opportunities to obtain hybrid compounds with a wide variety of activities. A group of 1,3,5 triazine derivatives containing a dipeptide, 2-ethylpiperazine, and a methoxy group as substituents was screened for their antimicrobial activity. An in vitro study was conducted on pathogenic bacteria (E. coli, S. aureus, B. subtilis, and M. luteus), yeasts (C. albicans), and filamentous fungi (A. fumigatus, A. flavus, F. solani, and P. citrinum) via microdilution in broth, and the results were compared with antibacterial (Streptomycin) and antifungal (Ketoconazole and Nystatin) antibiotics. Several s-triazine analogues have minimal inhibitory concentrations lower than the standard. To confirm the inhibitory potential of the most active compounds against gyrases E. coli and S. aureus, a bacterial gyrases inhibition assay, and molecular docking studies were performed. The most active s-triazine derivatives contained the -NH-Trp(Boc)-AlaOMe, -NH-Asp(OtBu)-AlaOMe, and -NH-PheOMe moieties in their structures.
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Affiliation(s)
- Dawid Maliszewski
- Department of Organic Chemistry, Medical University of Bialystok, 15-089 Bialystok, Poland; (D.M.); (A.W.)
| | - Rasime Demirel
- Department of Biology, Eskisehir Technical University, Eskişehir 26555, Turkey;
| | - Agnieszka Wróbel
- Department of Organic Chemistry, Medical University of Bialystok, 15-089 Bialystok, Poland; (D.M.); (A.W.)
| | - Maciej Baradyn
- Faculty of Chemistry, University of Bialystok, 15-245 Bialystok, Poland; (M.B.); (A.R.)
| | - Artur Ratkiewicz
- Faculty of Chemistry, University of Bialystok, 15-245 Bialystok, Poland; (M.B.); (A.R.)
| | - Danuta Drozdowska
- Department of Organic Chemistry, Medical University of Bialystok, 15-089 Bialystok, Poland; (D.M.); (A.W.)
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Characterization of the Biosynthetic Gene Cluster and Shunt Products Yields Insights into the Biosynthesis of Balmoralmycin. Appl Environ Microbiol 2022; 88:e0120822. [PMID: 36350133 PMCID: PMC9746310 DOI: 10.1128/aem.01208-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Angucyclines are a family of structurally diverse, aromatic polyketides with some members that exhibit potent bioactivity. Angucyclines have also attracted considerable attention due to the intriguing biosynthetic origins that underlie their structural complexity and diversity. Balmoralmycin (compound 1) represents a unique group of angucyclines that contain an angular benz[α]anthracene tetracyclic system, a characteristic C-glycosidic bond-linked deoxy-sugar (d-olivose), and an unsaturated fatty acid chain. In this study, we identified a Streptomyces strain that produces balmoralmycin and seven biosynthetically related coproducts (compounds 2-8). Four of the coproducts (compounds 5-8) are novel compounds that feature a highly oxygenated or fragmented lactone ring, and three of them (compounds 3-5) exhibited cytotoxicity against the human pancreatic cancer cell line MIA PaCa-2 with IC50 values ranging from 0.9 to 1.2 μg/mL. Genome sequencing and CRISPR/dCas9-assisted gene knockdown led to the identification of the ~43 kb balmoralmycin biosynthetic gene cluster (bal BGC). The bal BGC encodes a type II polyketide synthase (PKS) system for assembling the angucycline aglycone, six enzymes for generating the deoxysugar d-olivose, and a hybrid type II/III PKS system for synthesizing the 2,4-decadienoic acid chain. Based on the genetic and chemical information, we propose a mechanism for the biosynthesis of balmoralmycin and the shunt products. The chemical and genetic studies yielded insights into the biosynthetic origin of the structural diversity of angucyclines. IMPORTANCE Angucyclines are structurally diverse aromatic polyketides that have attracted considerable attention due to their potent bioactivity and intriguing biosynthetic origin. Balmoralmycin is a representative of a small family of angucyclines with unique structural features and an unknown biosynthetic origin. We report a newly isolated Streptomyces strain that produces balmoralmycin in a high fermentation titer as well as several structurally related shunt products. Based on the chemical and genetic information, a biosynthetic pathway that involves a type II polyketide synthase (PKS) system, cyclases/aromatases, oxidoreductases, and other ancillary enzymes was established. The elucidation of the balmoralmycin pathway enriches our understanding of how structural diversity is generated in angucyclines and opens the door for the production of balmoralmycin derivatives via pathway engineering.
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Salman M, Sharma P, Kumar M, Ethayathulla AS, Kaur P. Targeting novel sites in DNA gyrase for development of anti-microbials. Brief Funct Genomics 2022; 22:180-194. [PMID: 36064602 DOI: 10.1093/bfgp/elac029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 07/28/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Antimicrobial resistance in bacteria poses major challenges in selection of the therapeutic regime for managing the infectious disease. There is currently an upsurge in the appearance of multiple drug resistance in bacterial pathogens and a decline in the discovery of novel antibiotics. DNA gyrase is an attractive target used for antibiotic discovery due to its vital role in bacterial DNA replication and segregation in addition to its absence in mammalian organisms. Despite the presence of successful antibiotics targeting this enzyme, there is a need to bypass the resistance against this validated drug target. Hence, drug development in DNA gyrase is a highly active research area. In addition to the conventional binding sites for the novobiocin and fluoroquinolone antibiotics, several novel sites are being exploited for drug discovery. The binding sites for novel bacterial type II topoisomerase inhibitor (NBTI), simocyclinone, YacG, Thiophene and CcdB are structurally and biochemically validated active sites, which inhibit the supercoiling activity of topoisomerases. The novel chemical moieties with varied scaffolds have been identified to target DNA gyrase. Amongst them, the NBTI constitutes the most advanced DNA gyrase inhibitor which are in phase III trial of drug development. The present review aims to classify the novel binding sites other than the conventional novobiocin and quinolone binding pocket to bypass the resistance due to mutations in the DNA gyrase enzyme. These sites can be exploited for the identification of new scaffolds for the development of novel antibacterial compounds.
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Affiliation(s)
- Mohd Salman
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India
| | - Priyanka Sharma
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India
| | - Mukesh Kumar
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India
| | - A S Ethayathulla
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India
| | - Punit Kaur
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India
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7
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Johnson RA, Chan AN, Ward RD, McGlade CA, Hatfield BM, Peters JM, Li B. Inhibition of Isoleucyl-tRNA Synthetase by the Hybrid Antibiotic Thiomarinol. J Am Chem Soc 2021; 143:12003-12013. [PMID: 34342433 DOI: 10.1021/jacs.1c02622] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hybrid antibiotics are an emerging antimicrobial strategy to overcome antibiotic resistance. The natural product thiomarinol A is a hybrid of two antibiotics: holothin, a dithiolopyrrolone (DTP), and marinolic acid, a close analogue of the drug mupirocin that is used to treat methicillin-resistant Staphylococcus aureus (MRSA). DTPs disrupt metal homeostasis by chelating metal ions in cells, whereas mupirocin targets the essential enzyme isoleucyl-tRNA synthetase (IleRS). Thiomarinol A is over 100-fold more potent than mupirocin against mupirocin-sensitive MRSA; however, its mode of action has been unknown. We show that thiomarinol A targets IleRS. A knockdown of the IleRS-encoding gene, ileS, exhibited sensitivity to a synthetic analogue of thiomarinol A in a chemical genomics screen. Thiomarinol A inhibits MRSA IleRS with a picomolar Ki and binds to IleRS with low femtomolar affinity, 1600 times more tightly than mupirocin. We find that thiomarinol A remains effective against high-level mupirocin-resistant MRSA and provide evidence to support a dual mode of action for thiomarinol A that may include both IleRS inhibition and metal chelation. We demonstrate that MRSA develops resistance to thiomarinol A to a substantially lesser degree than mupirocin and the potent activity of thiomarinol A requires hybridity between DTP and mupirocin. Our findings identify a mode of action of a natural hybrid antibiotic and demonstrate the potential of hybrid antibiotics to combat antibiotic resistance.
