1
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Batey SFD, Davie MJ, Hems ES, Liston JD, Scott TA, Alt S, Francklyn CS, Wilkinson B. The catechol moiety of obafluorin is essential for antibacterial activity. RSC Chem Biol 2023; 4:926-941. [PMID: 37920400 PMCID: PMC10619133 DOI: 10.1039/d3cb00127j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 08/11/2023] [Indexed: 11/04/2023] Open
Abstract
Obafluorin is a Pseudomonas fluorescens antibacterial natural product that inhibits threonyl-tRNA synthetase (ThrRS). It acts as a broad-spectrum antibiotic against a range of clinically relevant pathogens and comprises a strained β-lactone ring decorated with catechol and 4-nitro-benzyl moieties. The catechol moiety is widespread in nature and its role in the coordination of ferric iron has been well-characterised in siderophores and Trojan horse antibiotics. Here we use a combination of mutasynthesis, bioassays, enzyme assays and metal binding studies to delineate the role of the catechol moiety in the bioactivity of obafluorin. We use P. fluorescens biosynthetic mutants to generate obafluorin analogues with modified catechol moieties. We demonstrate that an intact catechol is required for both antibacterial activity and inhibition of the ThrRS molecular target. Although recent work showed that the obafluorin catechol coordinates Zn2+ in the ThrRS active site, we find that obafluorin is a weak Zn2+ binder in vitro, contrasting with a strong, specific 1 : 1 interaction with Fe3+. We use bioassays with siderophore transporter mutants to probe the role of the obafluorin catechol in Fe3+-mediated uptake. Surprisingly, obafluorin does not behave as a Trojan horse antibiotic but instead exhibits increased antibacterial activity in the presence of Fe3+. We further demonstrate that Fe3+ binding prevents the hydrolytic breakdown of the β-lactone ring, revealing a hitherto unreported function for the catechol moiety in natural product bioactivity.
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Affiliation(s)
- Sibyl F D Batey
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - Melissa J Davie
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - Edward S Hems
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - Jonathon D Liston
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - Thomas A Scott
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - Silke Alt
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - Christopher S Francklyn
- Department of Biochemistry, College of Medicine, University of Vermont, Burlington Vermont 05405 USA
| | - Barrie Wilkinson
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
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2
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Buitrago JAR, Leitis G, Kaņepe-Lapsa I, Rudnickiha A, Parisini E, Jirgensons A. Synthesis and evaluation of an agrocin 84 toxic moiety (TM84) analogue as a malarial threonyl tRNA synthetase inhibitor. Org Biomol Chem 2023. [PMID: 37335076 DOI: 10.1039/d3ob00670k] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
An analogue of a toxic moiety (TM84) of natural product agrocin 84 containing threonine amide instead of 2,3-dihydroxy-4-methylpentanamide was prepared and evaluated as a putative Plasmodium falciparum threonyl t-RNA synthetase (PfThrRS) inhibitor. This TM84 analogue features submicromolar inhibitory potency (IC50 = 440 nM) comparable to that of borrelidin (IC50 = 43 nM) and therefore complements chemotypes known to inhibit malarial PfThrRS, which are currently limited to borrelidin and its analogues. The crystal structure of the inhibitor in complex with the E. coli homologue enzyme (EcThrRS) was obtained, revealing crucial ligand-protein interactions that will pave the way for the design of novel ThrRS inhibitors.
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Affiliation(s)
| | - Gundars Leitis
- Latvian Institute of Organic Synthesis, Riga LV-1006, Latvia
| | | | | | - Emilio Parisini
- Latvian Institute of Organic Synthesis, Riga LV-1006, Latvia
- Department of Chemistry "G. Ciamician", University of Bologna, 40126, Bologna, Italy.
