1
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Addington E, Sandalli S, Roe AJ. Current understandings of colibactin regulation. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001427. [PMID: 38314762 PMCID: PMC10924459 DOI: 10.1099/mic.0.001427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 01/12/2024] [Indexed: 02/07/2024]
Abstract
The biosynthetic machinery for the production of colibactin is encoded by 19 genes (clbA - S) within the pks pathogenicity island harboured by many E. coli of the B2-phylogroup. Colibactin is a potent genotoxic metabolite which causes DNA-damage and which has potential roles in microbial competition and fitness of pks+ bacteria. Colibactin has also been strongly implicated in the development of colorectal cancer. Given the genotoxicity of colibactin and the metabolic cost of its synthesis, the regulatory system governing the clb cluster is accordingly highly complex, and many of the mechanisms remain to be elucidated. In this review we summarise the current understanding of regulation of colibactin biosynthesis by internal molecular components and how these factors are modulated by signals from the external environment.
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Affiliation(s)
- Emily Addington
- School of Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Scotland, UK
| | - Sofia Sandalli
- School of Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Scotland, UK
| | - Andrew J. Roe
- School of Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Scotland, UK
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2
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Mongia M, Yasaka TM, Liu Y, Guler M, Lu L, Bhagwat A, Behsaz B, Wang M, Dorrestein PC, Mohimani H. Fast mass spectrometry search and clustering of untargeted metabolomics data. Nat Biotechnol 2024:10.1038/s41587-023-01985-4. [PMID: 38168990 DOI: 10.1038/s41587-023-01985-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 09/12/2023] [Indexed: 01/05/2024]
Abstract
The throughput of mass spectrometers and the amount of publicly available metabolomics data are growing rapidly, but analysis tools such as molecular networking and Mass Spectrometry Search Tool do not scale to searching and clustering billions of mass spectral data in metabolomics repositories. To address this limitation, we designed MASST+ and Networking+, which can process datasets that are up to three orders of magnitude larger than those processed by state-of-the-art tools.
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Affiliation(s)
- Mihir Mongia
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Tyler M Yasaka
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Yudong Liu
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Mustafa Guler
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Liang Lu
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Aditya Bhagwat
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Bahar Behsaz
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
- Chemia Biosciences Inc., Pittsburgh, PA, USA
| | - Mingxun Wang
- Computer Science and Engineering, University of California Riverside, Riverside, CA, USA
| | - Pieter C Dorrestein
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, San Diego, CA, USA
- Department of Pharmacology and Pediatrics, University of California San Diego, San Diego, CA, USA
| | - Hosein Mohimani
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA.
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3
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Bosveli A, Griboura N, Kampouropoulos I, Kalaitzakis D, Montagnon T, Vassilikogiannakis G. The Rapid Synthesis of Colibactin Warhead Model Compounds Using New Metal-Free Photocatalytic Cyclopropanation Reactions Facilitates the Investigation of Biological Mechanisms. Chemistry 2023; 29:e202301713. [PMID: 37452669 DOI: 10.1002/chem.202301713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/06/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Herein, we report the synthesis of a series of colibactin warhead model compounds using two newly developed metal-free photocatalytic cyclopropanation reactions. These mild cyclopropanations expand the known applications of eosin within synthesis. A halogen atom transfer reaction mode has been harnessed so that dihalides can be used as the cyclopropanating agents. The colibactin warhead models were then used to provide new insight into two key mechanisms in colibactin chemistry. An explanation is provided for why the colibactin warhead sometimes undergoes a ring expansion-addition reaction to give fused cyclobutyl products while at other times nucleophiles add directly to the cyclopropyl unit (as when DNA adds to colibactin). Finally, we provide some evidence that Cu(II) chelated to colibactin may catalyze an important oxidation of the colibactin-DNA adduct. The Cu(I) generated as a result could then also play a role in inducing double strand breaks in DNA.
