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Uchiyama H, Kudo T, Yamaguchi T, Obana N, Watanabe K, Abe K, Miyazaki H, Toyofuku M, Nomura N, Akeda Y, Nakao R. Mucosal adjuvanticity and mucosal booster effect of colibactin-depleted probiotic Escherichia coli membrane vesicles. Hum Vaccin Immunother 2024; 20:2337987. [PMID: 38658133 PMCID: PMC11057659 DOI: 10.1080/21645515.2024.2337987] [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: 11/21/2023] [Accepted: 03/29/2024] [Indexed: 04/26/2024] Open
Abstract
There is a growing interest in development of novel vaccines against respiratory tract infections, due to COVID-19 pandemic. Here, we examined mucosal adjuvanticity and the mucosal booster effect of membrane vesicles (MVs) of a novel probiotic E. coli derivative lacking both flagella and potentially carcinogenic colibactin (ΔflhDΔclbP). ΔflhDΔclbP-derived MVs showed rather strong mucosal adjuvanticity as compared to those of a single flagellar mutant strain (ΔflhD-MVs). In addition, glycoengineered ΔflhDΔclbP-MVs displaying serotype-14 pneumococcal capsular polysaccharide (CPS14+MVs) were well-characterized based on biological and physicochemical parameters. Subcutaneous (SC) and intranasal (IN) booster effects of CPS14+MVs on systemic and mucosal immunity were evaluated in mice that have already been subcutaneously prime-immunized with the same MVs. With a two-dose regimen, an IN boost (SC-IN) elicited stronger IgA responses than homologous prime-boost immunization (SC-SC). With a three-dose regimen, serum IgG levels were comparable among all tested regimens. Homologous immunization (SC-SC-SC) elicited the highest IgM responses among all regimens tested, whereas SC-SC-SC failed to elicit IgA responses in blood and saliva. Furthermore, serum IgA and salivary SIgA levels were increased with an increased number of IN doses administrated. Notably, SC-IN-IN induced not only robust IgG response, but also the highest IgA response in both serum and saliva among the groups. The present findings suggest the potential of a heterologous three-dose administration for building both systemic and mucosal immunity, e.g. an SC-IN-IN vaccine regimen could be beneficial. Another important observation was abundant packaging of colibactin in MVs, suggesting increased applicability of ΔflhDΔclbP-MVs in the context of vaccine safety.
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Affiliation(s)
- Hiroki Uchiyama
- Department of Bacteriology I, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
- Department of Vascular Surgery, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Toshifumi Kudo
- Department of Vascular Surgery, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Takehiro Yamaguchi
- Department of Bacteriology I, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
| | - Nozomu Obana
- Tsukuba Transborder Medical Research Center, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
- Microbiology Research Center for Sustainability, University of Tsukuba, Tsukuba, Japan
| | - Kenji Watanabe
- Department of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Kimihiro Abe
- Department of Bacteriology I, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
- Research Center for Drug and Vaccine Development, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
| | - Hidetaka Miyazaki
- Department of Oculoplastic, Orbital and Lacrimal Surgery, Aichi Medical University, Nagakute, Japan
- Department of Oral and Maxillofacial Surgery, Division of Oral Health Sciences, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Masanori Toyofuku
- Microbiology Research Center for Sustainability, University of Tsukuba, Tsukuba, Japan
| | - Nobuhiko Nomura
- Microbiology Research Center for Sustainability, University of Tsukuba, Tsukuba, Japan
| | - Yukihiro Akeda
- Department of Bacteriology I, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
| | - Ryoma Nakao
- Department of Bacteriology I, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
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2
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Turocy T, Crawford JM. Bacterial small molecule metabolites implicated in gastrointestinal cancer development. Nat Rev Microbiol 2024:10.1038/s41579-024-01103-4. [PMID: 39375475 DOI: 10.1038/s41579-024-01103-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2024] [Indexed: 10/09/2024]
Abstract
Numerous associations have been identified between cancer and the composition and function of the human microbiome. As cancer remains the second leading global cause of mortality, investigating the carcinogenic contributions of microbiome members could advance our understanding of cancer risk and support potential therapeutic interventions. Although fluctuations in bacterial species have been associated with cancer progression, studying their small molecule metabolites offers one avenue to establish support for causal relationships and the molecular mechanisms governing host-microorganism interactions. In this Review, we explore the expanding repertoire of small molecule metabolites and their mechanisms implicated in the risk of developing gastrointestinal cancers.
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Affiliation(s)
- Tayah Turocy
- Department of Chemistry, Yale University, New Haven, CT, USA
- Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT, USA
| | - Jason M Crawford
- Department of Chemistry, Yale University, New Haven, CT, USA.
- Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT, USA.
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA.
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3
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Genotoxins: The Mechanistic Links between Escherichia coli and Colorectal Cancer. Cancers (Basel) 2023; 15:cancers15041152. [PMID: 36831495 PMCID: PMC9954437 DOI: 10.3390/cancers15041152] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/06/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
Emerging evidence indicates bacterial infections contribute to the formation of cancers. Bacterial genotoxins are effectors that cause DNA damage by introducing single- and double-strand DNA breaks in the host cells. The first bacterial genotoxin cytolethal distending toxin (CDT) was a protein identified in 1987 in a pathogenic strain in Escherichia coli (E. coli) isolated from a young patient. The peptide-polyketide genotoxin colibactin is produced by the phylogenetic group B2 of E. coli. Recently, a protein produced by attaching/effacing (A/E) pathogens, including enteropathogenic and enterohemorrhagic E. coli (EPEC and EHEC) and their murine equivalent Citrobacter rodentium (CR), has been reported as a novel protein genotoxin, being injected via the type III secretion system (T3SS) into host cells and harboring direct DNA digestion activity with a catalytic histidine-aspartic acid dyad. These E. coli-produced genotoxins impair host DNA, which results in senescence or apoptosis of the target cells if the damage is beyond repair. Conversely, host cells can survive and proliferate if the genotoxin-induced DNA damage is not severe enough to kill them. The surviving cells may accumulate genomic instability and acquire malignant traits. This review presents the cellular responses of infection with the genotoxins-producing E. coli and discusses the current knowledge of the tumorigenic potential of these toxins.
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Velilla JA, Kenney GE, Gaudet R. Structure and function of prodrug-activating peptidases. Biochimie 2023; 205:124-135. [PMID: 36803695 PMCID: PMC10030199 DOI: 10.1016/j.biochi.2022.07.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 07/25/2022] [Indexed: 11/11/2022]
Abstract
Bacteria protect themselves from the toxicity of antimicrobial metabolites they produce through several strategies. In one resistance mechanism, bacteria assemble a non-toxic precursor on an N-acyl-d-asparagine prodrug motif in the cytoplasm, then export it to the periplasm where a dedicated d-amino peptidase hydrolyzes the prodrug motif. These prodrug-activating peptidases contain an N-terminal periplasmic S12 hydrolase domain and C-terminal transmembrane domains (TMDs) of varying lengths: type I peptidases contain three transmembrane helices, and type II peptidases have an additional C-terminal ABC half-transporter. We review studies which have addressed the role of the TMD in function, the substrate specificity, and the biological assembly of ClbP, the type I peptidase that activates colibactin. We use modeling and sequence analyses to extend those insights to other prodrug-activating peptidases and ClbP-like proteins which are not part of prodrug resistance gene clusters. These ClbP-like proteins may play roles in the biosynthesis or degradation of other natural products, including antibiotics, may adopt different TMD folds, and have different substrate specificity compared to prodrug-activating homologs. Finally, we review the data supporting the long-standing hypothesis that ClbP interacts with transporters in the cell and that this association is important for the export of other natural products. Future investigations of this hypothesis as well as of the structure and function of type II peptidases will provide a complete account of the role of prodrug-activating peptidases in the activation and secretion of bacterial toxins.
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Affiliation(s)
- José A Velilla
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford St, Cambridge, MA, 02138, USA
| | - Grace E Kenney
- Department of Chemistry and Chemical Biology, Harvard University, 38 Oxford St, Cambridge, MA, USA
| | - Rachelle Gaudet
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford St, Cambridge, MA, 02138, USA.
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5
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Velilla JA, Volpe MR, Kenney GE, Walsh RM, Balskus EP, Gaudet R. Structural basis of colibactin activation by the ClbP peptidase. Nat Chem Biol 2023; 19:151-158. [PMID: 36253550 PMCID: PMC9889268 DOI: 10.1038/s41589-022-01142-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 08/12/2022] [Indexed: 02/04/2023]
Abstract
Colibactin, a DNA cross-linking agent produced by gut bacteria, is implicated in colorectal cancer. Its biosynthesis uses a prodrug resistance mechanism: a non-toxic precursor assembled in the cytoplasm is activated after export to the periplasm. This activation is mediated by ClbP, an inner-membrane peptidase with an N-terminal periplasmic catalytic domain and a C-terminal three-helix transmembrane domain. Although the transmembrane domain is required for colibactin activation, its role in catalysis is unclear. Our structure of full-length ClbP bound to a product analog reveals an interdomain interface important for substrate binding and enzyme stability and interactions that explain the selectivity of ClbP for the N-acyl-D-asparagine prodrug motif. Based on structural and biochemical evidence, we propose that ClbP dimerizes to form an extended substrate-binding site that can accommodate a pseudodimeric precolibactin with its two terminal prodrug motifs in the two ClbP active sites, thus enabling the coordinated activation of both electrophilic warheads.
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Affiliation(s)
- José A Velilla
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Matthew R Volpe
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Grace E Kenney
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Richard M Walsh
- Harvard Cryo-EM Center for Structural Biology, Harvard Medical School, Boston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Rachelle Gaudet
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
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Pandey H, Tang DWT, Wong SH, Lal D. Gut Microbiota in Colorectal Cancer: Biological Role and Therapeutic Opportunities. Cancers (Basel) 2023; 15:cancers15030866. [PMID: 36765824 PMCID: PMC9913759 DOI: 10.3390/cancers15030866] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/23/2023] [Accepted: 01/24/2023] [Indexed: 02/03/2023] Open
Abstract
Colorectal cancer (CRC) is the second-leading cause of cancer-related deaths worldwide. While CRC is thought to be an interplay between genetic and environmental factors, several lines of evidence suggest the involvement of gut microbiota in promoting inflammation and tumor progression. Gut microbiota refer to the ~40 trillion microorganisms that inhabit the human gut. Advances in next-generation sequencing technologies and metagenomics have provided new insights into the gut microbial ecology and have helped in linking gut microbiota to CRC. Many studies carried out in humans and animal models have emphasized the role of certain gut bacteria, such as Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, and colibactin-producing Escherichia coli, in the onset and progression of CRC. Metagenomic studies have opened up new avenues for the application of gut microbiota in the diagnosis, prevention, and treatment of CRC. This review article summarizes the role of gut microbiota in CRC development and its use as a biomarker to predict the disease and its potential therapeutic applications.
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Affiliation(s)
- Himani Pandey
- Redcliffe Labs, Electronic City, Noida 201301, India
| | - Daryl W. T. Tang
- School of Biological Sciences, Nanyang Technological University, Singapore 308232, Singapore
| | - Sunny H. Wong
- Centre for Microbiome Medicine, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
- Correspondence: (S.H.W.); (D.L.)
| | - Devi Lal
- Department of Zoology, Ramjas College, University of Delhi, Delhi 110007, India
- Correspondence: (S.H.W.); (D.L.)