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3
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Rodríguez D, González-Bello C. Siderophores: Chemical Tools for Precise Antibiotic Delivery. Bioorg Med Chem Lett 2023; 87:129282. [PMID: 37031730 DOI: 10.1016/j.bmcl.2023.129282] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/02/2023] [Accepted: 04/06/2023] [Indexed: 04/11/2023]
Abstract
The success of precision medicine coupled with the disappointing impact of broad-spectrum antibiotic use on microbiome stability and bacterial resistance, has triggered a shift in antibiotic design strategies toward precision antibiotics. This also includes the implementation of novel vectorization approaches directed to improve the internalization of antibacterial agents into deadly gram-negative pathogens through precise and well-defined mechanisms. The conjugation of antibiotics to siderophores (iron scavengers), which are compounds that are able to afford stable iron-complexes that facilitate the internalization into the cell by using bacterial iron uptake pathways as gateways, is a strategy that has begun to show excellent results with the commercialization of the first antibiotic based on this principle, cefiderocol. This digests review provides an overview of the molecular basis for this antibiotic-siderophore conjugation approach, along with recent successful examples and highlights future challenges facing this booming research area.
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Affiliation(s)
- Diana Rodríguez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Jenaro de la Fuente s/n, 15782 Santiago de Compostela, Spain
| | - Concepción González-Bello
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Jenaro de la Fuente s/n, 15782 Santiago de Compostela, Spain.
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4
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Kim DY, Yeom S, Park J, Lee H, Kim HJ. Cytoplasmic Delivery of an Antibiotic, Trimethoprim, with a Simple Bidentate Catechol Analog as a Siderophore Mimetic. ACS Infect Dis 2023; 9:554-566. [PMID: 36753707 DOI: 10.1021/acsinfecdis.2c00556] [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: 02/10/2023]
Abstract
Concerns about antibiotic-resistant Gram-negative pathogens are escalating, and accordingly siderophore-based intracellular antibiotic delivery is attracting more attention as an effective means to overcome these infections. Despite the successful clinical translation of this strategy, the delivery potential of siderophores has been limited to periplasm targeting, and this has appreciably restricted the repertoire of applicable antibiotics. To overcome this shortcoming of the current technology, this study focused on investigating the capability of simple bidentate catechol analogs to function as vehicles for cytoplasmic antibiotic delivery. Specifically, by employing trimethoprim, an inhibitor of dihydrofolate reductase located in the cytoplasm, as a model antibiotic, a chemical library of chelator-antibiotic conjugates featuring four different catechol analogs was prepared. Then, their various pharmacological properties and antimicrobial activities were evaluated. Analysis of these characterization data led to the identification of the active conjugates exhibiting notable iron- and trimethoprim-dependent potency against Escherichia coli. Further characterization of these hit molecules using E. coli mutant strains revealed that 2,3-dihydroxybenzoate could effectively deliver several corresponding conjugates to the cytoplasm by exploiting the siderophore uptake machineries present across the outer and inner membranes, originally designated for the native siderophore of E. coli, enterobactin. Considering the synthetic simplicity, such a catechol analog could have appreciable usage in potentiating cytoplasm-active antibiotics against recalcitrant Gram-negative pathogens.
