1
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Affiliation(s)
- Grayson L Chadwick
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Dipti D Nayak
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Michael Rother
- Fakultät Biologie, Technische Universität Dresden, Dresden 01062, Germany
| | - William W Metcalf
- Department of Microbiology, University of Illinois, Urbana, IL 61874
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2
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Polidore ALA, Caserio AD, Zhu L, Metcalf WW. Complete Biochemical Characterization of Pantaphos Biosynthesis Highlights an Unusual Role for a SAM-Dependent Methyltransferase. Angew Chem Int Ed Engl 2024; 63:e202317262. [PMID: 38141166 PMCID: PMC10873477 DOI: 10.1002/anie.202317262] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 12/25/2023]
Abstract
Pantaphos is small molecule virulence factor made by the plant pathogen Pantoea ananatis. An 11 gene operon, designated hvr for high virulence, is required for production of this phosphonic acid natural product, but the metabolic steps used in its production have yet to be established. Herein, we determine the complete biosynthetic pathway using a combination of bioinformatics, in vitro biochemistry and in vivo heterologous expression. Only 6 of the 11 hvr genes are needed to produce pantaphos, while a seventh is likely to be required for export. Surprisingly, the pathway involves a series of O-methylated intermediates, which are then hydrolyzed to produce the final product. The methylated intermediates are produced by an irreversible S-adenosylmethione (SAM)-dependent methyltransferase that is required to drive a thermodynamically unfavorable dehydration in the preceding step, a function not previously attributed to members of this enzyme class. Methylation of pantaphos by the same enzyme is also likely to limit its toxicity in the producing organism. The pathway also involves a novel flavin-dependent monooxygenase that differs from homologous proteins due to its endogenous flavin-reductase activity. Heterologous production of pantaphos by Escherichia coli strains expressing the minimal gene set strongly supports the in vitro biochemical data.
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Affiliation(s)
- Alexander L A Polidore
- Department of Microbiology, University of Illinois at Urbana-Champaign, 601 S. Goodwin, Urbana, IL 61874, USA
| | - Angelica D Caserio
- Department of Microbiology, University of Illinois at Urbana-Champaign, 601 S. Goodwin, Urbana, IL 61874, USA
| | - Lingyang Zhu
- Department of Chemistry, University of Illinois at Urbana-Champaign, 505 S Mathews Ave, Urbana, IL 61874, USA
| | - William W Metcalf
- Department of Microbiology, University of Illinois at Urbana-Champaign, 601 S. Goodwin, Urbana, IL 61874, USA
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, IL 61874, USA
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3
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Bown L, Hirota R, Goettge MN, Cui J, Krist DT, Zhu L, Giurgiu C, van der Donk WA, Ju KS, Metcalf WW. A Novel Pathway for Biosynthesis of the Herbicidal Phosphonate Natural Product Phosphonothrixin Is Widespread in Actinobacteria. J Bacteriol 2023; 205:e0048522. [PMID: 37074199 PMCID: PMC10210982 DOI: 10.1128/jb.00485-22] [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: 12/22/2022] [Accepted: 03/23/2023] [Indexed: 04/20/2023] Open
Abstract
Phosphonothrixin is an herbicidal phosphonate natural product with an unusual, branched carbon skeleton. Bioinformatic analyses of the ftx gene cluster, which is responsible for synthesis of the compound, suggest that early steps of the biosynthetic pathway, up to production of the intermediate 2,3-dihydroxypropylphosphonic acid (DHPPA) are identical to those of the unrelated phosphonate natural product valinophos. This conclusion was strongly supported by the observation of biosynthetic intermediates from the shared pathway in spent media from two phosphonothrixin producing strains. Biochemical characterization of ftx-encoded proteins confirmed these early steps, as well as subsequent steps involving the oxidation of DHPPA to 3-hydroxy-2-oxopropylphosphonate and its conversion to phosphonothrixin by the combined action of an unusual heterodimeric, thiamine-pyrophosphate (TPP)-dependent ketotransferase and a TPP-dependent acetolactate synthase. The frequent observation of ftx-like gene clusters within actinobacteria suggests that production of compounds related to phosphonothrixin is common within these bacteria. IMPORTANCE Phosphonic acid natural products, such as phosphonothrixin, have great potential for biomedical and agricultural applications; however, discovery and development of these compounds requires detailed knowledge of the metabolism involved in their biosynthesis. The studies reported here reveal the biochemical pathway phosphonothrixin production, which enhances our ability to design strains that overproduce this potentially useful herbicide. This knowledge also improves our ability to predict the products of related biosynthetic gene clusters and the functions of homologous enzymes.
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Affiliation(s)
- Luke Bown
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Ryuichi Hirota
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima City, Hiroshima, Japan
| | - Michelle N. Goettge
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Jerry Cui
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - David T. Krist
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Lingyang Zhu
- Department of Chemistry and the Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Constantin Giurgiu
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Wilfred A. van der Donk
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Chemistry and the Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Kou-San Ju
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, Ohio, USA
- Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, USA
- Center for Applied Plant Sciences, The Ohio State University, Columbus, Ohio, USA
| | - William W. Metcalf
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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4
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Blin K, Shaw S, Augustijn HE, Reitz ZL, Biermann F, Alanjary M, Fetter A, Terlouw BR, Metcalf WW, Helfrich EJN, van Wezel GP, Medema MH, Weber T. antiSMASH 7.0: new and improved predictions for detection, regulation, chemical structures and visualisation. Nucleic Acids Res 2023:7151336. [PMID: 37140036 DOI: 10.1093/nar/gkad344] [Citation(s) in RCA: 191] [Impact Index Per Article: 191.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/31/2023] [Accepted: 04/26/2023] [Indexed: 05/05/2023] Open
Abstract
Microorganisms produce small bioactive compounds as part of their secondary or specialised metabolism. Often, such metabolites have antimicrobial, anticancer, antifungal, antiviral or other bio-activities and thus play an important role for applications in medicine and agriculture. In the past decade, genome mining has become a widely-used method to explore, access, and analyse the available biodiversity of these compounds. Since 2011, the 'antibiotics and secondary metabolite analysis shell-antiSMASH' (https://antismash.secondarymetabolites.org/) has supported researchers in their microbial genome mining tasks, both as a free to use web server and as a standalone tool under an OSI-approved open source licence. It is currently the most widely used tool for detecting and characterising biosynthetic gene clusters (BGCs) in archaea, bacteria, and fungi. Here, we present the updated version 7 of antiSMASH. antiSMASH 7 increases the number of supported cluster types from 71 to 81, as well as containing improvements in the areas of chemical structure prediction, enzymatic assembly-line visualisation and gene cluster regulation.