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Affiliation(s)
- Rachel A Johnson
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Andrew N Chan
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Ryan D Ward
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Caylie A McGlade
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Breanne M Hatfield
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Jason M Peters
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin 53726, United States
| | - Bo Li
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.,Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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Towards Conformation-Sensitive Inhibition of Gyrase: Implications of Mechanistic Insight for the Identification and Improvement of Inhibitors. Molecules 2021; 26:molecules26051234. [PMID: 33669078 PMCID: PMC7956263 DOI: 10.3390/molecules26051234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 02/19/2021] [Accepted: 02/20/2021] [Indexed: 12/17/2022] Open
Abstract
Gyrase is a bacterial type IIA topoisomerase that catalyzes negative supercoiling of DNA. The enzyme is essential in bacteria and is a validated drug target in the treatment of bacterial infections. Inhibition of gyrase activity is achieved by competitive inhibitors that interfere with ATP- or DNA-binding, or by gyrase poisons that stabilize cleavage complexes of gyrase covalently bound to the DNA, leading to double-strand breaks and cell death. Many of the current inhibitors suffer from severe side effects, while others rapidly lose their antibiotic activity due to resistance mutations, generating an unmet medical need for novel, improved gyrase inhibitors. DNA supercoiling by gyrase is associated with a series of nucleotide- and DNA-induced conformational changes, yet the full potential of interfering with these conformational changes as a strategy to identify novel, improved gyrase inhibitors has not been explored so far. This review highlights recent insights into the mechanism of DNA supercoiling by gyrase and illustrates the implications for the identification and development of conformation-sensitive and allosteric inhibitors.
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Novel Amino Acid Derivatives of Quinolines as Potential Antibacterial and Fluorophore Agents. Sci Pharm 2020. [DOI: 10.3390/scipharm88040057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A new series of amino acid derivatives of quinolines was synthesized through the hydrolysis of amino acid methyl esters of quinoline carboxamides with alkali hydroxide. The compounds were purified on silica gel by column chromatography and further characterized by TLC, NMR and ESI-TOF mass spectrometry. All compounds were screened for in vitro antimicrobial activity against different bacterial strains using the microdilution method. Most of the synthesized amino acid-quinolines show more potent or equipotent inhibitory action against the tested bacteria than their correspond esters. In addition, many of them exhibit fluorescent properties and could possibly be utilized as fluorophores. Molecular docking and simulation studies of the compounds at putative bacterial target enzymes suggest that the antimicrobial potency of these synthesized analogues could be due to enzyme inhibition via their favorable binding at the fluoroquinolone binding site at the GyrA subunit of DNA gyrase and/or the ParC subunit of topoisomerase-IV.
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Yang C, Wang X, Zhang L, Dong W, Yang C, Shi X, Fan Y, Wang Y, Lv H, Wang W, Zhao Y. Investigation of kinetics and mechanism for the degradation of antibiotic norfloxacin in wastewater by UV/H2O2. J Taiwan Inst Chem Eng 2020. [DOI: 10.1016/j.jtice.2020.09.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Yi L, Lü X. New Strategy on Antimicrobial-resistance: Inhibitors of DNA Replication Enzymes. Curr Med Chem 2019; 26:1761-1787. [PMID: 29110590 DOI: 10.2174/0929867324666171106160326] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 08/31/2017] [Accepted: 10/30/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND Antimicrobial resistance is found in all microorganisms and has become one of the biggest threats to global health. New antimicrobials with different action mechanisms are effective weapons to fight against antibiotic-resistance. OBJECTIVE This review aims to find potential drugs which can be further developed into clinic practice and provide clues for developing more effective antimicrobials. METHODS DNA replication universally exists in all living organisms and is a complicated process in which multiple enzymes are involved in. Enzymes in bacterial DNA replication of initiation and elongation phases bring abundant targets for antimicrobial development as they are conserved and indispensable. In this review, enzyme inhibitors of DNA helicase, DNA primase, topoisomerases, DNA polymerase and DNA ligase were discussed. Special attentions were paid to structures, activities and action modes of these enzyme inhibitors. RESULTS Among these enzymes, type II topoisomerase is the most validated target with abundant inhibitors. For type II topoisomerase inhibitors (excluding quinolones), NBTIs and benzimidazole urea derivatives are the most promising inhibitors because of their good antimicrobial activity and physicochemical properties. Simultaneously, DNA gyrase targeted drugs are particularly attractive in the treatment of tuberculosis as DNA gyrase is the sole type II topoisomerase in Mycobacterium tuberculosis. Relatively, exploitation of antimicrobial inhibitors of the other DNA replication enzymes are primeval, in which inhibitors of topo III are even blank so far. CONCLUSION This review demonstrates that inhibitors of DNA replication enzymes are abundant, diverse and promising, many of which can be developed into antimicrobials to deal with antibioticresistance.
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Affiliation(s)
- Lanhua Yi
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province 712100, China
| | - Xin Lü
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province 712100, China
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Kalhor H, Sadeghi S, Marashiyan M, Kalhor R, Aghaei Gharehbolagh S, Akbari Eidgahi MR, Rahimi H. Identification of new DNA gyrase inhibitors based on bioactive compounds from streptomyces: structure-based virtual screening and molecular dynamics simulations approaches. J Biomol Struct Dyn 2019; 38:791-806. [PMID: 30916622 DOI: 10.1080/07391102.2019.1588784] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
DNA gyrase enzyme has vital role in bacterial survival and can be considered as a potential drug target. Owing to the appearance of resistance to gyrase-targeted drugs, especially fluoroquinolone, screening new compounds which bind more efficiently to the mutant binding pocket is essential. Hence, in this work, using Smina Autodock and through structure-based virtual screening of StreptomeDB, several natural products were discovered based on the SimocyclinoneD8 (SD8) binding pocket of GyrA subunit of DNA gyrase. After evaluation of binding affinity, binding modes, critical interactions and physicochemical and pharmaceutical properties, three lead compounds were selected for further analysis. Afterward 60 ns molecular dynamics simulations were performed and binding free energies were calculated by the molecular mechanics/Poisson-Boltzmann surface area method. Also, interaction of the selected lead compounds with the mutated GyrA protein was evaluated. Results indicated that all of the selected compounds could bind to the both wild-type and mutated GyrA with the binding affinities remarkably higher than SimocyclinoneD8. Interestingly, we noticed that the selected compounds comprised angucycline moiety in their structure which could sufficiently interact with GyrA and block the DNA binding pocket of DNA gyrase, in silico. In conclusion, three DNA gyrase inhibitors were identified successfully which were highly capable of impeding DNA gyrase and can be considered as potential drug candidates for treatment of fluoroquinolone-resistant strains.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Hourieh Kalhor
- Department and Biotechnology Research Center, Semnan University of Medical Sciences, Semnan, Iran
| | - Solmaz Sadeghi
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahya Marashiyan
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Reyhaneh Kalhor
- Department of Biology, Qom Branch, Islamic Azad University, Qom, Iran
| | - Sanaz Aghaei Gharehbolagh
- Department of Medical Mycology & Parasitology School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Hamzeh Rahimi
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
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Durdagi S, Tahir Ul Qamar M, Salmas RE, Tariq Q, Anwar F, Ashfaq UA. Investigating the molecular mechanism of staphylococcal DNA gyrase inhibitors: A combined ligand-based and structure-based resources pipeline. J Mol Graph Model 2018; 85:122-129. [PMID: 30176384 DOI: 10.1016/j.jmgm.2018.07.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 01/12/2023]
Abstract
Appropriate therapeutic solutions against Staphylococcal infections are currently limited. To work out the complex task of challenging drug resistance in Staphylococcus aureus, new compounds with novel modes of action are required. In this study, we performed target-driven virtual screening to filter exhaustive phytochemical libraries that can inhibit the activity of S. aureus DNA Gyrase B (Gyr B). Three top-ranked hit molecules (Mangostenone E, Candenatenin A and 2,4,4'-trihydroxydihydrochalcone) were identified from comprehensive molecular docking studies based on their strong spatial affinity with key catalytic residues of the binding pocket of DNA GyrB, especially with the well-known crucial residue Asp81. Molecular dynamics (MD) simulations were performed for these identified hit molecules for better understanding of their dynamical and structural profiles throughout the MD simulations. These compounds can be explored as future lead optimization molecules to discover a new class of antibiotics against resistant Staphylococcus aureus strains.