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Affiliation(s)
- Artemis Bosveli
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003, Iraklion, Crete
| | - Nefeli Griboura
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003, Iraklion, Crete
| | | | - Dimitris Kalaitzakis
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003, Iraklion, Crete
| | - Tamsyn Montagnon
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003, Iraklion, Crete
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4
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DiBello M, Healy AR, Nikolayevskiy H, Xu Z, Herzon SB. Structure Elucidation of Secondary Metabolites: Current Frontiers and Lingering Pitfalls. Acc Chem Res 2023; 56:1656-1668. [PMID: 37220079 PMCID: PMC10468810 DOI: 10.1021/acs.accounts.3c00183] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Analytical methods allow for the structure determination of submilligram quantities of complex secondary metabolites. This has been driven in large part by advances in NMR spectroscopic capabilities, including access to high-field magnets equipped with cryogenic probes. Experimental NMR spectroscopy may now be complemented by remarkably accurate carbon-13 NMR calculations using state-of-the-art DFT software packages. Additionally, microED analysis stands to have a profound effect on structure elucidation by providing X-ray-like images of microcrystalline samples of analytes. Nonetheless, lingering pitfalls in structure elucidation remain, particularly for isolates that are unstable or highly oxidized. In this Account, we discuss three projects from our laboratory that highlight nonoverlapping challenges to the field, with implications for chemical, synthetic, and mechanism of action studies. We first discuss the lomaiviticins, complex unsaturated polyketide natural products disclosed in 2001. The original structures were derived from NMR, HRMS, UV-vis, and IR analysis. Owing to the synthetic challenges presented by their structures and the absence of X-ray crystallographic data, the structure assignments remained untested for nearly two decades. In 2021, the Nelson group at Caltech carried out microED analysis of (-)-lomaiviticin C, leading to the startling discovery that the original structure assignment of the lomaiviticins was incorrect. Acquisition of higher-field (800 MHz 1H, cold probe) NMR data as well as DFT calculations provided insights into the basis for the original misassignment and lent further support to the new structure identified by microED. Reanalysis of the 2001 data set reveals that the two structure assignments are nearly indistinguishable, underscoring the limitations of NMR-based characterization. We then discuss the structure elucidation of colibactin, a complex, nonisolable microbiome metabolite implicated in colorectal cancer. The colibactin biosynthetic gene cluster was detected in 2006, but owing to colibactin's instability and low levels of production, it could not be isolated or characterized. We used a combination of chemical synthesis, mechanism of action studies, and biosynthetic analysis to identify the substructures in colibactin. These studies, coupled with isotope labeling and tandem MS analysis of colibactin-derived DNA interstrand cross-links, ultimately led to a structure assignment for the metabolite. We then discuss the ocimicides, plant secondary metabolites that were studied as agents against drug-resistant P. falciparum. We synthesized the core structure of the ocimicides and found significant discrepancies between our experimental NMR spectroscopic data and that reported for the natural products. We determined the theoretical carbon-13 NMR shifts for 32 diastereomers of the ocimicides. These studies indicated that a revision of the connectivity of the metabolites is likely needed. We end with some thoughts on the frontiers of secondary metabolite structure determination. As modern NMR computational methods are straightforward to execute, we advocate for their systematic use in validating the assignments of novel secondary metabolites.
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Affiliation(s)
- Mikaela DiBello
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Alan R Healy
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Herman Nikolayevskiy
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Zhi Xu
- 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
- Departments of Pharmacology and Therapeutic Radiology, Yale School of Medicine, New Haven, Connecticut 06520, United States
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5
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Bonhomme S, Contreras-Martel C, Dessen A, Macheboeuf P. Architecture of a PKS-NRPS hybrid megaenzyme involved in the biosynthesis of the genotoxin colibactin. Structure 2023:S0969-2126(23)00095-3. [PMID: 37059096 DOI: 10.1016/j.str.2023.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 10/21/2022] [Accepted: 03/20/2023] [Indexed: 04/16/2023]
Abstract
The genotoxin colibactin produced by Escherichia coli is involved in the development of colorectal cancers. This secondary metabolite is synthesized by a multi-protein machinery, mainly composed of non-ribosomal peptide synthetase (NRPS)/polyketide synthase (PKS) enzymes. In order to decipher the function of a PKS-NRPS hybrid enzyme implicated in a key step of colibactin biosynthesis, we conducted an extensive structural characterization of the ClbK megaenzyme. Here we present the crystal structure of the complete trans-AT PKS module of ClbK showing structural specificities of hybrid enzymes. In addition, we report the SAXS solution structure of the full-length ClbK hybrid that reveals a dimeric organization as well as several catalytic chambers. These results provide a structural framework for the transfer of a colibactin precursor through a PKS-NRPS hybrid enzyme and can pave the way for re-engineering PKS-NRPS hybrid megaenzymes to generate diverse metabolites with many applications.
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Affiliation(s)
- Sarah Bonhomme
- University Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), Bacterial Pathogenesis Group, 38000 Grenoble, France
| | - Carlos Contreras-Martel
- University Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), Bacterial Pathogenesis Group, 38000 Grenoble, France
| | - Andréa Dessen
- University Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), Bacterial Pathogenesis Group, 38000 Grenoble, France
| | - Pauline Macheboeuf
- University Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), Bacterial Pathogenesis Group, 38000 Grenoble, France.
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6
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Cao Y, Oh J, Xue M, Martin AL, Song D, Crawford JM, Herzon SB, Palm NW. Commensal microbiota from patients with inflammatory bowel disease produce genotoxic metabolites. Science 2022; 378:eabm3233. [PMID: 36302024 PMCID: PMC9993714 DOI: 10.1126/science.abm3233] [Citation(s) in RCA: 72] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Microbiota-derived metabolites that elicit DNA damage can contribute to colorectal cancer (CRC). However, the full spectrum of genotoxic chemicals produced by indigenous gut microbes remains to be defined. We established a pipeline to systematically evaluate the genotoxicity of an extensive collection of gut commensals from inflammatory bowel disease patients. We identified isolates from divergent phylogenies whose metabolites caused DNA damage and discovered a distinctive family of genotoxins-termed the indolimines-produced by the CRC-associated species Morganella morganii. A non-indolimine-producing M. morganii mutant lacked genotoxicity and failed to exacerbate colon tumorigenesis in mice. These studies reveal the existence of a previously unexplored universe of genotoxic small molecules from the microbiome that may affect host biology in homeostasis and disease.