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Affiliation(s)
- Kai Blin
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs.Lyngby, Denmark
| | - Simon Shaw
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs.Lyngby, Denmark
| | - Hannah E Augustijn
- Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands
- Bioinformatics Group, Wageningen University, Wageningen, The Netherlands
| | - Zachary L Reitz
- Bioinformatics Group, Wageningen University, Wageningen, The Netherlands
| | - Friederike Biermann
- Bioinformatics Group, Wageningen University, Wageningen, The Netherlands
- Institute of Molecular Bio Science, Goethe-University Frankfurt, Frankfurt am Main, Germany
- LOEWE Center for Translational Biodiversity Genomics. Frankfurt am Main, Germany
| | - Mohammad Alanjary
- Bioinformatics Group, Wageningen University, Wageningen, The Netherlands
| | - Artem Fetter
- Bioinformatics Group, Wageningen University, Wageningen, The Netherlands
- Institute of Technical Chemistry, Leibniz University Hannover, Hannover, Germany
| | - Barbara R Terlouw
- Bioinformatics Group, Wageningen University, Wageningen, The Netherlands
| | - William W Metcalf
- Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, IL, USA
- Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - Eric J N Helfrich
- Institute of Molecular Bio Science, Goethe-University Frankfurt, Frankfurt am Main, Germany
- LOEWE Center for Translational Biodiversity Genomics. Frankfurt am Main, Germany
| | - Gilles P van Wezel
- Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands
| | - Marnix H Medema
- Bioinformatics Group, Wageningen University, Wageningen, The Netherlands
| | - Tilmann Weber
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs.Lyngby, Denmark
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5
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Zhao M, Shin GY, Stice S, Bown JL, Coutinho T, Metcalf WW, Gitaitis R, Kvitko B, Dutta B. A Novel Biosynthetic Gene Cluster Across the Pantoea Species Complex Is Important for Pathogenicity in Onion. Mol Plant Microbe Interact 2023; 36:176-188. [PMID: 36534063 PMCID: PMC10433531 DOI: 10.1094/mpmi-08-22-0165-r] [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] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Onion center rot is caused by at least four species of genus Pantoea (P. ananatis, P. agglomerans, P. allii, and P. stewartii subsp. indologenes). Critical onion pathogenicity determinants for P. ananatis were recently described, but whether those determinants are common among other onion-pathogenic Pantoea species remains unknown. In this work, we report onion pathogenicity determinants in P. stewartii subsp. indologenes and P. allii. We identified two distinct secondary metabolite biosynthetic gene clusters present separately in different strains of onion-pathogenic P. stewartii subsp. indologenes. One cluster is similar to the previously described HiVir phosphonate biosynthetic cluster identified in P. ananatis and another is a novel putative phosphonate biosynthetic gene cluster, which we named Halophos. The Halophos gene cluster was also identified in P. allii strains. Both clusters are predicted to be phosphonate biosynthetic clusters based on the presence of a characteristic phosphoenolpyruvate phosphomutase (pepM) gene. The deletion of the pepM gene from either HiVir or Halophos clusters in P. stewartii subsp. indologenes caused loss of necrosis on onion leaves and red onion scales and resulted in significantly lower bacterial populations compared with the corresponding wild-type and complemented strains. Seven (halB to halH) of 11 genes (halA to halK) in the Halophos gene cluster are required for onion necrosis phenotypes. The onion nonpathogenic strain PNA15-2 (P. stewartii subsp. indologenes) gained the capacity to cause foliar necrosis on onion via exogenous expression of a minimal seven-gene Halophos cluster (genes halB to halH). Furthermore, cell-free culture filtrates of PNA14-12 expressing the intact Halophos gene cluster caused necrosis on onion leaves consistent with the presence of a secreted toxin. Based on the similarity of proteins to those with experimentally determined functions, we are able to predict most of the steps in Halophos biosynthesis. Together, these observations indicate that production of the toxin phosphonate seems sufficient to account for virulence of a variety of different Pantoea strains, although strains differ in possessing a single but distinct phosphonate biosynthetic cluster. Overall, this is the first report of onion pathogenicity determinants in P. stewartii subsp. indologenes and P. allii. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Mei Zhao
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, P. R. China
- Department of Plant Pathology, University of Georgia, Tifton GA USA
| | - Gi Yoon Shin
- Department of Plant Pathology, University of Georgia, Athens GA USA
| | - Shaun Stice
- Department of Plant Pathology, University of Georgia, Athens GA USA
| | - Jonathon Luke Bown
- Department of Microbiology, University of Illinois, Urbana-Champaign, IL
| | - Teresa Coutinho
- The Genomics Research Institute, University of Pretoria, Hatfield, South Africa
| | - William W. Metcalf
- Department of Microbiology, University of Illinois, Urbana-Champaign, IL
| | - Ron Gitaitis
- Department of Plant Pathology, University of Georgia, Tifton GA USA
| | - Brian Kvitko
- Department of Plant Pathology, University of Georgia, Athens GA USA
| | - Bhabesh Dutta
- Department of Plant Pathology, University of Georgia, Tifton GA USA
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6
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Lloyd CT, Iwig DF, Wang B, Cossu M, Metcalf WW, Boal AK, Booker SJ. Discovery, structure, and mechanism of a tetraether lipid synthase. Nature 2022; 609:197-203. [PMID: 35882349 PMCID: PMC9433317 DOI: 10.1038/s41586-022-05120-2] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 07/18/2022] [Indexed: 11/20/2022]
Abstract
Archaea synthesize isoprenoid-based ether-linked membrane lipids, which enable them to withstand extreme environmental conditions, such as high temperatures, high salinity, and low or high pH values1–5. In some archaea, such as Methanocaldococcus jannaschii, these lipids are further modified by forming carbon–carbon bonds between the termini of two lipid tails within one glycerophospholipid to generate the macrocyclic archaeol or forming two carbon–carbon bonds between the termini of two lipid tails from two glycerophospholipids to generate the macrocycle glycerol dibiphytanyl glycerol tetraether (GDGT)1,2. GDGT contains two 40-carbon lipid chains (biphytanyl chains) that span both leaflets of the membrane, providing enhanced stability to extreme conditions. How these specialized lipids are formed has puzzled scientists for decades. The reaction necessitates the coupling of two completely inert sp3-hybridized carbon centres, which, to our knowledge, has not been observed in nature. Here we show that the gene product of mj0619 from M. jannaschii, which encodes a radical S-adenosylmethionine enzyme, is responsible for biphytanyl chain formation during synthesis of both the macrocyclic archaeol and GDGT membrane lipids6. Structures of the enzyme show the presence of four metallocofactors: three [Fe4S4] clusters and one mononuclear rubredoxin-like iron ion. In vitro mechanistic studies show that Csp3–Csp3 bond formation takes place on fully saturated archaeal lipid substrates and involves an intermediate bond between the substrate carbon and a sulfur of one of the [Fe4S4] clusters. Our results not only establish the biosynthetic route for tetraether formation but also improve the use of GDGT in GDGT-based paleoclimatology indices7–10. In Methanocaldococcus jannaschii, a radical S-adenosylmethionine enzyme catalyses the formation of the biphytanyl chain.
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Affiliation(s)
- Cody T Lloyd
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, USA
| | - David F Iwig
- The Howard Hughes Medical Institute, Pennsylvania State University, University. Park, PA, USA
| | - Bo Wang
- The Howard Hughes Medical Institute, Pennsylvania State University, University. Park, PA, USA
| | - Matteo Cossu
- Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - William W Metcalf
- Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, IL, USA.,Institute for Genomic Biology, University of Illinois Urbana- Champaign, Urbana, IL, USA
| | - Amie K Boal
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, USA. .,The Howard Hughes Medical Institute, Pennsylvania State University, University. Park, PA, USA.
| | - Squire J Booker
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, USA. .,The Howard Hughes Medical Institute, Pennsylvania State University, University. Park, PA, USA. .,Department of Chemistry, Pennsylvania State University, University Park, PA, USA.
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7
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Parkinson EI, Lakkis HG, Alwali AA, Metcalf MEM, Modi R, Metcalf WW. An Unusual Oxidative Rearrangement Catalyzed by a Divergent Member of the 2-Oxoglutarate-Dependent Dioxygenase Superfamily during Biosynthesis of Dehydrofosmidomycin. Angew Chem Int Ed Engl 2022; 61:e202206173. [PMID: 35588368 PMCID: PMC9296572 DOI: 10.1002/anie.202206173] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Indexed: 12/20/2022]
Abstract
The biosynthesis of the natural product dehydrofosmidomycin involves an unusual transformation in which 2-(trimethylamino)ethylphosphonate is rearranged, desaturated and demethylated by the enzyme DfmD, a divergent member of the 2-oxoglutarate-dependent dioxygenase superfamily. Although other members of this enzyme family catalyze superficially similar transformations, the combination of all three reactions in a single enzyme has not previously been observed. By characterizing the products of in vitro reactions with labeled and unlabeled substrates, we show that DfmD performs this transformation in two steps, with the first involving desaturation of the substrate to form 2-(trimethylamino)vinylphosphonate, and the second involving rearrangement and demethylation to form methyldehydrofosmidomycin. These data reveal significant differences from the desaturation and rearrangement reactions catalyzed by other family members.