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7
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clbP Gene, a Potential New Member of the β-Lactamase Family. Int J Mol Sci 2022; 23:ijms232415642. [PMID: 36555283 PMCID: PMC9778894 DOI: 10.3390/ijms232415642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 12/05/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
The colibactin island (pks) of Escherichia coli formed by 19 genes (55-Kb), encodes non-ribosomal peptide (NRP) and polyketide (PK) synthases, which allow the synthesis of colibactin, a suspected hybrid PK-NRP compound that causes damage to DNA in eukaryotic cells. The clbP, an unusual essential gene, is found in the operon structure with the clbS gene in the pks-encoded machinery. Interestingly, the clbP gene has been annotated as a β-lactamase but no previous study has reported its β-lactamase characteristics. In this study, we (i) investigated the β-lactamase properties of the clbP gene in silico by analysing its phylogenetic relationship with bacterial β-lactamase and peptidase enzymes, (ii) compared its three-dimensional (3D) protein structure with those of bacterial β-lactamase proteins using the Phyr2 database and PyMOL software, and (iii) evaluated in vitro its putative enzymatic activities, including β-lactamase, nuclease, and ribonuclease using protein expression and purification from an E. coli BL21 strain. In this study, we reveal a structural configuration of toxin/antitoxin systems in this island. Thus, similar to the toxin/antitoxin systems, the role of the clbP gene within the pks-island gene group appears as an antitoxin, insofar as it is responsible for the activation of the toxin, which is colibactin. In silico, our analyses revealed that ClbP belonged to the superfamily of β-lactamase, class C. Furthermore, in vitro we were unable to demonstrate its β-lactamase activity, likely due to the fact that the clbP gene requires co-expression with other genes, such as the genes present in the pks-island (19 genes). More research is needed to better understand its actions, particularly with regards to antibiotics, and to discover whether it has any additional functions due to the importance of this gene and its toxicity.
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8
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Mousa WK. The microbiome-product colibactin hits unique cellular targets mediating host–microbe interaction. Front Pharmacol 2022; 13:958012. [PMID: 36172175 PMCID: PMC9510844 DOI: 10.3389/fphar.2022.958012] [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: 05/31/2022] [Accepted: 08/18/2022] [Indexed: 11/20/2022] Open
Abstract
The human microbiota produces molecules that are evolved to interact with the diverse cellular machinery of both the host and microbes, mediating health and diseases. One of the most puzzling microbiome molecules is colibactin, a genotoxin encoded in some commensal and extraintestinal microbes and is implicated in initiating colorectal cancer. The colibactin cluster was discovered more than 15 years ago, and most of the research studies have been focused on revealing the biosynthesis and precise structure of the cryptic encoded molecule(s) and the mechanism of carcinogenesis. In 2022, the Balskus group revealed that colibactin not only hits targets in the eukaryotic cell machinery but also in the prokaryotic cell. To that end, colibactin crosslinks the DNA resulting in activation of the SOS signaling pathway, leading to prophage induction from bacterial lysogens and modulation of virulence genes in pathogenic species. These unique activities of colibactin highlight its ecological role in shaping gut microbial communities and further consequences that impact human health. This review dives in-depth into the molecular mechanisms underpinning colibactin cellular targets in eukaryotic and prokaryotic cells, aiming to understand the fine details of the role of secreted microbiome chemistry in mediating host–microbe and microbe–microbe interactions. This understanding translates into a better realization of microbiome potential and how this could be advanced to future microbiome-based therapeutics or diagnostic biomarkers.
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Affiliation(s)
- Walaa K. Mousa
- College of Pharmacy, Al Ain University, Abu Dhabi, United Arab Emirates
- College of Pharmacy, Mansoura University, Mansoura, Egypt
- *Correspondence: Walaa K. Mousa,
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9
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Abstract
Bacterial genotoxins are peptide or protein virulence factors produced by several pathogens, which make single-strand breaks (SSBs) and/or double-strand DNA breaks (DSBs) in the target host cells. If host DNA inflictions are not resolved on time, host cell apoptosis, cell senescence, and/or even bacterial pathogen-related cancer may occur. Two multi-protein AB toxins, cytolethal distending toxin (CDT) produced by over 30 bacterial pathogens and typhoid toxin from Salmonella Typhi, as well as small polyketide-peptides named colibactin that causes the DNA interstrand cross-linking and subsequent DSBs is the most well-characterized bacterial genotoxins. Using these three examples, this review discusses the mechanisms by which these toxins deliver themselves into the nucleus of the target host cells and exert their genotoxic functions at the structural and functional levels.
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Affiliation(s)
- Liaoqi Du
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Jeongmin Song
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
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10
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Hirayama Y, Sato M, Watanabe K. Advancing the Biosynthetic and Chemical Understanding of the Carcinogenic Risk Factor Colibactin and Its Producers. Biochemistry 2022; 61:2782-2790. [PMID: 35723977 DOI: 10.1021/acs.biochem.2c00229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recent studies have shown that Escherichia coli often carries a biosynthetic gene cluster termed either the pks island or the clb cluster that allows the production of a genotoxic polyketide-nonribosomal peptide hybrid secondary metabolite called colibactin. While the gene cluster is not always expressed, when the strain that resides in the colon produces the genotoxin, it is suspected to become a risk factor for colorectal cancer. Therefore, there is great interest in devising a simple method for the detection of colibactin-producing strains and understanding the detailed mechanism of how colibactin can induce oncogenesis, to develop convenient early screening methods and possible preventive treatments against colorectal cancer. However, the definitive chemical structure of colibactin remained elusive until recently, primarily due to its low yield and instability. In this review, we will briefly trace the recent studies leading to the identification of the structure of the active intact colibactin. Subsequently, we will describe our efforts toward developing simple methods for detecting colibactin producers, where we established methods based on the conventional polymerase chain reaction and loop-mediated isothermal amplification techniques. We also designed an activity-based fluorogenic probe for detecting colibactin-producing strains that could discern colibactin production levels among the E. coli strains screened. Using the probe, we isolated a wild-type high-colibactin-producing strain from a colorectal cancer tissue sample that proved to be valuable in identifying new colibactin metabolites and structurally characterizing them by nuclear magnetic resonance. Those techniques and the chemical insight they furnished should improve the fight against colorectal cancer.
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Affiliation(s)
- Yuichiro Hirayama
- Department of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Tobetsu 061-0293, Japan
| | - Michio Sato
- Department of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Kenji Watanabe
- Department of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
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11
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Cascone A, Lalowski M, Lindholm D, Eriksson O. Unveiling the Function of the Mitochondrial Filament-Forming Protein LACTB in Lipid Metabolism and Cancer. Cells 2022; 11:cells11101703. [PMID: 35626737 PMCID: PMC9139886 DOI: 10.3390/cells11101703] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 02/04/2023] Open
Abstract
LACTB is a relatively unknown mitochondrial protein structurally related to the bacterial penicillin-binding and beta-lactamase superfamily of serine proteases. LACTB has recently gained an increased interest due to its potential role in lipid metabolism and tumorigenesis. To date, around ninety studies pertaining to LACTB have been published, but the exact biochemical and cell biological function of LACTB still remain elusive. In this review, we summarise the current knowledge about LACTB with particular attention to the implications of the recently published study on the cryo-electron microscopy structure of the filamentous form of LACTB. From this and other studies, several specific properties of LACTB emerge, suggesting that the protein has distinct functions in different physiological settings. Resolving these issues by further research may ultimately lead to a unified model of LACTB’s function in cell and organismal physiology. LACTB is the only member of its protein family in higher animals and LACTB may, therefore, be of particular interest for future drug targeting initiatives.
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Affiliation(s)
- Annunziata Cascone
- Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, FIN-00014 Helsinki, Finland; (A.C.); (D.L.)
| | - Maciej Lalowski
- HiLIFE, Meilahti Clinical Proteomics Core Facility, Faculty of Medicine, University of Helsinki, FIN-00014 Helsinki, Finland;
| | - Dan Lindholm
- Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, FIN-00014 Helsinki, Finland; (A.C.); (D.L.)
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2, Tukholmankatu 8, FIN-00290 Helsinki, Finland
| | - Ove Eriksson
- Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, FIN-00014 Helsinki, Finland; (A.C.); (D.L.)
- Correspondence:
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12
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Tang JW, Liu X, Ye W, Li ZR, Qian PY. Biosynthesis and bioactivities of microbial genotoxin colibactins. Nat Prod Rep 2022; 39:991-1014. [PMID: 35288725 DOI: 10.1039/d1np00050k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Covering: up to 2021Colibactin(s), a group of secondary metabolites produced by the pks island (clb cluster) of Escherichia coli, shows genotoxicity relevant to colorectal cancer and thus significantly affects human health. Over the last 15 years, substantial efforts have been exerted to reveal the molecular structure of colibactin, but progress is slow owing to its instability, low titer, and elusive and complex biosynthesis logic. Fortunately, benefiting from the discovery of the prodrug mechanism, over 40 precursors of colibactin have been reported. Some key biosynthesis genes located on the pks island have also been characterised. Using an integrated bioinformatics, metabolomics, and chemical synthesis approach, researchers have recently characterised the structure and possible biosynthesis processes of colibactin, thereby providing new insights into the unique biosynthesis logic and the underlying mechanism of the biological activity of colibactin. Early developments in the study of colibactin have been summarised in several previous reviews covering various study periods, whereas the two most recent reviews have focused primarily on the chemical synthesis of colibactin. The present review aims to provide an update on the biosynthesis and bioactivities of colibactin.
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Affiliation(s)
- Jian-Wei Tang
- Department of Ocean Science, Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China. .,Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China
| | - Xin Liu
- Department of Ocean Science, Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China. .,Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China
| | - Wei Ye
- Department of Ocean Science, Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China. .,State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Zhong-Rui Li
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Pei-Yuan Qian
- Department of Ocean Science, Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China. .,Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China
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13
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Detection of pks Island mRNAs Using Toehold Sensors in Escherichia coli. Life (Basel) 2021; 11:life11111280. [PMID: 34833155 PMCID: PMC8625898 DOI: 10.3390/life11111280] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/15/2021] [Accepted: 11/18/2021] [Indexed: 12/14/2022] Open
Abstract
Synthetic biologists have applied biomolecular engineering approaches toward the goal of novel biological devices and have shown progress in diverse areas of medicine and biotechnology. Especially promising is the application of synthetic biological devices towards a novel class of molecular diagnostics. As an example, a de-novo-designed riboregulator called toehold switch, with its programmability and compatibility with field-deployable devices showed promising in vitro applications for viral RNA detection such as Zika and Corona viruses. However, the in vivo application of high-performance RNA sensors remains challenging due to the secondary structure of long mRNA species. Here, we introduced ‘Helper RNAs’ that can enhance the functionality of toehold switch sensors by mitigating the effect of secondary structures around a target site. By employing the helper RNAs, previously reported mCherry mRNA sensor showed improved fold-changes in vivo. To further generalize the Helper RNA approaches, we employed automatic design pipeline for toehold sensors that target the essential genes within the pks island, an important target of biomedical research in connection with colorectal cancer. The toehold switch sensors showed fold-changes upon the expression of full-length mRNAs that apparently depended sensitively on the identity of the gene as well as the predicted local structure within the target region of the mRNA. Still, the helper RNAs could improve the performance of toehold switch sensors in many instances, with up to 10-fold improvement over no helper cases. These results suggest that the helper RNA approaches can further assist the design of functional RNA devices in vivo with the aid of the streamlined automatic design software developed here. Further, our solutions for screening and stabilizing single-stranded region of mRNA may find use in other in vivo mRNA-sensing applications such as cas13 crRNA design, transcriptome engineering, and trans-cleaving ribozymes.
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14
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Zhou T, Hirayama Y, Tsunematsu Y, Suzuki N, Tanaka S, Uchiyama N, Goda Y, Yoshikawa Y, Iwashita Y, Sato M, Miyoshi N, Mutoh M, Ishikawa H, Sugimura H, Wakabayashi K, Watanabe K. Isolation of New Colibactin Metabolites from Wild-Type Escherichia coli and In Situ Trapping of a Mature Colibactin Derivative. J Am Chem Soc 2021; 143:5526-5533. [PMID: 33787233 DOI: 10.1021/jacs.1c01495] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Colibactin is a polyketide-nonribosomal peptide hybrid secondary metabolite that can form interstrand cross-links in double-stranded DNA. Colibactin-producing Escherichia coli has also been linked to colorectal oncogenesis. Thus, there is a strong interest in understanding the role colibactin may play in oncogenesis. Here, using the high-colibactin-producing wild-type E. coli strain we isolated from a clinical sample with the activity-based fluorescent probe we developed earlier, we were able to identify colibactin 770, which was recently identified and proposed as the complete form of colibactin, along with colibactin 788, 406, 416, 420, and 430 derived from colibactin 770 through structural rearrangements and solvolysis. Furthermore, we were able to trap the degrading mature colibactin species by converting the diketone moiety into quinoxaline in situ in the crude culture extract to form colibactin 860 at milligram scale. This allowed us to determine the stereochemically complex structure of the rearranged form of an intact colibactin, colibactin 788, in detail. Furthermore, our study suggested that we were capturing only a few percent of the actual colibactin produced by the microbe, providing a crude quantitative insight into the inherent instability of this compound. Through the structural assignment of colibactins and their degradative products by the combination of LC-HRMS and NMR spectroscopies, we were able to elucidate further the fate of inherently unstable colibactin, which could help acquire a more complete picture of colibactin metabolism and identify key DNA adducts and biomarkers for diagnosing colorectal cancer.