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Affiliation(s)
- Serdar Durdagi
- Computational Biology and Molecular Simulations Laboratory, Department of Biophysics, School of Medicine, Bahcesehir University, Istanbul, Turkey; Neuroscience Program, Graduate School of Health Sciences, Bahcesehir University, Istanbul, Turkey.
| | | | - Ramin Ekhteiari Salmas
- Computational Biology and Molecular Simulations Laboratory, Department of Biophysics, School of Medicine, Bahcesehir University, Istanbul, Turkey
| | - Quratulain Tariq
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad (GCUF), Faisalabad, Pakistan
| | - Farooq Anwar
- Department of Chemistry, University of Sargodha, Sargodha, Pakistan
| | - Usman Ali Ashfaq
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad (GCUF), Faisalabad, Pakistan.
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14
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Khan T, Sankhe K, Suvarna V, Sherje A, Patel K, Dravyakar B. DNA gyrase inhibitors: Progress and synthesis of potent compounds as antibacterial agents. Biomed Pharmacother 2018; 103:923-938. [DOI: 10.1016/j.biopha.2018.04.021] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 03/24/2018] [Accepted: 04/03/2018] [Indexed: 12/22/2022] Open
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15
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Abstract
New antibacterials that modulate less explored targets are needed to fight the emerging bacterial resistance. DNA gyrase and topoisomerase IV are attractive targets in this search. These are both type II topoisomerases that can cleave both DNA strands, and can thus alter DNA topology during replication or similar processes. Currently, there are no ATP-competitive inhibitors of these two enzymes on the market, as the only aminocoumarin representative, novobiocin, was withdrawn due to safety concerns. The search for novel ATP-competitive inhibitors is a focus of ongoing industrial and academical research. This review summarizes the recent efforts in the design, synthesis and evaluation of GyrB/ParE inhibitors. The various approaches to achieve improved antibacterial activities are described, with particular reference to Gram-negative bacteria.
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16
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Badshah SL, Ullah A. New developments in non-quinolone-based antibiotics for the inhibiton of bacterial gyrase and topoisomerase IV. Eur J Med Chem 2018; 152:393-400. [DOI: 10.1016/j.ejmech.2018.04.059] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 04/23/2018] [Accepted: 04/29/2018] [Indexed: 01/06/2023]
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17
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Kaguni JM. The Macromolecular Machines that Duplicate the Escherichia coli Chromosome as Targets for Drug Discovery. Antibiotics (Basel) 2018. [PMID: 29538288 PMCID: PMC5872134 DOI: 10.3390/antibiotics7010023] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
DNA replication is an essential process. Although the fundamental strategies to duplicate chromosomes are similar in all free-living organisms, the enzymes of the three domains of life that perform similar functions in DNA replication differ in amino acid sequence and their three-dimensional structures. Moreover, the respective proteins generally utilize different enzymatic mechanisms. Hence, the replication proteins that are highly conserved among bacterial species are attractive targets to develop novel antibiotics as the compounds are unlikely to demonstrate off-target effects. For those proteins that differ among bacteria, compounds that are species-specific may be found. Escherichia coli has been developed as a model system to study DNA replication, serving as a benchmark for comparison. This review summarizes the functions of individual E. coli proteins, and the compounds that inhibit them.
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Affiliation(s)
- Jon M Kaguni
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824-1319, USA.
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18
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Delgado JL, Hsieh CM, Chan NL, Hiasa H. Topoisomerases as anticancer targets. Biochem J 2018; 475:373-398. [PMID: 29363591 PMCID: PMC6110615 DOI: 10.1042/bcj20160583] [Citation(s) in RCA: 260] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 12/14/2017] [Accepted: 12/21/2017] [Indexed: 12/15/2022]
Abstract
Many cancer type-specific anticancer agents have been developed and significant advances have been made toward precision medicine in cancer treatment. However, traditional or nonspecific anticancer drugs are still important for the treatment of many cancer patients whose cancers either do not respond to or have developed resistance to cancer-specific anticancer agents. DNA topoisomerases, especially type IIA topoisomerases, are proved therapeutic targets of anticancer and antibacterial drugs. Clinically successful topoisomerase-targeting anticancer drugs act through topoisomerase poisoning, which leads to replication fork arrest and double-strand break formation. Unfortunately, this unique mode of action is associated with the development of secondary cancers and cardiotoxicity. Structures of topoisomerase-drug-DNA ternary complexes have revealed the exact binding sites and mechanisms of topoisomerase poisons. Recent advances in the field have suggested a possibility of designing isoform-specific human topoisomerase II poisons, which may be developed as safer anticancer drugs. It may also be possible to design catalytic inhibitors of topoisomerases by targeting certain inactive conformations of these enzymes. Furthermore, identification of various new bacterial topoisomerase inhibitors and regulatory proteins may inspire the discovery of novel human topoisomerase inhibitors. Thus, topoisomerases remain as important therapeutic targets of anticancer agents.
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Affiliation(s)
- Justine L Delgado
- Division of Medicinal and Natural Products Chemistry, Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, 115 S Grand Ave., S321 Pharmacy Building, Iowa City, IA 52242, U.S.A
| | - Chao-Ming Hsieh
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei City 100, Taiwan
| | - Nei-Li Chan
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei City 100, Taiwan
| | - Hiroshi Hiasa
- Department of Pharmacology, University of Minnesota Medical School, 6-120 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455, U.S.A.
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19
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Buttner MJ, Schäfer M, Lawson DM, Maxwell A. Structural insights into simocyclinone as an antibiotic, effector ligand and substrate. FEMS Microbiol Rev 2018; 42:4604775. [PMID: 29126195 PMCID: PMC5812520 DOI: 10.1093/femsre/fux055] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 11/07/2017] [Indexed: 12/25/2022] Open
Abstract
Simocyclinones are antibiotics produced by Streptomyces and Kitasatospora species that inhibit the validated drug target DNA gyrase in a unique way, and they are thus of therapeutic interest. Structural approaches have revealed their mode of action, the inducible-efflux mechanism in the producing organism, and given insight into one step in their biosynthesis. The crystal structures of simocyclinones bound to their target (gyrase), the transcriptional repressor SimR and the biosynthetic enzyme SimC7 reveal fascinating insight into how molecular recognition is achieved with these three unrelated proteins.
