1
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Crooke AM, Chand AK, Cui Z, Balskus EP. Elucidation of chalkophomycin biosynthesis reveals N-hydroxypyrrole-forming enzymes. bioRxiv 2024:2024.01.24.577118. [PMID: 38328124 PMCID: PMC10849742 DOI: 10.1101/2024.01.24.577118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Reactive functional groups, such as N-nitrosamines, impart unique bioactivities to the natural products in which they are found. Recent work has illuminated enzymatic N-nitrosation reactions in microbial natural product biosynthesis, motivating an interest in discovering additional metabolites constructed using such reactivity. Here, we use a genome mining approach to identify over 400 cryptic biosynthetic gene clusters (BGCs) encoding homologs of the N-nitrosating biosynthetic enzyme SznF, including the BGC for chalkophomycin, a CuII-binding metabolite that contains a C-type diazeniumdiolate and N-hydroxypyrrole. Characterizing chalkophomycin biosynthetic enzymes reveals previously unknown enzymes responsible for N-hydroxypyrrole biosynthesis, including the first prolyl-N-hydroxylase, and a key step in assembly of the diazeniumdiolate-containing amino acid graminine. Discovery of this pathway enriches our understanding of the biosynthetic logic employed in constructing unusual heteroatom-heteroatom bond-containing functional groups, enabling future efforts in natural product discovery and biocatalysis.
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Affiliation(s)
- Anne Marie Crooke
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Anika K. Chand
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Zheng Cui
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Emily P. Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
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2
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Glasser NR, Cui D, Risser DD, Okafor CD, Balskus EP. Accelerating the discovery of alkyl halide-derived natural products using halide depletion. Nat Chem 2024; 16:173-182. [PMID: 38216751 PMCID: PMC10849952 DOI: 10.1038/s41557-023-01390-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 10/30/2023] [Indexed: 01/14/2024]
Abstract
Even in the genomic era, microbial natural product discovery workflows can be laborious and limited in their ability to target molecules with specific structural features. Here we leverage an understanding of biosynthesis to develop a workflow that targets the discovery of alkyl halide-derived natural products by depleting halide anions, a key biosynthetic substrate for enzymatic halogenation, from microbial growth media. By comparing the metabolomes of bacterial cultures grown in halide-replete and deficient media, we rapidly discovered the nostochlorosides, the products of an orphan halogenase-encoding gene cluster from Nostoc punctiforme ATCC 29133. We further found that these products, a family of unusual chlorinated glycolipids featuring the rare sugar gulose, are polymerized via an unprecedented enzymatic etherification reaction. Together, our results highlight the power of leveraging an understanding of biosynthetic logic to streamline natural product discovery.
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Affiliation(s)
- Nathaniel R Glasser
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Dongtao Cui
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Douglas D Risser
- Department of Biology, University of the Pacific, Stockton, CA, USA
| | - C Denise Okafor
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, USA
- Department of Chemistry, Pennsylvania State University, University Park, PA, USA
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
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3
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Altshuller M, He X, MacKrell EJ, Wernke KM, Wong JWH, Sellés-Baiget S, Wang TY, Chou TF, Duxin JP, Balskus EP, Herzon SB, Semlow DR. The Fanconi anemia pathway repairs colibactin-induced DNA interstrand cross-links. bioRxiv 2024:2024.01.30.576698. [PMID: 38352618 PMCID: PMC10862771 DOI: 10.1101/2024.01.30.576698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Colibactin is a secondary metabolite produced by bacteria present in the human gut and is implicated in the progression of colorectal cancer and inflammatory bowel disease. This genotoxin alkylates deoxyadenosines on opposite strands of host cell DNA to produce DNA interstrand cross-links (ICLs) that block DNA replication. While cells have evolved multiple mechanisms to resolve ("unhook") ICLs encountered by the replication machinery, little is known about which of these pathways promote resistance to colibactin-induced ICLs. Here, we use Xenopus egg extracts to investigate replication-coupled repair of plasmids engineered to contain site-specific colibactin-ICLs. We show that replication fork stalling at a colibactin-ICL leads to replisome disassembly and activation of the Fanconi anemia ICL repair pathway, which unhooks the colibactin-ICL through nucleolytic incisions. These incisions generate a DNA double-strand break intermediate in one sister chromatid, which can be repaired by homologous recombination, and a monoadduct ("ICL remnant") in the other. Our data indicate that translesion synthesis past the colibactin-ICL remnant depends on Polη and a Polκ-REV1-Polζ polymerase complex. Although translesion synthesis past colibactin-induced DNA damage is frequently error-free, it can introduce T>N point mutations that partially recapitulate the mutation signature associated with colibactin exposure in vivo. Taken together, our work provides a biochemical framework for understanding how cells tolerate a naturally-occurring and clinically-relevant ICL.
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Affiliation(s)
- Maria Altshuller
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Xu He
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Elliot J. MacKrell
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Kevin M. Wernke
- Department of Chemistry, Yale University, New Haven, CT, USA
| | - Joel W. H. Wong
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Selene Sellés-Baiget
- TheNovo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ting-Yu Wang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Proteome Exploration Laboratory, Beckman Institute, California Institute of Technology, Pasadena, CA, USA
| | - Tsui-Fen Chou
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Proteome Exploration Laboratory, Beckman Institute, California Institute of Technology, Pasadena, CA, USA
| | - Julien P. Duxin
- TheNovo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emily P. Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Seth B. Herzon
- Department of Chemistry, Yale University, New Haven, CT, USA
| | - Daniel R. Semlow
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
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4
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Kountz DJ, Balskus EP. A diversified, widespread microbial gene cluster encodes homologs of methyltransferases involved in methanogenesis. bioRxiv 2023:2023.07.31.551370. [PMID: 37577662 PMCID: PMC10418091 DOI: 10.1101/2023.07.31.551370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Analyses of microbial genomes have revealed unexpectedly wide distributions of enzymes from specialized metabolism, including methanogenesis, providing exciting opportunities for discovery. Here, we identify a family of gene clusters (the type 1 mlp gene clusters (MGCs)) that encodes homologs of the soluble coenzyme M methyltransferases (SCMTs) involved in methylotrophic methanogenesis and is widespread in bacteria and archaea. Type 1 MGCs are expressed and regulated in medically, environmentally, and industrially important organisms, making them likely to be physiologically relevant. Enzyme annotation, analysis of genomic context, and biochemical experiments suggests these gene clusters play a role in methyl-sulfur and/or methyl-selenide metabolism in numerous anoxic environments, including the human gut microbiome, potentially impacting sulfur and selenium cycling in diverse, anoxic environments.
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Affiliation(s)
- Duncan J. Kountz
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Emily P. Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
- Howard Hughes Medical Institute, Harvard University, Cambridge, Massachusetts 02138, United States
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5
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Mayers JR, Varon J, Zhou RR, Daniel-Ivad M, Beaulieu C, Bholse A, Glasser NR, Lichtenauer FM, Ng J, Vera MP, Huttenhower C, Perrella MA, Clish CB, Zhao SD, Baron RM, Balskus EP. Identification and targeting of microbial putrescine acetylation in bloodstream infections. bioRxiv 2023:2023.09.21.558834. [PMID: 37790300 PMCID: PMC10542159 DOI: 10.1101/2023.09.21.558834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
The growth of antimicrobial resistance (AMR) has highlighted an urgent need to identify bacterial pathogenic functions that may be targets for clinical intervention. Although severe bacterial infections profoundly alter host metabolism, prior studies have largely ignored alterations in microbial metabolism in this context. Performing metabolomics on patient and mouse plasma samples, we identify elevated levels of bacterially-derived N-acetylputrescine during gram-negative bloodstream infections (BSI), with higher levels associated with worse clinical outcomes. We discover that SpeG is the bacterial enzyme responsible for acetylating putrescine and show that blocking its activity reduces bacterial proliferation and slows pathogenesis. Reduction of SpeG activity enhances bacterial membrane permeability and results in increased intracellular accumulation of antibiotics, allowing us to overcome AMR of clinical isolates both in culture and in vivo. This study highlights how studying pathogen metabolism in the natural context of infection can reveal new therapeutic strategies for addressing challenging infections.
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Affiliation(s)
- Jared R. Mayers
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA 02115
- Harvard Medical School, Boston, MA, USA 02115
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA 02138
| | - Jack Varon
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA 02115
- Harvard Medical School, Boston, MA, USA 02115
| | - Ruixuan R. Zhou
- Department of Statistics, University of Illinois at Urbana Champaign, Champaign, IL, USA 61820
| | - Martin Daniel-Ivad
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA 02138
- Broad Institute of MIT and Harvard, Cambridge, MA, USA 02142
| | | | - Amrisha Bholse
- Broad Institute of MIT and Harvard, Cambridge, MA, USA 02142
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA 02115
| | - Nathaniel R. Glasser
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA 02138
| | | | - Julie Ng
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA 02115
- Harvard Medical School, Boston, MA, USA 02115
| | - Mayra Pinilla Vera
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA 02115
| | - Curtis Huttenhower
- Broad Institute of MIT and Harvard, Cambridge, MA, USA 02142
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA 02115
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Mark A. Perrella
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA 02115
- Harvard Medical School, Boston, MA, USA 02115
| | - Clary B. Clish
- Broad Institute of MIT and Harvard, Cambridge, MA, USA 02142
| | - Sihai D. Zhao
- Department of Statistics, University of Illinois at Urbana Champaign, Champaign, IL, USA 61820
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana Champaign, Champaign, IL, USA 61820
| | - Rebecca M. Baron
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA 02115
- Harvard Medical School, Boston, MA, USA 02115
| | - Emily P. Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA 02138
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA 02138
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6
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Nagashima K, Zhao A, Atabakhsh K, Bae M, Blum JE, Weakley A, Jain S, Meng X, Cheng AG, Wang M, Higginbottom S, Dimas A, Murugkar P, Sattely ES, Moon JJ, Balskus EP, Fischbach MA. Mapping the T cell repertoire to a complex gut bacterial community. Nature 2023; 621:162-170. [PMID: 37587342 PMCID: PMC10948025 DOI: 10.1038/s41586-023-06431-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/13/2023] [Indexed: 08/18/2023]
Abstract
Certain bacterial strains from the microbiome induce a potent, antigen-specific T cell response1-5. However, the specificity of microbiome-induced T cells has not been explored at the strain level across the gut community. Here, we colonize germ-free mice with complex defined communities (roughly 100 bacterial strains) and profile T cell responses to each strain. The pattern of responses suggests that many T cells in the gut repertoire recognize several bacterial strains from the community. We constructed T cell hybridomas from 92 T cell receptor (TCR) clonotypes; by screening every strain in the community against each hybridoma, we find that nearly all the bacteria-specific TCRs show a one-to-many TCR-to-strain relationship, including 13 abundant TCR clonotypes that each recognize 18 Firmicutes. By screening three pooled bacterial genomic libraries, we discover that these 13 clonotypes share a single target: a conserved substrate-binding protein from an ATP-binding cassette transport system. Peripheral regulatory T cells and T helper 17 cells specific for an epitope from this protein are abundant in community-colonized and specific pathogen-free mice. Our work reveals that T cell recognition of commensals is focused on widely conserved, highly expressed cell-surface antigens, opening the door to new therapeutic strategies in which colonist-specific immune responses are rationally altered or redirected.
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Affiliation(s)
- Kazuki Nagashima
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
- ChEM-H Institute, Stanford University, Stanford, CA, USA
| | - Aishan Zhao
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
- ChEM-H Institute, Stanford University, Stanford, CA, USA
| | - Katayoon Atabakhsh
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
- ChEM-H Institute, Stanford University, Stanford, CA, USA
| | - Minwoo Bae
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Jamie E Blum
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford, CA, USA
| | - Allison Weakley
- ChEM-H Institute, Stanford University, Stanford, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Sunit Jain
- ChEM-H Institute, Stanford University, Stanford, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Xiandong Meng
- ChEM-H Institute, Stanford University, Stanford, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Alice G Cheng
- Department of Gastroenterology, Stanford School of Medicine, Stanford, CA, USA
| | - Min Wang
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
- ChEM-H Institute, Stanford University, Stanford, CA, USA
| | - Steven Higginbottom
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
- ChEM-H Institute, Stanford University, Stanford, CA, USA
| | - Alex Dimas
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
- ChEM-H Institute, Stanford University, Stanford, CA, USA
| | | | - Elizabeth S Sattely
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford, CA, USA
| | - James J Moon
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Cambridge, MA, USA
| | - Michael A Fischbach
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA.