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Affiliation(s)
- Do Young Kim
- Department of Chemistry and Center for ProteoGeonomics Research, Korea University, Seoul 02841, Republic of Korea
| | - Suyeon Yeom
- Department of Chemistry and Center for ProteoGeonomics Research, Korea University, Seoul 02841, Republic of Korea
| | - Jimin Park
- Department of Chemistry and Center for ProteoGeonomics Research, Korea University, Seoul 02841, Republic of Korea
| | - Heeyeong Lee
- Department of Chemistry and Center for ProteoGeonomics Research, Korea University, Seoul 02841, Republic of Korea
| | - Hak Joong Kim
- Department of Chemistry and Center for ProteoGeonomics Research, Korea University, Seoul 02841, Republic of Korea
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5
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Fisher JF, Mobashery S. β-Lactams from the Ocean. Mar Drugs 2023; 21:86. [PMID: 36827127 PMCID: PMC9963991 DOI: 10.3390/md21020086] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/21/2023] [Accepted: 01/24/2023] [Indexed: 01/27/2023] Open
Abstract
The title of this essay is as much a question as it is a statement. The discovery of the β-lactam antibiotics-including penicillins, cephalosporins, and carbapenems-as largely (if not exclusively) secondary metabolites of terrestrial fungi and bacteria, transformed modern medicine. The antibiotic β-lactams inactivate essential enzymes of bacterial cell-wall biosynthesis. Moreover, the ability of the β-lactams to function as enzyme inhibitors is of such great medical value, that inhibitors of the enzymes which degrade hydrolytically the β-lactams, the β-lactamases, have equal value. Given this privileged status for the β-lactam ring, it is therefore a disappointment that the exemplification of this ring in marine secondary metabolites is sparse. It may be that biologically active marine β-lactams are there, and simply have yet to be encountered. In this report, we posit a second explanation: that the value of the β-lactam to secure an ecological advantage in the marine environment might be compromised by its close structural similarity to the β-lactones of quorum sensing. The steric and reactivity similarities between the β-lactams and the β-lactones represent an outside-of-the-box opportunity for correlating new structures and new enzyme targets for the discovery of compelling biological activities.
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Affiliation(s)
- Jed F Fisher
- Department of Chemistry & Biochemistry, 354 McCourtney Hall, University of Note Dame, Notre Dame, IN 46656-5670, USA
| | - Shahriar Mobashery
- Department of Chemistry & Biochemistry, 354 McCourtney Hall, University of Note Dame, Notre Dame, IN 46656-5670, USA
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6
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Rejuvenating the Activity of Usual Antibiotics on Resistant Gram-Negative Bacteria: Recent Issues and Perspectives. Int J Mol Sci 2023; 24:ijms24021515. [PMID: 36675027 PMCID: PMC9864949 DOI: 10.3390/ijms24021515] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/05/2023] [Accepted: 01/09/2023] [Indexed: 01/13/2023] Open
Abstract
Antibiotic resistance continues to evolve and spread beyond all boundaries, resulting in an increase in morbidity and mortality for non-curable infectious diseases. Due to the failure of conventional antimicrobial therapy and the lack of introduction of a novel class of antibiotics, novel strategies have recently emerged to combat these multidrug-resistant infectious microorganisms. In this review, we highlight the development of effective antibiotic combinations and of antibiotics with non-antibiotic activity-enhancing compounds to address the widespread emergence of antibiotic-resistant strains.
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7
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Zakalyukina YV, Pavlov NA, Lukianov DA, Marina VI, Belozerova OA, Tashlitsky VN, Guglya EB, Osterman IA, Biryukov MV. A New Albomycin-Producing Strain of Streptomyces globisporus subsp. globisporus May Provide Protection for Ants Messor structor. INSECTS 2022; 13:1042. [PMID: 36421945 PMCID: PMC9693239 DOI: 10.3390/insects13111042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/03/2022] [Accepted: 11/07/2022] [Indexed: 06/16/2023]
Abstract
There are several well-studied examples of protective symbiosis between insect host and symbiotic actinobacteria, producing antimicrobial metabolites to inhibit host pathogens. These mutualistic relationships are best described for some wasps and leaf-cutting ants, while a huge variety of insect species still remain poorly explored. For the first time, we isolated actinobacteria from the harvester ant Messor structor and evaluated the isolates' potential as antimicrobial producers. All isolates could be divided into two morphotypes of single and mycelial cells. We found that the most common mycelial morphotype was observed among soldiers and least common among larvae in the studied laboratory colony. The representative of this morphotype was identified as Streptomyces globisporus subsp. globisporus 4-3 by a polyphasic approach. It was established using a E. coli JW5503 pDualRep2 system that crude broths of mycelial isolates inhibited protein synthesis in reporter strains, but it did not disrupt the in vitro synthesis of proteins in cell-free extracts. An active compound was extracted, purified and identified as albomycin δ2. The pronounced ability of albomycin to inhibit the growth of entomopathogens suggests that Streptomyces globisporus subsp. globisporus may be involved in defensive symbiosis with the Messor structor ant against infections.