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Affiliation(s)
- Elizabeth I. Parkinson
- Institute for Genomic BiologyUniversity of Illinois at Urbana-Champaign1206 W. Gregory Dr.UrbanaIL 61801USA
- Department of ChemistryPurdue UniversityHerbert C. Brown Laboratory of Chemistry, Room 4103E560 Oval Drive, Box 59West LafayetteIN 47907USA
- Department of Medicinal Chemistry and Molecular PharmacologyPurdue UniversityHerbert C. Brown Laboratory of Chemistry, Room 4103E560 Oval Drive, Box 59West LafayetteIN 47907USA
| | - Hani G. Lakkis
- Department of ChemistryPurdue UniversityHerbert C. Brown Laboratory of Chemistry, Room 4103E560 Oval Drive, Box 59West LafayetteIN 47907USA
| | - Amir A. Alwali
- Department of ChemistryPurdue UniversityHerbert C. Brown Laboratory of Chemistry, Room 4103E560 Oval Drive, Box 59West LafayetteIN 47907USA
| | - Mary Elizabeth M. Metcalf
- Institute for Genomic BiologyUniversity of Illinois at Urbana-Champaign1206 W. Gregory Dr.UrbanaIL 61801USA
- Department of MicrobiologyUniversity of Illinois at Urbana-Champaign, B103C&LSL601 S. GoodwinUrbanaIL 61801USA
| | - Ramya Modi
- Department of ChemistryPurdue UniversityHerbert C. Brown Laboratory of Chemistry, Room 4103E560 Oval Drive, Box 59West LafayetteIN 47907USA
| | - William W. Metcalf
- Institute for Genomic BiologyUniversity of Illinois at Urbana-Champaign1206 W. Gregory Dr.UrbanaIL 61801USA
- Department of MicrobiologyUniversity of Illinois at Urbana-Champaign, B103C&LSL601 S. GoodwinUrbanaIL 61801USA
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8
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Parkinson EI, Lakkis HG, Alwali AA, Metcalf MEM, Modi R, Metcalf WW. An Unusual Oxidative Rearrangement Catalyzed by a Divergent Member of the 2‐Oxoglutarate‐Dependent Dioxygenase Superfamily during Biosynthesis of Dehydrofosmidomycin. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206173] [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)
| | | | | | | | - Ramya Modi
- Purdue University Chemistry UNITED STATES
| | - William W. Metcalf
- University of Illinois Urbana-Champaign Microbiology 601 S. GoodwinB103 CLSL 61801 Urbana UNITED STATES
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9
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Spietz RL, Payne D, Kulkarni G, Metcalf WW, Roden EE, Boyd ES. Investigating Abiotic and Biotic Mechanisms of Pyrite Reduction. Front Microbiol 2022; 13:878387. [PMID: 35615515 PMCID: PMC9124975 DOI: 10.3389/fmicb.2022.878387] [Citation(s) in RCA: 8] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 03/31/2022] [Indexed: 11/16/2022] Open
Abstract
Pyrite (FeS2) has a very low solubility and therefore has historically been considered a sink for iron (Fe) and sulfur (S) and unavailable to biology in the absence of oxygen and oxidative weathering. Anaerobic methanogens were recently shown to reduce FeS2 and assimilate Fe and S reduction products to meet nutrient demands. However, the mechanism of FeS2 mineral reduction and the forms of Fe and S assimilated by methanogens remained unclear. Thermodynamic calculations described herein indicate that H2 at aqueous concentrations as low as 10-10 M favors the reduction of FeS2, with sulfide (HS-) and pyrrhotite (Fe1- x S) as products; abiotic laboratory experiments confirmed the reduction of FeS2 with dissolved H2 concentrations greater than 1.98 × 10-4 M H2. Growth studies of Methanosarcina barkeri provided with FeS2 as the sole source of Fe and S resulted in H2 production but at concentrations too low to drive abiotic FeS2 reduction, based on abiotic laboratory experimental data. A strain of M. barkeri with deletions in all [NiFe]-hydrogenases maintained the ability to reduce FeS2 during growth, providing further evidence that extracellular electron transport (EET) to FeS2 does not involve H2 or [NiFe]-hydrogenases. Physical contact between cells and FeS2 was required for mineral reduction but was not required to obtain Fe and S from dissolution products. The addition of a synthetic electron shuttle, anthraquinone-2,6-disulfonate, allowed for biological reduction of FeS2 when physical contact between cells and FeS2 was prohibited, indicating that exogenous electron shuttles can mediate FeS2 reduction. Transcriptomics experiments revealed upregulation of several cytoplasmic oxidoreductases during growth of M. barkeri on FeS2, which may indicate involvement in provisioning low potential electrons for EET to FeS2. Collectively, the data presented herein indicate that reduction of insoluble FeS2 by M. barkeri occurred via electron transfer from the cell surface to the mineral surface resulting in the generation of soluble HS- and mineral-associated Fe1- x S. Solubilized Fe(II), but not HS-, from mineral-associated Fe1- x S reacts with aqueous HS- yielding aqueous iron sulfur clusters (FeS aq ) that likely serve as the Fe and S source for methanogen growth and activity. FeS aq nucleation and subsequent precipitation on the surface of cells may result in accelerated EET to FeS2, resulting in positive feedback between cell activity and FeS2 reduction.
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Affiliation(s)
- Rachel L. Spietz
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, United States
| | - Devon Payne
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, United States
| | - Gargi Kulkarni
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - William W. Metcalf
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Eric E. Roden
- Department of Geosciences, University of Wisconsin, Madison, WI, United States
| | - Eric S. Boyd
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, United States
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10
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Vasan AK, Haloi N, Geddes E, Prasanna A, Wen PC, Metcalf WW, Hergenrother P, Tajkhorshid E. Characterizing permeation energetics and mechanisms through membrane transport proteins in high-dimensional conformational space. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.2759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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11
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Thomsen J, Weidenbach K, Metcalf WW, Schmitz RA. Genetic Methods and Construction of Chromosomal Mutations in Methanogenic Archaea. Methods Mol Biol 2022; 2522:105-117. [PMID: 36125745 DOI: 10.1007/978-1-0716-2445-6_6] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Genetic manipulation through markerless exchange enables the modification of several genomic regions without leaving a selection marker in the genome. Here, a method using hpt coding for hypoxanthine phosphoribosyltransferase as a counter selectable marker is described. For Methanosarcina species a chromosomal deletion of the hpt gene is firstly generated, which confers resistance to the purine analogue 8-aza-2,6-diaminopurine (8-ADP). In a second step, the reintroduction of the hpt gene on a plasmid leads to a selectable loss of 8-ADP resistance after a homologous recombination event (pop-in). A subsequent pop-out event restores the 8-ADP resistance and can generate chromosomal mutants with frequencies of about 50%.
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Affiliation(s)
- Johanna Thomsen
- Institute For General Microbiology, Christian-Albrechts-University, Kiel, Germany
| | - Katrin Weidenbach
- Institute For General Microbiology, Christian-Albrechts-University, Kiel, Germany
| | | | - Ruth A Schmitz
- Institute For General Microbiology, Christian-Albrechts-University, Kiel, Germany.