- ChEM-H Institute, Stanford University, Stanford, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
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7
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Jenkins DJ, Woolston BM, Hood-Pishchany MI, Pelayo P, Konopaski AN, Quinn Peters M, France MT, Ravel J, Mitchell CM, Rakoff-Nahoum S, Whidbey C, Balskus EP. Bacterial amylases enable glycogen degradation by the vaginal microbiome. Nat Microbiol 2023; 8:1641-1652. [PMID: 37563289 PMCID: PMC10465358 DOI: 10.1038/s41564-023-01447-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 07/11/2023] [Indexed: 08/12/2023]
Abstract
The human vaginal microbiota is frequently dominated by lactobacilli and transition to a more diverse community of anaerobic microbes is associated with health risks. Glycogen released by lysed epithelial cells is believed to be an important nutrient source in the vagina. However, the mechanism by which vaginal bacteria metabolize glycogen is unclear, with evidence implicating both bacterial and human enzymes. Here we biochemically characterize six glycogen-degrading enzymes (GDEs), all of which are pullanases (PulA homologues), from vaginal bacteria that support the growth of amylase-deficient Lactobacillus crispatus on glycogen. We reveal variations in their pH tolerance, substrate preferences, breakdown products and susceptibility to inhibition. Analysis of vaginal microbiome datasets shows that these enzymes are expressed in all community state types. Finally, we confirm the presence and activity of bacterial and human GDEs in cervicovaginal fluid. This work establishes that bacterial GDEs can participate in the breakdown of glycogen, providing insight into metabolism that may shape the vaginal microbiota.
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Affiliation(s)
- Dominick J Jenkins
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Benjamin M Woolston
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Department of Chemical Engineering, Northeastern University, Boston, MA, USA
| | - M Indriati Hood-Pishchany
- Division of Infectious Diseases and Division of Gastroenterology, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Paula Pelayo
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | | | - M Quinn Peters
- Department of Chemistry, Seattle University, Seattle, WA, USA
| | - Michael T France
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jacques Ravel
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Caroline M Mitchell
- Vincent Center for Reproductive Biology, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Seth Rakoff-Nahoum
- Division of Infectious Diseases and Division of Gastroenterology, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA.
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
| | | | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
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8
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Woo AYM, Aguilar Ramos MA, Narayan R, Richards-Corke KC, Wang ML, Sandoval-Espinola WJ, Balskus EP. Publisher Correction: Targeting the human gut microbiome with small-molecule inhibitors. Nat Rev Chem 2023:10.1038/s41570-023-00513-x. [PMID: 37311851 DOI: 10.1038/s41570-023-00513-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Affiliation(s)
- Amelia Y M Woo
- Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA, USA
| | | | - Rohan Narayan
- Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA, USA
| | | | - Michelle L Wang
- Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA, USA
| | - Walter J Sandoval-Espinola
- Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA, USA
- Universidad Nacional de Asunción, Facultad de Ciencias Exactas y Naturales, Departamento de Biotecnología, Laboratorio de Biotecnología Microbiana, San Lorenzo, Paraguay
| | - Emily P Balskus
- Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
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9
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Mandelbaum N, Zhang L, Carasso S, Ziv T, Lifshiz-Simon S, Davidovich I, Luz I, Berinstein E, Gefen T, Cooks T, Talmon Y, Balskus EP, Geva-Zatorsky N. Extracellular vesicles of the Gram-positive gut symbiont Bifidobacterium longum induce immune-modulatory, anti-inflammatory effects. NPJ Biofilms Microbiomes 2023; 9:30. [PMID: 37270554 DOI: 10.1038/s41522-023-00400-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 05/18/2023] [Indexed: 06/05/2023] Open
Abstract
The gut microbiota is now well known to affect the host's immune system. One way of bacterial communication with host cells is via the secretion of vesicles, small membrane structures containing various cargo. Research on vesicles secreted by Gram-positive gut bacteria, their mechanisms of interaction with the host and their immune-modulatory effects are still relatively scarce. Here we characterized the size, protein content, and immune-modulatory effects of extracellular vesicles (EVs) secreted by a newly sequenced Gram-positive human gut symbiont strain - Bifidobacterium longum AO44. We found that B. longum EVs exert anti-inflammatory effects, inducing IL-10 secretion from both splenocytes and dendritic cells (DC)-CD4+ T cells co-cultures. Furthermore, the EVs protein content showed enrichment in ABC transporters, quorum sensing proteins, and extracellular solute-binding proteins, which were previously shown to have a prominent function in the anti-inflammatory effect of other strains of B. longum. This study underlines the importance of bacterial vesicles in facilitating the gut bacterial immune-modulatory effects on the host and sheds light on bacterial vesicles as future therapeutics.
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Affiliation(s)
- Noa Mandelbaum
- Department of Cell Biology and Cancer Science, Rappaport Faculty of Medicine and Research Institute, Rappaport Technion Integrated Cancer Center (RTICC), Technion-Israel Institute of Technology, Haifa, 31096, Israel
| | - Lihan Zhang
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Shaqed Carasso
- Department of Cell Biology and Cancer Science, Rappaport Faculty of Medicine and Research Institute, Rappaport Technion Integrated Cancer Center (RTICC), Technion-Israel Institute of Technology, Haifa, 31096, Israel
| | - Tamar Ziv
- Smoler Proteomics Center, Lokey Interdisciplinary Center for Life Sciences & Engineering, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Sapir Lifshiz-Simon
- Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Irina Davidovich
- Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Ishai Luz
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, 84105, Israel
| | - Elliot Berinstein
- Department of Cell Biology and Cancer Science, Rappaport Faculty of Medicine and Research Institute, Rappaport Technion Integrated Cancer Center (RTICC), Technion-Israel Institute of Technology, Haifa, 31096, Israel
| | - Tal Gefen
- Department of Cell Biology and Cancer Science, Rappaport Faculty of Medicine and Research Institute, Rappaport Technion Integrated Cancer Center (RTICC), Technion-Israel Institute of Technology, Haifa, 31096, Israel
| | - Tomer Cooks
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, 84105, Israel
| | - Yeshayahu Talmon
- Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Naama Geva-Zatorsky
- Department of Cell Biology and Cancer Science, Rappaport Faculty of Medicine and Research Institute, Rappaport Technion Integrated Cancer Center (RTICC), Technion-Israel Institute of Technology, Haifa, 31096, Israel.
- Humans and the Microbiome, CIFAR, Toronto, Canada.
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10
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Van Cura D, Ng TL, Huang J, Hager H, Hartwig JF, Keasling JD, Balskus EP. Discovery of the Azaserine Biosynthetic Pathway Uncovers a Biological Route for α-Diazoester Production. Angew Chem Int Ed Engl 2023:e202304646. [PMID: 37151182 DOI: 10.1002/anie.202304646] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 05/09/2023]
Abstract
Azaserine is a bacterial metabolite containing a biologically unusual and synthetically enabling α-diazoester functional group. Here, we report the discovery of the azaserine (aza) biosynthetic gene cluster from Glycomyces harbinensis. Discovery of related gene clusters reveals previously unappreciated azaserine producers, and heterologous expression of the aza gene cluster confirms its role in azaserine assembly. Notably, this gene cluster encodes homologs of hydrazonoacetic acid (HYAA)-producing enzymes, implicating HYAA in α-diazoester biosynthesis. Isotope feeding and biochemical experiments support this hypothesis. These discoveries indicate that a 2-electron oxidation of a hydrazonoacetyl intermediate is required for α-diazoester formation, constituting a distinct logic for diazo biosynthesis. Uncovering this biological route for α-diazoester synthesis now enables the production of a highly versatile carbene precursor in cells, facilitating approaches for engineering complete carbene-mediated biosynthetic transformations in vivo.
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Affiliation(s)
- Devon Van Cura
- Harvard University, Chemistry and Chemical Biology, UNITED STATES
| | - Tai L Ng
- Harvard University, Chemistry and Chemical Biology, UNITED STATES
| | - Jing Huang
- Lawrence Berkeley Laboratory: E O Lawrence Berkeley National Laboratory, Biological Systems and Engineering Division, UNITED STATES
| | - Harry Hager
- Harvard University, Chemistry and Chemical Biology, UNITED STATES
| | - John F Hartwig
- University of California Berkeley, Chemistry, UNITED STATES
| | - Jay D Keasling
- Lawrence Berkeley Laboratory: E O Lawrence Berkeley National Laboratory, Biological Systems and Engineering Division, UNITED STATES
| | - Emily P Balskus
- Harvard University, Department of Chemistry and Chemical Biology, 12 Oxford St., Mallinckrodt 303N, 2138, Cambridge, UNITED STATES
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11
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Huang J, Quest A, Cruz-Morales P, Deng K, Pereira JH, Van Cura D, Kakumanu R, Baidoo EEK, Dan Q, Chen Y, Petzold CJ, Northen TR, Adams PD, Clark DS, Balskus EP, Hartwig JF, Mukhopadhyay A, Keasling JD. Complete integration of carbene-transfer chemistry into biosynthesis. Nature 2023; 617:403-408. [PMID: 37138074 DOI: 10.1038/s41586-023-06027-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/28/2023] [Indexed: 05/05/2023]
Abstract
Biosynthesis is an environmentally benign and renewable approach that can be used to produce a broad range of natural and, in some cases, new-to-nature products. However, biology lacks many of the reactions that are available to synthetic chemists, resulting in a narrower scope of accessible products when using biosynthesis rather than synthetic chemistry. A prime example of such chemistry is carbene-transfer reactions1. Although it was recently shown that carbene-transfer reactions can be performed in a cell and used for biosynthesis2,3, carbene donors and unnatural cofactors needed to be added exogenously and transported into cells to effect the desired reactions, precluding cost-effective scale-up of the biosynthesis process with these reactions. Here we report the access to a diazo ester carbene precursor by cellular metabolism and a microbial platform for introducing unnatural carbene-transfer reactions into biosynthesis. The α-diazoester azaserine was produced by expressing a biosynthetic gene cluster in Streptomyces albus. The intracellularly produced azaserine was used as a carbene donor to cyclopropanate another intracellularly produced molecule-styrene. The reaction was catalysed by engineered P450 mutants containing a native cofactor with excellent diastereoselectivity and a moderate yield. Our study establishes a scalable, microbial platform for conducting intracellular abiological carbene-transfer reactions to functionalize a range of natural and new-to-nature products and expands the scope of organic products that can be produced by cellular metabolism.
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Affiliation(s)
- Jing Huang
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA
| | - Andrew Quest
- Department of Chemistry, University of California, Berkeley, CA, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Pablo Cruz-Morales
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Kai Deng
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA
- Department of Biomaterials and Biomanufacturing, Sandia National Laboratories, Livermore, CA, USA
| | - Jose Henrique Pereira
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Devon Van Cura
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Ramu Kakumanu
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA
| | - Edward E K Baidoo
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA
| | - Qingyun Dan
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA
| | - Yan Chen
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA
| | - Christopher J Petzold
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA
| | - Trent R Northen
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Paul D Adams
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Bioengineering, University of California, Berkeley, CA, USA
| | - Douglas S Clark
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA.
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - John F Hartwig
- Department of Chemistry, University of California, Berkeley, CA, USA.
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - Aindrila Mukhopadhyay
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA.
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - Jay D Keasling
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA.
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA.
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark.
- Department of Bioengineering, University of California, Berkeley, CA, USA.