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Affiliation(s)
- Yiyun Cao
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06519, USA
| | - Joonseok Oh
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
- Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT 06516, USA
| | - Mengzhao Xue
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, New York, NY 10065, USA
| | - Anjelica L. Martin
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06519, USA
| | - Deguang Song
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06519, USA
| | - Jason M. Crawford
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
- Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT 06516, USA
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Seth B. Herzon
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Noah W. Palm
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06519, USA
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7
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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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8
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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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9
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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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10
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Wernke KM, Tirla A, Xue M, Surovtseva YV, Menges FS, Herzon SB. Probing Microbiome Genotoxicity: A Stable Colibactin Provides Insight into Structure-Activity Relationships and Facilitates Mechanism of Action Studies. J Am Chem Soc 2021; 143:15824-15833. [PMID: 34524796 DOI: 10.1021/jacs.1c07559] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Colibactin is a genotoxic metabolite produced by commensal-pathogenic members of the human microbiome that possess the clb (aka pks) biosynthetic gene cluster. clb+ bacteria induce tumorigenesis in models of intestinal inflammation and have been causally linked to oncogenesis in humans. While colibactin is believed underlie these effects, it has not been possible to study the molecule directly due to its instability. Herein, we report the synthesis and biological studies of colibactin 742 (4), a stable colibactin derivative. We show that colibactin 742 (4) induces DNA interstrand-cross-links, activation of the Fanconi Anemia DNA repair pathway, and G2/M arrest in a manner similar to clb+E. coli. The linear precursor 9, which mimics the biosynthetic precursor to colibactin, also recapitulates the bacterial phenotype. In the course of this work, we discovered a novel cyclization pathway that was previously undetected in MS-based studies of colibactin, suggesting a refinement to the natural product structure and its mode of DNA binding. Colibactin 742 (4) and its precursor 9 will allow researchers to study colibactin's genotoxic effects independent of the producing organism for the first time.
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Affiliation(s)
- Kevin M Wernke
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Alina Tirla
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Mengzhao Xue
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Yulia V Surovtseva
- Yale Center for Molecular Discovery, Yale University, West Haven, Connecticut 06516, United States
| | - Fabian S Menges
- Chemical and Biophysical Instrumentation Center, Yale University, New Haven, Connecticut 06511, 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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11
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Kim CS, Turocy T, Moon G, Shine EE, Crawford JM. Escherichia coli-Derived γ-Lactams and Structurally Related Metabolites Are Produced at the Intersection of Colibactin and Fatty Acid Biosynthesis. Org Lett 2021; 23:6895-6899. [PMID: 34406772 PMCID: PMC10577019 DOI: 10.1021/acs.orglett.1c02461] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Colibactin is a genotoxic hybrid polyketide-nonribosomal peptide that drives colorectal cancer initiation. While clinical data suggest colibactin genotoxicity in vivo is largely caused by the major DNA-cross-linking metabolite, the colibactin locus produces a diverse collection of metabolites with mostly unknown biological activities. Here, we describe 10 new colibactin pathway metabolites (1-10) that are dependent on its α-aminomalonyl-carrier protein. The most abundant metabolites, 1 and 2, were isolated and structurally characterized mainly by nuclear magnetic resonance spectroscopy to be γ-lactam derivatives, and the remaining related structures were inferred via shared biosynthetic logic. Our proposed formation of 1-10, which is supported by stereochemical analysis, invokes cross-talk between colibactin and fatty acid biosynthesis, illuminating further the complexity of this diversity-oriented pathway.
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Affiliation(s)
- Chung Sub Kim
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
- Institute of Biomolecular Design & Discovery, Yale University, West Haven, Connecticut 06516, United States
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Tayah Turocy
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
- Institute of Biomolecular Design & Discovery, Yale University, West Haven, Connecticut 06516, United States
| | - Gyuri Moon
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Emilee E. Shine
- Institute of Biomolecular Design & Discovery, Yale University, West Haven, Connecticut 06516, United States
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut 06536, United States
- Present address: Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States
| | - Jason M. Crawford
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
- Institute of Biomolecular Design & Discovery, Yale University, West Haven, Connecticut 06516, United States
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut 06536, United States
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12
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Silpe J, Balskus EP. Deciphering Human Microbiota-Host Chemical Interactions. ACS CENTRAL SCIENCE 2021; 7:20-29. [PMID: 33532566 PMCID: PMC7844856 DOI: 10.1021/acscentsci.0c01030] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Indexed: 05/04/2023]
Abstract
Our gut harbors more microbes than any other body site, and accumulating evidence suggests that these organisms have a sizable impact on human health. Though efforts to classify the metabolic activities that define this microbial community have transformed the way we think about health and disease, our knowledge of gut microbially produced small molecules and their effects on host biology remains in its infancy. This Outlook surveys a range of approaches, hurdles, and advances in defining the chemical repertoire of the gut microbiota, drawing on examples with particularly strong links to human health. Progress toward understanding and manipulating this chemical language is being made with diverse chemical and biological expertise and could hold the key for combatting certain human diseases.