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Affiliation(s)
- Tao Zhou
- Adenoprevent Co., Ltd., Shizuoka 422-8526, Japan
- Department of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Yuichiro Hirayama
- Department of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Yuta Tsunematsu
- Department of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Nanami Suzuki
- Department of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Seiji Tanaka
- National Institute of Health Sciences, Kawasaki 210-9501, Japan
| | - Nahoko Uchiyama
- National Institute of Health Sciences, Kawasaki 210-9501, Japan
| | - Yukihiro Goda
- National Institute of Health Sciences, Kawasaki 210-9501, Japan
| | - Yuko Yoshikawa
- School of Veterinary Medicine, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan
| | - Yuji Iwashita
- Department of Tumor Pathology, Hamamatsu University School of Medicine, Shizuoka 431-3192, Japan
| | - Michio Sato
- Department of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Noriyuki Miyoshi
- Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Michihiro Mutoh
- Department of Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Hideki Ishikawa
- Department of Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Haruhiko Sugimura
- Department of Tumor Pathology, Hamamatsu University School of Medicine, Shizuoka 431-3192, Japan
| | - Keiji Wakabayashi
- Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Kenji Watanabe
- Adenoprevent Co., Ltd., Shizuoka 422-8526, Japan
- Department of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
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15
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Williams PC, Wernke KM, Tirla A, Herzon SB. Employing chemical synthesis to study the structure and function of colibactin, a "dark matter" metabolite. Nat Prod Rep 2020; 37:1532-1548. [PMID: 33174565 PMCID: PMC7700718 DOI: 10.1039/d0np00072h] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Covering: 2015 to 2020 The field of natural products is dominated by a discovery paradigm that follows the sequence: isolation, structure elucidation, chemical synthesis, and then elucidation of mechanism of action and structure-activity relationships. Although this discovery paradigm has proven successful in the past, researchers have amassed enough evidence to conclude that the vast majority of nature's secondary metabolites - biosynthetic "dark matter" - cannot be identified and studied by this approach. Many biosynthetic gene clusters (BGCs) are expressed at low levels, or not at all, and in some instances a molecule's instability to fermentation or isolation prevents detection entirely. Here, we discuss an alternative approach to natural product identification that addresses these challenges by enlisting synthetic chemistry to prepare putative natural product fragments and structures as guided by biosynthetic insight. We demonstrate the utility of this approach through our structure elucidation of colibactin, an unisolable genotoxin produced by pathogenic bacteria in the human gut.
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Affiliation(s)
- Peyton C Williams
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, USA.
| | - Kevin M Wernke
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, USA.
| | - Alina Tirla
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, USA.
| | - Seth B Herzon
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, USA. and Department of Pharmacology, Yale School of Medicine, New Haven, Connecticut 06520, USA
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16
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Lopez LR, Bleich RM, Arthur JC. Microbiota Effects on Carcinogenesis: Initiation, Promotion, and Progression. Annu Rev Med 2020; 72:243-261. [PMID: 33052764 DOI: 10.1146/annurev-med-080719-091604] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Carcinogenesis is a multistep process by which normal cells acquire genetic and epigenetic changes that result in cancer. In combination with host genetic susceptibility and environmental exposures, a prominent procarcinogenic role for the microbiota has recently emerged. In colorectal cancer (CRC), three nefarious microbes have been consistently linked to cancer development: (a) Colibactin-producing Escherichia coli initiates carcinogenic DNA damage, (b) enterotoxigenic Bacteroides fragilis promotes tumorigenesis via toxin-induced cell proliferation and tumor-promoting inflammation, and (c) Fusobacterium nucleatum enhances CRC progression through two adhesins, Fap2 and FadA, that promote proliferation and antitumor immune evasion and may contribute to metastases. Herein, we use these three prominent microbes to discuss the experimental evidence linking microbial activities to carcinogenesis and the specific mechanisms driving this stepwise process. Precisely defining mechanisms by which the microbiota impacts carcinogenesis at each stage is essential for developing microbiota-targeted strategies for the diagnosis, prognosis, and treatment of cancer.
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Affiliation(s)
- Lacey R Lopez
- Department of Microbiology and Immunology, The University of North Carolina, Chapel Hill, North Carolina 27599, USA; ,
| | - Rachel M Bleich
- Department of Biology, Appalachian State University, Boone, North Carolina 28608, USA;
| | - Janelle C Arthur
- Department of Microbiology and Immunology, The University of North Carolina, Chapel Hill, North Carolina 27599, USA; , .,Lineberger Comprehensive Cancer Center, The University of North Carolina, Chapel Hill, North Carolina 27599, USA.,Center for Gastrointestinal Biology and Disease, The University of North Carolina, Chapel Hill, North Carolina 27599, USA
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17
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Abstract
The nonribosomal peptide/polyketide hybrid colibactin can be considered a bacterial virulence factor involved in extraintestinal infection and also a procarcinogen. Nevertheless, and despite its genotoxic effect, colibactin expression can also inhibit bacterial or tumor growth and correlates with probiotic anti-inflammatory and analgesic properties. Although the biological function of this natural compound has been studied extensively, our understanding of the regulation of colibactin expression is still far from complete. We investigated in detail the role of regulatory elements involved in colibactin expression and in the growth conditions that promote colibactin expression. In this way, our data shed light on the regulatory mechanisms involved in colibactin expression and may support the expression and purification of this interesting nonribosomal peptide/polyketide hybrid for further molecular characterization. Colibactin is a nonribosomal peptide/polyketide hybrid natural product expressed by different members of the Enterobacteriaceae which can be correlated with induction of DNA double-strand breaks and interference with cell cycle progression in eukaryotes. Regulatory features of colibactin expression are only incompletely understood. We used Escherichia coli strain M1/5 as a model to investigate regulation of expression of the colibactin determinant at the transcriptional level and to characterize regulatory elements located within the colibactin pathogenicity island itself. We measured clbR transcription in vitro and observed that cultivation in defined minimal media led to increased colibactin expression relative to rich media. Transcription of clbR directly responds to iron availability. We also characterized structural DNA elements inside the colibactin determinant involved in ClbR-dependent regulation, i.e., ClbR binding sites and a variable number of tandem repeats located upstream of clbR. We investigated the impact of clbR overexpression or deletion at the transcriptome and proteome levels. Moreover, we compared global gene regulation under these conditions with that occurring upon overexpression or deletion of clbQ, which affects the flux of colibactin production. Combining the results of the transcriptome and proteome analyses with indirect measurements of colibactin levels by cell culture assays and an approximate quantification of colibactin via the second product of colibactin cleavage from precolibactin, N-myristoyl-d-asparagine, we demonstrate that the variable number of tandem repeats plays a significant regulatory role in colibactin expression. We identify ClbR as the only transcriptional activator known so far that is specific and essential for efficient regulation of colibactin production. IMPORTANCE The nonribosomal peptide/polyketide hybrid colibactin can be considered a bacterial virulence factor involved in extraintestinal infection and also a procarcinogen. Nevertheless, and despite its genotoxic effect, colibactin expression can also inhibit bacterial or tumor growth and correlates with probiotic anti-inflammatory and analgesic properties. Although the biological function of this natural compound has been studied extensively, our understanding of the regulation of colibactin expression is still far from complete. We investigated in detail the role of regulatory elements involved in colibactin expression and in the growth conditions that promote colibactin expression. In this way, our data shed light on the regulatory mechanisms involved in colibactin expression and may support the expression and purification of this interesting nonribosomal peptide/polyketide hybrid for further molecular characterization.
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18
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Abstract
The clb gene cluster encodes the biosynthesis of metabolites known as precolibactins and colibactins. The clb pathway is found in gut commensal E. coli, and clb metabolites are thought to initiate colorectal cancer via DNA cross-linking. Here we report confirmation of the structural assignment of the complex clb product precolibactin 886 via a biomimetic synthetic pathway. We show that a α-ketoimine linear precursor undergoes spontaneous cyclization to precolibactin 886 upon HPLC purification. Studies of this α-ketoimine and the related α-dicarbonyl revealed that these compounds are unexpectedly susceptible to nucleophilic cleavage under mildly basic conditions. This cleavage pathway forms other known clb metabolites or biosynthetic intermediates and explains the difficulties in isolating fully mature biosynthetic products. This cleavage also accounts for a recently identified colibactin–adenine adduct. The colibactin peptidase ClbP deacylates synthetic precolibactin 886 to form a non-genotoxic pyridone, suggesting precolibactin 886 lies off-path of the major biosynthetic route.
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19
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Massip C, Branchu P, Bossuet-Greif N, Chagneau CV, Gaillard D, Martin P, Boury M, Sécher T, Dubois D, Nougayrède JP, Oswald E. Deciphering the interplay between the genotoxic and probiotic activities of Escherichia coli Nissle 1917. PLoS Pathog 2019; 15:e1008029. [PMID: 31545853 PMCID: PMC6776366 DOI: 10.1371/journal.ppat.1008029] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 10/03/2019] [Accepted: 08/14/2019] [Indexed: 12/28/2022] Open
Abstract
Although Escherichia coli Nissle 1917 (EcN) has been used therapeutically for over a century, the determinants of its probiotic properties remain elusive. EcN produces two siderophore-microcins (Mcc) responsible for an antagonistic activity against other Enterobacteriaceae. EcN also synthesizes the genotoxin colibactin encoded by the pks island. Colibactin is a virulence factor and a putative pro-carcinogenic compound. Therefore, we aimed to decouple the antagonistic activity of EcN from its genotoxic activity. We demonstrated that the pks-encoded ClbP, the peptidase that activates colibactin, is required for the antagonistic activity of EcN. The analysis of a series of ClbP mutants revealed that this activity is linked to the transmembrane helices of ClbP and not the periplasmic peptidase domain, indicating the transmembrane domain is involved in some aspect of Mcc biosynthesis or secretion. A single amino acid substitution in ClbP inactivates the genotoxic activity but maintains the antagonistic activity. In an in vivo salmonellosis model, this point mutant reduced the clinical signs and the fecal shedding of Salmonella similarly to the wild type strain, whereas the clbP deletion mutant could neither protect nor outcompete the pathogen. The ClbP-dependent antibacterial effect was also observed in vitro with other E. coli strains that carry both a truncated form of the Mcc gene cluster and the pks island. In such strains, siderophore-Mcc synthesis also required the glucosyltransferase IroB involved in salmochelin production. This interplay between colibactin, salmochelin, and siderophore-Mcc biosynthetic pathways suggests that these genomic islands were co-selected and played a role in the evolution of E. coli from phylogroup B2. This co-evolution observed in EcN illustrates the fine margin between pathogenicity and probiotic activity, and the need to address both the effectiveness and safety of probiotics. Decoupling the antagonistic from the genotoxic activity by specifically inactivating ClbP peptidase domain opens the way to the safe use of EcN.