- Synthetic Biochemistry Center, Institute for Synthetic Biology, Shenzhen Institutes for Advanced Technologies, Shenzhen, China.
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12
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Woo AYM, Aguilar Ramos MA, Narayan R, Richards-Corke KC, Wang ML, Sandoval-Espinola WJ, Balskus EP. Targeting the human gut microbiome with small-molecule inhibitors. Nat Rev Chem 2023; 7:319-339. [PMID: 37117817 DOI: 10.1038/s41570-023-00471-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/20/2023] [Indexed: 04/30/2023]
Abstract
The human gut microbiome is a complex microbial community that is strongly linked to both host health and disease. However, the detailed molecular mechanisms underlying the effects of these microorganisms on host biology remain largely uncharacterized. The development of non-lethal, small-molecule inhibitors that target specific gut microbial activities enables a powerful but underutilized approach to studying the gut microbiome and a promising therapeutic strategy. In this Review, we will discuss the challenges of studying this microbial community, the historic use of small-molecule inhibitors in microbial ecology, and recent applications of this strategy. We also discuss the evidence suggesting that host-targeted drugs can affect the growth and metabolism of gut microbes. Finally, we address the issues of developing and implementing microbiome-targeted small-molecule inhibitors and define important future directions for this research.
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Affiliation(s)
- Amelia Y M Woo
- Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA, USA
| | | | - Rohan Narayan
- Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA, USA
| | | | - Michelle L Wang
- Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA, USA
| | - Walter J Sandoval-Espinola
- Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA, USA
- Universidad Nacional de Asunción, Facultad de Ciencias Exactas y Naturales, Departamento de Biotecnología, Laboratorio de Biotecnología Microbiana, San Lorenzo, Paraguay
| | - Emily P Balskus
- Harvard University, Department of Chemistry and Chemical Biology, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
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13
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Mehta RS, Mayers JR, Zhang Y, Bhosle A, Glasser NR, Nguyen LH, Ma W, Bae S, Branck T, Song K, Sebastian L, Pacheco JA, Seo HS, Clish C, Dhe-Paganon S, Ananthakrishnan AN, Franzosa EA, Balskus EP, Chan AT, Huttenhower C. Gut microbial metabolism of 5-ASA diminishes its clinical efficacy in inflammatory bowel disease. Nat Med 2023; 29:700-709. [PMID: 36823301 PMCID: PMC10928503 DOI: 10.1038/s41591-023-02217-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 01/10/2023] [Indexed: 02/25/2023]
Abstract
For decades, variability in clinical efficacy of the widely used inflammatory bowel disease (IBD) drug 5-aminosalicylic acid (5-ASA) has been attributed, in part, to its acetylation and inactivation by gut microbes. Identification of the responsible microbes and enzyme(s), however, has proved elusive. To uncover the source of this metabolism, we developed a multi-omics workflow combining gut microbiome metagenomics, metatranscriptomics and metabolomics from the longitudinal IBDMDB cohort of 132 controls and patients with IBD. This associated 12 previously uncharacterized microbial acetyltransferases with 5-ASA inactivation, belonging to two protein superfamilies: thiolases and acyl-CoA N-acyltransferases. In vitro characterization of representatives from both families confirmed the ability of these enzymes to acetylate 5-ASA. A cross-sectional analysis within the discovery cohort and subsequent prospective validation within the independent SPARC IBD cohort (n = 208) found three of these microbial thiolases and one acyl-CoA N-acyltransferase to be epidemiologically associated with an increased risk of treatment failure among 5-ASA users. Together, these data address a longstanding challenge in IBD management, outline a method for the discovery of previously uncharacterized gut microbial activities and advance the possibility of microbiome-based personalized medicine.
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Affiliation(s)
- Raaj S Mehta
- Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Clinical & Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Jared R Mayers
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Yancong Zhang
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Biostatistics, T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
- Harvard Chan Microbiome in Public Health Center, T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Amrisha Bhosle
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Biostatistics, T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
- Harvard Chan Microbiome in Public Health Center, T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Nathaniel R Glasser
- Resnick Sustainability Institute, California Institute of Technology, Pasadena, CA, USA
| | - Long H Nguyen
- Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Clinical & Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Wenjie Ma
- Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Clinical & Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Sena Bae
- Department of Immunology & Infectious Disease, T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Tobyn Branck
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Biostatistics, T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Kijun Song
- Department of Cancer Biology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA
| | - Luke Sebastian
- Department of Cancer Biology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA
| | | | - Hyuk-Soo Seo
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Clary Clish
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sirano Dhe-Paganon
- Department of Cancer Biology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA
| | - Ashwin N Ananthakrishnan
- Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Clinical & Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Eric A Franzosa
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Biostatistics, T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Emily P Balskus
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Andrew T Chan
- Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Clinical & Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Immunology & Infectious Disease, T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Curtis Huttenhower
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Biostatistics, T. H. Chan School of Public Health, Harvard University, Boston, MA, USA.
- Harvard Chan Microbiome in Public Health Center, T. H. Chan School of Public Health, Harvard University, Boston, MA, USA.
- Department of Immunology & Infectious Disease, T. H. Chan School of Public Health, Harvard University, Boston, MA, USA.
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14
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Velilla JA, Volpe MR, Kenney GE, Walsh RM, Balskus EP, Gaudet R. Structural basis of colibactin activation by the ClbP peptidase. Nat Chem Biol 2023; 19:151-158. [PMID: 36253550 PMCID: PMC9889268 DOI: 10.1038/s41589-022-01142-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 08/12/2022] [Indexed: 02/04/2023]
Abstract
Colibactin, a DNA cross-linking agent produced by gut bacteria, is implicated in colorectal cancer. Its biosynthesis uses a prodrug resistance mechanism: a non-toxic precursor assembled in the cytoplasm is activated after export to the periplasm. This activation is mediated by ClbP, an inner-membrane peptidase with an N-terminal periplasmic catalytic domain and a C-terminal three-helix transmembrane domain. Although the transmembrane domain is required for colibactin activation, its role in catalysis is unclear. Our structure of full-length ClbP bound to a product analog reveals an interdomain interface important for substrate binding and enzyme stability and interactions that explain the selectivity of ClbP for the N-acyl-D-asparagine prodrug motif. Based on structural and biochemical evidence, we propose that ClbP dimerizes to form an extended substrate-binding site that can accommodate a pseudodimeric precolibactin with its two terminal prodrug motifs in the two ClbP active sites, thus enabling the coordinated activation of both electrophilic warheads.
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Affiliation(s)
- José A Velilla
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Matthew R Volpe
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Grace E Kenney
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Richard M Walsh
- Harvard Cryo-EM Center for Structural Biology, Harvard Medical School, Boston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Rachelle Gaudet
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
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15
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Volpe MR, Velilla JA, Daniel-Ivad M, Yao JJ, Stornetta A, Villalta PW, Huang HC, Bachovchin DA, Balbo S, Gaudet R, Balskus EP. A small molecule inhibitor prevents gut bacterial genotoxin production. Nat Chem Biol 2023; 19:159-167. [PMID: 36253549 PMCID: PMC9889270 DOI: 10.1038/s41589-022-01147-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 08/19/2022] [Indexed: 02/04/2023]
Abstract
The human gut bacterial genotoxin colibactin is a possible key driver of colorectal cancer (CRC) development. Understanding colibactin's biological effects remains difficult owing to the instability of the proposed active species and the complexity of the gut microbiota. Here, we report small molecule boronic acid inhibitors of colibactin biosynthesis. Designed to mimic the biosynthetic precursor precolibactin, these compounds potently inhibit the colibactin-activating peptidase ClbP. Using biochemical assays and crystallography, we show that they engage the ClbP binding pocket, forming a covalent bond with the catalytic serine. These inhibitors reproduce the phenotypes observed in a clbP deletion mutant and block the genotoxic effects of colibactin on eukaryotic cells. The availability of ClbP inhibitors will allow precise, temporal control over colibactin production, enabling further study of its contributions to CRC. Finally, application of our inhibitors to related peptidase-encoding pathways highlights the power of chemical tools to probe natural product biosynthesis.
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Affiliation(s)
- Matthew R. Volpe
- grid.38142.3c000000041936754XDepartment of Chemistry and Chemical Biology, Harvard University, Cambridge, MA USA
| | - José A. Velilla
- grid.38142.3c000000041936754XDepartment of Molecular and Cellular Biology, Harvard University, Cambridge, MA USA
| | - Martin Daniel-Ivad
- grid.38142.3c000000041936754XDepartment of Chemistry and Chemical Biology, Harvard University, Cambridge, MA USA
| | - Jenny J. Yao
- grid.38142.3c000000041936754XDepartment of Chemistry and Chemical Biology, Harvard University, Cambridge, MA USA
| | - Alessia Stornetta
- grid.17635.360000000419368657Masonic Cancer Center, University of Minnesota, Minneapolis, MN USA
| | - Peter W. Villalta
- grid.17635.360000000419368657Masonic Cancer Center, University of Minnesota, Minneapolis, MN USA ,grid.17635.360000000419368657Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN USA
| | - Hsin-Che Huang
- grid.51462.340000 0001 2171 9952Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY USA
| | - Daniel A. Bachovchin
- grid.51462.340000 0001 2171 9952Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY USA
| | - Silvia Balbo
- grid.17635.360000000419368657Masonic Cancer Center, University of Minnesota, Minneapolis, MN USA ,grid.17635.360000000419368657Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN USA
| | - Rachelle Gaudet
- grid.38142.3c000000041936754XDepartment of Molecular and Cellular Biology, Harvard University, Cambridge, MA USA
| | - Emily P. Balskus
- grid.38142.3c000000041936754XDepartment of Chemistry and Chemical Biology, Harvard University, Cambridge, MA USA ,grid.38142.3c000000041936754XHoward Hughes Medical Institute, Harvard University, Cambridge, MA USA
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16
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Balskus EP. Elucidating the Chemistry and Biology of the Human Microbiome. Biochemistry 2022; 61:2777-2778. [DOI: 10.1021/acs.biochem.2c00652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Emily P. Balskus
- Harvard University, Department of Chemistry and Chemical Biology, Cambridge, Massachusetts 02138, United States
- Howard Hughes Medical Institute, Harvard University, Cambridge, Massachusetts 02138, United States
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17
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Dong X, Guthrie BGH, Alexander M, Noecker C, Ramirez L, Glasser NR, Turnbaugh PJ, Balskus EP. Genetic manipulation of the human gut bacterium Eggerthella lenta reveals a widespread family of transcriptional regulators. Nat Commun 2022; 13:7624. [PMID: 36494336 PMCID: PMC9734109 DOI: 10.1038/s41467-022-33576-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 09/21/2022] [Indexed: 12/13/2022] Open
Abstract
Eggerthella lenta is a prevalent human gut Actinobacterium implicated in drug, dietary phytochemical, and bile acid metabolism and associated with multiple human diseases. No genetic tools are currently available for the direct manipulation of E. lenta. Here, we construct shuttle vectors and develop methods to transform E. lenta and other Coriobacteriia. With these tools, we characterize endogenous E. lenta constitutive and inducible promoters using a reporter system and construct inducible expression systems, enabling tunable gene regulation. We also achieve genome editing by harnessing an endogenous type I-C CRISPR-Cas system. Using these tools to perform genetic knockout and complementation, we dissect the functions of regulatory proteins and enzymes involved in catechol metabolism, revealing a previously unappreciated family of membrane-spanning LuxR-type transcriptional regulators. Finally, we employ our genetic toolbox to study the effects of E. lenta genes on mammalian host biology. By greatly expanding our ability to study and engineer gut Coriobacteriia, these tools will reveal mechanistic details of host-microbe interactions and provide a roadmap for genetic manipulation of other understudied human gut bacteria.
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Affiliation(s)
- Xueyang Dong
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Ben G H Guthrie
- Department of Microbiology & Immunology, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Margaret Alexander
- Department of Microbiology & Immunology, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Cecilia Noecker
- Department of Microbiology & Immunology, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Lorenzo Ramirez
- Department of Microbiology & Immunology, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Nathaniel R Glasser
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Peter J Turnbaugh
- Department of Microbiology & Immunology, University of California San Francisco, San Francisco, CA, 94143, USA.,Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA. .,Howard Hughes Medical Institute, Harvard University, Cambridge, MA, 02138, USA.