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12
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Haloi N, Vasan AK, Geddes EJ, Prasanna A, Wen PC, Metcalf WW, Hergenrother PJ, Tajkhorshid E. Rationalizing the generation of broad spectrum antibiotics with the addition of a positive charge. Chem Sci 2021; 12:15028-15044. [PMID: 34909143 PMCID: PMC8612397 DOI: 10.1039/d1sc04445a] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [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: 08/13/2021] [Accepted: 10/13/2021] [Indexed: 11/28/2022] Open
Abstract
Antibiotic resistance of Gram-negative bacteria is largely attributed to the low permeability of their outer membrane (OM). Recently, we disclosed the eNTRy rules, a key lesson of which is that the introduction of a primary amine enhances OM permeation in certain contexts. To understand the molecular basis for this finding, we perform an extensive set of molecular dynamics (MD) simulations and free energy calculations comparing the permeation of aminated and amine-free antibiotic derivatives through the most abundant OM porin of E. coli, OmpF. To improve sampling of conformationally flexible drugs in MD simulations, we developed a novel, Monte Carlo and graph theory based algorithm to probe more efficiently the rotational and translational degrees of freedom visited during the permeation of the antibiotic molecule through OmpF. The resulting pathways were then used for free-energy calculations, revealing a lower barrier against the permeation of the aminated compound, substantiating its greater OM permeability. Further analysis revealed that the amine facilitates permeation by enabling the antibiotic to align its dipole to the luminal electric field of the porin and form favorable electrostatic interactions with specific, highly-conserved charged residues. The importance of these interactions in permeation was further validated with experimental mutagenesis and whole cell accumulation assays. Overall, this study provides insights on the importance of the primary amine for antibiotic permeation into Gram-negative pathogens that could help the design of future antibiotics. We also offer a new computational approach for calculating free-energy of processes where relevant molecular conformations cannot be efficiently captured. A rapid pathway sampling method combining Monte Carlo and graph theory, developed to describe permeation pathways through outer membrane porins, can distinguish between structurally similar analogs with different permeabilities.![]()
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Affiliation(s)
- Nandan Haloi
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Archit Kumar Vasan
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Emily J Geddes
- Department of Chemistry, University of Illinois at Urbana-Champaign Urbana IL 61801 USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Arjun Prasanna
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA.,Department of Microbiology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Po-Chao Wen
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - William W Metcalf
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA.,Department of Microbiology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Paul J Hergenrother
- Department of Chemistry, University of Illinois at Urbana-Champaign Urbana IL 61801 USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Emad Tajkhorshid
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
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13
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Tryon JH, Rote JC, Chen L, Robey MT, Vega MM, Phua WC, Metcalf WW, Ju KS, Kelleher NL, Thomson RJ. Genome Mining and Metabolomics Uncover a Rare d-Capreomycidine Containing Natural Product and Its Biosynthetic Gene Cluster. ACS Chem Biol 2020; 15:3013-3020. [PMID: 33151679 DOI: 10.1021/acschembio.0c00663] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the metabolomics-driven genome mining of a new cyclic-guanidino incorporating non-ribosomal peptide synthetase (NRPS) gene cluster and full structure elucidation of its associated hexapeptide product, faulknamycin. Structural studies unveiled that this natural product contained the previously unknown (R,S)-stereoisomer of capreomycidine, d-capreomycidine. Furthermore, heterologous expression of the identified gene cluster successfully reproduces faulknamycin production without an observed homologue of VioD, the pyridoxal phosphate (PLP)-dependent enzyme found in all previous l-capreomycidine biosynthesis. An alternative NRPS-dependent pathway for d-capreomycidine biosynthesis is proposed.
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Affiliation(s)
- James H. Tryon
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Jennifer C. Rote
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Li Chen
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Matthew T. Robey
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Marvin M. Vega
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Wan Cheng Phua
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - William W. Metcalf
- Carl R. Woese Institute for Genomic Biology and The Department of Microbiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Kou-San Ju
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
- The Division of Medicinal Chemistry and Pharmacognosy, Center for Applied Plant Sciences, and Infectious Diseases Institute, The Ohio State University, Columbus, Ohio 43210, United States
| | - Neil L. Kelleher
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Regan J. Thomson
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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14
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Nayak DD, Liu A, Agrawal N, Rodriguez-Carerro R, Dong SH, Mitchell DA, Nair SK, Metcalf WW. Functional interactions between posttranslationally modified amino acids of methyl-coenzyme M reductase in Methanosarcina acetivorans. PLoS Biol 2020; 18:e3000507. [PMID: 32092071 PMCID: PMC7058361 DOI: 10.1371/journal.pbio.3000507] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 03/05/2020] [Accepted: 02/04/2020] [Indexed: 01/27/2023] Open
Abstract
The enzyme methyl-coenzyme M reductase (MCR) plays an important role in mediating global levels of methane by catalyzing a reversible reaction that leads to the production or consumption of this potent greenhouse gas in methanogenic and methanotrophic archaea. In methanogenic archaea, the alpha subunit of MCR (McrA) typically contains four to six posttranslationally modified amino acids near the active site. Recent studies have identified enzymes performing two of these modifications (thioglycine and 5-[S]-methylarginine), yet little is known about the formation and function of the remaining posttranslationally modified residues. Here, we provide in vivo evidence that a dedicated S-adenosylmethionine-dependent methyltransferase encoded by a gene we designated methylcysteine modification (mcmA) is responsible for formation of S-methylcysteine in Methanosarcina acetivorans McrA. Phenotypic analysis of mutants incapable of cysteine methylation suggests that the S-methylcysteine residue might play a role in adaption to mesophilic conditions. To examine the interactions between the S-methylcysteine residue and the previously characterized thioglycine, 5-(S)-methylarginine modifications, we generated M. acetivorans mutants lacking the three known modification genes in all possible combinations. Phenotypic analyses revealed complex, physiologically relevant interactions between the modified residues, which alter the thermal stability of MCR in a combinatorial fashion that is not readily predictable from the phenotypes of single mutants. High-resolution crystal structures of inactive MCR lacking the modified amino acids were indistinguishable from the fully modified enzyme, suggesting that interactions between the posttranslationally modified residues do not exert a major influence on the static structure of the enzyme but rather serve to fine-tune the activity and efficiency of MCR.
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Affiliation(s)
- Dipti D. Nayak
- Carl R. Woese Institute of Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
- Department of Microbiology, University of Illinois, Urbana, Illinois, United States of America
| | - Andi Liu
- Department of Microbiology, University of Illinois, Urbana, Illinois, United States of America
| | - Neha Agrawal
- Department of Biochemistry, University of Illinois, Urbana, Illinois, United States of America
| | - Roy Rodriguez-Carerro
- Department of Microbiology, University of Illinois, Urbana, Illinois, United States of America
| | - Shi-Hui Dong
- Department of Biochemistry, University of Illinois, Urbana, Illinois, United States of America
| | - Douglas A. Mitchell
- Carl R. Woese Institute of Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
- Department of Microbiology, University of Illinois, Urbana, Illinois, United States of America
- Department of Chemistry, University of Illinois, Urbana, Illinois, United States of America
| | - Satish K. Nair
- Department of Biochemistry, University of Illinois, Urbana, Illinois, United States of America
- Center for Biophysics & Quantitative Biology, University of Illinois, Urbana, Illinois, United States of America
| | - William W. Metcalf
- Carl R. Woese Institute of Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
- Department of Microbiology, University of Illinois, Urbana, Illinois, United States of America
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15
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Nayak DD, Metcalf WW. Methylamine-specific methyltransferase paralogs in Methanosarcina are functionally distinct despite frequent gene conversion. ISME J 2019; 13:2173-2182. [PMID: 31053830 PMCID: PMC6776008 DOI: 10.1038/s41396-019-0428-6] [Citation(s) in RCA: 5] [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] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/28/2019] [Accepted: 04/03/2019] [Indexed: 11/09/2022]
Abstract
Sequenced archaeal genomes are mostly smaller and more streamlined than typical bacterial genomes; however, members of the Methanosarcina genus within the Euryarchaeaota are a significant exception, with M. acetivorans being the largest archaeal genome (5.8 Mbp) sequenced thus far. This finding is partially explained by extensive gene duplication within Methanosarcina spp. Significantly, the evolutionary pressures leading to gene duplication and subsequent genome expansion have not been well investigated, especially with respect to biological methane production (methanogenesis), which is the key biological trait of these environmentally important organisms. In this study, we address this question by specifically probing the functional evolution of two methylamine-specific methyltransferase paralogs in members of the Methanosarcina genus. Using the genetically tractable strain, M. acetivorans, we first show that the two paralogs have distinct cellular functions: one being required for methanogenesis from methylamine, the other for use of methylamine as a nitrogen source. Subsequently, through comparative sequence analyses, we show that functional divergence of paralogs is primarily mediated by divergent evolution of the 5' regulatory region, despite frequent gene conversion within the coding sequence. This unique evolutionary paradigm for functional divergence of genes post-duplication underscores a divergent role for an enzyme singularly associated with methanogenic metabolism in other aspects of cell physiology.