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Affiliation(s)
- Justin
E. Silpe
- Department of Chemistry and
Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Emily P. Balskus
- Department of Chemistry and
Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
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13
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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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14
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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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15
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Pang B, Chen Y, Gan F, Yan C, Jin L, Gin JW, Petzold CJ, Keasling JD. Investigation of Indigoidine Synthetase Reveals a Conserved Active-Site Base Residue of Nonribosomal Peptide Synthetase Oxidases. J Am Chem Soc 2020; 142:10931-10935. [PMID: 32510939 DOI: 10.1021/jacs.0c04328] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Nonribosomal peptide synthetase (NRPS) oxidase (Ox) domains oxidize protein-bound intermediates to install crucial structural motifs in bioactive natural products. The mechanism of this domain remains elusive. Here, by studying indigoidine synthetase, a single-module NRPS involved in the biosynthesis of indigoidine and several other bacterial secondary metabolites, we demonstrate that its Ox domain utilizes an active-site base residue, tyrosine 665, to deprotonate a protein-bound l-glutaminyl residue. We further validate the generality of this active-site residue among NRPS Ox domains. These findings not only resolve the biosynthetic pathway mediated by indigoidine synthetase but enable mechanistic insight into NRPS Ox domains.
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Affiliation(s)
- Bo Pang
- QB3 Institute, University of California, Berkeley, Berkeley, California 94720, United States.,Joint BioEnergy Institute, Emeryville, California 94608, United States.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Yan Chen
- Joint BioEnergy Institute, Emeryville, California 94608, United States.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Fei Gan
- QB3 Institute, University of California, Berkeley, Berkeley, California 94720, United States.,Joint BioEnergy Institute, Emeryville, California 94608, United States.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Chunsheng Yan
- Joint BioEnergy Institute, Emeryville, California 94608, United States
| | - Liyuan Jin
- Joint BioEnergy Institute, Emeryville, California 94608, United States
| | - Jennifer W Gin
- Joint BioEnergy Institute, Emeryville, California 94608, United States.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Christopher J Petzold
- Joint BioEnergy Institute, Emeryville, California 94608, United States.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jay D Keasling
- QB3 Institute, University of California, Berkeley, Berkeley, California 94720, United States.,Joint BioEnergy Institute, Emeryville, California 94608, United States.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.,Department of Chemical & Biomolecular Engineering and Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States.,Novo Nordisk Foundation Center for Biosustainability, Technical University Denmark, DK 2970 Horsholm, Denmark.,Center for Synthetic Biochemistry, Shenzhen Institutes for Advanced Technologies, Shenzhen 518055, P. R. China
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16
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Aron AT, Gentry EC, McPhail KL, Nothias LF, Nothias-Esposito M, Bouslimani A, Petras D, Gauglitz JM, Sikora N, Vargas F, van der Hooft JJJ, Ernst M, Kang KB, Aceves CM, Caraballo-Rodríguez AM, Koester I, Weldon KC, Bertrand S, Roullier C, Sun K, Tehan RM, Boya P CA, Christian MH, Gutiérrez M, Ulloa AM, Tejeda Mora JA, Mojica-Flores R, Lakey-Beitia J, Vásquez-Chaves V, Zhang Y, Calderón AI, Tayler N, Keyzers RA, Tugizimana F, Ndlovu N, Aksenov AA, Jarmusch AK, Schmid R, Truman AW, Bandeira N, Wang M, Dorrestein PC. Reproducible molecular networking of untargeted mass spectrometry data using GNPS. Nat Protoc 2020; 15:1954-1991. [PMID: 32405051 DOI: 10.1038/s41596-020-0317-5] [Citation(s) in RCA: 290] [Impact Index Per Article: 72.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 03/03/2020] [Indexed: 02/06/2023]
Abstract
Global Natural Product Social Molecular Networking (GNPS) is an interactive online small molecule-focused tandem mass spectrometry (MS2) data curation and analysis infrastructure. It is intended to provide as much chemical insight as possible into an untargeted MS2 dataset and to connect this chemical insight to the user's underlying biological questions. This can be performed within one liquid chromatography (LC)-MS2 experiment or at the repository scale. GNPS-MassIVE is a public data repository for untargeted MS2 data with sample information (metadata) and annotated MS2 spectra. These publicly accessible data can be annotated and updated with the GNPS infrastructure keeping a continuous record of all changes. This knowledge is disseminated across all public data; it is a living dataset. Molecular networking-one of the main analysis tools used within the GNPS platform-creates a structured data table that reflects the molecular diversity captured in tandem mass spectrometry experiments by computing the relationships of the MS2 spectra as spectral similarity. This protocol provides step-by-step instructions for creating reproducible, high-quality molecular networks. For training purposes, the reader is led through a 90- to 120-min procedure that starts by recalling an example public dataset and its sample information and proceeds to creating and interpreting a molecular network. Each data analysis job can be shared or cloned to disseminate the knowledge gained, thus propagating information that can lead to the discovery of molecules, metabolic pathways, and ecosystem/community interactions.