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18
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Martins T, Glasser NR, Kountz DJ, Oliveira P, Balskus EP, Leão PN. Biosynthesis of the Unusual Carbon Skeleton of Nocuolin A. ACS Chem Biol 2022; 17:2528-2537. [PMID: 36044983 PMCID: PMC9486936 DOI: 10.1021/acschembio.2c00464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 08/15/2022] [Indexed: 11/28/2022]
Abstract
Nocuolin A is a cytotoxic cyanobacterial metabolite that is proposed to be produced by enzymes of the noc biosynthetic gene cluster. Nocuolin A features a 1,2,3-oxadiazine moiety, a structural feature unique among natural products and, so far, inaccessible through organic synthesis, suggesting that novel enzymatic chemistry might be involved in its biosynthesis. This heterocycle is substituted with two alkyl chains and a 3-hydroxypropanoyl moiety. We report here our efforts to elucidate the origin of the carbon skeleton of nocuolin A. Supplementation of cyanobacterial cultures with stable isotope-labeled fatty acids revealed that the central C13 chain is assembled from two medium-chain fatty acids, hexanoic and octanoic acids. Using biochemical assays, we show that a fatty acyl-AMP ligase, NocH, activates both fatty acids as acyl adenylates, which are loaded onto an acyl carrier protein domain and undergo a nondecarboxylative Claisen condensation catalyzed by the ketosynthase NocG. This enzyme is part of a phylogenetically well-defined clade within similar genomic contexts. NocG presents a unique combination of characteristics found in other ketosynthases, namely in terms of substrate specificity and reactivity. Further supplementation experiments indicate that the 3-hydroxypropanoyl moiety of 1 originates from methionine, through an as-yet-uncharacterized mechanism. This work provides ample biochemical evidence connecting the putative noc biosynthetic gene cluster to nocuolin A and identifies the origin of all its carbon atoms, setting the stage for elucidation of its unusual biosynthetic chemistry.
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Affiliation(s)
- Teresa
P. Martins
- CIIMAR
− Interdisciplinary Centre of Marine and Environmental Research, University of Porto, 4450-208 Matosinhos, Portugal
- ICBAS
− Institute of Biomedical Sciences Abel Salazar, University of Porto, 4050-313 Porto, Portugal
| | - Nathaniel R. Glasser
- Department
of Chemistry and Chemical Biology, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - Duncan J. Kountz
- Department
of Chemistry and Chemical Biology, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - Paulo Oliveira
- i3S
− Institute for Research and Innovation in Health, University of Porto, 4200-135 Porto, Portugal
- IBMC
− Institute of Molecular and Cell Biology, University of Porto, 4200-135 Porto, Portugal
- Department
of Biology, Faculty of Sciences, University
of Porto, 4169-00 Porto, Portugal
| | - Emily P. Balskus
- Department
of Chemistry and Chemical Biology, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - Pedro N. Leão
- CIIMAR
− Interdisciplinary Centre of Marine and Environmental Research, University of Porto, 4450-208 Matosinhos, Portugal
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19
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Fu B, Nazemi A, Levin BJ, Yang Z, Kulik HJ, Balskus EP. Mechanistic Studies of a Skatole-Forming Glycyl Radical Enzyme Suggest Reaction Initiation via Hydrogen Atom Transfer. J Am Chem Soc 2022; 144:11110-11119. [PMID: 35704859 PMCID: PMC9248008 DOI: 10.1021/jacs.1c13580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Gut microbial decarboxylation
of amino acid-derived arylacetates
is a chemically challenging enzymatic transformation which generates
small molecules that impact host physiology. The glycyl radical enzyme
(GRE) indoleacetate decarboxylase from Olsenella uli (Ou IAD) performs the non-oxidative radical decarboxylation
of indole-3-acetate (I3A) to yield skatole, a disease-associated metabolite
produced in the guts of swine and ruminants. Despite the importance
of IAD, our understanding of its mechanism is limited. Here, we characterize
the mechanism of Ou IAD, evaluating previously proposed
hypotheses of: (1) a Kolbe-type decarboxylation reaction involving
an initial 1-e– oxidation of the carboxylate of
I3A or (2) a hydrogen atom abstraction from the α-carbon of
I3A to generate an initial carbon-centered radical. Site-directed
mutagenesis, kinetic isotope effect experiments, analysis of reactions
performed in D2O, and computational modeling are consistent
with a mechanism involving initial hydrogen atom transfer. This finding
expands the types of radical mechanisms employed by GRE decarboxylases
and non-oxidative decarboxylases, more broadly. Elucidating the mechanism
of IAD decarboxylation enhances our understanding of radical enzymes
and may inform downstream efforts to modulate this disease-associated
metabolism.
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Affiliation(s)
- Beverly Fu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Azadeh Nazemi
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Benjamin J Levin
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Zhongyue Yang
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Heather J Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States.,Howard Hughes Medical Institute, Harvard University, Cambridge, Massachusetts 02138, United States
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20
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Backman LRF, Huang YY, Andorfer MC, Gold B, Raines RT, Balskus EP, Drennan CL. Structurally investigating a niche pathway for chemical reversal of proline hydroxylation in the pathogen
Clostridioides difficile. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.r2341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Ronald T. Raines
- Department of ChemistryMassachusetts Institute of TechnologyCambridgeMA
| | - Emily P. Balskus
- Harvard UniversityCambridgeMA
- Howard Hughes Medical InstituteCambridgeMA
| | - Catherine L. Drennan
- Massachusetts Institute of TechnologyCambridgeMA
- Howard Hughes Medical InstituteCambridgeMA
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21
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Bloom SM, Mafunda NA, Woolston BM, Hayward MR, Frempong JF, Abai AB, Xu J, Mitchell AJ, Westergaard X, Hussain FA, Xulu N, Dong M, Dong KL, Gumbi T, Ceasar FX, Rice JK, Choksi N, Ismail N, Ndung'u T, Ghebremichael MS, Relman DA, Balskus EP, Mitchell CM, Kwon DS. Cysteine dependence of Lactobacillus iners is a potential therapeutic target for vaginal microbiota modulation. Nat Microbiol 2022; 7:434-450. [PMID: 35241796 PMCID: PMC10473153 DOI: 10.1038/s41564-022-01070-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 01/27/2022] [Indexed: 12/28/2022]
Abstract
Vaginal microbiota composition affects many facets of reproductive health. Lactobacillus iners-dominated microbial communities are associated with poorer outcomes, including higher risk of bacterial vaginosis (BV), compared with vaginal microbiota rich in L. crispatus. Unfortunately, standard-of-care metronidazole therapy for BV typically results in dominance of L. iners, probably contributing to post-treatment relapse. Here we generate an L. iners isolate collection comprising 34 previously unreported isolates from 14 South African women with and without BV and 4 previously unreported isolates from 3 US women. We also report an associated genome catalogue comprising 1,218 vaginal Lactobacillus isolate genomes and metagenome-assembled genomes from >300 women across 4 continents. We show that, unlike L. crispatus, L. iners growth is dependent on L-cysteine in vitro and we trace this phenotype to the absence of canonical cysteine biosynthesis pathways and a restricted repertoire of cysteine-related transport mechanisms. We further show that cysteine concentrations in cervicovaginal lavage samples correlate with Lactobacillus abundance in vivo and that cystine uptake inhibitors selectively inhibit L. iners growth in vitro. Combining an inhibitor with metronidazole promotes L. crispatus dominance of defined BV-like communities in vitro by suppressing L. iners growth. Our findings enable a better understanding of L. iners biology and suggest candidate treatments to modulate the vaginal microbiota to improve reproductive health for women globally.
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Affiliation(s)
- Seth M Bloom
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Nomfuneko A Mafunda
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Benjamin M Woolston
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Department of Chemical Engineering, Northeastern University, Boston, MA, USA
| | - Matthew R Hayward
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Josephine F Frempong
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Medical Scientist Training Program, Washington University School of Medicine, St Louis, MO, USA
| | - Aaron B Abai
- Harvard College, Harvard University, Cambridge, MA, USA
| | - Jiawu Xu
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
| | - Alissa J Mitchell
- Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA, USA
- William Carey University College of Osteopathic Medicine, Hattiesburg, MS, USA
| | - Xavier Westergaard
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA, USA
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Fatima A Hussain
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Nondumiso Xulu
- HIV Pathogenesis Programme (HPP), The Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Mary Dong
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Massachusetts General Hospital, Boston, MA, USA
| | - Krista L Dong
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | | | | | - Justin K Rice
- Harvard Medical School, Boston, MA, USA
- Ronald O. Perelman Department of Emergency Medicine, NYU School of Medicine, New York, NY, USA
| | - Namit Choksi
- Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA, USA
- Rishihood University - School of Healthcare, Sonepat, Haryana, India
| | - Nasreen Ismail
- HIV Pathogenesis Programme (HPP), The Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Thumbi Ndung'u
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- HIV Pathogenesis Programme (HPP), The Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
- Africa Health Research Institute (AHRI), Durban, South Africa
- Max Planck Institute for Infection Biology, Berlin, Germany
- Division of Infection and Immunity, University College London, London, UK
| | - Musie S Ghebremichael
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - David A Relman
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Infectious Diseases Section, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Caroline M Mitchell
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Harvard Medical School, Boston, MA, USA
- Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA, USA
| | - Douglas S Kwon
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA.
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.
- Harvard Medical School, Boston, MA, USA.
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22
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Braffman NR, Ruskoski TB, Davis KM, Glasser NR, Johnson C, Okafor CD, Boal AK, Balskus EP. Structural basis for an unprecedented enzymatic alkylation in cylindrocyclophane biosynthesis. eLife 2022; 11:75761. [PMID: 35212625 PMCID: PMC8916777 DOI: 10.7554/elife.75761] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/24/2022] [Indexed: 11/13/2022] Open
Abstract
The cyanobacterial enzyme CylK assembles the cylindrocyclophane natural products by performing two unusual alkylation reactions, forming new carbon–carbon bonds between aromatic rings and secondary alkyl halide substrates. This transformation is unprecedented in biology, and the structure and mechanism of CylK are unknown. Here, we report X-ray crystal structures of CylK, revealing a distinctive fusion of a Ca2+-binding domain and a β-propeller fold. We use a mutagenic screening approach to locate CylK’s active site at its domain interface, identifying two residues, Arg105 and Tyr473, that are required for catalysis. Anomalous diffraction datasets collected with bound bromide ions, a product analog, suggest that these residues interact with the alkyl halide electrophile. Additional mutagenesis and molecular dynamics simulations implicate Asp440 in activating the nucleophilic aromatic ring. Bioinformatic analysis of CylK homologs from other cyanobacteria establishes that they conserve these key catalytic amino acids, but they are likely associated with divergent reactivity and altered secondary metabolism. By gaining a molecular understanding of this unusual biosynthetic transformation, this work fills a gap in our understanding of how alkyl halides are activated and used by enzymes as biosynthetic intermediates, informing enzyme engineering, catalyst design, and natural product discovery.