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Affiliation(s)
- Mark J Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Martin Schäfer
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - David M Lawson
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Anthony Maxwell
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
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20
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Incerti M, Vicini P, Geronikaki A, Eleftheriou P, Tsagkadouras A, Zoumpoulakis P, Fotakis C, Ćirić A, Glamočlija J, Soković M. New N-(2-phenyl-4-oxo-1,3-thiazolidin-3-yl)-1,2-benzothiazole-3-carboxamides and acetamides as antimicrobial agents. MEDCHEMCOMM 2017; 8:2142-2154. [PMID: 30108732 DOI: 10.1039/c7md00334j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/09/2017] [Indexed: 11/21/2022]
Abstract
A series of 21 novel N-[2-phenyl-4-oxo-1,3-thiazolidin-3-yl]-1,2-benzothiazole-3-carboxamides/acetamides (4a-4p) as well as a series of N'-(halophenylmethylidene)-1,2-benzothiazole-3-acetohydrazides (3h-3p) have been synthesized and evaluated for their antimicrobial activity against eight bacterial and eight fungal species, among them plant, animal and human pathogens and food contaminating species. All compounds appeared to be potent and the best activity was exhibited by compound 4d with MIC in the range of 10.7-21.4 μmol mL-1 × 10-2 and MBC of 21.4-40.2 μmol mL-1 × 10-2. The best antifungal activity was observed for compounds 4p and 3h. Elucidation of the relationship between the antimicrobial activity and molecular properties of the synthesized compounds was also performed. Synthetic intermediates were also tested with several exhibiting good antimicrobial activities. Docking studies for some compounds were performed.
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Affiliation(s)
- Matteo Incerti
- Dipartimento di Scienze degli Alimenti e del Farmaco , Universita' degli Studi di Parma , Italy
| | - Paola Vicini
- Dipartimento di Scienze degli Alimenti e del Farmaco , Universita' degli Studi di Parma , Italy
| | - Athina Geronikaki
- Aristotle University , School of Pharmacy , Thessaloniki , 54124 , Greece . ; ; Tel: +30 2310 997616
| | - Phaedra Eleftheriou
- Department of Medical Laboratory Studies , School of Health and Medical Care , Alexander Technological Educational Institute of Thessaloniki , Greece
| | - Athanasios Tsagkadouras
- Department of Medical Laboratory Studies , School of Health and Medical Care , Alexander Technological Educational Institute of Thessaloniki , Greece
| | - Panagiotis Zoumpoulakis
- Institute of Biology , Medicinal Chemistry and Biotechnology , National Hellenic Research Foundation , 48 Vas. Constantinou Ave. , 11635 , Athens , Greece
| | - Charalmpos Fotakis
- Institute of Biology , Medicinal Chemistry and Biotechnology , National Hellenic Research Foundation , 48 Vas. Constantinou Ave. , 11635 , Athens , Greece
| | - Ana Ćirić
- Mycological Laboratory , Department of Plant Physiology , Institute for Biological Research , Siniša Stanković , University of Belgrade , Bulevar , Serbia
| | - Jasmina Glamočlija
- Mycological Laboratory , Department of Plant Physiology , Institute for Biological Research , Siniša Stanković , University of Belgrade , Bulevar , Serbia
| | - Marina Soković
- Mycological Laboratory , Department of Plant Physiology , Institute for Biological Research , Siniša Stanković , University of Belgrade , Bulevar , Serbia
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21
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Hurley KA, Santos TMA, Fensterwald MR, Rajendran M, Moore JT, Balmond EI, Blahnik BJ, Faulkner KC, Foss MH, Heinrich VA, Lammers MG, Moore LC, Reynolds GD, Shearn-Nance GP, Stearns BA, Yao ZW, Shaw JT, Weibel DB. Targeting quinolone- and aminocoumarin-resistant bacteria with new gyramide analogs that inhibit DNA gyrase. MEDCHEMCOMM 2017; 8:942-951. [PMID: 30034678 PMCID: PMC6051542 DOI: 10.1039/c7md00012j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Accepted: 02/21/2017] [Indexed: 11/21/2022]
Abstract
Bacterial DNA gyrase is an essential type II topoisomerase that enables cells to overcome topological barriers encountered during replication, transcription, recombination, and repair. This enzyme is ubiquitous in bacteria and represents an important clinical target for antibacterial therapy. In this paper we report the characterization of three exciting new gyramide analogs-from a library of 183 derivatives-that are potent inhibitors of DNA gyrase and are active against clinical strains of gram-negative bacteria (Escherichia coli, Shigella flexneri, and Salmonella enterica; 3 of 10 wild-type strains tested) and gram-positive bacteria (Bacillus spp., Enterococcus spp., Staphylococcus spp., and Streptococcus spp.; all 9 of the wild-type strains tested). E. coli strains resistant to the DNA gyrase inhibitors ciprofloxacin and novobiocin display very little cross-resistance to these new gyramides. In vitro studies demonstrate that the new analogs are potent inhibitors of the DNA supercoiling activity of DNA gyrase (IC50s of 47-170 nM) but do not alter the enzyme's ATPase activity. Although mutations that confer bacterial cells resistant to these new gyramides map to the genes encoding the subunits of the DNA gyrase (gyrA and gyrB genes), overexpression of GyrA, GyrB, or GyrA and GyrB together does not suppress the inhibitory effect of the gyramides. These observations support the hypothesis that the gyramides inhibit DNA gyrase using a mechanism that is unique from other known inhibitors.
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Affiliation(s)
- Katherine A. Hurley
- Department of Biochemistry
, University of Wisconsin – Madison
,
Madison
, Wisconsin
, USA
.
| | - Thiago M. A. Santos
- Department of Biochemistry
, University of Wisconsin – Madison
,
Madison
, Wisconsin
, USA
.
| | - Molly R. Fensterwald
- Department of Chemistry
, University of California – Davis
,
Davis
, California
, USA
.
| | - Madhusudan Rajendran
- Department of Biochemistry
, University of Wisconsin – Madison
,
Madison
, Wisconsin
, USA
.
| | - Jared T. Moore
- Department of Chemistry
, University of California – Davis
,
Davis
, California
, USA
.
| | - Edward I. Balmond
- Department of Chemistry
, University of California – Davis
,
Davis
, California
, USA
.
| | - Brice J. Blahnik
- Department of Biochemistry
, University of Wisconsin – Madison
,
Madison
, Wisconsin
, USA
.
| | - Katherine C. Faulkner
- Department of Biochemistry
, University of Wisconsin – Madison
,
Madison
, Wisconsin
, USA
.
| | - Marie H. Foss
- Department of Biochemistry
, University of Wisconsin – Madison
,
Madison
, Wisconsin
, USA
.
| | - Victoria A. Heinrich
- Department of Biochemistry
, University of Wisconsin – Madison
,
Madison
, Wisconsin
, USA
.
| | - Matthew G. Lammers
- Department of Biochemistry
, University of Wisconsin – Madison
,
Madison
, Wisconsin
, USA
.
| | - Lucas C. Moore
- Department of Chemistry
, University of California – Davis
,
Davis
, California
, USA
.
| | - Gregory D. Reynolds
- Department of Biochemistry
, University of Wisconsin – Madison
,
Madison
, Wisconsin
, USA
.
| | - Galen P. Shearn-Nance
- Department of Chemistry
, University of California – Davis
,
Davis
, California
, USA
.
| | | | - Zi W. Yao
- Department of Chemistry
, University of California – Davis
,
Davis
, California
, USA
.
| | - Jared T. Shaw
- Department of Chemistry
, University of California – Davis
,
Davis
, California
, USA
.
| | - Douglas B. Weibel
- Department of Biochemistry
, University of Wisconsin – Madison
,
Madison
, Wisconsin
, USA
.