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Affiliation(s)
- Dipti D Nayak
- Carl R. Woese Institute for Genomic Biology, University of Illinois, 1206 W. Gregory Drive, Urbana, IL, 61801, USA.
| | - William W Metcalf
- Department of Microbiology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA
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16
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Farley KR, Metcalf WW. The streptothricin acetyltransferase (sat) gene as a positive selectable marker for methanogenic archaea. FEMS Microbiol Lett 2019; 366:5586563. [PMID: 31605529 DOI: 10.1093/femsle/fnz216] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [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: 08/09/2019] [Accepted: 10/10/2019] [Indexed: 11/14/2022] Open
Abstract
A repertoire of sophisticated genetic tools has significantly enhanced studies of Methanosarcina genera, yet the lack of multiple positive selectable markers has limited the types of genetic experiments that can be performed. In this study, we report the development of an additional positive selection system for Methanosarcina that utilizes the antibiotic nourseothricin and the Streptomyces rochei streptothricin acetyltransferase (sat) gene, which may be broadly applicable to other groups of methanogenic archaea. Nourseothricin was found to inhibit growth of four different methanogen species at concentrations ≤300 μg/ml in liquid or on solid media. Selection of nourseothricin resistant transformants was possible in two genetically tractable Methanosarcina species, M. acetivorans and M. barkeri, using the sat gene as a positive selectable marker. Additionally, the sat marker was useful for constructing a gene deletion mutant strain of M. acetivorans, emphasizing its utility as a second positive selectable marker for genetic analyses of Methanosarcina genera. Interestingly, two human gut-associated methanogens Methanobrevibacter smithii and Methanomassillicoccus luminyensis were more sensitive to nourseothricin than either Methanosarcina species, suggesting the nourseothricin-sat gene pair may provide a robust positive selection system for development of genetic tools in these and other methanogens.
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Affiliation(s)
- Kristen R Farley
- Department of Microbiology, B103 Chemical and Life Sciences Laboratory, University of Illinois Urbana-Champaign, 601 S. Goodwin Avenue, Urbana, Illinois 61801
| | - William W Metcalf
- Department of Microbiology, B103 Chemical and Life Sciences Laboratory, University of Illinois Urbana-Champaign, 601 S. Goodwin Avenue, Urbana, Illinois 61801
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17
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Parkinson EI, Erb A, Eliot AC, Ju KS, Metcalf WW. Fosmidomycin biosynthesis diverges from related phosphonate natural products. Nat Chem Biol 2019; 15:1049-1056. [PMID: 31451762 PMCID: PMC7098449 DOI: 10.1038/s41589-019-0343-1] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 07/09/2019] [Indexed: 12/04/2022]
Abstract
Fosmidomycin and related molecules comprise a family of phosphonate natural products with potent antibacterial, antimalarial and herbicidal activities. To understand the biosynthesis of these compounds, we characterized the fosmidomycin producer, Streptomyces lavendulae, using biochemical and genetic approaches. Surprisingly, we were unable to elicit production of fosmidomycin, instead observing the unsaturated derivative dehydrofosmidomycin, which we showed potently inhibits 1-deoxy-D-xylulose 5-phosphate reductoisomerase and has bioactivity against a number of bacteria. The genes required for dehydrofosmidomycin biosynthesis were established by heterologous expression experiments. Bioinformatics analyses, characterization of intermediates, and in vitro biochemistry show that the biosynthetic pathway involves conversion of a two-carbon phosphonate precursor into the unsaturated three-carbon product via a highly unusual rearrangement reaction, catalyzed by the 2-oxoglutarate dependent dioxygenase DfmD. The required genes and biosynthetic pathway for dehydrofosmidomycin differ substantially from that of the related natural product FR-900098, suggesting that the ability to produce these bioactive molecules arose via convergent evolution.
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Affiliation(s)
- Elizabeth I Parkinson
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | - Annette Erb
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Andrew C Eliot
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Kou-San Ju
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Microbiology and the Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, OH, USA
| | - William W Metcalf
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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18
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Petronikolou N, Ortega MA, Borisova SA, Nair SK, Metcalf WW. Molecular Basis of Bacillus subtilis ATCC 6633 Self-Resistance to the Phosphono-oligopeptide Antibiotic Rhizocticin. ACS Chem Biol 2019; 14:742-750. [PMID: 30830751 DOI: 10.1021/acschembio.9b00030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Rhizocticins are phosphono-oligopeptide antibiotics that contain a toxic C-terminal ( Z) -l -2-amino-5-phosphono-3-pentenoic acid (APPA) moiety. APPA is an irreversible inhibitor of threonine synthase (ThrC), a pyridoxal 5'-phosphate (PLP)-dependent enzyme that catalyzes the conversion of O-phospho-l-homoserine to l-threonine. ThrCs are essential for the viability of bacteria, plants, and fungi and are a target for antibiotic development, as de novo threonine biosynthetic pathway is not found in humans. Given the ability of APPA to interfere in threonine metabolism, it is unclear how the producing strain B. subtilis ATCC 6633 circumvents APPA toxicity. Notably, in addition to the housekeeping APPA-sensitive ThrC ( BsThrC), B. subtilis encodes a second threonine synthase (RhiB) encoded within the rhizocticin biosynthetic gene cluster. Kinetic and spectroscopic analyses show that PLP-dependent RhiB is an authentic threonine synthase, converting O-phospho-l-homoserine to threonine with a catalytic efficiency comparable to BsThrC. To understand the structural basis of inhibition, we determined the crystal structure of APPA bound to the housekeeping BsThrC, revealing a covalent complex between the inhibitor and PLP. Structure-based sequence analyses reveal structural determinants within the RhiB active site that contribute to rendering this ThrC homologue resistant to APPA. Together, this work establishes the self-resistance mechanism utilized by B. subtilis ATCC 6633 against APPA exemplifying one of many ways by which bacteria can overcome phosphonate toxicity.
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Affiliation(s)
- Nektaria Petronikolou
- Department of Biochemistry, University of Illinois at Urbana−Champaign, Roger Adams Laboratory, 600 S. Mathews Ave., Urbana, Illinois 61801, United States
| | - Manuel A. Ortega
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, 1206 W. Gregory Drive, Urbana, Illinois 61801, United States
| | - Svetlana A. Borisova
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, 1206 W. Gregory Drive, Urbana, Illinois 61801, United States
| | - Satish K. Nair
- Department of Biochemistry, University of Illinois at Urbana−Champaign, Roger Adams Laboratory, 600 S. Mathews Ave., Urbana, Illinois 61801, United States
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, 1206 W. Gregory Drive, Urbana, Illinois 61801, United States
- Center for Biophysics and Computational Biology, University of Illinois at Urbana−Champaign, Roger Adams Laboratory, 600 S. Mathews Ave., Urbana Illinois 61801, United States
| | - William W. Metcalf
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, 1206 W. Gregory Drive, Urbana, Illinois 61801, United States
- Department of Microbiology, University of Illinois at Urbana−Champaign, Chemical and Life Sciences Laboratory, 601 S. Goodwin Ave., Urbana, Illinois 61801, United States
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19
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Abstract
Methanogenic archaea generate methane as a by-product of anaerobic respiration using CO2, C1 compounds (like methanol or methylated amines), or acetate as terminal electron acceptors. Methanogens are an untapped resource for biotechnological advances related to methane production as well as methane consumption. However, key biological features of these organisms remain poorly understood. One such feature is the enzyme methyl-coenzyme M reductase (referred to as MCR), which catalyzes the last step in the methanogenic pathway and results in methane formation. Gene essentiality has limited genetic analyses of MCR thus far. Therefore, studies of this important enzyme have been limited to biochemical and biophysical techniques that are especially laborious and often reliant on sophisticated instrumentation that is not commonly available. In this chapter, we outline our recently developed CRISPR-Cas9-based genome editing tools and describe how these tools have been used for the introduction of a tandem affinity purification tag at the chromosomal mcr locus in the model methanogen, Methanosarcina acetivorans C2A. We also report a protocol for rapid affinity purification of MCR from M. acetivorans C2A that will enable high-throughput studies of this enzyme in the future.