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Affiliation(s)
- Nathaniel R Braffman
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States
| | - Terry B Ruskoski
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, United States
| | - Katherine M Davis
- Department of Chemistry, Pennsylvania State University, University Park, United States
| | - Nathaniel R Glasser
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States
| | - Cassidy Johnson
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States
| | - C Denise Okafor
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, United States
| | - Amie K Boal
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, United States
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States
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23
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Abstract
Molybdenum- and tungsten-dependent proteins catalyze essential processes in living organisms and biogeochemical cycles. Among these enzymes, members of the dimethyl sulfoxide (DMSO) reductase superfamily are considered the most diverse, facilitating a wide range of chemical transformations that can be categorized as oxygen atom installation, removal, and transfer. Importantly, DMSO reductase enzymes provide high efficiency and excellent selectivity while operating under mild conditions without conventional oxidants such as oxygen or peroxides. Despite the potential utility of these enzymes as biocatalysts, such applications have not been fully explored. In addition, the vast majority of DMSO reductase enzymes still remain uncharacterized. In this review, we describe the reactivities, proposed mechanisms, and potential synthetic applications of selected enzymes in the DMSO reductase superfamily. We also highlight emerging opportunities to discover new chemical activity and current challenges in studying and engineering proteins in the DMSO reductase superfamily. Expected final online publication date for the Annual Review of Biochemistry, Volume 91 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Chi Chip Le
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA;
| | - Minwoo Bae
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA;
| | - Sina Kiamehr
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA;
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA;
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24
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Eusebio N, Rego A, Glasser NR, Castelo-Branco R, Balskus EP, Leão PN. Distribution and diversity of dimetal-carboxylate halogenases in cyanobacteria. BMC Genomics 2021; 22:633. [PMID: 34461836 PMCID: PMC8406957 DOI: 10.1186/s12864-021-07939-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/14/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Halogenation is a recurring feature in natural products, especially those from marine organisms. The selectivity with which halogenating enzymes act on their substrates renders halogenases interesting targets for biocatalyst development. Recently, CylC - the first predicted dimetal-carboxylate halogenase to be characterized - was shown to regio- and stereoselectively install a chlorine atom onto an unactivated carbon center during cylindrocyclophane biosynthesis. Homologs of CylC are also found in other characterized cyanobacterial secondary metabolite biosynthetic gene clusters. Due to its novelty in biological catalysis, selectivity and ability to perform C-H activation, this halogenase class is of considerable fundamental and applied interest. The study of CylC-like enzymes will provide insights into substrate scope, mechanism and catalytic partners, and will also enable engineering these biocatalysts for similar or additional C-H activating functions. Still, little is known regarding the diversity and distribution of these enzymes. RESULTS In this study, we used both genome mining and PCR-based screening to explore the genetic diversity of CylC homologs and their distribution in bacteria. While we found non-cyanobacterial homologs of these enzymes to be rare, we identified a large number of genes encoding CylC-like enzymes in publicly available cyanobacterial genomes and in our in-house culture collection of cyanobacteria. Genes encoding CylC homologs are widely distributed throughout the cyanobacterial tree of life, within biosynthetic gene clusters of distinct architectures (combination of unique gene groups). These enzymes are found in a variety of biosynthetic contexts, which include fatty-acid activating enzymes, type I or type III polyketide synthases, dialkylresorcinol-generating enzymes, monooxygenases or Rieske proteins. Our study also reveals that dimetal-carboxylate halogenases are among the most abundant types of halogenating enzymes in the phylum Cyanobacteria. CONCLUSIONS Our data show that dimetal-carboxylate halogenases are widely distributed throughout the Cyanobacteria phylum and that BGCs encoding CylC homologs are diverse and mostly uncharacterized. This work will help guide the search for new halogenating biocatalysts and natural product scaffolds.
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Affiliation(s)
- Nadia Eusebio
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Matosinhos, Portugal
| | - Adriana Rego
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Matosinhos, Portugal
| | - Nathaniel R Glasser
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Raquel Castelo-Branco
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Matosinhos, Portugal
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
| | - Pedro N Leão
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Matosinhos, Portugal.
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25
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Abstract
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The genomic era has dramatically changed how we discover and investigate
microbial biochemistry. In particular, the exponential expansion in
the number of sequenced microbial genomes provides investigators with
a vast wealth of sequence data to exploit for the discovery of biochemical
functions and mechanisms, as well as novel enzymes and metabolites.
In contrast to early biochemical work, which was largely characterized
by “forward” approaches that proceed from biomass to
enzyme to gene, the availability of genome sequences enables the discovery
of new microbial metabolic activities, enzymes, and metabolites by
“reverse” approaches that originate with genetic information
or by approaches that incorporate features of both forward and reverse
methodologies. In the genomic era, the canonical organization of microbial
genomes into gene clusters presents a singular opportunity for the
utilization of genomic data. Specifically, genomic context (information
gleaned from the genes surrounding a gene of interest in the chromosome)
is a powerful tool for chemical discovery in microbial systems because
of the functional and/or physiological relationship that usually exists
between genes found within a gene cluster. This means that the investigator
can use this inferred link to generate hypotheses about the functions
of individual genes in the cluster or even the function of the entire
cluster itself. Here, we discuss how analysis of genomic context in
combination with a mechanistic understanding of enzymes can facilitate
numerous facets of microbial biochemical research including the identification
of biosynthetic gene clusters, the discovery of important and novel
enzymes, the elucidation of natural product structures, and the identification
of new metabolic pathways. We highlight work from our laboratory using
genomic context to discover and study biosynthetic pathways that produce
natural products, including the cylindrocyclophanes, nitrogen–nitrogen
bond-containing metabolites, and the gut microbial genotoxin colibactin.
Although use of genomic context is most commonly associated with studies
of natural product biosynthesis, we also show that it can be applied
to the study of primary metabolism. We illustrate this with examples
from our work studying the members of the glycyl radical enzyme superfamily
involved in choline and 4-hydroxyproline degradation in the human
gut. Looking forward, we envision increased opportunities to use such
information, with the combination of biochemical knowledge and computational
tools poised to fuel a new revolution in our ability to connect genes
and their biochemical functions. In particular, we note a need for
methods that computationally formalize the functional association
between genes when such associations are not obvious from manual gene
annotations. Such tools will drastically augment the feasibility and
scope of gene cluster analysis and accelerate the discovery of new
microbial enzymes, metabolites, and metabolic processes.
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Affiliation(s)
- Duncan J. Kountz
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Emily P. Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
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26
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Murray KJ, Carlson ES, Stornetta A, Balskus EP, Villalta PW, Balbo S. Extension of Diagnostic Fragmentation Filtering for Automated Discovery in DNA Adductomics. Anal Chem 2021; 93:5754-5762. [PMID: 33797876 DOI: 10.1021/acs.analchem.0c04895] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Development of high-resolution/accurate mass liquid chromatography-coupled tandem mass spectrometry (LC-MS/MS) methodology enables the characterization of covalently modified DNA induced by interaction with genotoxic agents in complex biological samples. Constant neutral loss monitoring of 2'-deoxyribose or the nucleobases using data-dependent acquisition represents a powerful approach for the unbiased detection of DNA modifications (adducts). The lack of available bioinformatics tools necessitates manual processing of acquired spectral data and hampers high throughput application of these techniques. To address this limitation, we present an automated workflow for the detection and curation of putative DNA adducts by using diagnostic fragmentation filtering of LC-MS/MS experiments within the open-source software MZmine. The workflow utilizes a new feature detection algorithm, DFBuilder, which employs diagnostic fragmentation filtering using a user-defined list of fragmentation patterns to reproducibly generate feature lists for precursor ions of interest. The DFBuilder feature detection approach readily fits into a complete small-molecule discovery workflow and drastically reduces the processing time associated with analyzing DNA adductomics results. We validate our workflow using a mixture of authentic DNA adduct standards and demonstrate the effectiveness of our approach by reproducing and expanding the results of a previously published study of colibactin-induced DNA adducts. The reported workflow serves as a technique to assess the diagnostic potential of novel fragmentation pattern combinations for the unbiased detection of chemical classes of interest.
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Affiliation(s)
- Kevin J Murray
- Masonic Cancer Center, University of Minnesota, 2231 6th Street SE, Minneapolis, Minnesota 55455, United States
| | - Erik S Carlson
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Alessia Stornetta
- Masonic Cancer Center, University of Minnesota, 2231 6th Street SE, Minneapolis, Minnesota 55455, United States
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Peter W Villalta
- Masonic Cancer Center, University of Minnesota, 2231 6th Street SE, Minneapolis, Minnesota 55455, United States.,Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Silvia Balbo
- Masonic Cancer Center, University of Minnesota, 2231 6th Street SE, Minneapolis, Minnesota 55455, United States.,Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, Minnesota 55455, United States
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27
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Dawson CD, Irwin SM, Backman LRF, Le C, Wang JX, Vennelakanti V, Yang Z, Kulik HJ, Drennan CL, Balskus EP. Molecular basis of C-S bond cleavage in the glycyl radical enzyme isethionate sulfite-lyase. Cell Chem Biol 2021; 28:1333-1346.e7. [PMID: 33773110 PMCID: PMC8473560 DOI: 10.1016/j.chembiol.2021.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 02/04/2021] [Accepted: 03/03/2021] [Indexed: 01/07/2023]
Abstract
Desulfonation of isethionate by the bacterial glycyl radical enzyme (GRE) isethionate sulfite-lyase (IslA) generates sulfite, a substrate for respiration that in turn produces the disease-associated metabolite hydrogen sulfide. Here, we present a 2.7 Å resolution X-ray structure of wild-type IslA from Bilophila wadsworthia with isethionate bound. In comparison with other GREs, alternate positioning of the active site β strands allows for distinct residue positions to contribute to substrate binding. These structural differences, combined with sequence variations, create a highly tailored active site for the binding of the negatively charged isethionate substrate. Through the kinetic analysis of 14 IslA variants and computational analyses, we probe the mechanism by which radical chemistry is used for C-S bond cleavage. This work further elucidates the structural basis of chemistry within the GRE superfamily and will inform structure-based inhibitor design of IsIA and thus of microbial hydrogen sulfide production.
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Affiliation(s)
- Christopher D Dawson
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Stephania M Irwin
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA
| | - Lindsey R F Backman
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Chip Le
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA
| | - Jennifer X Wang
- Harvard Center for Mass Spectrometry, Faculty of Arts and Sciences Division of Science, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA
| | - Vyshnavi Vennelakanti
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Zhongyue Yang
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Heather J Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Catherine L Drennan
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA; Broad Institute, Cambridge, MA 02139, USA.