- Department of Chemistry
, University of Wisconsin – Madison
,
Madison
, Wisconsin
, USA
- Department of Biomedical Engineering
, University of Wisconsin – Madison
,
Madison
, Wisconsin
, USA
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22
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Advances in the Chemistry of Natural and Semisynthetic Topoisomerase I/II Inhibitors. STUDIES IN NATURAL PRODUCTS CHEMISTRY 2017. [DOI: 10.1016/b978-0-444-63929-5.00002-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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23
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Fakhruzzaman M, Inukai Y, Yanagida Y, Kino H, Igarashi M, Eguchi Y, Utsumi R. Study on in vivo effects of bacterial histidine kinase inhibitor, Waldiomycin, in Bacillus subtilis and Staphylococcus aureus. J GEN APPL MICROBIOL 2016; 61:177-84. [PMID: 26582287 DOI: 10.2323/jgam.61.177] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Two-component signal transduction systems (TCSs) represent one of the primary means by which bacteria sense and respond to changes in their environment, both intra- and extracellular. The highly conserved WalK (histidine kinase)/WalR (response regulator) TCS is essential for cell wall metabolism of low G+C Gram-positive bacteria and acts as a master regulatory system in controlling and coordinating cell wall metabolism with cell division. Waldiomycin, a WalK inhibitor, has been discovered by screening metabolites from actinomycetes and belongs to the family of angucycline antibiotics. In the present study, we have shown that waldiomycin inhibited autophosphorylation of WalK histidine kinases in vitro from Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, and Streptococcus mutans at half-maximal inhibitory concentrations of 10.2, 8.8, 9.2, and 25.8 μM, respectively. Quantitative RT-PCR studies of WalR regulon genes have suggested that waldiomycin repressed the WalK/WalR system in B. subtilis and S. aureus cells. Morphology of waldiomycin-treated S. aureus cells displayed increased aggregation instead of proper cellular dissemination. Furthermore, autolysis profiles of S. aureus cells revealed that waldiomycin-treated cells were highly resistant to Triton X-100- and lysostaphin-induced lysis. These phenotypes are consistent with those of cells starved for the WalK/WalR system, indicating that waldiomycin inhibited the autophosphorylation activity of WalK in cells. We have also confirmed that waldiomycin inhibits WalK autophosphorylation in vivo by actually observing the phosphorylated WalK ratio in cells using Phos-tag SDS-PAGE. The results of our current study strongly suggest that waldiomycin targets WalK histidine kinases and inhibits the WalR regulon genes expression, thereby affecting both cell wall metabolism and cell division.
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Affiliation(s)
- Md Fakhruzzaman
- Department of Bioscience, Graduate School of Agriculture, Kinki University
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24
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Jaing CJ, McLoughlin KS, Thissen JB, Zemla A, Gardner SN, Vergez LM, Bourguet F, Mabery S, Fofanov VY, Koshinsky H, Jackson PJ. Identification of Genome-Wide Mutations in Ciprofloxacin-Resistant F. tularensis LVS Using Whole Genome Tiling Arrays and Next Generation Sequencing. PLoS One 2016; 11:e0163458. [PMID: 27668749 PMCID: PMC5036845 DOI: 10.1371/journal.pone.0163458] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/08/2016] [Indexed: 11/19/2022] Open
Abstract
Francisella tularensis is classified as a Class A bioterrorism agent by the U.S. government due to its high virulence and the ease with which it can be spread as an aerosol. It is a facultative intracellular pathogen and the causative agent of tularemia. Ciprofloxacin (Cipro) is a broad spectrum antibiotic effective against Gram-positive and Gram-negative bacteria. Increased Cipro resistance in pathogenic microbes is of serious concern when considering options for medical treatment of bacterial infections. Identification of genes and loci that are associated with Ciprofloxacin resistance will help advance the understanding of resistance mechanisms and may, in the future, provide better treatment options for patients. It may also provide information for development of assays that can rapidly identify Cipro-resistant isolates of this pathogen. In this study, we selected a large number of F. tularensis live vaccine strain (LVS) isolates that survived in progressively higher Ciprofloxacin concentrations, screened the isolates using a whole genome F. tularensis LVS tiling microarray and Illumina sequencing, and identified both known and novel mutations associated with resistance. Genes containing mutations encode DNA gyrase subunit A, a hypothetical protein, an asparagine synthase, a sugar transamine/perosamine synthetase and others. Structural modeling performed on these proteins provides insights into the potential function of these proteins and how they might contribute to Cipro resistance mechanisms.
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Affiliation(s)
- Crystal J. Jaing
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
- * E-mail:
| | - Kevin S. McLoughlin
- Computations Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - James B. Thissen
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Adam Zemla
- Computations Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Shea N. Gardner
- Computations Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Lisa M. Vergez
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Feliza Bourguet
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Shalini Mabery
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | | | | | - Paul J. Jackson
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
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25
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Schäfer M, Stevenson CEM, Wilkinson B, Lawson DM, Buttner MJ. Substrate-Assisted Catalysis in Polyketide Reduction Proceeds via a Phenolate Intermediate. Cell Chem Biol 2016; 23:1091-1097. [PMID: 27617849 PMCID: PMC5039031 DOI: 10.1016/j.chembiol.2016.07.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 07/17/2016] [Accepted: 07/26/2016] [Indexed: 12/22/2022]
Abstract
SimC7 is a polyketide ketoreductase involved in biosynthesis of the angucyclinone moiety of the gyrase inhibitor simocyclinone D8 (SD8). SimC7, which belongs to the short-chain dehydrogenase/reductase (SDR) superfamily, catalyzes reduction of the C-7 carbonyl of the angucyclinone, and the resulting hydroxyl is essential for antibiotic activity. SimC7 shares little sequence similarity with characterized ketoreductases, suggesting it might have a distinct mechanism. To investigate this possibility, we determined the structures of SimC7 alone, with NADP+, and with NADP+ and the substrate 7-oxo-SD8. These structures show that SimC7 is distinct from previously characterized polyketide ketoreductases, lacking the conserved catalytic triad, including the active-site tyrosine that acts as central acid-base catalyst in canonical SDR proteins. Taken together with functional analyses of active-site mutants, our data suggest that SimC7 catalyzes a substrate-assisted, two-step reaction for reduction of the C-7 carbonyl group involving intramolecular transfer of a substrate-derived proton to generate a phenolate intermediate. SimC7 catalyzes reduction of the C-7 carbonyl of the angucyclinone of simocyclinone SimC7 lacks the conserved catalytic triad characteristic of canonical ketoreductases SimC7 reduces the C-7 carbonyl via a substrate-assisted, two-step reaction This involves intramolecular transfer of a substrate proton to generate a phenolate
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Affiliation(s)
- Martin Schäfer
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Clare E M Stevenson
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Barrie Wilkinson
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - David M Lawson
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Mark J Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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26
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Microwave-assisted synthesis, molecular docking and antimicrobial activity of novel 2-(3-aryl,1-phenyl-1H-pyrazol-4-yl)-8H-pyrano[2,3-f]chromen-4-ones. Med Chem Res 2016. [DOI: 10.1007/s00044-016-1505-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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27
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Bilyk O, Brötz E, Tokovenko B, Bechthold A, Paululat T, Luzhetskyy A. New Simocyclinones: Surprising Evolutionary and Biosynthetic Insights. ACS Chem Biol 2016; 11:241-50. [PMID: 26566170 DOI: 10.1021/acschembio.5b00669] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Simocyclinone D8 (1, SD8) has attracted attention due to its highly complex hybrid structure and the unusual way it inhibits bacterial DNA gyrase by preventing DNA binding to the enzyme. Although a hypothesis explaining simocyclinone biosynthesis has been previously proposed, little was proven in vivo due to the genetic inaccessibility of the producer strain. Herein, we report discovery of three new D-type simocyclinones (D9, D10, and D11) produced by Kitasatospora sp. and Streptomyces sp. NRRL B-24484, as well as the identification and annotation of their biosynthetic gene clusters. Unexpectedly, the arrangement of the newly discovered biosynthetic gene clusters is starkly different from the previously published one, despite the nearly identical structures of D8 and D9 simocyclinones. The gene inactivation and expression studies have disproven the role of a modular polyketide synthase (PKS) system in the assembly of the linear dicarboxylic acid. Instead, the new stand-alone ketosynthase genes were shown to be involved in the biosynthesis of the tetraene chain. Additionally, we identified the gene responsible for the conversion of simocyclinone D9 (2, SD9) into D8.