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Affiliation(s)
- Dipti D Nayak
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, United States; Department of Microbiology, University of Illinois, Urbana, IL, United States
| | - William W Metcalf
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, United States; Department of Microbiology, University of Illinois, Urbana, IL, United States.
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20
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Goettge MN, Cioni JP, Ju KS, Pallitsch K, Metcalf WW. PcxL and HpxL are flavin-dependent, oxime-forming N-oxidases in phosphonocystoximic acid biosynthesis in Streptomyces. J Biol Chem 2018; 293:6859-6868. [PMID: 29540479 PMCID: PMC5936822 DOI: 10.1074/jbc.ra118.001721] [Citation(s) in RCA: 6] [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: 01/02/2018] [Revised: 03/12/2018] [Indexed: 12/13/2022] Open
Abstract
Several oxime-containing small molecules have useful properties, including antimicrobial, insecticidal, anticancer, and immunosuppressive activities. Phosphonocystoximate and its hydroxylated congener, hydroxyphosphonocystoximate, are recently discovered oxime-containing natural products produced by Streptomyces sp. NRRL S-481 and Streptomyces regensis NRRL WC-3744, respectively. The biosynthetic pathways for these two compounds are proposed to diverge at an early step in which 2-aminoethylphosphonate (2AEPn) is converted to (S)-1-hydroxy-2-aminoethylphosphonate ((S)-1H2AEPn) in S. regensis but not in Streptomyces sp. NRRL S-481). Subsequent installation of the oxime moiety into either 2AEPn or (S)-1H2AEPn is predicted to be catalyzed by PcxL or HpxL from Streptomyces sp. NRRL S-481 and S. regensis NRRL WC-3744, respectively, whose sequence and predicted structural characteristics suggest they are unusual N-oxidases. Here, we show that recombinant PcxL and HpxL catalyze the FAD- and NADPH-dependent oxidation of 2AEPn and 1H2AEPn, producing a mixture of the respective aldoximes and nitrosylated phosphonic acid products. Measurements of catalytic efficiency indicated that PcxL has almost an equal preference for 2AEPn and (R)-1H2AEPn. 2AEPn was turned over at a 10-fold higher rate than (R)-1H2AEPn under saturating conditions, resulting in a similar but slightly lower kcat/Km We observed that (S)-1H2AEPn is a relatively poor substrate for PcxL but is clearly the preferred substrate for HpxL, consistent with the proposed biosynthetic pathway in S. regensis. HpxL also used both 2AEPn and (R)-1H2AEPn, with the latter inhibiting HpxL at high concentrations. Bioinformatic analysis indicated that PcxL and HpxL are members of a new class of oxime-forming N-oxidases that are broadly dispersed among bacteria.
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Affiliation(s)
- Michelle N Goettge
- From the Department of Microbiology and the Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801 and
| | - Joel P Cioni
- From the Department of Microbiology and the Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801 and
| | - Kou-San Ju
- From the Department of Microbiology and the Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801 and
| | - Katharina Pallitsch
- the Institute of Organic Chemistry, University of Vienna, 1090 Vienna, Austria
| | - William W Metcalf
- From the Department of Microbiology and the Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801 and
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21
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Parkinson EI, Tryon JH, Goering AW, Ju KS, McClure RA, Kemball JD, Zhukovsky S, Labeda DP, Thomson RJ, Kelleher NL, Metcalf WW. Discovery of the Tyrobetaine Natural Products and Their Biosynthetic Gene Cluster via Metabologenomics. ACS Chem Biol 2018; 13:1029-1037. [PMID: 29510029 DOI: 10.1021/acschembio.7b01089] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Natural products (NPs) are a rich source of medicines, but traditional discovery methods are often unsuccessful due to high rates of rediscovery. Genetic approaches for NP discovery are promising, but progress has been slow due to the difficulty of identifying unique biosynthetic gene clusters (BGCs) and poor gene expression. We previously developed the metabologenomics method, which combines genomic and metabolomic data to discover new NPs and their BGCs. Here, we utilize metabologenomics in combination with molecular networking to discover a novel class of NPs, the tyrobetaines: nonribosomal peptides with an unusual trimethylammonium tyrosine residue. The BGC for this unusual class of compounds was identified using metabologenomics and computational structure prediction data. Heterologous expression confirmed the BGC and suggests an unusual mechanism for trimethylammonium formation. Overall, the discovery of the tyrobetaines shows the great potential of metabologenomics combined with molecular networking and computational structure prediction for identifying interesting biosynthetic reactions and novel NPs.
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Affiliation(s)
- Elizabeth I. Parkinson
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - James H. Tryon
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Anthony W. Goering
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Kou-San Ju
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Ryan A. McClure
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Jeremy D. Kemball
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Sara Zhukovsky
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - David P. Labeda
- Mycotoxin Prevention and Applied Microbiology Research Unit, USDA-ARS National Center for Agricultural Utilization Research, Peoria, Illinois 61604, United States
| | - Regan J. Thomson
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Neil L. Kelleher
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - William W. Metcalf
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
- Department of Microbiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801 United States
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22
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Nayak DD, Mahanta N, Mitchell DA, Metcalf WW. Post-translational thioamidation of methyl-coenzyme M reductase, a key enzyme in methanogenic and methanotrophic Archaea. eLife 2017; 6. [PMID: 28880150 PMCID: PMC5589413 DOI: 10.7554/elife.29218] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [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: 06/02/2017] [Accepted: 08/11/2017] [Indexed: 12/14/2022] Open
Abstract
Methyl-coenzyme M reductase (MCR), found in strictly anaerobic methanogenic and methanotrophic archaea, catalyzes the reversible production and consumption of the potent greenhouse gas methane. The α subunit of MCR (McrA) contains several unusual post-translational modifications, including a rare thioamidation of glycine. Based on the presumed function of homologous genes involved in the biosynthesis of thioviridamide, a thioamide-containing natural product, we hypothesized that the archaeal tfuA and ycaO genes would be responsible for post-translational installation of thioglycine into McrA. Mass spectrometric characterization of McrA from the methanogenic archaeon Methanosarcina acetivorans lacking tfuA and/or ycaO revealed the presence of glycine, rather than thioglycine, supporting this hypothesis. Phenotypic characterization of the ∆ycaO-tfuA mutant revealed a severe growth rate defect on substrates with low free energy yields and at elevated temperatures (39°C - 45°C). Our analyses support a role for thioglycine in stabilizing the protein secondary structure near the active site.