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28
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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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29
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Bloom SM, Mafunda NA, Woolston BM, Hayward MR, Frempong JF, Xu J, Mitchell A, Westergaard X, Rice JK, Choksi N, Balskus EP, Mitchell CM, Kwon DS. 1207. Combining standard bacterial vaginosis treatment with cystine uptake inhibitors to block growth of Lactobacillus iners is a potential a target for shifting the cervicovaginal microbiota towards health-associated Lactobacillus crispatus-dominant communities. Open Forum Infect Dis 2020. [PMCID: PMC7777507 DOI: 10.1093/ofid/ofaa439.1392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Background Cervicovaginal microbiota domination by Lactobacillus crispatus is associated with beneficial health outcomes, whereas L. iners dominance has more adverse associations. However bacterial vaginosis (BV) treatment with metronidazole (MTZ) typically leads to domination by L. iners rather than L. crispatus. L. iners differs from other lactobacilli by its inability to grow in MRS media. We hypothesized that exploring this growth difference would identify targets for selective L. iners inhibition. Methods Bacteria were grown anaerobically. Nutrient uptake and metabolism were assessed using UPLC-MS/MS and isotopically labeled substrates. Bacterial genome annotation employed Prodigal, Roary, and EggNOG. Competition experiments with mock mixed communities were analyzed by 16S rRNA gene sequencing. We confirmed result generalizability using a diverse collection of South African and North American strains and genomes. Results Supplementing MRS broth with L-cysteine (Cys) or L-cystine permitted robust L. iners growth, while L. crispatus grew without Cys supplementation. Despite their different growth requirements, neither species could synthesize Cys via canonical pathways. Adding the cystine uptake inhibitors S-methyl-L-cysteine (SMC, Fig 1) or seleno-DL-cystine (SDLC) blocked growth of L. iners but not other lactobacilli, suggesting L. iners lacks mechanisms other lactobacilli use to exploit complex exogenous Cys sources. Notably, cydABCD, an operon with Cys/glutathione transport and redox homeostasis activities, is absent from L. iners but present in non-iners Lactobacillus species. Consistent with possible roles for cydABCD in explaining the observed phenotypes, (1) L. iners failed to take up exogenous glutathione and (2) supplementing MRS with reducing agents permitted L. iners growth, which could be blocked by SMC or SDLC. In growth competitions testing L. iners and L. crispatus within mock BV-like communities, SMC plus MTZ outperformed MTZ alone in promoting L. crispatus dominance (Figs 2&3). Figure 1: S-methyl-L-cysteine (SMC) selectively blocks growth of L. iners but not other cervicovaginal Lactobacillus species in cysteine-supplemented MRS broth. Growth was measured by optical density and inhibition calculated relative to Cys-supplemented no-inhibitor control during exponential growth. Values displayed are median (+/- maximum/minimum) for 3 replicates from a single experiment. In all panels, representative data are shown from 1 of >=2 independent experiments for each bacterial strain and media condition. Results are representative of multiple strains for L. iners (n = 16), L. crispatus (n = 7), and L. jensenii (n = 2). ![]()
Figure 2: Relative abundance of L. crispatus, L. iners, or various BV-associated bacteria in mock bacterial communities grown in rich, non-selective media with or without metronidazole (MTZ) and/or SMC. Relative abundance was determined by bacterial 16S rRNA gene sequencing. Data are shown for three representative mock communities with 5 replicates per media condition. ![]()
Figure 3: Ratio of L. crispatus to other species in the mock bacterial communities depicted in Figure 2. Statistical significance determined via 1-way ANOVA of log10-transformed ratios with post-hoc Tukey test; selected pairwise comparisons are shown (***, p < 0.001). ![]()
Conclusion L. iners has unique requirements for exogenous cysteine/cystine or a reduced environment for growth. Targeting cystine uptake to inhibit L. iners is a potential strategy for shifting cervicovaginal microbiota towards L. crispatus-dominant communities. Disclosures Douglas S. Kwon, MD, PhD, Day Zero Diagnostics (Consultant, Shareholder, Other Financial or Material Support, co-founder)
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Affiliation(s)
- Seth M Bloom
- Massachusetts General Hospital, Boston, Massachusetts
| | | | | | | | | | - Jiawu Xu
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, Massachusetts
| | | | | | | | | | | | | | - Douglas S Kwon
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, Massachusetts
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30
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Bollenbach M, Ortega M, Orman M, Drennan CL, Balskus EP. Discovery of a Cyclic Choline Analog That Inhibits Anaerobic Choline Metabolism by Human Gut Bacteria. ACS Med Chem Lett 2020; 11:1980-1985. [PMID: 33062182 DOI: 10.1021/acsmedchemlett.0c00005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 03/25/2020] [Indexed: 12/24/2022] Open
Abstract
The anaerobic conversion of choline to trimethylamine (TMA) by the human gut microbiota has been linked to multiple human diseases. The potential impact of this microbial metabolic activity on host health has inspired multiple efforts to identify small molecule inhibitors. Here, we use information about the structure and mechanism of the bacterial enzyme choline TMA-lyase (CutC) to develop a cyclic choline analog that inhibits the conversion of choline to TMA in bacterial whole cells and in a complex gut microbial community. In vitro biochemical assays and a crystal structure suggest that this analog is a competitive, mechanism-based inhibitor. This work demonstrates the utility of structure-based design to access inhibitors of radical enzymes from the human gut microbiota.
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Affiliation(s)
- Maud Bollenbach
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | | | - Marina Orman
- 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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Ngo LP, Rai P, Wilson MR, Swartz C, Winters J, Su Y, Ge J, Chan TK, Balskus EP, Chow V, Recio L, Samson LD, Engelward BP. Abstract IA20: Novel cell microarray technologies for studies of DNA damage and cell survival and applications for studies of microbe-induced DNA damage. Cancer Prev Res (Phila) 2020. [DOI: 10.1158/1940-6215.envcaprev19-ia20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Genotoxicity testing is critical for predicting adverse effects of pharmaceutical, industrial, and environmental chemicals. The comet assay is a commonly used approach for detecting DNA damage that is based on the underlying principle that damaged DNA migrates more readily than undamaged DNA when electrophoresed in agarose. We previously developed a higher-throughput version of the comet assay (Wood DK, PNAS 2010). For the “CometChip” assay, cells are loaded into an array of agarose microwells to create a cell microarray. The CometChip can be fully automated, making the assay more than 1000X faster, while improving reproducibility. While effective for detecting single-strand breaks, abasic sites, and alkali-sensitive sites, the alkaline comet assay is not effective for detection of carcinogenic bulky DNA lesions that do not impact DNA mobility and that require metabolic activation. To overcome this, we use DNA replication inhibitors (hydroxyurea and 1-β-d-arabinofuranosyl cytosine) shown to trap single-strand breaks that are formed during nucleotide excision repair, which normally removes bulky lesions. Thus, comet-undetectable bulky lesions are converted into comet-detectable single-strand breaks. Together with HepaRG™ cells that recapitulate in vivo metabolic capacity, we have thus created the “HepaCometChip,” which provides a more broadly effective approach for detection of DNA damage. In addition to genotoxicity testing, the microwell array has also been harnessed for use in a cell survival assay. For the “MicroColonyChip” (Ngo LP, Cell Reports 2019), cells are loaded into the agarose microwell array and allowed to grow to form microcolonies. Differences in cell survival can be detected by changes in the distribution of colony sizes, a novel metric for cell survival quantitation. The assay is as sensitive as the traditional “gold standard” colony-forming assay, yet it takes days instead of weeks to complete. Parallel studies of genotoxicity and cytotoxicity can thus be performed using a shared microwell platform. These tools have broad utility, including studies of microbe-induced DNA damage. Examples of S. pneumoniae and E. coli microbial product-induced double-strand breaks and interstrand crosslinks contribute to an emerging paradigm wherein pathogen-induced DNA damage has the potential to promote disease.
Citation Format: Le P. Ngo, Prashant Rai, Matthew R. Wilson, Carole Swartz, John Winters, Yang Su, Jing Ge, Tze-Khee Chan, Emily P. Balskus, Vincent Chow, Les Recio, Leona D. Samson, Bevin P. Engelward. Novel cell microarray technologies for studies of DNA damage and cell survival and applications for studies of microbe-induced DNA damage [abstract]. In: Proceedings of the AACR Special Conference on Environmental Carcinogenesis: Potential Pathway to Cancer Prevention; 2019 Jun 22-24; Charlotte, NC. Philadelphia (PA): AACR; Can Prev Res 2020;13(7 Suppl): Abstract nr IA20.
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Affiliation(s)
- Le P. Ngo
- 1Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA,
| | - Prashant Rai
- 2Singapore-MIT Alliance for Research and Technology, Singapore,
| | | | - Carole Swartz
- 4Toxicology Program, Integrated Laboratory Systems, Inc., Research Triangle Park, NC,
| | - John Winters
- 2Singapore-MIT Alliance for Research and Technology, Singapore,
| | - Yang Su
- 5Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
| | - Jing Ge
- 1Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA,
| | - Tze-Khee Chan
- 1Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA,
| | | | - Vincent Chow
- 2Singapore-MIT Alliance for Research and Technology, Singapore,
| | - Les Recio
- 4Toxicology Program, Integrated Laboratory Systems, Inc., Research Triangle Park, NC,
| | - Leona D. Samson
- 1Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA,
- 5Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
| | - Bevin P. Engelward
- 1Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA,
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32
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McBride MJ, Sil D, Ng TL, Crooke AM, Kenney GE, Tysoe CR, Zhang B, Balskus EP, Boal AK, Krebs C, Bollinger JM. A Peroxodiiron(III/III) Intermediate Mediating Both N-Hydroxylation Steps in Biosynthesis of the N-Nitrosourea Pharmacophore of Streptozotocin by the Multi-domain Metalloenzyme SznF. J Am Chem Soc 2020; 142:11818-11828. [PMID: 32511919 DOI: 10.1021/jacs.0c03431] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The alkylating warhead of the pancreatic cancer drug streptozotocin (SZN) contains an N-nitrosourea moiety constructed from Nω-methyl-l-arginine (l-NMA) by the multi-domain metalloenzyme SznF. The enzyme's central heme-oxygenase-like (HO-like) domain sequentially hydroxylates Nδ and Nω' of l-NMA. Its C-terminal cupin domain then rearranges the triply modified arginine to Nδ-hydroxy-Nω-methyl-Nω-nitroso-l-citrulline, the proposed donor of the functional pharmacophore. Here we show that the HO-like domain of SznF can bind Fe(II) and use it to capture O2, forming a peroxo-Fe2(III/III) intermediate. This intermediate has absorption- and Mössbauer-spectroscopic features similar to those of complexes previously trapped in ferritin-like diiron oxidases and oxygenases (FDOs) and, more recently, the HO-like fatty acid oxidase UndA. The SznF peroxo-Fe2(III/III) complex is an intermediate in both hydroxylation steps, as shown by the concentration-dependent acceleration of its decay upon exposure to either l-NMA or Nδ-hydroxy-Nω-methyl-l-Arg (l-HMA). The Fe2(III/III) cluster produced upon decay of the intermediate has a small Mössbauer quadrupole splitting parameter, implying that, unlike the corresponding product states of many FDOs, it lacks an oxo-bridge. The subsequent decomposition of the product cluster to one or more paramagnetic Fe(III) species over several hours explains why SznF was previously purified and crystallographically characterized without its cofactor. Programmed instability of the oxidized form of the cofactor appears to be a unifying characteristic of the emerging superfamily of HO-like diiron oxidases and oxygenases (HDOs).
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Affiliation(s)
| | | | - Tai L Ng
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Anne Marie Crooke
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Grace E Kenney
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | | | | | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
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33
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Kenny DJ, Plichta DR, Shungin D, Koppel N, Hall AB, Fu B, Vasan RS, Shaw SY, Vlamakis H, Balskus EP, Xavier RJ. Cholesterol Metabolism by Uncultured Human Gut Bacteria Influences Host Cholesterol Level. Cell Host Microbe 2020; 28:245-257.e6. [PMID: 32544460 PMCID: PMC7435688 DOI: 10.1016/j.chom.2020.05.013] [Citation(s) in RCA: 128] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/01/2020] [Accepted: 05/18/2020] [Indexed: 02/07/2023]
Abstract
The human microbiome encodes extensive metabolic capabilities, but our understanding of the mechanisms linking gut microbes to human metabolism remains limited. Here, we focus on the conversion of cholesterol to the poorly absorbed sterol coprostanol by the gut microbiota to develop a framework for the identification of functional enzymes and microbes. By integrating paired metagenomics and metabolomics data from existing cohorts with biochemical knowledge and experimentation, we predict and validate a group of microbial cholesterol dehydrogenases that contribute to coprostanol formation. These enzymes are encoded by ismA genes in a clade of uncultured microorganisms, which are prevalent in geographically diverse human cohorts. Individuals harboring coprostanol-forming microbes have significantly lower fecal cholesterol levels and lower serum total cholesterol with effects comparable to those attributed to variations in lipid homeostasis genes. Thus, cholesterol metabolism by these microbes may play important roles in reducing intestinal and serum cholesterol concentrations, directly impacting human health. Bioinformatics enabled discovery of ismA, a microbial cholesterol dehydrogenase Metagenomic species with ismA genes form coprostanol in microbial communities ismA+ species are associated with decreased fecal and serum cholesterol in humans Effect sizes of ismA+ species on serum cholesterol are on par with human genetics
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Affiliation(s)
- Douglas J Kenny
- Broad Institute of MIT and Harvard, Cambridge, MA, USA; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | | | - Dmitry Shungin
- Broad Institute of MIT and Harvard, Cambridge, MA, USA; Department of Odontology, Umeå University, Umeå, Sweden
| | - Nitzan Koppel
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | | | - Beverly Fu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Ramachandran S Vasan
- Boston University and NHLBI's Framingham Heart Study, Framingham, MA, USA; Sections of Preventive Medicine and Epidemiology and Cardiovascular Medicine, Departments of Medicine and Epidemiology, Boston University Schools of Medicine and Public Health, Boston, MA, USA
| | - Stanley Y Shaw
- Harvard Medical School, Boston, MA, USA; HMS and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, MA
| | - Hera Vlamakis
- Broad Institute of MIT and Harvard, Cambridge, MA, USA; Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
| | - Ramnik J Xavier
- Broad Institute of MIT and Harvard, Cambridge, MA, USA; Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA, USA; Center for Computational and Integrative Biology and Department of Molecular Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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34
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Bisanz JE, Soto-Perez P, Noecker C, Aksenov AA, Lam KN, Kenney GE, Bess EN, Haiser HJ, Kyaw TS, Yu FB, Rekdal VM, Ha CWY, Devkota S, Balskus EP, Dorrestein PC, Allen-Vercoe E, Turnbaugh PJ. A Genomic Toolkit for the Mechanistic Dissection of Intractable Human Gut Bacteria. Cell Host Microbe 2020; 27:1001-1013.e9. [PMID: 32348781 PMCID: PMC7292766 DOI: 10.1016/j.chom.2020.04.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/20/2020] [Accepted: 04/03/2020] [Indexed: 01/08/2023]
Abstract
Despite the remarkable microbial diversity found within humans, our ability to link genes to phenotypes is based upon a handful of model microorganisms. We report a comparative genomics platform for Eggerthella lenta and other Coriobacteriia, a neglected taxon broadly relevant to human health and disease. We uncover extensive genetic and metabolic diversity and validate a tool for mapping phenotypes to genes and sequence variants. We also present a tool for the quantification of strains from metagenomic sequencing data, enabling the identification of genes that predict bacterial fitness. Competitive growth is reproducible under laboratory conditions and attributable to intrinsic growth rates and resource utilization. Unique signatures of in vivo competition in gnotobiotic mice include an adhesin enriched in poor colonizers. Together, these computational and experimental resources represent a strong foundation for the continued mechanistic dissection of the Coriobacteriia and a template that can be applied to study other genetically intractable taxa.