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Affiliation(s)
- Yuliya V. Zakalyukina
- Center for Translational Medicine, Sirius University of Science and Technology, Olympic Avenue 1, 354340 Sochi, Russia
- Department of Soil Science, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Nikolay A. Pavlov
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
| | - Dmitrii A. Lukianov
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Valeria I. Marina
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Olga A. Belozerova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Miklukho-Maklaya st. 16/10, 117997 Moscow, Russia
| | - Vadim N. Tashlitsky
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Elena B. Guglya
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Miklukho-Maklaya st. 16/10, 117997 Moscow, Russia
- Institute of Translational Medicine, Pirogov Russian National Research Medical University, Ostrovityanova st. 1, 117997 Moscow, Russia
| | - Ilya A. Osterman
- Center for Translational Medicine, Sirius University of Science and Technology, Olympic Avenue 1, 354340 Sochi, Russia
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Mikhail V. Biryukov
- Center for Translational Medicine, Sirius University of Science and Technology, Olympic Avenue 1, 354340 Sochi, Russia
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
- Department of Biology, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
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8
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Ongpipattanakul C, Desormeaux EK, DiCaprio A, van der Donk WA, Mitchell DA, Nair SK. Mechanism of Action of Ribosomally Synthesized and Post-Translationally Modified Peptides. Chem Rev 2022; 122:14722-14814. [PMID: 36049139 PMCID: PMC9897510 DOI: 10.1021/acs.chemrev.2c00210] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a natural product class that has undergone significant expansion due to the rapid growth in genome sequencing data and recognition that they are made by biosynthetic pathways that share many characteristic features. Their mode of actions cover a wide range of biological processes and include binding to membranes, receptors, enzymes, lipids, RNA, and metals as well as use as cofactors and signaling molecules. This review covers the currently known modes of action (MOA) of RiPPs. In turn, the mechanisms by which these molecules interact with their natural targets provide a rich set of molecular paradigms that can be used for the design or evolution of new or improved activities given the relative ease of engineering RiPPs. In this review, coverage is limited to RiPPs originating from bacteria.
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Affiliation(s)
- Chayanid Ongpipattanakul
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Emily K. Desormeaux
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Adam DiCaprio
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Wilfred A. van der Donk
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.,Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.,Department of Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.,Departments of Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, USA.,Corresponding authors Wilfred A. van der Donk, , 217-244-5360, Douglas A. Mitchell, , 217-333-1345, Satish K. Nair, , 217-333-0641
| | - Douglas A. Mitchell
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.,Department of Microbiology, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.,Departments of Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, USA.,Corresponding authors Wilfred A. van der Donk, , 217-244-5360, Douglas A. Mitchell, , 217-333-1345, Satish K. Nair, , 217-333-0641
| | - Satish K. Nair
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.,Departments of Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, USA.,Corresponding authors Wilfred A. van der Donk, , 217-244-5360, Douglas A. Mitchell, , 217-333-1345, Satish K. Nair, , 217-333-0641
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Wu Z, Shao J, Zheng J, Liu B, Li Z, Shen N. A zero-sum game or an interactive frame? Iron competition between bacteria and humans in infection war. Chin Med J (Engl) 2022; 135:1917-1926. [PMID: 35830263 PMCID: PMC9746790 DOI: 10.1097/cm9.0000000000002233] [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: 01/04/2022] [Indexed: 11/26/2022] Open
Abstract
ABSTRACT Iron is an essential trace element for both humans and bacteria. It plays a vital role in life, such as in redox reactions and electron transport. Strict regulatory mechanisms are necessary to maintain iron homeostasis because both excess and insufficient iron are harmful to life. Competition for iron is a war between humans and bacteria. To grow, reproduce, colonize, and successfully cause infection, pathogens have evolved various mechanisms for iron uptake from humans, principally Fe 3+ -siderophore and Fe 2+ -heme transport systems. Humans have many innate immune mechanisms that regulate the distribution of iron and inhibit bacterial iron uptake to help resist bacterial invasion and colonization. Meanwhile, researchers have invented detection test strips and coupled antibiotics with siderophores to create tools that take advantage of this battle for iron, to help eliminate pathogens. In this review, we summarize bacterial and human iron metabolism, competition for iron between humans and bacteria, siderophore sensors, antibiotics coupled with siderophores, and related phenomena. We also discuss how competition for iron can be used for diagnosis and treatment of infection in the future.