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Affiliation(s)
- Allegra T Aron
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Emily C Gentry
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Kerry L McPhail
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, USA
| | - Louis-Félix Nothias
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Mélissa Nothias-Esposito
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Amina Bouslimani
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Daniel Petras
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Julia M Gauglitz
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Nicole Sikora
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Fernando Vargas
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | | | - Madeleine Ernst
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Kyo Bin Kang
- College of Pharmacy, Sookmyung Women's University, Seoul, Korea
| | - Christine M Aceves
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | | | - Irina Koester
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Kelly C Weldon
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
- Center of Microbiome Innovation, University of California San Diego, La Jolla, CA, USA
| | - Samuel Bertrand
- Groupe Mer, Molécules, Santé-EA 2160, UFR des Sciences Pharmaceutiques et Biologiques, Université de Nantes, Nantes, France
- ThalassOMICS Metabolomics Facility, Plateforme Corsaire, Biogenouest, Nantes, France
| | - Catherine Roullier
- College of Pharmacy, Sookmyung Women's University, Seoul, Korea
- ThalassOMICS Metabolomics Facility, Plateforme Corsaire, Biogenouest, Nantes, France
| | - Kunyang Sun
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Richard M Tehan
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, USA
| | - Cristopher A Boya P
- Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Panama City, Panama
- Department of Biotechnology, Acharya Nagarjuna University, Guntur, Nagarjuna Nagar, India
| | - Martin H Christian
- Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Panama City, Panama
| | - Marcelino Gutiérrez
- Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Panama City, Panama
| | | | | | - Randy Mojica-Flores
- Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Panama City, Panama
- Departamento de Química, Universidad Autónoma de Chiriquí (UNACHI), David, Chiriquí, Panama
| | - Johant Lakey-Beitia
- Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Panama City, Panama
| | - Victor Vásquez-Chaves
- Centro de Investigaciones en Productos Naturales (CIPRONA), Universidad de Costa Rica, San José, Costa Rica
| | - Yilue Zhang
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Angela I Calderón
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Nicole Tayler
- Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Panama City, Panama
- Department of Biotechnology, Acharya Nagarjuna University, Guntur, Nagarjuna Nagar, India
| | - Robert A Keyzers
- School of Chemical & Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Fidele Tugizimana
- Centre for Plant Metabolomics Research, Department of Biochemistry, University of Johannesburg, Auckland Park, South Africa
- International R&D Division, Omnia Group (Pty) Ltd., Johannesburg, South Africa
| | - Nombuso Ndlovu
- Centre for Plant Metabolomics Research, Department of Biochemistry, University of Johannesburg, Auckland Park, South Africa
| | - Alexander A Aksenov
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Alan K Jarmusch
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Robin Schmid
- Institute of Inorganic and Analytical Chemistry, University of Münster, Münster, Germany
| | - Andrew W Truman
- Department of Molecular Microbiology, John Innes Centre, Norwich, UK
| | - Nuno Bandeira
- Department of Computer Science and Engineering, University of California, San Diego, La Jolla, CA, USA.
| | - Mingxun Wang
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA.
| | - Pieter C Dorrestein
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA.
- Center for Computational Mass Spectrometry, University of California, San Diego, La Jolla, CA, USA.
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA.
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA.
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17
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Wernke KM, Xue M, Tirla A, Kim CS, Crawford JM, Herzon SB. Structure and bioactivity of colibactin. Bioorg Med Chem Lett 2020; 30:127280. [PMID: 32527463 DOI: 10.1016/j.bmcl.2020.127280] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/16/2020] [Accepted: 05/18/2020] [Indexed: 12/27/2022]
Abstract
Colibactin is a secondary metabolite produced by certain strains of bacteria found in the human gut. The presence of colibactin-producing bacteria has been correlated to colorectal cancer in humans. Colibactin was first discovered in 2006, but because it is produced in small quantities and is unstable, it has yet to be isolated from bacterial cultures. Here we summarize advances in the field since ~2017 that have led to the identification of the structure of colibactin as a heterodimer containing two DNA-reactive electrophilic cyclopropane residues. Colibactin has been shown to form interstrand cross-links by alkylation of adenine residues on opposing strands of DNA. The structure of colibactin contains two thiazole rings separated by a two-carbon linker that is thought to exist as an α-aminoketone following completion of the biosynthetic pathway. However, synthetic studies have now established that this α-aminoketone is unstable toward aerobic oxidation; the resulting oxidation products are in turn unstable toward nucleophilic cleavage under mild conditions. These data provide a simple molecular-level explanation for colibactin's instability and potentially also explain the observation that cell-to-cell contact is required for genotoxic effects.