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Affiliation(s)
- Jordan E Bisanz
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Paola Soto-Perez
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Cecilia Noecker
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Alexander A Aksenov
- Collaborative Mass Spectrometry Innovation Center, Department of Pediatrics, Center for Microbiome Innovation, Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, San Diego, CA 92093, USA
| | - Kathy N Lam
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Grace E Kenney
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Elizabeth N Bess
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Henry J Haiser
- Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA
| | - Than S Kyaw
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Feiqiao B Yu
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Vayu M Rekdal
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Connie W Y Ha
- Department of Medicine, Division of Gastroenterology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Suzanne Devkota
- Department of Medicine, Division of Gastroenterology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Pieter C Dorrestein
- Collaborative Mass Spectrometry Innovation Center, Department of Pediatrics, Center for Microbiome Innovation, Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, San Diego, CA 92093, USA
| | - Emma Allen-Vercoe
- Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Peter J Turnbaugh
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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Balskus EP. Abstract IA21: Deciphering the human gut microbiome with chemistry. Cancer Res 2020. [DOI: 10.1158/1538-7445.mvc2020-ia21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The human body is colonized by trillions of microorganisms that exert a profound influence on human biology, in part by providing functional capabilities that extend beyond those of host cells. In particular, there is growing evidence linking chemical processes carried out by the human gut microbiome to diseases such as colorectal cancer. However, we still do not understand the vast majority of the molecular mechanisms underlying this phenomenon. Major obstacles faced in surmounting this knowledge gap include the difficulty in linking functions associated with the human gut microbiota to specific microbial enzymes and the challenge of controlling these activities in complex microbial communities. This talk will discuss my lab’s efforts to characterize gut microbial metabolic activities that are linked to colorectal cancer, including a gut microbial genotoxin called colibactin. Gaining a molecular understanding of cancer-associated gut microbial activities will not only help to elucidate the mechanisms by which these organisms contribute to carcinogenesis but should also enable efforts to treat and prevent disease by manipulating this microbial community.
Citation Format: Emily P. Balskus. Deciphering the human gut microbiome with chemistry [abstract]. In: Proceedings of the AACR Special Conference on the Microbiome, Viruses, and Cancer; 2020 Feb 21-24; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2020;80(8 Suppl):Abstract nr IA21.
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36
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Backman LRF, Huang YY, Andorfer MC, Gold B, Raines RT, Balskus EP, Drennan CL. Molecular basis for catabolism of the abundant metabolite trans-4-hydroxy-L-proline by a microbial glycyl radical enzyme. eLife 2020; 9:e51420. [PMID: 32180548 PMCID: PMC7077986 DOI: 10.7554/elife.51420] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 02/19/2020] [Indexed: 02/04/2023] Open
Abstract
The glycyl radical enzyme (GRE) superfamily utilizes a glycyl radical cofactor to catalyze difficult chemical reactions in a variety of anaerobic microbial metabolic pathways. Recently, a GRE, trans-4-hydroxy-L-proline (Hyp) dehydratase (HypD), was discovered that catalyzes the dehydration of Hyp to (S)-Δ1-pyrroline-5-carboxylic acid (P5C). This enzyme is abundant in the human gut microbiome and also present in prominent bacterial pathogens. However, we lack an understanding of how HypD performs its unusual chemistry. Here, we have solved the crystal structure of HypD from the pathogen Clostridioides difficile with Hyp bound in the active site. Biochemical studies have led to the identification of key catalytic residues and have provided insight into the radical mechanism of Hyp dehydration.
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Affiliation(s)
- Lindsey RF Backman
- Department of Chemistry, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Yolanda Y Huang
- Department of Chemistry and Chemical Biology, Harvard UniversityCambridgeUnited States
| | - Mary C Andorfer
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Brian Gold
- Department of Chemistry, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Ronald T Raines
- Department of Chemistry, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard UniversityCambridgeUnited States
| | - Catherine L Drennan
- Department of Chemistry, Massachusetts Institute of TechnologyCambridgeUnited States
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
- Howard Hughes Medical Institute, Massachusetts Institute of TechnologyCambridgeUnited States
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Fu B, Balskus EP. Discovery of CC bond-forming and bond-breaking radical enzymes: enabling transformations for metabolic engineering. Curr Opin Biotechnol 2020; 65:94-101. [PMID: 32171888 PMCID: PMC7670169 DOI: 10.1016/j.copbio.2020.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/03/2020] [Accepted: 02/04/2020] [Indexed: 11/23/2022]
Abstract
Radical enzymes catalyze difficult C—C bond-forming and bond-breaking transformations. Radical enzymes catalyzing unprecedented reactions continue to be discovered. The products of radical enzymes are often of high value. Understanding mechanisms of radical enzymes will aid metabolic engineering efforts.
Radical enzymes catalyze some of the most chemically challenging C—C bond-forming and bond-breaking reactions. Advances in DNA sequencing have accelerated the discovery of radical enzymes from microbes, including radical S-adenosylmethionine (rSAM) enzymes, glycyl radical enzymes (GREs), and diiron enzymes. These enzymes catalyze various reactions that yield products of industrial relevance (e.g. aromatics, hydrocarbons, and natural product derivatives), making their incorporation into engineered metabolic pathways enticing. Elucidating the mechanisms of radical enzymes that cleave and construct C—C bonds will enable further enzyme discovery and engineering efforts.
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Affiliation(s)
- Beverly Fu
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Cambridge, MA 02138, United States
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Cambridge, MA 02138, United States.
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38
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Maini Rekdal V, Nol Bernadino P, Luescher MU, Kiamehr S, Le C, Bisanz JE, Turnbaugh PJ, Bess EN, Balskus EP. A widely distributed metalloenzyme class enables gut microbial metabolism of host- and diet-derived catechols. eLife 2020; 9:e50845. [PMID: 32067637 PMCID: PMC7028382 DOI: 10.7554/elife.50845] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 01/03/2020] [Indexed: 12/23/2022] Open
Abstract
Catechol dehydroxylation is a central chemical transformation in the gut microbial metabolism of plant- and host-derived small molecules. However, the molecular basis for this transformation and its distribution among gut microorganisms are poorly understood. Here, we characterize a molybdenum-dependent enzyme from the human gut bacterium Eggerthella lenta that dehydroxylates catecholamine neurotransmitters. Our findings suggest that this activity enables E. lenta to use dopamine as an electron acceptor. We also identify candidate dehydroxylases that metabolize additional host- and plant-derived catechols. These dehydroxylases belong to a distinct group of largely uncharacterized molybdenum-dependent enzymes that likely mediate primary and secondary metabolism in multiple environments. Finally, we observe catechol dehydroxylation in the gut microbiotas of diverse mammals, confirming the presence of this chemistry in habitats beyond the human gut. These results suggest that the chemical strategies that mediate metabolism and interactions in the human gut are relevant to a broad range of species and habitats.
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Affiliation(s)
- Vayu Maini Rekdal
- Department of Chemistry and Chemical BiologyHarvard UniversityCambridgeUnited States
| | - Paola Nol Bernadino
- Department of Chemistry and Molecular BiologyUniversity of California, IrvineIrvineUnited States
- Department of Chemistry and Molecular BiochemistryUniversity of California, IrvineIrvineUnited States
| | - Michael U Luescher
- Department of Chemistry and Chemical BiologyHarvard UniversityCambridgeUnited States
| | - Sina Kiamehr
- Department of Chemistry and Chemical BiologyHarvard UniversityCambridgeUnited States
| | - Chip Le
- Department of Chemistry and Chemical BiologyHarvard UniversityCambridgeUnited States
| | - Jordan E Bisanz
- Department of Microbiology and ImmunologyUniversity of California, San FranciscoSan FranciscoUnited States
| | - Peter J Turnbaugh
- Department of Microbiology and ImmunologyUniversity of California, San FranciscoSan FranciscoUnited States
- Chan Zuckerberg BiohubSan FranciscoUnited States
| | - Elizabeth N Bess
- Department of Chemistry and Molecular BiologyUniversity of California, IrvineIrvineUnited States
- Department of Chemistry and Molecular BiochemistryUniversity of California, IrvineIrvineUnited States
| | - Emily P Balskus
- Department of Chemistry and Chemical BiologyHarvard UniversityCambridgeUnited States
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Ng TL, McCallum ME, Zheng CR, Wang JX, Wu KJY, Balskus EP. The l-Alanosine Gene Cluster Encodes a Pathway for Diazeniumdiolate Biosynthesis. Chembiochem 2019; 21:1155-1160. [PMID: 31643127 DOI: 10.1002/cbic.201900565] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Indexed: 12/29/2022]
Abstract
N-Nitroso-containing natural products are bioactive metabolites with antibacterial and anticancer properties. In particular, compounds containing the diazeniumdiolate (N-nitrosohydroxylamine) group display a wide range of bioactivities ranging from cytotoxicity to metal chelation. Despite the importance of this structural motif, knowledge of its biosynthesis is limited. Herein we describe the discovery of a biosynthetic gene cluster in Streptomyces alanosinicus ATCC 15710 responsible for producing the diazeniumdiolate natural product l-alanosine. Gene disruption and stable isotope feeding experiments identified essential biosynthetic genes and revealed the source of the N-nitroso group. Additional biochemical characterization of the biosynthetic enzymes revealed that the non-proteinogenic amino acid l-2,3-diaminopropionic acid (l-Dap) is synthesized and loaded onto a free-standing peptidyl carrier protein (PCP) domain in l-alanosine biosynthesis, which we propose may be a mechanism of handling unstable intermediates generated en route to the diazeniumdiolate. These discoveries will facilitate efforts to determine the biochemistry of diazeniumdiolate formation.