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Affiliation(s)
- Oksana Bilyk
- Helmholtz-Institute
for Pharmaceutical Research Saarland, Saarland University Campus, Building
C2.3, 66123 Saarbrücken, Germany
| | - Elke Brötz
- Helmholtz-Institute
for Pharmaceutical Research Saarland, Saarland University Campus, Building
C2.3, 66123 Saarbrücken, Germany
| | - Bogdan Tokovenko
- Helmholtz-Institute
for Pharmaceutical Research Saarland, Saarland University Campus, Building
C2.3, 66123 Saarbrücken, Germany
| | - Andreas Bechthold
- University of Freiburg, Institute for Pharmaceutical
Sciences, Department for Pharmaceutical Biology and Biotechnology, Stefan-Meier-Straße 14, 79104 Freiburg, Germany
| | - Thomas Paululat
- University of Siegen, Faculty 4, Organic Chemistry
2, Adolf-Reichwein-Straße
2, 57068 Siegen, Germany
| | - Andriy Luzhetskyy
- Helmholtz-Institute
for Pharmaceutical Research Saarland, Saarland University Campus, Building
C2.3, 66123 Saarbrücken, Germany
- Universität des Saarlandes, Pharmazeutische Biotechnologie, Building C2.3, 66123 Saarbrücken, Germany
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28
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Austin MJ, Hearnshaw SJ, Mitchenall LA, McDermott PJ, Howell LA, Maxwell A, Searcey M. A natural product inspired fragment-based approach towards the development of novel anti-bacterial agents. MEDCHEMCOMM 2016. [DOI: 10.1039/c6md00229c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Simocyclinone D8 served as a natural product inspiration for the synthesis of a new DNA gyrase inhibitor.
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Affiliation(s)
| | | | | | | | | | - Anthony Maxwell
- Department of Biological Chemistry
- John Innes Centre
- Norwich NR4 7UH
- UK
| | - Mark Searcey
- School of Pharmacy
- University of East Anglia
- Norwich NR4 7TJ
- UK
| |
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29
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Preethi B, Ramanathan K. Molecular level understanding of resistance to nalidixic acid in Salmonella enteric serovar typhimurium associates with the S83F sequence type. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2015; 45:35-44. [PMID: 26329667 DOI: 10.1007/s00249-015-1073-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 07/15/2015] [Accepted: 08/12/2015] [Indexed: 02/04/2023]
Abstract
Nalidixic acid is an antibiotic drug used for treatment of Salmonellosis, a gastrointestinal infection. DNA gyrase subunit A (GyrA) of Salmonella typhimurium is the drug target for nalidixic acid. Resistance of GyrA to nalidixic acid, because of a point mutation in S. typhimurium, was recently reported. Substitution of Phe in place of Ser at locus 83 in GyrA of S. typhimurium has been experimentally associated with nalidixic acid resistance. Despite recent efforts, the mechanism of this resistance is not well understood. In this investigation we used computational techniques to address this shortcoming. Our results showed that contact with residue Arg 91 is certainly important for efficient binding of nalidixic acid to the target protein, and that mutation of this residue results in 180° rotation of the antibiotic in its binding pocket, around its own long axis. It is hoped these findings may enable development of new antibiotics against resistant forms of Salmonella.
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Affiliation(s)
- B Preethi
- Industrial Biotechnology Division, School of Bio Sciences and Technology, VIT University, Vellore, 632014, Tamil Nadu, India
| | - K Ramanathan
- Industrial Biotechnology Division, School of Bio Sciences and Technology, VIT University, Vellore, 632014, Tamil Nadu, India.
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Protective effect of Qnr on agents other than quinolones that target DNA gyrase. Antimicrob Agents Chemother 2015; 59:6689-95. [PMID: 26239981 DOI: 10.1128/aac.01292-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 07/30/2015] [Indexed: 12/16/2022] Open
Abstract
Qnr is a plasmid-encoded and chromosomally determined protein that protects DNA gyrase and topoisomerase IV from inhibition by quinolones. Despite its prevalence worldwide and existence prior to the discovery of quinolones, its native function is not known. Other synthetic compounds and natural products also target bacterial topoisomerases. A number were studied as molecular probes to gain insight into how Qnr acts. Qnr blocked inhibition by synthetic compounds with somewhat quinolone-like structure that target the GyrA subunit, such as the 2-pyridone ABT-719, the quinazoline-2,4-dione PD 0305970, and the spiropyrimidinetrione pyrazinyl-alkynyl-tetrahydroquinoline (PAT), indicating that Qnr is not strictly quinolone specific, but Qnr did not protect against GyrA-targeting simocyclinone D8 despite evidence that both simocyclinone D8 and Qnr affect DNA binding to gyrase. Qnr did not affect the activity of tricyclic pyrimidoindole or pyrazolopyridones, synthetic inhibitors of the GyrB subunit, or nonsynthetic GyrB inhibitors, such as coumermycin A1, novobiocin, gyramide A, or microcin B17.Thus, in this set of compounds the protective activity of Qnr was confined to those that, like quinolones, trap gyrase on DNA in cleaved complexes.
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Preethi B, Shanthi V, Ramanathan K. Investigation of Nalidixic Acid Resistance Mechanism in Salmonella enterica Using Molecular Simulation Techniques. Appl Biochem Biotechnol 2015. [DOI: 10.1007/s12010-015-1760-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ren Z, Schulz JE, Dong G. Catalytic Ortho-Acetoxylation of Masked Benzyl Alcohols via an Exo-Directing Mode. Org Lett 2015; 17:2696-9. [DOI: 10.1021/acs.orglett.5b01098] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhi Ren
- Department
of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Jonathan E. Schulz
- Department
of Chemistry and Biochemistry, Southwestern University, Georgetown, Texas 78626, United States
| | - Guangbin Dong
- Department
of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
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Nawaz M, Sung K, Kweon O, Khan S, Nawaz S, Steele R. Characterisation of novel mutations involved in quinolone resistance in Escherichia coli isolated from imported shrimp. Int J Antimicrob Agents 2015; 45:471-6. [DOI: 10.1016/j.ijantimicag.2014.11.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 11/13/2014] [Indexed: 10/24/2022]
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Synthesis, anti-microbial activity and molecular docking studies on triazolylcoumarin derivatives. J CHEM SCI 2015. [DOI: 10.1007/s12039-015-0810-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Schäfer M, Le TBK, Hearnshaw SJ, Maxwell A, Challis GL, Wilkinson B, Buttner MJ. SimC7 Is a Novel NAD(P)H-Dependent Ketoreductase Essential for the Antibiotic Activity of the DNA Gyrase Inhibitor Simocyclinone. J Mol Biol 2015; 427:2192-204. [PMID: 25861759 PMCID: PMC4451461 DOI: 10.1016/j.jmb.2015.03.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 03/30/2015] [Accepted: 03/31/2015] [Indexed: 01/02/2023]
Abstract
Simocyclinone D8 (SD8) is a potent DNA gyrase inhibitor produced by Streptomyces antibioticus Tü6040. The simocyclinone (sim) biosynthetic gene cluster has been sequenced and a hypothetical biosynthetic pathway has been proposed. The tetraene linker in SD8 was suggested to be the product of a modular type I polyketide synthase working in trans with two monofunctional enzymes. One of these monofunctional enzymes, SimC7, was proposed to supply a dehydratase activity missing from two modules of the polyketide synthase. In this study, we report the function of SimC7. We isolated the entire ~ 72-kb sim cluster on a single phage artificial chromosome clone and produced simocyclinone heterologously in a Streptomyces coelicolor strain engineered for improved antibiotic production. Deletion of simC7 resulted in the production of a novel simocyclinone, 7-oxo-SD8, which unexpectedly carried a normal tetraene linker but was altered in the angucyclinone moiety. We demonstrate that SimC7 is an NAD(P)H-dependent ketoreductase that catalyzes the conversion of 7-oxo-SD8 into SD8. 7-oxo-SD8 was essentially inactive as a DNA gyrase inhibitor, and the reduction of the keto group by SimC7 was shown to be crucial for high-affinity binding to the enzyme. Thus, SimC7 is an angucyclinone ketoreductase that is essential for the biological activity of simocyclinone. The ~ 75-kb simocyclinone biosynthetic cluster was expressed in a heterologous system. SimC7 is a novel NAD(P)H-dependent ketoreductase. SimC7 function is essential for the antibiotic activity of the DNA gyrase inhibitor simocyclinone.