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Affiliation(s)
- Clémence Massip
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
- CHU Toulouse, Hôpital Purpan, Service de Bactériologie-Hygiène, Toulouse, France
| | - Priscilla Branchu
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | | | | | - Déborah Gaillard
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Patricia Martin
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Michèle Boury
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Thomas Sécher
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Damien Dubois
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
- CHU Toulouse, Hôpital Purpan, Service de Bactériologie-Hygiène, Toulouse, France
| | | | - Eric Oswald
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
- CHU Toulouse, Hôpital Purpan, Service de Bactériologie-Hygiène, Toulouse, France
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20
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Xue M, Kim CS, Healy AR, Wernke KM, Wang Z, Frischling MC, Shine EE, Wang W, Herzon SB, Crawford JM. Structure elucidation of colibactin and its DNA cross-links. Science 2019; 365:science.aax2685. [PMID: 31395743 DOI: 10.1126/science.aax2685] [Citation(s) in RCA: 142] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 07/24/2019] [Indexed: 12/18/2022]
Abstract
Colibactin is a complex secondary metabolite produced by some genotoxic gut Escherichia coli strains. The presence of colibactin-producing bacteria correlates with the frequency and severity of colorectal cancer in humans. However, because colibactin has not been isolated or structurally characterized, studying the physiological effects of colibactin-producing bacteria in the human gut has been difficult. We used a combination of genetics, isotope labeling, tandem mass spectrometry, and chemical synthesis to deduce the structure of colibactin. Our structural assignment accounts for all known biosynthetic and cell biology data and suggests roles for the final unaccounted enzymes in the colibactin gene cluster.
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Affiliation(s)
- Mengzhao Xue
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - Chung Sub Kim
- Department of Chemistry, Yale University, New Haven, CT 06520, USA.,Chemical Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Alan R Healy
- Department of Chemistry, Yale University, New Haven, CT 06520, USA.,Chemical Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Kevin M Wernke
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - Zhixun Wang
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | | | - Emilee E Shine
- Chemical Biology Institute, Yale University, West Haven, CT 06516, USA.,Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536, USA
| | - Weiwei Wang
- Department of Molecular Biophysics and Biochemistry, Yale School of Medicine, New Haven, CT 06520, USA.,W. M. Keck Biotechnology Resource Laboratory, Yale School of Medicine, New Haven, CT 06510, USA
| | - Seth B Herzon
- Department of Chemistry, Yale University, New Haven, CT 06520, USA. .,Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Jason M Crawford
- Department of Chemistry, Yale University, New Haven, CT 06520, USA. .,Chemical Biology Institute, Yale University, West Haven, CT 06516, USA.,Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536, USA
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21
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Dalal V, Kumar P, Rakhaminov G, Qamar A, Fan X, Hunter H, Tomar S, Golemi-Kotra D, Kumar P. Repurposing an Ancient Protein Core Structure: Structural Studies on FmtA, a Novel Esterase of Staphylococcus aureus. J Mol Biol 2019; 431:3107-3123. [DOI: 10.1016/j.jmb.2019.06.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 06/15/2019] [Accepted: 06/18/2019] [Indexed: 11/28/2022]
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22
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Volpe MR, Wilson MR, Brotherton CA, Winter ES, Johnson SE, Balskus EP. In Vitro Characterization of the Colibactin-Activating Peptidase ClbP Enables Development of a Fluorogenic Activity Probe. ACS Chem Biol 2019; 14:1097-1101. [PMID: 31059217 DOI: 10.1021/acschembio.9b00069] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The gut bacterial genotoxin colibactin is linked to the development of colorectal cancer. In the final stages of colibactin's biosynthesis, an inactive precursor (precolibactin) undergoes proteolytic cleavage by ClbP, an unusual inner-membrane-bound periplasmic peptidase, to generate the active genotoxin. This enzyme presents an opportunity to monitor and modulate colibactin biosynthesis, but its active form has not been studied in vitro and limited tools exist to measure its activity. Here, we describe the in vitro biochemical characterization of catalytically active, full-length ClbP. We elucidate its substrate preferences and use this information to develop a fluorogenic activity probe. This tool will enable the discovery of ClbP inhibitors and streamline identification of colibactin-producing bacteria.
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Affiliation(s)
- Matthew R. Volpe
- Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Matthew R. Wilson
- Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Carolyn A. Brotherton
- Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Ethan S. Winter
- Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Sheila E. Johnson
- Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Emily P. Balskus
- Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
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23
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Hirayama Y, Tsunematsu Y, Yoshikawa Y, Tamafune R, Matsuzaki N, Iwashita Y, Ohnishi I, Tanioka F, Sato M, Miyoshi N, Mutoh M, Ishikawa H, Sugimura H, Wakabayashi K, Watanabe K. Activity-Based Probe for Screening of High-Colibactin Producers from Clinical Samples. Org Lett 2019; 21:4490-4494. [PMID: 31192617 DOI: 10.1021/acs.orglett.9b01345] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
While high-colibactin-producing Escherichia coli is thought to be associated with colorectal oncogenesis, this study is complicated part due to an inability to isolate colibactin adequately. Here, we created fluorescent probes activated by ClbP, the colibactin-maturing peptidase, to identify high-colibactin-producing strains. Our probe served as a valuable clinical diagnostic tool that allowed simple high-throughput diagnostic screening of clinical samples. Furthermore, the probe also allowed identification of high-colibactin producers that would help advance our understanding of colibactin biosynthesis.
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Affiliation(s)
- Yuichiro Hirayama
- Department of Pharmaceutical Sciences , University of Shizuoka , Shizuoka 422-8526 , Japan
| | - Yuta Tsunematsu
- Department of Pharmaceutical Sciences , University of Shizuoka , Shizuoka 422-8526 , Japan
| | - Yuko Yoshikawa
- School of Veterinary Medicine, Faculty of Veterinary Science , Nippon Veterinary and Life Science University , Tokyo 180-8602 , Japan
| | - Ryota Tamafune
- Department of Pharmaceutical Sciences , University of Shizuoka , Shizuoka 422-8526 , Japan
| | - Nobuo Matsuzaki
- Department of Pharmaceutical Sciences , University of Shizuoka , Shizuoka 422-8526 , Japan
| | - Yuji Iwashita
- Department of Tumor Pathology , Hamamatsu University School of Medicine , Shizuoka 431-3192 , Japan
| | - Ippei Ohnishi
- Division of Pathology , Iwata City Hospital , Iwata 438-8550 , Japan
| | - Fumihiko Tanioka
- Division of Pathology , Iwata City Hospital , Iwata 438-8550 , Japan
| | - Michio Sato
- Department of Pharmaceutical Sciences , University of Shizuoka , Shizuoka 422-8526 , Japan
| | - Noriyuki Miyoshi
- Graduate School of Nutritional and Environmental Sciences , University of Shizuoka , Shizuoka 422-8526 , Japan
| | - Michihiro Mutoh
- Epidemiology and Prevention Division, Center for Public Health Sciences , National Cancer Center , Tokyo 104-0045 , Japan
| | - Hideki Ishikawa
- Department of Molecular-Targeting Cancer Prevention , Kyoto Prefectural University of Medicine , Kyoto 602-8566 , Japan
| | - Haruhiko Sugimura
- Department of Tumor Pathology , Hamamatsu University School of Medicine , Shizuoka 431-3192 , Japan
| | - Keiji Wakabayashi
- Graduate Division of Nutritional and Environmental Sciences , University of Shizuoka , Shizuoka 422-8526 , Japan
| | - Kenji Watanabe
- Department of Pharmaceutical Sciences , University of Shizuoka , Shizuoka 422-8526 , Japan
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24
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McErlean M, Overbay J, Van Lanen S. Refining and expanding nonribosomal peptide synthetase function and mechanism. J Ind Microbiol Biotechnol 2019; 46:493-513. [PMID: 30673909 PMCID: PMC6460464 DOI: 10.1007/s10295-018-02130-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 12/20/2018] [Indexed: 12/14/2022]
Abstract
Nonribosomal peptide synthetases (NRPSs) are involved in the biosynthesis of numerous peptide and peptide-like natural products that have been exploited in medicine, agriculture, and biotechnology, among other fields. As a consequence, there have been considerable efforts aimed at understanding how NRPSs orchestrate the assembly of these natural products. This review highlights several recent examples that continue to expand upon the fundamental knowledge of NRPS mechanism and includes (1) the discovery of new NRPS substrates and the mechanism by which these sometimes structurally complex substrates are made, (2) the characterization of new NRPS activities and domains that function during the process of peptide assembly, and (3) the various catalytic strategies that are utilized to release the NRPS product. These findings continue to strengthen the predictive power for connecting genes to products, thereby facilitating natural product discovery and development in the Genomics Era.
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Affiliation(s)
- Matt McErlean
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536, USA
| | - Jonathan Overbay
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536, USA
| | - Steven Van Lanen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536, USA.
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25
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Moodie LWK, Hubert M, Zhou X, Albers MF, Lundmark R, Wanrooij S, Hedberg C. Photoactivated Colibactin Probes Induce Cellular DNA Damage. Angew Chem Int Ed Engl 2018; 58:1417-1421. [DOI: 10.1002/anie.201812326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Indexed: 12/15/2022]
Affiliation(s)
| | - Madlen Hubert
- Integrative Medical Biology; Umeå University; 90187 Umeå Sweden
| | - Xin Zhou
- Medical Biochemistry and Biophysics; Umeå University; 90187 Umeå Sweden
| | | | - Richard Lundmark
- Integrative Medical Biology; Umeå University; 90187 Umeå Sweden
- Medical Biochemistry and Biophysics; Umeå University; 90187 Umeå Sweden
| | - Sjoerd Wanrooij
- Medical Biochemistry and Biophysics; Umeå University; 90187 Umeå Sweden
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26
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Moodie LWK, Hubert M, Zhou X, Albers MF, Lundmark R, Wanrooij S, Hedberg C. Photoactivated Colibactin Probes Induce Cellular DNA Damage. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201812326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
| | - Madlen Hubert
- Integrative Medical Biology; Umeå University; 90187 Umeå Sweden
| | - Xin Zhou
- Medical Biochemistry and Biophysics; Umeå University; 90187 Umeå Sweden
| | | | - Richard Lundmark
- Integrative Medical Biology; Umeå University; 90187 Umeå Sweden
- Medical Biochemistry and Biophysics; Umeå University; 90187 Umeå Sweden
| | - Sjoerd Wanrooij
- Medical Biochemistry and Biophysics; Umeå University; 90187 Umeå Sweden
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27
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Shine EE, Xue M, Patel JR, Healy AR, Surovtseva YV, Herzon SB, Crawford JM. Model Colibactins Exhibit Human Cell Genotoxicity in the Absence of Host Bacteria. ACS Chem Biol 2018; 13:3286-3293. [PMID: 30403848 DOI: 10.1021/acschembio.8b00714] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Colibactins are genotoxic secondary metabolites produced in select Enterobacteriaceae, which induce downstream DNA double-strand breaks (DSBs) in human cell lines and are thought to promote the formation of colorectal tumors. Although key structural and functional features of colibactins have been elucidated, the full molecular mechanisms regulating these phenotypes remain unknown. Here, we demonstrate that free model colibactins induce DSBs in human cell cultures and do not require delivery by host bacteria. Through domain-targeted editing, we demonstrate that a subset of native colibactins generated from observed module skipping in the nonribosomal peptide synthetase-polyketide synthase (NRPS-PKS) biosynthetic assembly line share DNA alkylation phenotypes with the model colibactins in vitro. However, module skipping eliminates the strong DNA interstrand cross-links formed by the wild-type pathway in cell culture. This product diversification during the modular NRPS-PKS biosynthesis produces a family of metabolites with varying observed mechanisms of action (DNA alkylation versus cross-linking) in cell culture. The presence of membranes separating human cells from model colibactins attenuated genotoxicity, suggesting that membrane diffusion limits colibactin activity and could account for the reported bacterium-human cell-to-cell contact phenotype. Additionally, extracellular supplementation of the colibactin resistance protein ClbS was able to intercept colibactins in an Escherichia coli-human cell transient infection model. Our studies demonstrate that free model colibactins recapitulate cellular phenotypes associated with module-skipped products in the native colibactin pathway and define specific protein domains that are required for efficient DNA interstrand cross-linking in the native pathway.