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Affiliation(s)
- Dipti D Nayak
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, United States
| | - Nilkamal Mahanta
- Department of Chemistry, University of Illinois, Urbana, United States
| | - Douglas A Mitchell
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, United States.,Department of Chemistry, University of Illinois, Urbana, United States.,Department of Microbiology, University of Illinois, Urbana, United States
| | - William W Metcalf
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, United States.,Department of Microbiology, University of Illinois, Urbana, United States
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23
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Abstract
Although Cas9-mediated genome editing has proven to be a powerful genetic tool in eukaryotes, its application in Bacteria has been limited because of inefficient targeting or repair; and its application to Archaea has yet to be reported. Here we describe the development of a Cas9-mediated genome-editing tool that allows facile genetic manipulation of the slow-growing methanogenic archaeon Methanosarcina acetivorans Introduction of both insertions and deletions by homology-directed repair was remarkably efficient and precise, occurring at a frequency of approximately 20% relative to the transformation efficiency, with the desired mutation being found in essentially all transformants examined. Off-target activity was not observed. We also observed that multiple single-guide RNAs could be expressed in the same transcript, reducing the size of mutagenic plasmids and simultaneously simplifying their design. Cas9-mediated genome editing reduces the time needed to construct mutants by more than half (3 vs. 8 wk) and allows simultaneous construction of double mutants with high efficiency, exponentially decreasing the time needed for complex strain constructions. Furthermore, coexpression the nonhomologous end-joining (NHEJ) machinery from the closely related archaeon, Methanocella paludicola, allowed efficient Cas9-mediated genome editing without the need for a repair template. The NHEJ-dependent mutations included deletions ranging from 75 to 2.7 kb in length, most of which appear to have occurred at regions of naturally occurring microhomology. The combination of homology-directed repair-dependent and NHEJ-dependent genome-editing tools comprises a powerful genetic system that enables facile insertion and deletion of genes, rational modification of gene expression, and testing of gene essentiality.
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Affiliation(s)
- Dipti D Nayak
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - William W Metcalf
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
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24
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Labeda DP, Dunlap CA, Rong X, Huang Y, Doroghazi JR, Ju KS, Metcalf WW. Phylogenetic relationships in the family Streptomycetaceae using multi-locus sequence analysis. Antonie Van Leeuwenhoek 2016; 110:563-583. [DOI: 10.1007/s10482-016-0824-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 12/19/2016] [Indexed: 10/20/2022]
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25
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McClure RA, Goering AW, Ju KS, Baccile JA, Schroeder FC, Metcalf WW, Thomson RJ, Kelleher NL. Elucidating the Rimosamide-Detoxin Natural Product Families and Their Biosynthesis Using Metabolite/Gene Cluster Correlations. ACS Chem Biol 2016; 11:3452-3460. [PMID: 27809474 DOI: 10.1021/acschembio.6b00779] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
As microbial genome sequencing becomes more widespread, the capacity of microorganisms to produce an immense number of metabolites has come into better view. Utilizing a metabolite/gene cluster correlation platform, the biosynthetic origins of a new family of natural products, the rimosamides, were discovered. The rimosamides were identified in Streptomyces rimosus and associated with their NRPS/PKS-type gene cluster based upon their high frequency of co-occurrence across 179 strains of actinobacteria. This also led to the discovery of the related detoxin gene cluster. The core of each of these families of natural products contains a depsipeptide bond at the point of bifurcation in their unusual branched structures, the origins of which are definitively assigned to nonlinear biosynthetic pathways via heterologous expression in Streptomyces lividans. The rimosamides were found to antagonize the antibiotic activity of blasticidin S against Bacillus cereus.
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Affiliation(s)
- Ryan A. McClure
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Anthony W. Goering
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Kou-San Ju
- Carl R.
Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Joshua A. Baccile
- Boyce Thompson
Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Frank C. Schroeder
- Boyce Thompson
Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - William W. Metcalf
- Carl R.
Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
- Department of Microbiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Regan J. Thomson
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Neil. L Kelleher
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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26
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Labeda DP, Rong X, Huang Y, Doroghazi JR, Ju KS, Metcalf WW. Taxonomic evaluation of species in the Streptomyces hirsutus clade using multi-locus sequence analysis and proposals to reclassify several species in this clade. Int J Syst Evol Microbiol 2016; 66:2444-2450. [PMID: 26971011 PMCID: PMC10724943 DOI: 10.1099/ijsem.0.001017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [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: 01/06/2016] [Accepted: 03/08/2016] [Indexed: 12/18/2023] Open
Abstract
Previous phylogenetic analysis of species of the genus Streptomyces based on 16S rRNA gene sequences resulted in a statistically well-supported clade (100 % bootstrap value) containing eight species that exhibited very similar gross morphology in producing open looped (Retinaculum-Apertum) to spiral (Spira) chains of spiny- to hairysurfaced, dark green spores on their aerial mycelium. The type strains of the species in this clade, specifically Streptomyces bambergiensis, Streptomyces cyanoalbus, Streptomyces emeiensis, Streptomyces hirsutus, Streptomyces prasinopilosus and Streptomyces prasinus, were subjected to multi-locus sequence analysis (MLSA) utilizing partial sequences of the housekeeping genes atpD, gyrB, recA, rpoB and trpB to clarify their taxonomic status. The type strains of several recently described species with similar gross morphology, including Streptomyces chlorus, Streptomyces herbaceus, Streptomyces incanus, Streptomyces pratens and Streptomyces viridis, were also studied along with six unidentified green-spored Streptomyces strains from the ARS Culture Collection. The MLSAs suggest that three of the species under study (S. bambergiensis, S. cyanoalbus and S. emeiensis) represent synonyms of other previously described species (S. prasinus, S. hirsutus and S. prasinopilosus, respectively). These relationships were confirmed through determination of in silico DNA-DNA hybridization estimates based on draft genome sequences. The five recently described species appear to be phylogenetically distinct but the unidentified strains from the ARS Culture Collection could be identified as representatives of S. hirsutus, S. prasinopilosus or S. prasinus.
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Affiliation(s)
- David P. Labeda
- Mycotoxin Prevention and Applied Microbiology Research, USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria, IL, USA
| | - Xiaoying Rong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - Ying Huang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - James R. Doroghazi
- University of Illinois at Champaign-Urbana, Department of Microbiology and Institute for Genomic Biology, Urbana, IL, USA
| | - Kou-San Ju
- University of Illinois at Champaign-Urbana, Department of Microbiology and Institute for Genomic Biology, Urbana, IL, USA
| | - William W. Metcalf
- University of Illinois at Champaign-Urbana, Department of Microbiology and Institute for Genomic Biology, Urbana, IL, USA
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27
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Goering A, McClure RA, Doroghazi JR, Albright JC, Haverland NA, Zhang Y, Ju KS, Thomson RJ, Metcalf WW, Kelleher NL. Metabologenomics: Correlation of Microbial Gene Clusters with Metabolites Drives Discovery of a Nonribosomal Peptide with an Unusual Amino Acid Monomer. ACS Cent Sci 2016; 2:99-108. [PMID: 27163034 PMCID: PMC4827660 DOI: 10.1021/acscentsci.5b00331] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Indexed: 05/31/2023]
Abstract
For more than half a century the pharmaceutical industry has sifted through natural products produced by microbes, uncovering new scaffolds and fashioning them into a broad range of vital drugs. We sought a strategy to reinvigorate the discovery of natural products with distinctive structures using bacterial genome sequencing combined with metabolomics. By correlating genetic content from 178 actinomycete genomes with mass spectrometry-enabled analyses of their exported metabolomes, we paired new secondary metabolites with their biosynthetic gene clusters. We report the use of this new approach to isolate and characterize tambromycin, a new chlorinated natural product, composed of several nonstandard amino acid monomeric units, including a unique pyrrolidine-containing amino acid we name tambroline. Tambromycin shows antiproliferative activity against cancerous human B- and T-cell lines. The discovery of tambromycin via large-scale correlation of gene clusters with metabolites (a.k.a. metabologenomics) illuminates a path for structure-based discovery of natural products at a sharply increased rate.