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Affiliation(s)
- Zhenchao Wu
- Department of Pulmonary and Critical Care Medicine, Peking University Third Hospital, Beijing 100191, China
- Center for Infectious Diseases, Peking University Third Hospital, Beijing 100191, China
| | - Jiqi Shao
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Jiajia Zheng
- Department of Laboratory Medicine, Peking University Third Hospital, Beijing 100191, China
| | - Beibei Liu
- Department of Pulmonary and Critical Care Medicine, Peking University Third Hospital, Beijing 100191, China
| | - Zhiyuan Li
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Ning Shen
- Department of Pulmonary and Critical Care Medicine, Peking University Third Hospital, Beijing 100191, China
- Center for Infectious Diseases, Peking University Third Hospital, Beijing 100191, China
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10
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Kushwaha V, Capalash N. Aminoacyl-tRNA synthetase (AARS) as an attractive drug target in neglected tropical trypanosomatid diseases-Leishmaniasis, Human African Trypanosomiasis and Chagas disease. Mol Biochem Parasitol 2022; 251:111510. [PMID: 35988745 DOI: 10.1016/j.molbiopara.2022.111510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 08/09/2022] [Accepted: 08/16/2022] [Indexed: 10/15/2022]
Abstract
TriTryp diseases (Leishmaniasis, Human African Trypanosomiasis (HAT), and Chagas disease) are devastating parasitic neglected tropical diseases (NTDs) that affect billions of people in developing countries, cause high mortality in humans, and impose a large socio-economic burden. The current treatment options against tritryp diseases are suboptimal and challenging due to the emergence of resistance against available tritryp drugs. Hence, designing and developing effective anti-tritryp drugs with novel targets are required. Aminoacyl-tRNA synthetases (AARSs) involved in specific aminoacylation of transfer RNAs (tRNAs), interrupt protein synthesis through inhibitors, and retard the parasite growth. AaRSs have long been studied as therapeutic targets in bacteria, and three aaRS inhibitors, mupirocin (against IleRS), tavaborole AN2690 (against LeuRS), and halofuginone (against ProRS), are already in clinical practice. The structural differences between tritryp and human aaRSs and the presence of unique sequences (N-terminal domain/C-terminal domain/catalytic domain) make them potential target for developing selective inhibitors. Drugs based on a single aaRS target developed by high-throughput screening (HTS) are less effective due to the emergence of resistance. However, designing multi-targeted drugs may be a better strategy for resistance development. In this perspective, we discuss the characteristics of tritryp aaRSs, sequence conservation in their orthologs and their peculiarities, recent advancements towards the single-target and multi-target aaRS inhibitors developed through rational design.
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Affiliation(s)
- Vikas Kushwaha
- Department of Biotechnology, Panjab University, Sector-25, South Campus, Chandigarh 160025, India.
| | - Neena Capalash
- Department of Biotechnology, Panjab University, Sector-25, South Campus, Chandigarh 160025, India.