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Affiliation(s)
- Emilee E. Shine
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut 06536, United States
- Chemical Biology Institute, Yale University, West Haven, Connecticut 06516, United States
| | - Mengzhao Xue
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Jaymin R. Patel
- Chemical Biology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520, United States
| | - Alan R. Healy
- Chemical Biology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Yulia V. Surovtseva
- Yale Center for Molecular Discovery, West Haven, Connecticut 06516, United States
| | - Seth B. Herzon
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
- Department of Pharmacology, Yale School of Medicine, New Haven, Connecticut 06520, United States
| | - Jason M. Crawford
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut 06536, United States
- Chemical Biology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
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28
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Wassenaar TM. E. coli and colorectal cancer: a complex relationship that deserves a critical mindset. Crit Rev Microbiol 2018; 44:619-632. [DOI: 10.1080/1040841x.2018.1481013] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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29
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Faïs T, Delmas J, Barnich N, Bonnet R, Dalmasso G. Colibactin: More Than a New Bacterial Toxin. Toxins (Basel) 2018; 10:toxins10040151. [PMID: 29642622 PMCID: PMC5923317 DOI: 10.3390/toxins10040151] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 04/06/2018] [Accepted: 04/07/2018] [Indexed: 12/16/2022] Open
Abstract
Cyclomodulins are bacterial toxins that interfere with the eukaryotic cell cycle. A new cyclomodulin called colibactin, which is synthetized by the pks genomic island, was discovered in 2006. Despite many efforts, colibactin has not yet been purified, and its structure remains elusive. Interestingly, the pks island is found in members of the family Enterobacteriaceae (mainly Escherichia coli and Klebsiella pneumoniae) isolated from different origins, including from intestinal microbiota, septicaemia, newborn meningitis, and urinary tract infections. Colibactin-producing bacteria induce chromosomal instability and DNA damage in eukaryotic cells, which leads to senescence of epithelial cells and apoptosis of immune cells. The pks island is mainly observed in B2 phylogroup E. coli strains, which include extra-intestinal pathogenic E. coli strains, and pksE. coli are over-represented in biopsies isolated from colorectal cancer. In addition, pksE. coli bacteria increase the number of tumours in diverse colorectal cancer mouse models. Thus, colibactin could have a major impact on human health. In the present review, we will focus on the biological effects of colibactin, the distribution of the pks island, and summarize what is currently known about its synthesis and its structure.
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Affiliation(s)
- Tiphanie Faïs
- Université Clermont Auvergne, Inserm U1071, M2iSH, USC-INRA 2018, F-63000 Clermont-Ferrand, France.
- CHU Clermont-Ferrand, Laboratoire de Bactériologie, Centre de Biologie, F-63003 Clermont-Ferrand, France.
| | - Julien Delmas
- Université Clermont Auvergne, Inserm U1071, M2iSH, USC-INRA 2018, F-63000 Clermont-Ferrand, France.
- CHU Clermont-Ferrand, Laboratoire de Bactériologie, Centre de Biologie, F-63003 Clermont-Ferrand, France.
| | - Nicolas Barnich
- Université Clermont Auvergne, Inserm U1071, M2iSH, USC-INRA 2018, F-63000 Clermont-Ferrand, France.
| | - Richard Bonnet
- Université Clermont Auvergne, Inserm U1071, M2iSH, USC-INRA 2018, F-63000 Clermont-Ferrand, France.
- CHU Clermont-Ferrand, Laboratoire de Bactériologie, Centre de Biologie, F-63003 Clermont-Ferrand, France.
| | - Guillaume Dalmasso
- Université Clermont Auvergne, Inserm U1071, M2iSH, USC-INRA 2018, F-63000 Clermont-Ferrand, France.
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30
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Tripathi P, Shine EE, Healy AR, Kim CS, Herzon SB, Bruner SD, Crawford JM. ClbS Is a Cyclopropane Hydrolase That Confers Colibactin Resistance. J Am Chem Soc 2017; 139:17719-17722. [PMID: 29112397 DOI: 10.1021/jacs.7b09971] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Certain commensal Escherichia coli contain the clb biosynthetic gene cluster that codes for small molecule prodrugs known as precolibactins. Precolibactins are converted to colibactins by N-deacylation; the latter are postulated to be genotoxic and to contribute to colorectal cancer formation. Though advances toward elucidating (pre)colibactin biosynthesis have been made, the functions and mechanisms of several clb gene products remain poorly understood. Here we report the 2.1 Å X-ray structure and molecular function of ClbS, a gene product that confers resistance to colibactin toxicity in host bacteria and which has been shown to be important for bacterial viability. The structure harbors a potential colibactin binding site and shares similarity to known hydrolases. In vitro studies using a synthetic colibactin analog and ClbS or an active site residue mutant reveal cyclopropane hydrolase activity that converts the electrophilic cyclopropane of the colibactins into an innocuous hydrolysis product. As the cyclopropane has been shown to be essential for genotoxic effects in vitro, this ClbS-catalyzed ring-opening provides a means for the bacteria to circumvent self-induced genotoxicity. Our study provides a molecular-level view of the first reported cyclopropane hydrolase and support for a specific mechanistic role of this enzyme in colibactin resistance.
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Affiliation(s)
- Prabhanshu Tripathi
- Department of Chemistry, University of Florida , Gainesville, Florida 32611, United States
| | - Emilee E Shine
- Department of Microbial Pathogenesis, Yale School of Medicine , New Haven, Connecticut 06536, United States.,Chemical Biology Institute, Yale University , West Haven, Connecticut 06516, United States
| | - Alan R Healy
- Chemical Biology Institute, Yale University , West Haven, Connecticut 06516, United States.,Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States
| | - Chung Sub Kim
- Chemical Biology Institute, Yale University , West Haven, Connecticut 06516, United States.,Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States
| | - Seth B Herzon
- Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.,Department of Pharmacology, Yale School of Medicine , New Haven, Connecticut 06520, United States
| | - Steven D Bruner
- Department of Chemistry, University of Florida , Gainesville, Florida 32611, United States
| | - Jason M Crawford
- Department of Microbial Pathogenesis, Yale School of Medicine , New Haven, Connecticut 06536, United States.,Chemical Biology Institute, Yale University , West Haven, Connecticut 06516, United States.,Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States
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31
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Guntaka NS, Healy AR, Crawford JM, Herzon SB, Bruner SD. Structure and Functional Analysis of ClbQ, an Unusual Intermediate-Releasing Thioesterase from the Colibactin Biosynthetic Pathway. ACS Chem Biol 2017; 12:2598-2608. [PMID: 28846367 PMCID: PMC5830302 DOI: 10.1021/acschembio.7b00479] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Colibactin is a genotoxic hybrid nonribosomal peptide/polyketide secondary metabolite produced by various pathogenic and probiotic bacteria residing in the human gut. The presence of colibactin metabolites has been correlated to colorectal cancer formation in several studies. The specific function of many gene products in the colibactin gene cluster can be predicted. However, the role of ClbQ, a type II editing thioesterase, has not been established. The importance of ClbQ has been demonstrated by genetic deletions that abolish colibactin cytotoxic activity, and recent studies suggest an atypical role in releasing pathway intermediates from the assembly line. Here we report the 2.0 Å crystal structure and biochemical characterization of ClbQ. Our data reveal that ClbQ exhibits greater catalytic efficiency toward acyl-thioester substrates as compared to precolibactin intermediates and does not discriminate among carrier proteins. Cyclized pyridone-containing colibactins, which are off-pathway derivatives, are not viable substrates for ClbQ, while linear precursors are, supporting a role of ClbQ in facilitating the promiscuous off-loading of premature precolibactin metabolites and novel insights into colibactin biosynthesis.
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Affiliation(s)
- Naga Sandhya Guntaka
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Alan R. Healy
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
- Chemical Biology Institute, Yale University, West Haven, Connecticut 06516, United States
| | - Jason M. Crawford
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
- Chemical Biology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut 06536, United States
| | - Seth B. Herzon
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
- Department of Pharmacology, Yale School of Medicine, New Haven, Connecticut 06520, United States
| | - Steven D. Bruner
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
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32
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Healy AR, Herzon SB. Molecular Basis of Gut Microbiome-Associated Colorectal Cancer: A Synthetic Perspective. J Am Chem Soc 2017; 139:14817-14824. [PMID: 28949546 DOI: 10.1021/jacs.7b07807] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A significant challenge toward studies of the human microbiota involves establishing causal links between bacterial metabolites and human health and disease states. Certain strains of commensal Escherichia coli harbor the 54-kb clb gene cluster which codes for small molecules named precolibactins and colibactins. Several studies suggest colibactins are genotoxins and support a role for clb metabolites in colorectal cancer formation. Significant advances toward elucidating the structures and biosynthesis of the precolibactins and colibactins have been made using genetic approaches, but their full structures remain unknown. In this Perspective we describe recent synthetic efforts that have leveraged biosynthetic advances and shed light on the mechanism of action of clb metabolites. These studies indicate that deletion of the colibactin peptidase ClbP, a modification introduced to promote accumulation of precolibactins, leads to the production of non-genotoxic pyridone-based isolates derived from the diversion of linear biosynthetic intermediates toward alternative cyclization pathways. Furthermore, these studies suggest the active genotoxins (colibactins) are unsaturated imines that are potent DNA damaging agents, thereby confirming an earlier mechanism of action hypothesis. Although these imines have very recently been detected in bacterial extracts, they have to date confounded isolation. As the power of "meta-omics" approaches to natural products discovery further advance, we anticipate that chemical synthetic and biosynthetic studies will become increasingly interdependent.
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Affiliation(s)
- Alan R Healy
- Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.,Chemical Biology Institute, Yale University , West Haven, Connecticut 06516, United States
| | - Seth B Herzon
- Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.,Department of Pharmacology, Yale School of Medicine , New Haven, Connecticut 06520, United States
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33
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Song LQ, Zhang YY, Pu JY, Tang MC, Peng C, Tang GL. Catalysis of Extracellular Deamination by a FAD-Linked Oxidoreductase after Prodrug Maturation in the Biosynthesis of Saframycin A. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201704726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Li-Qiang Song
- Key Laboratory of Bio-organic and Natural Products Chemistry; Shanghai Institute of Organic Chemistry; Chinese Academy of Sciences (CAS); Shanghai 200032 China
| | - Ying-Ying Zhang
- Key Laboratory of Bio-organic and Natural Products Chemistry; Shanghai Institute of Organic Chemistry; Chinese Academy of Sciences (CAS); Shanghai 200032 China
| | - Jin-Yue Pu
- Key Laboratory of Bio-organic and Natural Products Chemistry; Shanghai Institute of Organic Chemistry; Chinese Academy of Sciences (CAS); Shanghai 200032 China
| | - Man-Cheng Tang
- Key Laboratory of Bio-organic and Natural Products Chemistry; Shanghai Institute of Organic Chemistry; Chinese Academy of Sciences (CAS); Shanghai 200032 China
| | - Chao Peng
- National Center for Protein Science (Shanghai); Institute of Biochemistry and Cell Biology; Shanghai Institutes for Biological Sciences, CAS; Shanghai 200031 China
| | - Gong-Li Tang
- Key Laboratory of Bio-organic and Natural Products Chemistry; Shanghai Institute of Organic Chemistry; Chinese Academy of Sciences (CAS); Shanghai 200032 China
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34
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Song LQ, Zhang YY, Pu JY, Tang MC, Peng C, Tang GL. Catalysis of Extracellular Deamination by a FAD-Linked Oxidoreductase after Prodrug Maturation in the Biosynthesis of Saframycin A. Angew Chem Int Ed Engl 2017; 56:9116-9120. [PMID: 28561936 DOI: 10.1002/anie.201704726] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Indexed: 12/28/2022]
Abstract
The biosynthesis of antibiotics in bacteria is usually believed to be an intracellular process, at the end of which the matured compounds are exported outside the cells. The biosynthesis of saframycin A (SFM-A), an antitumor antibiotic, requires a cryptic fatty acyl chain to guide the construction of a pentacyclic tetrahydroisoquinoline scaffold; however, the follow-up deacylation and deamination steps remain unknown. Herein we demonstrate that SfmE, a membrane-bound peptidase, hydrolyzes the fatty acyl chain to release the amino group; and SfmCy2, a secreted oxidoreductase covalently associated with FAD, subsequently performs an oxidative deamination extracellularly. These results not only fill in the missing steps of SFM-A biosynthesis, but also reveal that a FAD-binding oxidoreductase catalyzes an unexpected deamination reaction through an unconventional extracellular pathway in Streptmyces bacteria.