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Affiliation(s)
- Martin Schäfer
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Tung B K Le
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Stephen J Hearnshaw
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Anthony Maxwell
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Gregory L Challis
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Barrie Wilkinson
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Mark J Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
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Abstract
DNA topoisomerases are enzymes that control the topology of DNA in all cells. There are two types, I and II, classified according to whether they make transient single- or double-stranded breaks in DNA. Their reactions generally involve the passage of a single- or double-strand segment of DNA through this transient break, stabilized by DNA-protein covalent bonds. All topoisomerases can relax DNA, but DNA gyrase, present in all bacteria, can also introduce supercoils into DNA. Because of their essentiality in all cells and the fact that their reactions proceed via DNA breaks, topoisomerases have become important drug targets; the bacterial enzymes are key targets for antibacterial agents. This article discusses the structure and mechanism of topoisomerases and their roles in the bacterial cell. Targeting of the bacterial topoisomerases by inhibitors, including antibiotics in clinical use, is also discussed.
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Schröder W, Bernhardt J, Marincola G, Klein-Hitpass L, Herbig A, Krupp G, Nieselt K, Wolz C. Altering gene expression by aminocoumarins: the role of DNA supercoiling in Staphylococcus aureus. BMC Genomics 2014; 15:291. [PMID: 24734910 PMCID: PMC4023603 DOI: 10.1186/1471-2164-15-291] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 03/17/2014] [Indexed: 11/29/2022] Open
Abstract
Background It has been shown previously that aminocoumarin antibiotics such as novobiocin lead to immediate downregulation of recA expression and thereby inhibit the SOS response, mutation frequency and recombination capacity in Staphylococcus aureus. Aminocoumarins function by inhibiting the ATPase activity of DNA gyrase subunit B with a severe impact on DNA supercoiling. Results Here, we have analysed the global impact of the DNA relaxing agent novobiocin on gene expression in S. aureus. Using a novobiocin-resistant mutant, it became evident that the change in recA expression is due to gyrase inhibition. Microarray analysis and northern blot hybridisation revealed that the expression levels of a distinct set of genes were increased (e.g., recF-gyrB-gyrA, the rib operon and the ure operon) or decreased (e.g., arlRS, recA, lukA, hlgC and fnbA) by novobiocin. The two-component ArlRS system was previously found to decrease the level of supercoiling in S. aureus. Thus, downregulation of arlRS might partially compensate for the relaxing effect of novobiocin. Global analysis and gene mapping of supercoiling-sensitive genes did not provide any indication that they are clustered in the genome. Promoter fusion assays confirmed that the responsiveness of a given gene is intrinsic to the promoter region but independent of the chromosomal location. Conclusions The results indicate that the molecular properties of a given promoter, rather than the chromosomal topology, dictate the responsiveness to changes in supercoiling in the pathogen Staphylococcus aureus.
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Affiliation(s)
| | | | | | | | | | | | | | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Elfriede-Aulhorn-Strasse 6, 72076 Tübingen, Germany.
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Abstract
The most common prokaryotic signal transduction mechanisms are the one-component systems in which a single polypeptide contains both a sensory domain and a DNA-binding domain. Among the >20 classes of one-component systems, the TetR family of regulators (TFRs) are widely associated with antibiotic resistance and the regulation of genes encoding small-molecule exporters. However, TFRs play a much broader role, controlling genes involved in metabolism, antibiotic production, quorum sensing, and many other aspects of prokaryotic physiology. There are several well-established model systems for understanding these important proteins, and structural studies have begun to unveil the mechanisms by which they bind DNA and recognize small-molecule ligands. The sequences for more than 200,000 TFRs are available in the public databases, and genomics studies are identifying their target genes. Three-dimensional structures have been solved for close to 200 TFRs. Comparison of these structures reveals a common overall architecture of nine conserved α helices. The most important open question concerning TFR biology is the nature and diversity of their ligands and how these relate to the biochemical processes under their control.
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Hearnshaw SJ, Edwards MJ, Stevenson CE, Lawson DM, Maxwell A. A new crystal structure of the bifunctional antibiotic simocyclinone D8 bound to DNA gyrase gives fresh insight into the mechanism of inhibition. J Mol Biol 2014; 426:2023-33. [PMID: 24594357 PMCID: PMC4018983 DOI: 10.1016/j.jmb.2014.02.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 02/19/2014] [Accepted: 02/24/2014] [Indexed: 01/08/2023]
Abstract
Simocyclinone D8 (SD8) is an antibiotic produced by Streptomyces antibioticus that targets DNA gyrase. A previous structure of SD8 complexed with the N-terminal domain of the DNA gyrase A protein (GyrA) suggested that four SD8 molecules stabilized a tetramer of the protein; subsequent mass spectrometry experiments suggested that a protein dimer with two symmetry-related SD8s was more likely. This work describes the structures of a further truncated form of the GyrA N-terminal domain fragment with and without SD8 bound. The structure with SD8 has the two SD8 molecules bound within the same GyrA dimer. This new structure is entirely consistent with the mutations in GyrA that confer SD8 resistance and, by comparison with a new apo structure of the GyrA N-terminal domain, reveals the likely conformation changes that occur upon SD8 binding and the detailed mechanism of SD8 inhibition of gyrase. Isothermal titration calorimetry experiments are consistent with the crystallography results and further suggest that a previously observed complex between SD8 and GyrB is ~ 1000-fold weaker than the interaction with GyrA. Fragment engineered to reveal biologically relevant structure of GyrA–drug complex. This structure fully explains all available biochemical/biophysical/genetic data. Binding site in GyrB is ~ 1000-fold weaker than site in GyrA.
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Affiliation(s)
- Stephen J Hearnshaw
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Marcus J Edwards
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Clare E Stevenson
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - David M Lawson
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Anthony Maxwell
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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40
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Gaskell LM, Nguyen T, Ellis KC. Defining a minimum pharmacophore for simocyclinone D8 disruption of DNA gyrase binding to DNA. Med Chem Res 2014. [DOI: 10.1007/s00044-014-0942-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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41
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Zettler J, Xia H, Burkard N, Kulik A, Grond S, Heide L, Apel AK. New aminocoumarins from the rare actinomycete Catenulispora acidiphila DSM 44928: identification, structure elucidation, and heterologous production. Chembiochem 2014; 15:612-21. [PMID: 24554531 DOI: 10.1002/cbic.201300712] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Indexed: 11/08/2022]
Abstract
Genome mining led to the discovery of a novel aminocoumarin gene cluster in the rare actinomycete Catenulispora acidiphila DSM 44928. Sequence analysis revealed the presence of genes putatively involved in export/resistance, regulation, and biosynthesis of the aminocoumarin moiety and its halogenation, as well as several genes with so far unknown function. Two new aminocoumarins, cacibiocin A and B, were identified in the culture broth of C. acidiphila. Heterologous expression of the putative gene cluster in Streptomyces coelicolor M1152 confirmed that this cluster is responsible for cacibiocin biosynthesis. Furthermore, total production levels of cacibiocins could be increased by heterologous expression and screening of different culture media from an initial yield of 4.9 mg L(-1) in C. acidiphila to 60 mg L(-1) in S. coelicolor M1152. By HR-MS and NMR analysis, cacibiocin A was found to contain a 3-amino-4,7-dihydroxycoumarin moiety linked by an amide bond to a pyrrole-2,5-dicarboxylic acid. The latter structural motif has not been identified previously in any natural compound. Additionally, cacibiocin B contains two chlorine atoms at positions 6' and 8' of the aminocoumarin moiety.