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11
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S51 Family Peptidases Provide Resistance to Peptidyl-Nucleotide Antibiotic McC. mBio 2022; 13:e0080522. [PMID: 35467414 PMCID: PMC9239234 DOI: 10.1128/mbio.00805-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microcin C (McC)-like compounds are natural Trojan horse peptide-nucleotide antibiotics produced by diverse bacteria. The ribosomally synthesized peptide parts of these antibiotics are responsible for their facilitated transport into susceptible cells. Once inside the cell, the peptide part is degraded, releasing the toxic payload, an isoaspartyl-nucleotide that inhibits aspartyl-tRNA synthetase, an enzyme essential for protein synthesis. Bacteria that produce microcin C-like compounds have evolved multiple ways to avoid self-intoxication. Here, we describe a new strategy through the action of S51 family peptidases, which we name MccG. MccG cleaves the toxic isoaspartyl-nucleotide, rendering it inactive. While some MccG homologs are encoded by gene clusters responsible for biosynthesis of McC-like compounds, most are encoded by standalone genes whose products may provide a basal level of resistance to peptide-nucleotide antibiotics in phylogenetically distant bacteria.
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12
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Johnston CW, Badran AH. Natural and engineered precision antibiotics in the context of resistance. Curr Opin Chem Biol 2022; 69:102160. [PMID: 35660248 DOI: 10.1016/j.cbpa.2022.102160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 04/18/2022] [Accepted: 04/22/2022] [Indexed: 12/14/2022]
Abstract
Antibiotics are essential weapons in our fight against infectious disease, yet the consequences of broad-spectrum antibiotic use on microbiome stability and pathogen resistance are prompting investigations into more selective alternatives. Echoing the advent of precision medicine in oncology, precision antibiotics with focused activities are emerging as a means of addressing infections without damaging microbiomes or incentivizing resistance. Historically, antibiotic design principles have been gleaned from Nature, and reinvestigation of overlooked antibacterials is now providing scaffolds and targets for the design of pathogen-specific drugs. In this perspective, we summarize the biosynthetic and antibacterial mechanisms used to access these activities, and discuss how such strategies may be co-opted through engineering approaches to afford precision antibiotics.
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Affiliation(s)
- Chad W Johnston
- Department of Pharmacology & Chemical Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Ahmed H Badran
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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13
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Biosynthesis and Chemical Synthesis of Albomycin Nucleoside Antibiotics. Antibiotics (Basel) 2022; 11:antibiotics11040438. [PMID: 35453190 PMCID: PMC9032320 DOI: 10.3390/antibiotics11040438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 03/21/2022] [Accepted: 03/21/2022] [Indexed: 11/17/2022] Open
Abstract
The widespread emergence of antibiotic-resistant bacteria highlights the urgent need for new antimicrobial agents. Albomycins are a group of naturally occurring sideromycins with a thionucleoside antibiotic conjugated to a ferrichrome-type siderophore. The siderophore moiety serves as a vehicle to deliver albomycins into bacterial cells via a “Trojan horse” strategy. Albomycins function as specific inhibitors of seryl-tRNA synthetases and exhibit potent antimicrobial activities against both Gram-negative and Gram-positive bacteria, including many clinical pathogens. These distinctive features make albomycins promising drug candidates for the treatment of various bacterial infections, especially those caused by multidrug-resistant pathogens. We herein summarize findings on the discovery and structure elucidation, mechanism of action, biosynthesis and immunity, and chemical synthesis of albomcyins, with special focus on recent advances in the biosynthesis and chemical synthesis over the past decade (2012–2022). A thorough understanding of the biosynthetic pathway provides the basis for pathway engineering and combinatorial biosynthesis to create new albomycin analogues. Chemical synthesis of natural congeners and their synthetic analogues will be useful for systematic structure–activity relationship (SAR) studies, and thereby assist the design of novel albomycin-derived antimicrobial agents.