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Affiliation(s)
- Li-Qiang Song
- Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (CAS), Shanghai, 200032, China
| | - Ying-Ying Zhang
- Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (CAS), Shanghai, 200032, China
| | - Jin-Yue Pu
- Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (CAS), Shanghai, 200032, China
| | - Man-Cheng Tang
- Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (CAS), Shanghai, 200032, China
| | - Chao Peng
- National Center for Protein Science (Shanghai), Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, CAS, Shanghai, 200031, China
| | - Gong-Li Tang
- Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (CAS), Shanghai, 200032, China
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35
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Naumann TA, Bakota EL, Price NPJ. Recognition of corn defense chitinases by fungal polyglycine hydrolases. Protein Sci 2017; 26:1214-1223. [PMID: 28383143 DOI: 10.1002/pro.3175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 04/03/2017] [Accepted: 04/03/2017] [Indexed: 11/07/2022]
Abstract
Polyglycine hydrolases (PGH)s are secreted fungal endoproteases that cleave peptide bonds in the polyglycine interdomain linker of ChitA chitinase, an antifungal protein from domesticated corn (Zea mays ssp. mays). These target-specific endoproteases are unusual because they do not cut a specific peptide bond but select one of many Gly-Gly bonds within the polyglycine region. Some Gly-Gly bonds are cleaved frequently while others are never cleaved. Moreover, we have previously shown that PGHs from different fungal pathogens prefer to cleave different Gly-Gly peptide bonds. It is not understood how PGHs selectively cleave the ChitA linker, especially because its polyglycine structure lacks peptide sidechains. To gain insights into this process we synthesized several peptide analogs of ChitA to evaluate them as potential substrates and inhibitors of Es-cmp, a PGH from the plant pathogenic fungus Epicoccum sorghi. Our results showed that part of the PGH recognition site for substrate chitinases is adjacent to the polyglycine linker on the carboxy side. More specifically, four amino acid residues were implicated, each spaced four residues apart on an alpha helix. Moreover, analogous peptides with selective Gly->sarcosine (N-methylglycine) mutations or a specific Ser->Thr mutation retained inhibitor activity but were no longer cleaved by PGH. Additonally, our findings suggest that peptide analogs of ChitA that inhibit PGH activity could be used to strengthen plant defenses.
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Affiliation(s)
- Todd A Naumann
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agriculture Utilization Research, Peoria, IL, 61604
| | - Erica L Bakota
- Renewable Product Technology Research Unit, National Center for Agriculture Utilization Research, Peoria, IL, 61604
| | - Neil P J Price
- Functional Foods Research Unit, National Center for Agriculture Utilization Research, Peoria, IL, 61604
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36
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Lu MC, Chen YT, Chiang MK, Wang YC, Hsiao PY, Huang YJ, Lin CT, Cheng CC, Liang CL, Lai YC. Colibactin Contributes to the Hypervirulence of pks+ K1 CC23 Klebsiella pneumoniae in Mouse Meningitis Infections. Front Cell Infect Microbiol 2017; 7:103. [PMID: 28409125 PMCID: PMC5374149 DOI: 10.3389/fcimb.2017.00103] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 03/15/2017] [Indexed: 12/31/2022] Open
Abstract
Klebsiella pneumoniae is the most common pathogen of community-acquired meningitis in Taiwan. However, the lack of a physiologically relevant meningitis model for K. pneumoniae has impeded research into its pathogenesis mechanism. Based on the core genome MLST analyses, the hypervirulent K1 K. pneumoniae strains, which are etiologically implicated in adult meningitis, mostly belong to a single clonal complex, CC23. Some K1 CC23 K. pneumoniae strains carry a gene cluster responsible for colibactin production. Colibactin is a small genotoxic molecule biosynthesized by an NRPS-PKS complex, which is encoded by genes located on the pks island. Compared to other hypervirulent K. pneumoniae which primarily infect the liver, the colibactin-producing (pks+) K1 CC23 strains had significant tropism toward the brain of BALB/c mice. We aimed in this study to develop a physiologically relevant meningitis model with the use of pks+ K1 CC23 K. pneumoniae. Acute meningitis was successfully induced in adult BALB/c male mice through orogastric, intranasal, and intravenous inoculation of pks+ K1 CC23 K. pneumoniae. Besides the typical symptoms of bacterial meningitis, severe DNA damages, and caspase 3-independent cell death were elicited by the colibactin-producing K1 CC23 K. pneumoniae strain. The deletion of clbA, which abolished the production of colibactin, substantially hindered K. pneumoniae hypervirulence in the key pathogenic steps toward the development of meningitis. Our findings collectively demonstrated that colibactin was necessary but not sufficient for the meningeal tropism of pks+ K1 CC23 K. pneumoniae, and the mouse model established in this study can be applied to identify other virulence factors participating in the development of this life-threatening disease.
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Affiliation(s)
- Min-Chi Lu
- Division of Infectious Diseases, Department of Internal Medicine, China Medical University HospitalTaichung, Taiwan.,Department of Microbiology and Immunology, School of Medicine, China Medical UniversityTaichung, Taiwan
| | - Ying-Tsong Chen
- Institute of Molecular and Genomic Medicine, National Health Research InstitutesMiaoli County, Taiwan.,Institute of Genomics and Bioinformatics, National Chung Hsing UniversityTaichung, Taiwan
| | - Ming-Ko Chiang
- Department of Life Science, National Chung Cheng UniversityChia-Yi County, Taiwan
| | - Yao-Chen Wang
- Department of Internal Medicine, Chung Shan Medical University HospitalTaichung, Taiwan
| | - Pei-Yi Hsiao
- Department of Microbiology and Immunology, Chung Shan Medical UniversityTaichung, Taiwan
| | - Yi-Jhen Huang
- Institute of Genomics and Bioinformatics, National Chung Hsing UniversityTaichung, Taiwan
| | - Ching-Ting Lin
- Graduate Institute of Chinese Medicine, School of Chinese Medicine, China Medical UniversityTaichung, Taiwan
| | - Ching-Chang Cheng
- Laboratory Animal Service Center, China Medical UniversityTaichung, Taiwan
| | - Chih-Lung Liang
- Department of Microbiology and Immunology, Chung Shan Medical UniversityTaichung, Taiwan
| | - Yi-Chyi Lai
- Department of Internal Medicine, Chung Shan Medical University HospitalTaichung, Taiwan.,Department of Microbiology and Immunology, Chung Shan Medical UniversityTaichung, Taiwan
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37
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Trautman EP, Healy AR, Shine EE, Herzon SB, Crawford JM. Domain-Targeted Metabolomics Delineates the Heterocycle Assembly Steps of Colibactin Biosynthesis. J Am Chem Soc 2017; 139:4195-4201. [PMID: 28240912 DOI: 10.1021/jacs.7b00659] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Modular polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs) comprise giant multidomain enzymes responsible for the "assembly line" biosynthesis of many genetically encoded small molecules. Site-directed mutagenesis, protein biochemical, and structural studies have focused on elucidating the catalytic mechanisms of individual multidomain proteins and protein domains within these megasynthases. However, probing their functions at the cellular level typically has invoked the complete deletion (or overexpression) of multidomain-encoding genes or combinations of genes and comparing those mutants with a control pathway. Here we describe a "domain-targeted" metabolomic strategy that combines genome editing with pathway analysis to probe the functions of individual PKS and NRPS catalytic domains at the cellular metabolic level. We apply the approach to the bacterial colibactin pathway, a genotoxic NRPS-PKS hybrid pathway found in certain Escherichia coli. The pathway produces precolibactins, which are converted to colibactins by a dedicated peptidase, ClbP. Domain-targeted metabolomics enabled the characterization of "multidomain signatures", or functional readouts of NRPS-PKS domain contributions to the pathway-dependent metabolome. These multidomain signatures provided experimental support for individual domain contributions to colibactin biosynthesis and delineated the assembly line timing events of colibactin heterocycle formation. The analysis also led to the structural characterization of two reactive precolibactin metabolites. We demonstrate the fate of these reactive intermediates in the presence and absence of ClbP, which dictates the formation of distinct product groups resulting from alternative cyclization cascades. In the presence of the peptidase, the reactive intermediates are converted to a known genotoxic scaffold, providing metabolic support of our mechanistic model for colibactin-induced genotoxicity. Domain-targeted metabolomics could be more widely used to characterize NRPS-PKS pathways with unprecedented genetic and metabolic precision.
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Affiliation(s)
- Eric P Trautman
- Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.,Chemical Biology Institute, Yale University , West Haven, Connecticut 06516, United States
| | - Alan R Healy
- Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.,Chemical Biology Institute, Yale University , West Haven, Connecticut 06516, United States
| | - Emilee E Shine
- Chemical Biology Institute, Yale University , West Haven, Connecticut 06516, United States.,Department of Microbial Pathogenesis, Yale School of Medicine , New Haven, Connecticut 06536, United States
| | - Seth B Herzon
- Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.,Department of Pharmacology, Yale School of Medicine , New Haven, Connecticut 06520, United States
| | - Jason M Crawford
- Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.,Chemical Biology Institute, Yale University , West Haven, Connecticut 06516, United States.,Department of Microbial Pathogenesis, Yale School of Medicine , New Haven, Connecticut 06536, United States
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38
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Trautman EP, Crawford JM. Linking Biosynthetic Gene Clusters to their Metabolites via Pathway- Targeted Molecular Networking. Curr Top Med Chem 2016; 16:1705-16. [PMID: 26456470 PMCID: PMC5055756 DOI: 10.2174/1568026616666151012111046] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 08/25/2015] [Accepted: 09/08/2015] [Indexed: 12/16/2022]
Abstract
The connection of microbial biosynthetic gene clusters to the small molecule metabolites they encode is central to the discovery and characterization of new metabolic pathways with ecological and pharmacological potential. With increasing microbial genome sequence information being deposited into publicly available databases, it is clear that microbes have the coding capacity for many more biologically active small molecules than previously realized. Of increasing interest are the small molecules encoded by the human microbiome, as these metabolites likely mediate a variety of currently uncharacterized human-microbe interactions that influence health and disease. In this mini-review, we describe the ongoing biosynthetic, structural, and functional characterizations of the genotoxic colibactin pathway in gut bacteria as a thematic example of linking biosynthetic gene clusters to their metabolites. We also highlight other natural products that are produced through analogous biosynthetic logic and comment on some current disconnects between bioinformatics predictions and experimental structural characterizations. Lastly, we describe the use of pathway-targeted molecular networking as a tool to characterize secondary metabolic pathways within complex metabolomes and to aid in downstream metabolite structural elucidation efforts.
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Affiliation(s)
| | - Jason M Crawford
- Department of Chemistry, Faculty of Yale University, P.O. Box: 27392, West Haven, CT, 06516, USA.
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39
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Healy AR, Nikolayevskiy H, Patel JR, Crawford JM, Herzon SB. A Mechanistic Model for Colibactin-Induced Genotoxicity. J Am Chem Soc 2016; 138:15563-15570. [PMID: 27934011 DOI: 10.1021/jacs.6b10354] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Precolibactins and colibactins represent a family of natural products that are encoded by the clb gene cluster and are produced by certain commensal, extraintestinal, and probiotic E. coli. clb+ E. coli induce megalocytosis and DNA double-strand breaks in eukaryotic cells, but paradoxically, this gene cluster is found in the probiotic Nissle 1917. Evidence suggests precolibactins are converted to genotoxic colibactins by colibactin peptidase (ClbP)-mediated cleavage of an N-acyl-d-Asn side chain, and all isolation efforts have employed ΔclbP strains to facilitate accumulation of precolibactins. It was hypothesized that colibactins form unsaturated imines that alkylate DNA by cyclopropane ring opening (2 → 3). However, as no colibactins have been isolated, this hypothesis has not been tested experimentally. Additionally, precolibactins A-C (7-9) contain a pyridone that cannot generate the unsaturated imines that form the basis of this hypothesis. To resolve this, we prepared 13 synthetic colibactin derivatives and evaluated their DNA binding and alkylation activity. We show that unsaturated imines, but not the corresponding pyridone derivatives, potently alkylate DNA. The imine, unsaturated lactam, and cyclopropane are essential for efficient DNA alkylation. A cationic residue enhances activity. These studies suggest that precolibactins containing a pyridone are not responsible for the genotoxicity of the clb cluster. Instead, we propose that these are off-pathway fermentation products produced by a facile double cyclodehydration route that manifests in the absence of viable ClbP. The results presented herein provide a foundation to begin to connect metabolite structure with the disparate phenotypes associated with clb+ E. coli.