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Affiliation(s)
- Judith Zettler
- Eberhard-Karls-Universität Tübingen, Pharmazeutische Biologie, Auf der Morgenstelle 8, 72076 Tübingen (Germany); German Centre for Infection Research (DZIF), Partner site Tübingen (Germany)
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Harnessing evolutionary fitness in Plasmodium falciparum for drug discovery and suppressing resistance. Proc Natl Acad Sci U S A 2013; 111:799-804. [PMID: 24381157 DOI: 10.1073/pnas.1320886110] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Drug resistance emerges in an ecological context where fitness costs restrict the diversity of escape pathways. These pathways are targets for drug discovery, and here we demonstrate that we can identify small-molecule inhibitors that differentially target resistant parasites. Combining wild-type and mutant-type inhibitors may prevent the emergence of competitively viable resistance. We tested this hypothesis with a clinically derived chloroquine-resistant (CQ(r)) malaria parasite and with parasites derived by in vitro selection with Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) inhibitors. We screened a chemical library against CQ(s) and CQ(r) lines and discovered a drug-like compound (IDI-3783) that was potent only in the CQ(r) line. Surprisingly, in vitro selection of Plasmodium falciparum resistant to IDI-3783 restored CQ sensitivity, thereby indicating that CQ might once again be useful as a malaria therapy. In parallel experiments, we selected P. falciparum lines resistant to structurally unrelated PfDHODH inhibitors (Genz-666136 and DSM74). Both selections yielded resistant lines with the same point mutation in PfDHODH:E182D. We discovered a compound (IDI-6273) more potent against E182D than wild-type parasites. Selection of the E182D mutant with IDI-6273 yielded a reversion to the wild-type protein sequence and phenotype although the nucleotide sequence was different. Importantly, selection with a combination of Genz-669178, a wild-type PfDHODH inhibitor, and IDI-6273, a mutant-selective PfDHODH inhibitor, did not yield resistant parasites. These two examples demonstrate that the compromise between resistance and evolutionary fitness can be exploited to design therapies that prevent the emergence and spread of resistant organisms.
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Mayer C, Janin YL. Non-quinolone inhibitors of bacterial type IIA topoisomerases: a feat of bioisosterism. Chem Rev 2013; 114:2313-42. [PMID: 24313284 DOI: 10.1021/cr4003984] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Claudine Mayer
- Unité de Microbiologie Structurale, Département de Biologie Structurale et Chimie, Institut Pasteur , 25 rue du Dr. Roux, 75724 Paris Cedex 15, France
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Flavone-based analogues inspired by the natural product simocyclinone D8 as DNA gyrase inhibitors. Bioorg Med Chem Lett 2013; 23:5874-7. [DOI: 10.1016/j.bmcl.2013.08.094] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/22/2013] [Accepted: 08/26/2013] [Indexed: 01/27/2023]
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46
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Zou X, Zhou X, Lin Z, Deng Z, Yin D. A docking-based receptor library of antibiotics and its novel application in predicting chronic mixture toxicity for environmental risk assessment. ENVIRONMENTAL MONITORING AND ASSESSMENT 2013; 185:4513-4527. [PMID: 23143826 DOI: 10.1007/s10661-012-2885-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 09/11/2012] [Indexed: 06/01/2023]
Abstract
As organisms are typically exposed to chemical mixtures over long periods of time, chronic mixture toxicity is the best way to perform an environmental risk assessment (ERA). However, it is difficult to obtain the chronic mixture toxicity data due to the high expense and the complexity of the data acquisition method. Therefore, an approach was proposed in this study to predict chronic mixture toxicity. The acute (15 min exposure) and chronic (24 h exposure) toxicity of eight antibiotics and trimethoprim to Vibrio fischeri were determined in both single and binary mixtures. The results indicated that the risk quotients (RQs) of antibiotics should be based on the chronic mixture toxicity. To predict the chronic mixture toxicity, a docking-based receptor library of antibiotics and the receptor-library-based quantitative structure-activity relationship (QSAR) model were developed. Application of the developed QSAR model to the ERA of antibiotic mixtures demonstrated that there was a close affinity between RQs based on the observed chronic toxicity and the corresponding RQs based on the predicted data. The average coefficients of variations were 46.26 and 34.93 % and the determination coefficients (R (2)) were 0.999 and 0.998 for the low concentration group and the high concentration group, respectively. This result convinced us that the receptor library would be a promising tool for predicting the chronic mixture toxicity of antibiotics and that it can be further applied in ERA.
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Affiliation(s)
- Xiaoming Zou
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
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48
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Igarashi M, Watanabe T, Hashida T, Umekita M, Hatano M, Yanagida Y, Kino H, Kimura T, Kinoshita N, Inoue K, Sawa R, Nishimura Y, Utsumi R, Nomoto A. Waldiomycin, a novel WalK-histidine kinase inhibitor from Streptomyces sp. MK844-mF10. J Antibiot (Tokyo) 2013; 66:459-64. [DOI: 10.1038/ja.2013.33] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 02/13/2013] [Accepted: 02/19/2013] [Indexed: 11/09/2022]
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49
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Collin F, Thompson RE, Jolliffe KA, Payne RJ, Maxwell A. Fragments of the bacterial toxin microcin B17 as gyrase poisons. PLoS One 2013; 8:e61459. [PMID: 23593482 PMCID: PMC3622597 DOI: 10.1371/journal.pone.0061459] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 03/09/2013] [Indexed: 11/18/2022] Open
Abstract
Fluoroquinolones are very important drugs in the clinical antibacterial arsenal; their success is principally due to their mode of action: the stabilisation of a gyrase-DNA intermediate (the cleavage complex), which triggers a chain of events leading to cell death. Microcin B17 (MccB17) is a modified peptide bacterial toxin that acts by a similar mode of action, but is unfortunately unsuitable as a therapeutic drug. However, its structure and mechanism could inspire the design of new antibacterial compounds that are needed to circumvent the rise in bacterial resistance to current antibiotics. Here we describe the investigation of the structural features responsible for MccB17 activity and the identification of fragments of the toxin that retain the ability to stabilise the cleavage complex.
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Affiliation(s)
- Frédéric Collin
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Robert E. Thompson
- School of Chemistry, The University of Sydney, New South Wales, Australia
| | | | - Richard J. Payne
- School of Chemistry, The University of Sydney, New South Wales, Australia
| | - Anthony Maxwell
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
- * E-mail:
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50
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Chen SH, Chan NL, Hsieh TS. New mechanistic and functional insights into DNA topoisomerases. Annu Rev Biochem 2013; 82:139-70. [PMID: 23495937 DOI: 10.1146/annurev-biochem-061809-100002] [Citation(s) in RCA: 255] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
DNA topoisomerases are nature's tools for resolving the unique problems of DNA entanglement that occur owing to unwinding and rewinding of the DNA helix during replication, transcription, recombination, repair, and chromatin remodeling. These enzymes perform topological transformations by providing a transient DNA break, formed by a covalent adduct with the enzyme, through which strand passage can occur. The active site tyrosine is responsible for initiating two transesterifications to cleave and then religate the DNA backbone. The cleavage reaction intermediate is exploited by cytotoxic agents, which have important applications as antibiotics and anticancer drugs. The reactions mediated by these enzymes can also be regulated by their binding partners; one example is a DNA helicase capable of modulating the directionality of strand passage, enabling important functions like reannealing denatured DNA and resolving recombination intermediates. In this review, we cover recent advances in mechanistic insights into topoisomerases and their various cellular functions.
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Affiliation(s)
- Stefanie Hartman Chen
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA.
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