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Affiliation(s)
- Tai L Ng
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA
| | - Monica E McCallum
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA
| | - Christine R Zheng
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA
| | - Jennifer X Wang
- Small Molecule Mass Spectrometry Facility, Faculty of Arts and Sciences Division of Science, Harvard University, 52 Oxford Street, Cambridge, MA, 02138, USA
| | - Kelvin J Y Wu
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA
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40
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41
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Maini Rekdal V, Bess EN, Bisanz JE, Turnbaugh PJ, Balskus EP. Discovery and inhibition of an interspecies gut bacterial pathway for Levodopa metabolism. Science 2019; 364:364/6445/eaau6323. [PMID: 31196984 PMCID: PMC7745125 DOI: 10.1126/science.aau6323] [Citation(s) in RCA: 335] [Impact Index Per Article: 67.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 04/18/2019] [Accepted: 05/02/2019] [Indexed: 12/19/2022]
Abstract
The human gut microbiota metabolizes the Parkinson’s disease medication Levodopa (L-dopa), potentially reducing drug availability and causing side effects. However, the organisms, genes, and enzymes responsible for this activity in patients and their susceptibility to inhibition by host-targeted drugs are unknown. Here, we describe an interspecies pathway for gut bacterial L-dopa metabolism. Conversion of L-dopa to dopamine by a pyridoxal phosphate-dependent tyrosine decarboxylase from Enterococcus faecalis is followed by transformation of dopamine to m-tyramine by a molybdenum-dependent dehydroxylase from Eggerthella lenta. These enzymes predict drug metabolism in complex human gut microbiotas. Although a drug that targets host aromatic amino acid decarboxylase does not prevent gut microbial L-dopa decarboxylation, we identified a compound that inhibits this activity in Parkinson’s patient microbiotas and increases L-dopa bioavailability in mice.
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Affiliation(s)
- Vayu Maini Rekdal
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA
| | - Elizabeth N Bess
- Department of Microbiology and Immunology, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA.,Department of Chemistry, University of California, Irvine, 1102 Natural Sciences 2, Irvine, CA 92617, USA.,Department of Molecular Biology and Biochemistry, University of California, Irvine, 1102 Natural Sciences 2, Irvine, CA 92617, USA
| | - Jordan E Bisanz
- Department of Microbiology and Immunology, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Peter J Turnbaugh
- Department of Microbiology and Immunology, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA. .,Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
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42
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Martins TP, Rouger C, Glasser NR, Freitas S, de Fraissinette NB, Balskus EP, Tasdemir D, Leão PN. Chemistry, bioactivity and biosynthesis of cyanobacterial alkylresorcinols. Nat Prod Rep 2019; 36:1437-1461. [PMID: 30702733 PMCID: PMC6836626 DOI: 10.1039/c8np00080h] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Indexed: 12/18/2022]
Abstract
Covering: up to 2019 Alkylresorcinols are amphiphilic metabolites, well-known for their diverse biological activities, produced by both prokaryotes and eukaryotes. A few classes of alkylresorcinol scaffolds have been reported from the photoautotrophic cyanobacteria, ranging from the relatively simple hierridins to the more intricate cylindrocyclophanes. Recently, it has emerged that cyanobacteria employ two different biosynthetic pathways to produce unique alkylresorcinol scaffolds. However, these convergent pathways intersect by sharing biosynthetic elements which lead to common structural motifs. To obtain a broader view of the biochemical diversity of these compounds in cyanobacteria, we comprehensively cover the isolation, structure, biological activity and biosynthesis of their mono- and dialkylresorcinols. Moreover, we provide an overview of the diversity and distribution of alkylresorcinol-generating biosynthetic gene clusters in this phylum and highlight opportunities for discovery of novel alkylresorcinol scaffolds. Because some of these molecules have inspired notable syntheses, different approaches used to build these molecules in the laboratory are showcased.
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Affiliation(s)
- Teresa P. Martins
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR)
, University of Porto
,
Matosinhos
, Portugal
.
| | - Caroline Rouger
- Research Unit Marine Natural Products Chemistry
, GEOMAR Centre for Marine Biotechnology (GEOMAR-Biotech)
, GEOMAR Helmholtz Centre for Ocean Research Kiel
,
Germany
| | - Nathaniel R. Glasser
- Department of Chemistry & Chemical Biology
, Harvard University
,
Cambridge
, MA
, USA
| | - Sara Freitas
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR)
, University of Porto
,
Matosinhos
, Portugal
.
| | - Nelly B. de Fraissinette
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR)
, University of Porto
,
Matosinhos
, Portugal
.
| | - Emily P. Balskus
- Department of Chemistry & Chemical Biology
, Harvard University
,
Cambridge
, MA
, USA
| | - Deniz Tasdemir
- Research Unit Marine Natural Products Chemistry
, GEOMAR Centre for Marine Biotechnology (GEOMAR-Biotech)
, GEOMAR Helmholtz Centre for Ocean Research Kiel
,
Germany
| | - Pedro N. Leão
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR)
, University of Porto
,
Matosinhos
, Portugal
.
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Wilson MR, Jiang Y, Villalta PW, Stornetta A, Boudreau PD, Carrá A, Brennan CA, Chun E, Ngo L, Samson LD, Engelward BP, Garrett WS, Balbo S, Balskus EP. The human gut bacterial genotoxin colibactin alkylates DNA. Science 2019; 363:363/6428/eaar7785. [PMID: 30765538 DOI: 10.1126/science.aar7785] [Citation(s) in RCA: 322] [Impact Index Per Article: 64.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 10/16/2018] [Accepted: 12/21/2018] [Indexed: 12/13/2022]
Abstract
Certain Escherichia coli strains residing in the human gut produce colibactin, a small-molecule genotoxin implicated in colorectal cancer pathogenesis. However, colibactin's chemical structure and the molecular mechanism underlying its genotoxic effects have remained unknown for more than a decade. Here we combine an untargeted DNA adductomics approach with chemical synthesis to identify and characterize a covalent DNA modification from human cell lines treated with colibactin-producing E. coli Our data establish that colibactin alkylates DNA with an unusual electrophilic cyclopropane. We show that this metabolite is formed in mice colonized by colibactin-producing E. coli and is likely derived from an initially formed, unstable colibactin-DNA adduct. Our findings reveal a potential biomarker for colibactin exposure and provide mechanistic insights into how a gut microbe may contribute to colorectal carcinogenesis.
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Affiliation(s)
- Matthew R Wilson
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA
| | - Yindi Jiang
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA
| | - Peter W Villalta
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street Southeast, Minneapolis, MN 55455, USA
| | - Alessia Stornetta
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street Southeast, Minneapolis, MN 55455, USA
| | - Paul D Boudreau
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA
| | - Andrea Carrá
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street Southeast, Minneapolis, MN 55455, USA
| | - Caitlin A Brennan
- Department of Immunology and Infectious Diseases and Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115, USA
| | - Eunyoung Chun
- Department of Immunology and Infectious Diseases and Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115, USA
| | - Lizzie Ngo
- Department of Biological Engineering, MIT, Cambridge, MA 02139, USA
| | - Leona D Samson
- Department of Biological Engineering, MIT, Cambridge, MA 02139, USA
| | | | - Wendy S Garrett
- Department of Immunology and Infectious Diseases and Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115, USA.,Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA.,Department of Medical Oncology, Dana-Farber Institute, Boston, MA 02115, USA
| | - Silvia Balbo
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street Southeast, Minneapolis, MN 55455, USA.
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Volpe MR, Wilson MR, Brotherton CA, Winter ES, Johnson SE, Balskus EP. In Vitro Characterization of the Colibactin-Activating Peptidase ClbP Enables Development of a Fluorogenic Activity Probe. ACS Chem Biol 2019; 14:1097-1101. [PMID: 31059217 DOI: 10.1021/acschembio.9b00069] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The gut bacterial genotoxin colibactin is linked to the development of colorectal cancer. In the final stages of colibactin's biosynthesis, an inactive precursor (precolibactin) undergoes proteolytic cleavage by ClbP, an unusual inner-membrane-bound periplasmic peptidase, to generate the active genotoxin. This enzyme presents an opportunity to monitor and modulate colibactin biosynthesis, but its active form has not been studied in vitro and limited tools exist to measure its activity. Here, we describe the in vitro biochemical characterization of catalytically active, full-length ClbP. We elucidate its substrate preferences and use this information to develop a fluorogenic activity probe. This tool will enable the discovery of ClbP inhibitors and streamline identification of colibactin-producing bacteria.
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Affiliation(s)
- Matthew R. Volpe
- Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Matthew R. Wilson
- Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Carolyn A. Brotherton
- Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Ethan S. Winter
- Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Sheila E. Johnson
- Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Emily P. Balskus
- Department of Chemistry & Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
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Abstract
Covering: up to the end of 2017 The human body is composed of an equal number of human and microbial cells. While the microbial community inhabiting the human gastrointestinal tract plays an essential role in host health, these organisms have also been connected to various diseases. Yet, the gut microbial functions that modulate host biology are not well established. In this review, we describe metabolic functions of the human gut microbiota that involve metalloenzymes. These activities enable gut microbial colonization, mediate interactions with the host, and impact human health and disease. We highlight cases in which enzyme characterization has advanced our understanding of the gut microbiota and examples that illustrate the diverse ways in which metalloenzymes facilitate both essential and unique functions of this community. Finally, we analyze Human Microbiome Project sequencing datasets to assess the distribution of a prominent family of metalloenzymes in human-associated microbial communities, guiding future enzyme characterization efforts.
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48
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Schultz EE, Braffman NR, Luescher MU, Hager HH, Balskus EP. Biocatalytic Friedel–Crafts Alkylation Using a Promiscuous Biosynthetic Enzyme. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201814016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Erica E. Schultz
- Department of Chemistry Lake Forest College 555 Sheridan Rd Lake Forest IL 60045 USA
| | - Nathaniel R. Braffman
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St. Cambridge MA 02138 USA
| | - Michael U. Luescher
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St. Cambridge MA 02138 USA
| | - Harry H. Hager
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St. Cambridge MA 02138 USA
| | - Emily P. Balskus
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St. Cambridge MA 02138 USA
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49
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Schultz EE, Braffman NR, Luescher MU, Hager HH, Balskus EP. Biocatalytic Friedel–Crafts Alkylation Using a Promiscuous Biosynthetic Enzyme. Angew Chem Int Ed Engl 2019; 58:3151-3155. [DOI: 10.1002/anie.201814016] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Indexed: 02/02/2023]
Affiliation(s)
- Erica E. Schultz
- Department of Chemistry Lake Forest College 555 Sheridan Rd Lake Forest IL 60045 USA
| | - Nathaniel R. Braffman
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St. Cambridge MA 02138 USA
| | - Michael U. Luescher
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St. Cambridge MA 02138 USA
| | - Harry H. Hager
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St. Cambridge MA 02138 USA
| | - Emily P. Balskus
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St. Cambridge MA 02138 USA
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50
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Ng TL, Rohac R, Mitchell AJ, Boal AK, Balskus EP. An N-nitrosating metalloenzyme constructs the pharmacophore of streptozotocin. Nature 2019; 566:94-99. [PMID: 30728519 PMCID: PMC6369591 DOI: 10.1038/s41586-019-0894-z] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 12/12/2018] [Indexed: 12/31/2022]
Abstract
N-nitroso-containing small molecules, such as the bacterial natural product streptozotocin, are prominent carcinogens1,2 and important cancer chemotherapeutics3,4. Despite this functional group’s significant impact on human health, dedicated enzymes involved in N-nitroso assembly have not been identified. Here, we describe a metalloenzyme from streptozotocin biosynthesis (SznF) that catalyzes an oxidative rearrangement of the guanidine group of Nω-methyl-L-arginine to generate an N-nitrosourea product. Structural characterization and mutagenesis of SznF uncovered two separate active sites that promote distinct steps in this transformation using different iron-containing metallocofactors. The discovery of this biosynthetic reaction, which has little precedent in enzymology or organic synthesis, expands the catalytic capabilities of non-heme iron-dependent enzymes to include N–N bond formation. We find biosynthetic gene clusters encoding SznF homologs are widely distributed among bacteria, including environmental organisms, plant symbionts, and human pathogens, suggesting an unexpectedly diverse and uncharacterized microbial reservoir of bioactive N-nitroso metabolites.
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Affiliation(s)
- Tai L Ng
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Roman Rohac
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA
| | - Andrew J Mitchell
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Amie K Boal
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA. .,Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA.
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
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