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Affiliation(s)
- Kevin M Wernke
- Department of Chemistry, Yale University, New Haven, CT 06520, United States
| | - Mengzhao Xue
- Department of Chemistry, Yale University, New Haven, CT 06520, United States
| | - Alina Tirla
- Department of Chemistry, Yale University, New Haven, CT 06520, United States
| | - Chung Sub Kim
- Department of Chemistry, Yale University, New Haven, CT 06520, United States; Chemical Biology Institute, Yale University, West Haven, CT 06516, United States
| | - Jason M Crawford
- Department of Chemistry, Yale University, New Haven, CT 06520, United States; Chemical Biology Institute, Yale University, West Haven, CT 06516, United States; Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536, United States
| | - Seth B Herzon
- Department of Chemistry, Yale University, New Haven, CT 06520, United States; Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, United States.
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18
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Abstract
Colibactin is a genotoxic gut microbiome metabolite long suspected of playing an etiological role in colorectal cancer. Evidence suggests that colibactin forms DNA interstrand cross-links (ICLs) in eukaryotic cells and activates ICL repair pathways, leading to the production of ICL-dependent DNA double-strand breaks (DSBs). Here we show that colibactin ICLs can evolve directly to DNA DSBs. Using the topology of supercoiled plasmid DNA as a proxy for alkylation adduct stability, we find that colibactin-derived ICLs are unstable toward depurination and elimination of the 3' phosphate. This ICL degradation pathway leads progressively to single strand breaks (SSBs) and subsequently DSBs. The spontaneous conversion of ICLs to DSBs is consistent with the finding that nonhomologous end joining repair-deficient cells are sensitized to colibactin-producing bacteria. The results herein refine our understanding of colibactin-derived DNA damage and underscore the complexities underlying the DSB phenotype.
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Affiliation(s)
- Mengzhao Xue
- Department of Chemistry , Yale University , New Haven , Connecticut 06520 , United States
| | - Kevin M Wernke
- 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
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19
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Fabian NJ, Mannion AJ, Feng Y, Madden CM, Fox JG. Intestinal colonization of genotoxic Escherichia coli strains encoding colibactin and cytotoxic necrotizing factor in small mammal pets. Vet Microbiol 2019; 240:108506. [PMID: 31902483 DOI: 10.1016/j.vetmic.2019.108506] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 11/06/2019] [Accepted: 11/12/2019] [Indexed: 12/15/2022]
Abstract
Escherichia coli encoding colibactin (clb), cytolethal distending toxin (cdt), and hemolysin-associated cytotoxic necrotizing factor (cnf) are associated with various intestinal and extra-intestinal diseases in humans and animals. Small mammal pets are not evaluated for genotoxin-encoding E. coli. Thus, the prevalence of such strains is unknown. The objective of this study was to isolate and characterize genotoxin-encoding E. coli from healthy and ill small mammal pets examined at a veterinary clinic and at two animal adoption centers. E. coli isolates were cultured from fecal samples and biochemically characterized. A total of 65 animals, including mice, rats, rabbits, guinea pigs, and hedgehogs, were screened. Twenty-six E. coli isolates were obtained from 24 animals. Twelve of the 26 isolates (46.2 %) were PCR-positive for the pks genes clbA and clbQ. Two isolates (7.7 %) were PCR-positive for cnf. All isolates were PCR-negative for cdt. All genotoxin-encoding isolates belonged to the pathogen-associated phylogenetic group B2. Representative genotoxin-encoding isolates had serotypes previously associated with clinical disease in humans and animals. Isolates encoding pks or cnf induced megalocytosis and cytotoxicity to HeLa cells in vitro. Although most isolates were obtained from healthy pets, two guinea pigs with diarrhea had pks-positive isolates cultured from their feces. Whole genome sequencing on four representative isolates confirmed the presence of pks and cnf genes and identified other virulence factors associated with pathogenicity in animals and humans. Our results suggest that small mammalian pets may serve as a reservoir for potentially pathogenic E. coli and implicate a zoonotic risk.
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Affiliation(s)
- Niora J Fabian
- Division of Comparative Medicine, Massachusetts Institute of Technology, Building 16-825, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139, USA.
| | - Anthony J Mannion
- Division of Comparative Medicine, Massachusetts Institute of Technology, Building 16-825, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139, USA.
| | - Yan Feng
- Division of Comparative Medicine, Massachusetts Institute of Technology, Building 16-825, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139, USA.
| | - Carolyn M Madden
- Division of Comparative Medicine, Massachusetts Institute of Technology, Building 16-825, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139, USA.
| | - James G Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Building 16-825, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139, USA.