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Affiliation(s)
- Alan R Healy
- Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.,Chemical Biology Institute, Yale University , West Haven, Connecticut 06516, United States
| | - Herman Nikolayevskiy
- Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States
| | - Jaymin R Patel
- Chemical Biology Institute, Yale University , West Haven, Connecticut 06516, United States.,Department of Molecular, Cellular, and Developmental Biology, Yale University , New Haven, Connecticut 06520, United States
| | - Jason M Crawford
- Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.,Chemical Biology Institute, Yale University , West Haven, Connecticut 06516, United States.,Department of Microbial Pathogenesis, Yale School of Medicine , New Haven, Connecticut 06536, United States
| | - Seth B Herzon
- Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.,Department of Pharmacology, Yale School of Medicine , New Haven, Connecticut 06520, United States
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40
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Antibiotic Activity of Escherichia coli against Multiresistant Staphylococcus aureus. Antimicrob Agents Chemother 2016; 60:6986-6988. [PMID: 27600034 DOI: 10.1128/aac.00130-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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41
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Taieb F, Petit C, Nougayrède JP, Oswald E. The Enterobacterial Genotoxins: Cytolethal Distending Toxin and Colibactin. EcoSal Plus 2016; 7. [PMID: 27419387 DOI: 10.1128/ecosalplus.esp-0008-2016] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Indexed: 06/06/2023]
Abstract
While the DNA damage induced by ionizing radiation and by many chemical compounds and drugs is well characterized, the genotoxic insults inflicted by bacteria are only scarcely documented. However, accumulating evidence indicates that we are exposed to bacterial genotoxins. The prototypes of such bacterial genotoxins are the Cytolethal Distending Toxins (CDTs) produced by Escherichia coli and Salmonella enterica serovar Typhi. CDTs display the DNase structure fold and activity, and induce DNA strand breaks in the intoxicated host cell nuclei. E. coli and certain other Enterobacteriaceae species synthesize another genotoxin, colibactin. Colibactin is a secondary metabolite, a hybrid polyketide/nonribosomal peptide compound synthesized by a complex biosynthetic machinery. In this review, we summarize the current knowledge on CDT and colibactin produced by E. coli and/or Salmonella Typhi. We describe their prevalence, genetic determinants, modes of action, and impact in infectious diseases or gut colonization, and discuss the possible involvement of these genotoxigenic bacteria in cancer.
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Affiliation(s)
- Frederic Taieb
- Institut de Recherche en Santé Digestive (IRSD), INRA UMR1416, INSERM U1220, Université de Toulouse, CHU Purpan, Toulouse, FRANCE
| | - Claude Petit
- Institut de Recherche en Santé Digestive (IRSD), INRA UMR1416, INSERM U1220, Université de Toulouse, CHU Purpan, Toulouse, FRANCE
| | - Jean-Philippe Nougayrède
- Institut de Recherche en Santé Digestive (IRSD), INRA UMR1416, INSERM U1220, Université de Toulouse, CHU Purpan, Toulouse, FRANCE
| | - Eric Oswald
- Institut de Recherche en Santé Digestive (IRSD), INRA UMR1416, INSERM U1220, Université de Toulouse, CHU Purpan, Toulouse, FRANCE
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Brachmann AO, Garcie C, Wu V, Martin P, Ueoka R, Oswald E, Piel J. Colibactin biosynthesis and biological activity depend on the rare aminomalonyl polyketide precursor. Chem Commun (Camb) 2016; 51:13138-41. [PMID: 26191546 DOI: 10.1039/c5cc02718g] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The as-yet unidentified E. coli metabolite colibactin induces DNA damage in eukaryotic cells and promotes tumorigenesis. Its wide distribution in pathogenic and probiotic strains has raised great interest in its structure and biosynthesis. Here we show that colibactin formation involves a rare aminomalonyl unit used as a building block.
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Affiliation(s)
- A O Brachmann
- Institute of Microbiology, Eigenössische Technische Hochschule (ETH) Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zurich, Switzerland.
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43
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Faïs T, Delmas J, Cougnoux A, Dalmasso G, Bonnet R. Targeting colorectal cancer-associated bacteria: A new area of research for personalized treatments. Gut Microbes 2016; 7:329-333. [PMID: 27007710 PMCID: PMC4988430 DOI: 10.1080/19490976.2016.1155020] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Most cases of colorectal cancer (CRC) are sporadic, and numerous studies have suggested that gut microbiota may play a crucial role in CRC development. Escherichia coli is a member of the gut microbiota frequently associated with colorectal tumors. CRC-associated E. coli strains frequently harbor the pks genomic island. This genomic island is responsible for the synthesis of colibactin genotoxin, which increases tumor numbers in CRC mouse models. We recently showed that targeting ClbP, a key enzyme involved in colibactin synthesis, blocks the deleterious effect of this toxin in vitro and leads to a significant decrease in tumor numbers in vivo. Altogether, our results suggest that the personalized treatment of CRC should also take into consideration the bacteria associated with the tumor in order to limit their deleterious effects.
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Affiliation(s)
- T. Faïs
- Microbes, Inflammation, Intestin et Susceptibilité de l'Hôte (M2iSH), Clermont Université, Université d'Auvergne, Inserm U1071, INRA USC2018, Clermont-Ferrand, France,Laboratoire de Bactériologie, Center Hospitalier Universitaire, Clermont-Ferrand, France,Institut Universitaire de Technologie, Université d'Auvergne, Aubière, France
| | - J. Delmas
- Microbes, Inflammation, Intestin et Susceptibilité de l'Hôte (M2iSH), Clermont Université, Université d'Auvergne, Inserm U1071, INRA USC2018, Clermont-Ferrand, France,Laboratoire de Bactériologie, Center Hospitalier Universitaire, Clermont-Ferrand, France,Institut Universitaire de Technologie, Université d'Auvergne, Aubière, France
| | - A. Cougnoux
- Microbes, Inflammation, Intestin et Susceptibilité de l'Hôte (M2iSH), Clermont Université, Université d'Auvergne, Inserm U1071, INRA USC2018, Clermont-Ferrand, France,Institut Universitaire de Technologie, Université d'Auvergne, Aubière, France
| | - G. Dalmasso
- Microbes, Inflammation, Intestin et Susceptibilité de l'Hôte (M2iSH), Clermont Université, Université d'Auvergne, Inserm U1071, INRA USC2018, Clermont-Ferrand, France,Institut Universitaire de Technologie, Université d'Auvergne, Aubière, France
| | - R. Bonnet
- Microbes, Inflammation, Intestin et Susceptibilité de l'Hôte (M2iSH), Clermont Université, Université d'Auvergne, Inserm U1071, INRA USC2018, Clermont-Ferrand, France,Laboratoire de Bactériologie, Center Hospitalier Universitaire, Clermont-Ferrand, France,Institut Universitaire de Technologie, Université d'Auvergne, Aubière, France
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The Staphylococcus aureus Methicillin Resistance Factor FmtA Is a d-Amino Esterase That Acts on Teichoic Acids. mBio 2016; 7:e02070-15. [PMID: 26861022 PMCID: PMC4752606 DOI: 10.1128/mbio.02070-15] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED The methicillin resistance factor encoded by fmtA is a core member of the Staphylococcus aureus cell wall stimulon, but its function has remained elusive for the past two decades. First identified as a factor that affects methicillin resistance in S. aureus strains, FmtA was later shown to interact with teichoic acids and to localize to the cell division septum. We have made a breakthrough in understanding FmtA function. We show that FmtA hydrolyzes the ester bond between d-Ala and the backbone of teichoic acids, which are polyglycerol-phosphate or polyribitol-phosphate polymers found in the S. aureus cell envelope. FmtA contains two conserved motifs found in serine active-site penicillin-binding proteins (PBPs) and β-lactamases. The conserved SXXK motif was found to be important for the d-amino esterase activity of FmtA. Moreover, we show that deletion of fmtA (ΔfmtA) led to higher levels of d-Ala in teichoic acids, and this effect was reversed by complementation of ΔfmtA with fmtA. The positive charge on d-Ala partially masks the negative charge of the polyol-phosphate backbone of teichoic acids; hence, a change in the d-Ala content will result in modulation of their charge. Cell division, biofilm formation, autolysis, and colonization are among the many processes in S. aureus affected by the d-Ala content and overall charge of the cell surface teichoic acids. The esterase activity of FmtA and the regulation of fmtA suggest that FmtA functions as a modulator of teichoic acid charge, thus FmtA may be involved in S. aureus cell division, biofilm formation, autolysis, and colonization. IMPORTANCE Teichoic acids are involved in cell division, cell wall synthesis, biofilm formation, attachment of bacteria to artificial surfaces, and colonization. However, the function of teichoic acids is not fully understood. Modification by glycosylation and/or d-alanylation of the polyol-phosphate backbone of teichoic acids is important in the above cell processes. The intrinsic negative charge of teichoic acid backbone plays a role in the charge and/or pH of the bacterial surface, and d-alanylation represents a means through which bacteria modulate the charge or the pH of their surfaces. We discovered that FmtA removes d-Ala from teichoic acids. We propose FmtA may provide a temporal and spatial regulation of the bacterial cell surface charge in two ways, by removing the d-Ala from LTA to make it available to wall teichoic acid (WTA) in response to certain conditions and by removing it from WTA to allow the cell to reset its surface charge to a previous condition.
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Cougnoux A, Delmas J, Gibold L, Faïs T, Romagnoli C, Robin F, Cuevas-Ramos G, Oswald E, Darfeuille-Michaud A, Prati F, Dalmasso G, Bonnet R. Small-molecule inhibitors prevent the genotoxic and protumoural effects induced by colibactin-producing bacteria. Gut 2016; 65:278-85. [PMID: 25588406 DOI: 10.1136/gutjnl-2014-307241] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 12/10/2014] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Colorectal cancers (CRCs) are frequently colonised by colibactin toxin-producing Escherichia coli bacteria that induce DNA damage in host cells and exhibit protumoural activities. Our objective was to identify small molecules inhibiting the toxic effects induced by these colibactin-producing bacteria. DESIGN A structural approach was adopted for the identification of a putative ligand for the ClbP enzyme involved in the synthesis of colibactin. Intestinal epithelial cells and a CRC mouse model were used to assess the activity of the selected compounds in vitro and in vivo. RESULTS Docking experiments identified two boron-based compounds with computed ligand efficiency values (-0.8 and -0.9 kcal/mol/atom) consistent with data expected for medicinal chemistry leads. The crystalline structure of ClbP in complex with the compounds confirmed that the compounds were binding to the active site of ClbP. The two compounds (2 mM) suppressed the genotoxic activity of colibactin-producing E coli both in vitro and in vivo. The mean degree of suppression of DNA damage for the most efficient compound was 98±2% (95% CI). This compound also prevented cell proliferation and colibactin-producing E coli-induced tumourigenesis in mice. In a CRC murine model colonised by colibactin-producing E coli, the number of tumours decreased by 3.5-fold in animals receiving the compound in drinking water (p<0.01). CONCLUSIONS These results demonstrate that targeting colibactin production controls the genotoxic and protumoural effects induced by this toxin.