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Asenstorfer RE, Ryder MH, Jones GP. Agrocinopine C, a Ti-plasmid-coded enzyme-product, is a 2-O, 6-O linked phosphodiester of D-Glucose and sucrose. PHYTOCHEMISTRY 2022; 194:113013. [PMID: 34839131 DOI: 10.1016/j.phytochem.2021.113013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 11/06/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
Agrocinopine C is a small molecule found in crown gall tumours induced by pathogenic Agrobacterium radiobacter carrying the tumour-inducing plasmid pTi Bo542. This phosphodiester opine was isolated (at 0.02 g/100 g fresh wt.) from sunflower (Helianthus annuus L.) galls. It is structurally related to agrocinopine A and is a glucose-2-phosphodiester linked to the C6-hydroxy-methyl group of the glucose moiety of sucrose. Sugar-2-phosphates are uncommon in plant tissues, whether transformed by Agrobacterium or not. 1H and 31P NMR signal multiplicity indicates five-fold anomeric complexity of agrocinopine C in solution, implying that the permeases taking up these sucrose-phosphodiesters could recognise any one of the five anomers. Data suggests that the open chain aldehyde forms of the 2-phosphorylated opines agrocinopine C and agrocinopine A and the corresponding phosphorylated glucose-2-phosphoramidate component of the antibiotic agrocin 84 play a central role in agrocin's selective toxicity to certain strains of Agrobacterium after uptake via Ti plasmid-encoded permeases.
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Affiliation(s)
- Robert E Asenstorfer
- School of Agriculture, Food and Wine, University of Adelaide, Waite Research Institute, PMB 1, Glen Osmond, South Australia, 5064, Australia
| | - Maarten H Ryder
- School of Agriculture, Food and Wine, University of Adelaide, Waite Research Institute, PMB 1, Glen Osmond, South Australia, 5064, Australia.
| | - Graham P Jones
- School of Agriculture, Food and Wine, University of Adelaide, Waite Research Institute, PMB 1, Glen Osmond, South Australia, 5064, Australia
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Bauman KD, Butler KS, Moore BS, Chekan JR. Genome mining methods to discover bioactive natural products. Nat Prod Rep 2021; 38:2100-2129. [PMID: 34734626 PMCID: PMC8597713 DOI: 10.1039/d1np00032b] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Indexed: 12/22/2022]
Abstract
Covering: 2016 to 2021With genetic information available for hundreds of thousands of organisms in publicly accessible databases, scientists have an unprecedented opportunity to meticulously survey the diversity and inner workings of life. The natural product research community has harnessed this breadth of sequence information to mine microbes, plants, and animals for biosynthetic enzymes capable of producing bioactive compounds. Several orthogonal genome mining strategies have been developed in recent years to target specific chemical features or biological properties of bioactive molecules using biosynthetic, resistance, or transporter proteins. These "biosynthetic hooks" allow researchers to query for biosynthetic gene clusters with a high probability of encoding previously undiscovered, bioactive compounds. This review highlights recent case studies that feature orthogonal approaches that exploit genomic information to specifically discover bioactive natural products and their gene clusters.
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Affiliation(s)
- Katherine D Bauman
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92093, USA.
| | - Keelie S Butler
- Department of Chemistry and Biochemistry, University of North Carolina Greensboro, Greensboro, NC, 27402, USA.
| | - Bradley S Moore
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92093, USA.
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Jonathan R Chekan
- Department of Chemistry and Biochemistry, University of North Carolina Greensboro, Greensboro, NC, 27402, USA.