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20
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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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21
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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: 138] [Impact Index Per Article: 27.6] [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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22
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Jiang Y, Stornetta A, Villalta PW, Wilson MR, Boudreau PD, Zha L, Balbo S, Balskus EP. Reactivity of an Unusual Amidase May Explain Colibactin's DNA Cross-Linking Activity. J Am Chem Soc 2019; 141:11489-11496. [PMID: 31251062 PMCID: PMC6728428 DOI: 10.1021/jacs.9b02453] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Certain commensal and pathogenic bacteria produce colibactin, a small-molecule genotoxin that causes interstrand cross-links in host cell DNA. Although colibactin alkylates DNA, the molecular basis for cross-link formation is unclear. Here, we report that the colibactin biosynthetic enzyme ClbL is an amide bond-forming enzyme that links aminoketone and β-keto thioester substrates in vitro and in vivo. The substrate specificity of ClbL strongly supports a role for this enzyme in terminating the colibactin NRPS-PKS assembly line and incorporating two electrophilic cyclopropane warheads into the final natural product scaffold. This proposed transformation was supported by the detection of a colibactin-derived cross-linked DNA adduct. Overall, this work provides a biosynthetic explanation for colibactin's DNA cross-linking activity and paves the way for further study of its chemical structure and biological roles.
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Affiliation(s)
- Yindi Jiang
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, United States
| | - Alessia Stornetta
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street Southeast, Minneapolis, MN 55455, United States
| | - Peter W. Villalta
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street Southeast, Minneapolis, MN 55455, United States
| | - Matthew R. Wilson
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, United States
| | - Paul D. Boudreau
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, United States
| | - Li Zha
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, United States
| | - Silvia Balbo
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street Southeast, Minneapolis, MN 55455, United States
| | - Emily P. Balskus
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 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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Affiliation(s)
- Steven G Van Lanen
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky, USA
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25
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Kurnick SA, Mannion AJ, Feng Y, Madden CM, Chamberlain P, Fox JG. Genotoxic Escherichia coli Strains Encoding Colibactin, Cytolethal Distending Toxin, and Cytotoxic Necrotizing Factor in Laboratory Rats. Comp Med 2019; 69:103-113. [PMID: 30902120 PMCID: PMC6464076 DOI: 10.30802/aalas-cm-18-000099] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/13/2018] [Accepted: 11/29/2018] [Indexed: 02/06/2023]
Abstract
Although many Escherichia coli strains are considered commensals in mammals, strains encoding the cyclomodulin genotoxins are associated with clinical and subclinical disease in the urogenital and gastrointestinal tracts, meningitis, and inflammatory disorders. These genotoxins include the polyketide synthase (pks) pathogenicity island, cytolethal distending toxin (cdt), and hemolysin-associated cytotoxic necrotizing factor (cnf). E. coli strains are not excluded from rodents housed under SPF conditions in academic or vendor facilities. This study isolated and characterized genotoxin-encoding E. coli from laboratory rats obtained from 4 academic institutions and 3 vendors. A total of 69 distinct E. coli isolates were cultured from feces, rectal swab, nares, or vaginal swab of 52 rats and characterized biochemically. PCR analysis for cyclomodulin genes and phylogroup was performed on all 69 isolates. Of the 69 isolates, 45 (65%) were positive for pks, 20/69 (29%) were positive for cdt, and 4 (6%) were positive for cnf. Colibactin was the sole genotoxin identified in 21 of 45 pks+ isolates (47%), whereas cdt or cnf was also present in the remaining 24 isolates (53%); cdt and cnf were never present together or without pks. All genotoxin-associated strains were members of pathogen-associated phylogroup B2. Fisher exact and χ² tests demonstrated significant differences in genotoxin prevalence and API code distribution with regard to vendor. Select E. coli isolates were characterized by HeLa cell in vitro cytotoxicity assays, serotyped, and whole-genome sequenced. All isolates encoding cyclomodulins induced megalocytosis. Serotypes corresponded with vendor origin and cyclomodulin composition, with the cnf+ serotype representing a known human uropathogen. Whole-genome sequencing confirmed the presence of complete pks, cdt, and hemolysin-cnf pathogenicity islands. These findings indicate that genotoxin-encoding E. coli colonize laboratory rats from multiple commercial vendors and academic institutions and suggest the potential to contribute to clinical disease and introduce confounding variables into experimental rat models.
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Affiliation(s)
- Susanna A Kurnick
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Anthony J Mannion
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Yan Feng
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Carolyn M Madden
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Paul Chamberlain
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - James G Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts;,
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26
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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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27
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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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28
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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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29
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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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30
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Wang L, Ravichandran V, Yin Y, Yin J, Zhang Y. Natural Products from Mammalian Gut Microbiota. Trends Biotechnol 2018; 37:492-504. [PMID: 30392727 DOI: 10.1016/j.tibtech.2018.10.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/03/2018] [Accepted: 10/05/2018] [Indexed: 02/08/2023]
Abstract
The mammalian gut has a remarkable abundance of microbes. These microbes have strong potential to biosynthesize distinct metabolites that are promising drugs, and many more bioactive compounds have yet to be explored as potential drug candidates. These small bioactive molecules often mediate important host-microbe and microbe-microbe interactions. In this review, we provide perspectives on and challenges associated with three mining strategies - culture-based, (meta)genomics-based, and metabolomics-based mining approaches - for discovering natural products derived from biosynthetic gene clusters (BGCs) in mammalian gut microbiota. In addition, we comprehensively summarize the structures, biological functions, and BGCs of these compounds. Improving these techniques, including by using combinatorial approaches, may accelerate drug discovery from gut microbes.