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Affiliation(s)
- Antony Cougnoux
- Clermont Université, Université d'Auvergne; Inserm U1071; INRA USC2018, Clermont-Ferrand, France
| | - Julien Delmas
- Clermont Université, Université d'Auvergne; Inserm U1071; INRA USC2018, Clermont-Ferrand, France Centre Hospitalier Universitaire, Clermont-Ferrand, France
| | - Lucie Gibold
- Clermont Université, Université d'Auvergne; Inserm U1071; INRA USC2018, Clermont-Ferrand, France Centre Hospitalier Universitaire, Clermont-Ferrand, France
| | - Tiphanie Faïs
- Clermont Université, Université d'Auvergne; Inserm U1071; INRA USC2018, Clermont-Ferrand, France
| | - Chiara Romagnoli
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Frederic Robin
- Clermont Université, Université d'Auvergne; Inserm U1071; INRA USC2018, Clermont-Ferrand, France Centre Hospitalier Universitaire, Clermont-Ferrand, France
| | - Gabriel Cuevas-Ramos
- INRA; USC 1360, Université de Toulouse, Toulouse, France Inserm; UMR1043, Université de Toulouse, Toulouse, France CNRS; UMR5282, Université de Toulouse, Toulouse, France
| | - Eric Oswald
- INRA; USC 1360, Université de Toulouse, Toulouse, France Inserm; UMR1043, Université de Toulouse, Toulouse, France CNRS; UMR5282, Université de Toulouse, Toulouse, France UPS, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France CHU Toulouse; Hôpital Purpan; Service de bactériologie-Hygiène, Toulouse, France
| | - Arlette Darfeuille-Michaud
- Clermont Université, Université d'Auvergne; Inserm U1071; INRA USC2018, Clermont-Ferrand, France Institut Universitaire de Technologie, Université d'Auvergne, Aubière, France
| | - Fabio Prati
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Guillaume Dalmasso
- Clermont Université, Université d'Auvergne; Inserm U1071; INRA USC2018, Clermont-Ferrand, France
| | - Richard Bonnet
- Clermont Université, Université d'Auvergne; Inserm U1071; INRA USC2018, Clermont-Ferrand, France Centre Hospitalier Universitaire, Clermont-Ferrand, France
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46
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Gagnière J, Raisch J, Veziant J, Barnich N, Bonnet R, Buc E, Bringer MA, Pezet D, Bonnet M. Gut microbiota imbalance and colorectal cancer. World J Gastroenterol 2016; 22:501-518. [PMID: 26811603 PMCID: PMC4716055 DOI: 10.3748/wjg.v22.i2.501] [Citation(s) in RCA: 498] [Impact Index Per Article: 62.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 09/06/2015] [Accepted: 10/20/2015] [Indexed: 02/06/2023] Open
Abstract
The gut microbiota acts as a real organ. The symbiotic interactions between resident micro-organisms and the digestive tract highly contribute to maintain the gut homeostasis. However, alterations to the microbiome caused by environmental changes (e.g., infection, diet and/or lifestyle) can disturb this symbiotic relationship and promote disease, such as inflammatory bowel diseases and cancer. Colorectal cancer is a complex association of tumoral cells, non-neoplastic cells and a large amount of micro-organisms, and the involvement of the microbiota in colorectal carcinogenesis is becoming increasingly clear. Indeed, many changes in the bacterial composition of the gut microbiota have been reported in colorectal cancer, suggesting a major role of dysbiosis in colorectal carcinogenesis. Some bacterial species have been identified and suspected to play a role in colorectal carcinogenesis, such as Streptococcus bovis, Helicobacter pylori, Bacteroides fragilis, Enterococcus faecalis, Clostridium septicum, Fusobacterium spp. and Escherichia coli. The potential pro-carcinogenic effects of these bacteria are now better understood. In this review, we discuss the possible links between the bacterial microbiota and colorectal carcinogenesis, focusing on dysbiosis and the potential pro-carcinogenic properties of bacteria, such as genotoxicity and other virulence factors, inflammation, host defenses modulation, bacterial-derived metabolism, oxidative stress and anti-oxidative defenses modulation. We lastly describe how bacterial microbiota modifications could represent novel prognosis markers and/or targets for innovative therapeutic strategies.
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47
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MATE transport of the E. coli-derived genotoxin colibactin. Nat Microbiol 2016; 1:15009. [PMID: 27571755 DOI: 10.1038/nmicrobiol.2015.9] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/21/2015] [Indexed: 12/27/2022]
Abstract
Various forms of cancer have been linked to the carcinogenic activities of microorganisms(1-3). The virulent gene island polyketide synthase (pks) produces the secondary metabolite colibactin, a genotoxic molecule(s) causing double-stranded DNA breaks(4) and enhanced colorectal cancer development(5,6). Colibactin biosynthesis involves a prodrug resistance strategy where an N-terminal prodrug scaffold (precolibactin) is assembled, transported into the periplasm and cleaved to release the mature product(7-10). Here, we show that ClbM, a multidrug and toxic compound extrusion (MATE) transporter, is a key component involved in colibactin activity and transport. Disruption of clbM attenuated pks+ E. coli-induced DNA damage in vitro and significantly decreased the DNA damage response in gnotobiotic Il10(-/-) mice. Colonization experiments performed in mice or zebrafish animal models indicate that clbM is not implicated in E. coli niche establishment. The X-ray structure of ClbM shows a structural motif common to the recently described MATE family. The 12-transmembrane ClbM is characterized as a cation-coupled antiporter, and residues important to the cation-binding site are identified. Our data identify ClbM as a precolibactin transporter and provide the first structure of a MATE transporter with a defined and specific biological function.
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48
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Bossuet-Greif N, Dubois D, Petit C, Tronnet S, Martin P, Bonnet R, Oswald E, Nougayrède JP. Escherichia coli ClbS is a colibactin resistance protein. Mol Microbiol 2015; 99:897-908. [PMID: 26560421 DOI: 10.1111/mmi.13272] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2015] [Indexed: 12/24/2022]
Abstract
The genomic pks island codes for the biosynthetic machinery that produces colibactin, a peptide-polyketide metabolite. Colibactin is a genotoxin that contributes to the virulence of extra-intestinal pathogenic Escherichia coli and promotes colorectal cancer. In this work, we examined whether the pks-encoded clbS gene of unknown function could participate in the self-protection of E. coli-producing colibactin. A clbS mutant was not impaired in the ability to inflict DNA damage in HeLa cells, but the bacteria activated the SOS response and ceased to replicate. This autotoxicity phenotype was markedly enhanced in a clbS uvrB double mutant inactivated for DNA repair by nucleotide excision but was suppressed in a clbS clbA double mutant unable to produce colibactin. In addition, ectopic expression of clbS protected infected HeLa cells from colibactin. Thus, ClbS is a resistance protein blocking the genotoxicity of colibactin both in the procaryotic and the eucaryotic cells.
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Affiliation(s)
- Nadège Bossuet-Greif
- INRA, USC 1360, Toulouse, France.,Inserm, UMR 1043, Toulouse, France.,CNRS, UMR 5282, Toulouse, France.,Université de Toulouse, UPS, Toulouse, France
| | - Damien Dubois
- INRA, USC 1360, Toulouse, France.,Inserm, UMR 1043, Toulouse, France.,CNRS, UMR 5282, Toulouse, France.,Université de Toulouse, UPS, Toulouse, France.,CHU Toulouse, Service de bactériologie-Hygiène, Toulouse, France
| | - Claude Petit
- INRA, USC 1360, Toulouse, France.,Inserm, UMR 1043, Toulouse, France.,CNRS, UMR 5282, Toulouse, France.,Université de Toulouse, UPS, Toulouse, France.,INP-ENVT ESC, Toulouse, France
| | - Sophie Tronnet
- INRA, USC 1360, Toulouse, France.,Inserm, UMR 1043, Toulouse, France.,CNRS, UMR 5282, Toulouse, France.,Université de Toulouse, UPS, Toulouse, France
| | - Patricia Martin
- INRA, USC 1360, Toulouse, France.,Inserm, UMR 1043, Toulouse, France.,CNRS, UMR 5282, Toulouse, France.,Université de Toulouse, UPS, Toulouse, France.,CHU Toulouse, Service de bactériologie-Hygiène, Toulouse, France
| | - Richard Bonnet
- Université d'Auvergne, Inserm UMR 1071, INRA USC 2018, Clermont-Ferrand, France
| | - Eric Oswald
- INRA, USC 1360, Toulouse, France.,Inserm, UMR 1043, Toulouse, France.,CNRS, UMR 5282, Toulouse, France.,Université de Toulouse, UPS, Toulouse, France.,CHU Toulouse, Service de bactériologie-Hygiène, Toulouse, France
| | - Jean-Philippe Nougayrède
- INRA, USC 1360, Toulouse, France.,Inserm, UMR 1043, Toulouse, France.,CNRS, UMR 5282, Toulouse, France.,Université de Toulouse, UPS, Toulouse, France
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Bian X, Plaza A, Zhang Y, Müller R. Two more pieces of the colibactin genotoxin puzzle from Escherichia coli show incorporation of an unusual 1-aminocyclopropanecarboxylic acid moiety. Chem Sci 2015; 6:3154-3160. [PMID: 28706687 PMCID: PMC5490422 DOI: 10.1039/c5sc00101c] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 03/23/2015] [Indexed: 01/02/2023] Open
Abstract
Colibactin represents a structurally undefined class of bacterial genotoxin inducing DNA damage and genomic instability in mammalian cells, thus promoting tumour development and exacerbating lymphopenia in animal models. The colibactin biosynthetic gene cluster (clb) has been known for ten years and it encodes a hybrid nonribosomal peptide synthetase (NRPS)/polyketide synthase (PKS) assembly line. Nevertheless, the final chemical product(s) remain unknown. Previously, we and others reported several colibactin pathway-related metabolites including N-myristoyl-d-asparagine (1) as part of a prodrug precursor that is cleaved from the putative precolibactin to form active colibactin by the peptidase ClbP. Herein, we report two new colibactin pathway-related metabolites (2 and 3) isolated from a clbP mutant of the probiotic E. coli Nissle 1917 strain. Their structures were established by HRMS and NMR. Compound 2 shows an additional 4-aminopenatanoic acid moiety with respect to 1, while 3 is characterized by the presence of an unusual 7-methyl-4-azaspiro[2.4]hept-6-en-5-one residue. Moreover, we propose the biosynthetic pathway towards both intermediates on the basis of extensive gene inactivation and feeding experiments. The identification of 2 and 3 provides further insight into colibactin biosynthesis including the involvement and formation of a rare 1-aminocyclopropanecarboxylic acid unit. Thus, our work establishes additional steps of the pathway forming the bacterial genotoxin colibactin.
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Affiliation(s)
- Xiaoying Bian
- Department of Microbial Natural Products , Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS) , Helmholtz Centre for Infection Research (HZI) , Department of Pharmaceutical Biotechnology , Saarland University , Campus C2 3 , 66123 Saarbrücken , Germany . ; Tel: +49-681-30270201
- Shandong University-Helmholtz Institute of Biotechnology , State Key Laboratory of Microbial Technology , School of Life Science , Shandong University , Zhuzhou Road 168 , 266101 Qingdao , P. R. China . ; Tel: +86-531-88363082
| | - Alberto Plaza
- Department of Microbial Natural Products , Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS) , Helmholtz Centre for Infection Research (HZI) , Department of Pharmaceutical Biotechnology , Saarland University , Campus C2 3 , 66123 Saarbrücken , Germany . ; Tel: +49-681-30270201
| | - Youming Zhang
- Shandong University-Helmholtz Institute of Biotechnology , State Key Laboratory of Microbial Technology , School of Life Science , Shandong University , Zhuzhou Road 168 , 266101 Qingdao , P. R. China . ; Tel: +86-531-88363082
| | - Rolf Müller
- Department of Microbial Natural Products , Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS) , Helmholtz Centre for Infection Research (HZI) , Department of Pharmaceutical Biotechnology , Saarland University , Campus C2 3 , 66123 Saarbrücken , Germany . ; Tel: +49-681-30270201
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50
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Abstract
Members of the human microbiota are increasingly being correlated to human health and disease states, but the majority of the underlying microbial metabolites that regulate host-microbe interactions remain largely unexplored. Select strains of E. coli present in the human colon have been linked to initiating inflammation-induced colorectal cancer through an unknown small molecule-mediated process. The responsible nonribosomal peptide-polyketide hybrid pathway encodes “colibactin,” a largely uncharacterized family of small molecules. Genotoxic small molecules from this pathway capable of initiating cancer formation have remained elusive due to their high instability. Guided by metabolomic analyses, here we employ a combination of NMR spectroscopy and bioinformatics-guided isotopic labeling studies to characterize the colibactin warhead, an unprecedented substituted spirobicyclic structure. The warhead crosslinks duplex DNA in vitro, providing direct experimental evidence for colibactin’s DNA-damaging activity. The data support unexpected models for both colibactin biosynthesis and its mode of action.
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