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Rebuffat S. Ribosomally synthesized peptides, foreground players in microbial interactions: recent developments and unanswered questions. Nat Prod Rep 2021; 39:273-310. [PMID: 34755755 DOI: 10.1039/d1np00052g] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
It is currently well established that multicellular organisms live in tight association with complex communities of microorganisms including a large number of bacteria. These are immersed in complex interaction networks reflecting the relationships established between them and with host organisms; yet, little is known about the molecules and mechanisms involved in these mutual interactions. Ribosomally synthesized peptides, among which bacterial antimicrobial peptides called bacteriocins and microcins have been identified as contributing to host-microbe interplays, are either unmodified or post-translationally modified peptides. This review will unveil current knowledge on these ribosomal peptide-based natural products, their interplay with the host immune system, and their roles in microbial interactions and symbioses. It will include their major structural characteristics and post-translational modifications, the main rules of their maturation pathways, and the principal ecological functions they ensure (communication, signalization, competition), especially in symbiosis, taking select examples in various organisms. Finally, we address unanswered questions and provide a framework for deciphering big issues inspiring future directions in the field.
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Affiliation(s)
- Sylvie Rebuffat
- Laboratory Molecules of Communication and Adaptation of Microorganisms (MCAM, UMR 7245 CNRS-MNHN), National Museum of Natural History (MNHN), National Centre of Scientific Research (CNRS), CP 54, 57 rue Cuvier 75005, Paris, France.
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Sinorhizobium meliloti Functions Required for Resistance to Antimicrobial NCR Peptides and Bacteroid Differentiation. mBio 2021; 12:e0089521. [PMID: 34311575 PMCID: PMC8406287 DOI: 10.1128/mbio.00895-21] [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] [Indexed: 01/01/2023] Open
Abstract
Legumes of the Medicago genus have a symbiotic relationship with the bacterium Sinorhizobium meliloti and develop root nodules housing large numbers of intracellular symbionts. Members of the nodule-specific cysteine-rich peptide (NCR) family induce the endosymbionts into a terminal differentiated state. Individual cationic NCRs are antimicrobial peptides that have the capacity to kill the symbiont, but the nodule cell environment prevents killing. Moreover, the bacterial broad-specificity peptide uptake transporter BacA and exopolysaccharides contribute to protect the endosymbionts against the toxic activity of NCRs. Here, we show that other S. meliloti functions participate in the protection of the endosymbionts; these include an additional broad-specificity peptide uptake transporter encoded by the yejABEF genes and lipopolysaccharide modifications mediated by lpsB and lpxXL, as well as rpoH1, encoding a stress sigma factor. Strains with mutations in these genes show a strain-specific increased sensitivity profile against a panel of NCRs and form nodules in which bacteroid differentiation is affected. The lpsB mutant nodule bacteria do not differentiate, the lpxXL and rpoH1 mutants form some seemingly fully differentiated bacteroids, although most of the nodule bacteria are undifferentiated, while the yejABEF mutants form hypertrophied but nitrogen-fixing bacteroids. The nodule bacteria of all the mutants have a strongly enhanced membrane permeability, which is dependent on the transport of NCRs to the endosymbionts. Our results suggest that S. meliloti relies on a suite of functions, including peptide transporters, the bacterial envelope structures, and stress response regulators, to resist the aggressive assault of NCR peptides in the nodule cells. IMPORTANCE The nitrogen-fixing symbiosis of legumes with rhizobium bacteria has a predominant ecological role in the nitrogen cycle and has the potential to provide the nitrogen required for plant growth in agriculture. The host plants allow the rhizobia to colonize specific symbiotic organs, the nodules, in large numbers in order to produce sufficient reduced nitrogen for the plants' needs. Some legumes, including Medicago spp., produce massively antimicrobial peptides to keep this large bacterial population in check. These peptides, known as NCRs, have the potential to kill the rhizobia, but in nodules, they rather inhibit the division of the bacteria, which maintain a high nitrogen-fixing activity. In this study, we show that the tempering of the antimicrobial activity of the NCR peptides in the Medicago symbiont Sinorhizobium meliloti is multifactorial and requires the YejABEF peptide transporter, the lipopolysaccharide outer membrane, and the stress response regulator RpoH1.
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