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Affiliation(s)
- Leli Wang
- Laboratory of Animal Nutrition and Human Health, Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, College of Life Science, Hunan Normal University, 410081, Changsha, China; These authors contributed equally to this work
| | - Vinothkannan Ravichandran
- Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, Suzhou Institute of Shandong University, 266235, Qingdao, China; These authors contributed equally to this work
| | - Yulong Yin
- Laboratory of Animal Nutrition and Human Health, Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, College of Life Science, Hunan Normal University, 410081, Changsha, China; Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process; Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, 410125, Changsha, China
| | - Jia Yin
- Laboratory of Animal Nutrition and Human Health, Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, College of Life Science, Hunan Normal University, 410081, Changsha, China; Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, Suzhou Institute of Shandong University, 266235, Qingdao, China.
| | - Youming Zhang
- Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, Suzhou Institute of Shandong University, 266235, Qingdao, China.
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31
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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: 126] [Impact Index Per Article: 21.0] [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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32
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Miyanaga A, Kudo F, Eguchi T. Protein–protein interactions in polyketide synthase–nonribosomal peptide synthetase hybrid assembly lines. Nat Prod Rep 2018; 35:1185-1209. [DOI: 10.1039/c8np00022k] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The protein–protein interactions in polyketide synthase–nonribosomal peptide synthetase hybrids are summarized and discussed.
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Affiliation(s)
- Akimasa Miyanaga
- Department of Chemistry
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
| | - Fumitaka Kudo
- Department of Chemistry
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
| | - Tadashi Eguchi
- Department of Chemistry
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
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33
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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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34
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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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35
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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: 34] [Impact Index Per Article: 4.9] [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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36
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Abstract
Covering: up to 2017.Natural products are important secondary metabolites produced by bacterial and fungal species that play important roles in cellular growth and signaling, nutrient acquisition, intra- and interspecies communication, and virulence. A subset of natural products is produced by nonribosomal peptide synthetases (NRPSs), a family of large, modular enzymes that function in an assembly line fashion. Because of the pharmaceutical activity of many NRPS products, much effort has gone into the exploration of their biosynthetic pathways and the diverse products they make. Many interesting NRPS pathways have been identified and characterized from both terrestrial and marine bacterial sources. Recently, several NRPS pathways in human commensal bacterial species have been identified that produce molecules with antibiotic activity, suggesting another source of interesting NRPS pathways may be the commensal and pathogenic bacteria that live on the human body. The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) have been identified as a significant cause of human bacterial infections that are frequently multidrug resistant. The emerging resistance profile of these organisms has prompted calls from multiple international agencies to identify novel antibacterial targets and develop new approaches to treat infections from ESKAPE pathogens. Each of these species contains several NRPS biosynthetic gene clusters. While some have been well characterized and produce known natural products with important biological roles in microbial physiology, others have yet to be investigated. This review catalogs the NRPS pathways of ESKAPE pathogens. The exploration of novel NRPS products may lead to a better understanding of the chemical communication used by human pathogens and potentially to the discovery of novel therapeutic approaches.
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Affiliation(s)
- Andrew M Gulick
- Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA.
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37
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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: 57] [Impact Index Per Article: 8.1] [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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38
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Mousa WK, Athar B, Merwin NJ, Magarvey NA. Antibiotics and specialized metabolites from the human microbiota. Nat Prod Rep 2017; 34:1302-1331. [DOI: 10.1039/c7np00021a] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Human microbiota associated with each body site produce specialized molecules to kill human pathogens. Advanced bioinformatics tools will help to discover unique microbiome chemistry.
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Affiliation(s)
- Walaa K. Mousa
- Departments of Biochemistry and Biomedical Sciences & Chemistry and Chemical Biology
- M. G. DeGroote Institute for Infectious Disease Research
- McMaster University
- Hamilton
- Canada L8S 4K1
| | - Bilal Athar
- Departments of Biochemistry and Biomedical Sciences & Chemistry and Chemical Biology
- M. G. DeGroote Institute for Infectious Disease Research
- McMaster University
- Hamilton
- Canada L8S 4K1
| | - Nishanth J. Merwin
- Departments of Biochemistry and Biomedical Sciences & Chemistry and Chemical Biology
- M. G. DeGroote Institute for Infectious Disease Research
- McMaster University
- Hamilton
- Canada L8S 4K1
| | - Nathan A. Magarvey
- Departments of Biochemistry and Biomedical Sciences & Chemistry and Chemical Biology
- M. G. DeGroote Institute for Infectious Disease Research
- McMaster University
- Hamilton
- Canada L8S 4K1
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