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Affiliation(s)
- Anthony
W. Goering
- Departments
of Chemistry, Molecular Biosciences, and the Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
| | - Ryan A. McClure
- Departments
of Chemistry, Molecular Biosciences, and the Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
| | - James R. Doroghazi
- Department
of Microbiology and the Carl R. Woese Institute of Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Jessica C. Albright
- Departments
of Chemistry, Molecular Biosciences, and the Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
| | - Nicole A. Haverland
- Departments
of Chemistry, Molecular Biosciences, and the Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
| | - Yongbo Zhang
- Integrated
Molecular Structure Education and Research Center, Weinberg College
of Arts and Sciences, Northwestern University, Evanston, Illinois 60208, United States
| | - Kou-San Ju
- Department
of Microbiology and the Carl R. Woese Institute of Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Regan J. Thomson
- Departments
of Chemistry, Molecular Biosciences, and the Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
| | - William W. Metcalf
- Department
of Microbiology and the Carl R. Woese Institute of Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Neil L. Kelleher
- Departments
of Chemistry, Molecular Biosciences, and the Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
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28
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Smith MW, Davis RE, Youngblut ND, Kärnä T, Herfort L, Whitaker RJ, Metcalf WW, Tebo BM, Baptista AM, Simon HM. Metagenomic evidence for reciprocal particle exchange between the mainstem estuary and lateral bay sediments of the lower Columbia River. Front Microbiol 2015; 6:1074. [PMID: 26483785 PMCID: PMC4589670 DOI: 10.3389/fmicb.2015.01074] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [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: 05/27/2015] [Accepted: 09/18/2015] [Indexed: 11/27/2022] Open
Abstract
Lateral bays of the lower Columbia River estuary are areas of enhanced water retention that influence net ecosystem metabolism through activities of their diverse microbial communities. Metagenomic characterization of sediment microbiota from three disparate sites in two brackish lateral bays (Baker and Youngs) produced ∼100 Gbp of DNA sequence data analyzed subsequently for predicted SSU rRNA and peptide-coding genes. The metagenomes were dominated by Bacteria. A large component of Eukaryota was present in Youngs Bay samples, i.e., the inner bay sediment was enriched with the invasive New Zealand mudsnail, Potamopyrgus antipodarum, known for high ammonia production. The metagenome was also highly enriched with an archaeal ammonia oxidizer closely related to Nitrosoarchaeum limnia. Combined analysis of sequences and continuous, high-resolution time series of biogeochemical data from fixed and mobile platforms revealed the importance of large-scale reciprocal particle exchanges between the mainstem estuarine water column and lateral bay sediments. Deposition of marine diatom particles in sediments near Youngs Bay mouth was associated with a dramatic enrichment of Bacteroidetes (58% of total Bacteria) and corresponding genes involved in phytoplankton polysaccharide degradation. The Baker Bay sediment metagenome contained abundant Archaea, including diverse methanogens, as well as functional genes for methylotrophy and taxonomic markers for syntrophic bacteria, suggesting that active methane cycling occurs at this location. Our previous work showed enrichments of similar anaerobic taxa in particulate matter of the mainstem estuarine water column. In total, our results identify the lateral bays as both sources and sinks of biogenic particles significantly impacting microbial community composition and biogeochemical activities in the estuary.
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Affiliation(s)
- Maria W Smith
- Center for Coastal Margin Observation and Prediction and Institute of Environmental Health, Oregon Health & Science University, Portland OR, USA
| | - Richard E Davis
- Center for Coastal Margin Observation and Prediction and Institute of Environmental Health, Oregon Health & Science University, Portland OR, USA
| | | | - Tuomas Kärnä
- Center for Coastal Margin Observation and Prediction and Institute of Environmental Health, Oregon Health & Science University, Portland OR, USA
| | - Lydie Herfort
- Center for Coastal Margin Observation and Prediction and Institute of Environmental Health, Oregon Health & Science University, Portland OR, USA
| | - Rachel J Whitaker
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana IL, USA
| | - William W Metcalf
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana IL, USA
| | - Bradley M Tebo
- Center for Coastal Margin Observation and Prediction and Institute of Environmental Health, Oregon Health & Science University, Portland OR, USA
| | - António M Baptista
- Center for Coastal Margin Observation and Prediction and Institute of Environmental Health, Oregon Health & Science University, Portland OR, USA
| | - Holly M Simon
- Center for Coastal Margin Observation and Prediction and Institute of Environmental Health, Oregon Health & Science University, Portland OR, USA
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29
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Lieber DJ, Catlett J, Madayiputhiya N, Nandakumar R, Lopez MM, Metcalf WW, Buan NR. A multienzyme complex channels substrates and electrons through acetyl-CoA and methane biosynthesis pathways in Methanosarcina. PLoS One 2014; 9:e107563. [PMID: 25232733 PMCID: PMC4169405 DOI: 10.1371/journal.pone.0107563] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 08/20/2014] [Indexed: 11/25/2022] Open
Abstract
Multienzyme complexes catalyze important metabolic reactions in many organisms, but little is known about the complexes involved in biological methane production (methanogenesis). A crosslinking-mass spectrometry (XL-MS) strategy was employed to identify proteins associated with coenzyme M-coenzyme B heterodisulfide reductase (Hdr), an essential enzyme in all methane-producing archaea (methanogens). In Methanosarcina acetivorans, Hdr forms a multienzyme complex with acetyl-CoA decarbonylase synthase (ACDS), and F420-dependent methylene-H4MPT reductase (Mer). ACDS is essential for production of acetyl-CoA during growth on methanol, or for methanogenesis from acetate, whereas Mer is essential for methanogenesis from all substrates. Existence of a Hdr:ACDS:Mer complex is consistent with growth phenotypes of ACDS and Mer mutant strains in which the complex samples the redox status of electron carriers and directs carbon flux to acetyl-CoA or methanogenesis. We propose the Hdr:ACDS:Mer complex comprises a special class of multienzyme redox complex which functions as a "biological router" that physically links methanogenesis and acetyl-CoA biosynthesis pathways.
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Affiliation(s)
- Dillon J. Lieber
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Jennifer Catlett
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Nandu Madayiputhiya
- Redox Biology Center Metabolomics Core Facility, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Renu Nandakumar
- Redox Biology Center Metabolomics Core Facility, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Madeline M. Lopez
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - William W. Metcalf
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Nicole R. Buan
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
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30
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Cioni JP, Doroghazi J, Ju KS, Yu X, Evans BS, Lee J, Metcalf WW. Cyanohydrin phosphonate natural product from Streptomyces regensis. J Nat Prod 2014; 77:243-249. [PMID: 24437999 PMCID: PMC3993929 DOI: 10.1021/np400722m] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Indexed: 06/03/2023]
Abstract
Streptomyces regensis strain WC-3744 was identified as a potential phosphonic acid producer in a large-scale screen of microorganisms for the presence of the pepM gene, which encodes the key phosphonate biosynthetic enzyme phosphoenolpyruvate phosphonomutase. (31)P NMR revealed the presence of several unidentified phosphonates in spent medium after growth of S. regensis. These compounds were purified and structurally characterized via extensive 1D and 2D NMR spectroscopic and mass spectrometric analyses. Three new phosphonic acid metabolites, whose structures were confirmed by comparison to chemically synthesized standards, were observed: (2-acetamidoethyl)phosphonic acid (1), (2-acetamido-1-hydroxyethyl)phosphonic (3), and a novel cyanohydrin-containing phosphonate, (cyano(hydroxy)methyl)phosphonic acid (4). The gene cluster responsible for synthesis of these molecules was also identified from the draft genome sequence of S. regensis, laying the groundwork for future investigations into the metabolic pathway leading to this unusual natural product.
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Affiliation(s)
- Joel P. Cioni
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
| | - James
R. Doroghazi
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
| | - Kou-San Ju
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
| | - Xiaomin Yu
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
| | - Bradley S. Evans
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
| | - Jaeheon Lee
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
| | - William W. Metcalf
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
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31
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Ju KS, Doroghazi JR, Metcalf WW. Genomics-enabled discovery of phosphonate natural products and their biosynthetic pathways. J Ind Microbiol Biotechnol 2014; 41:345-56. [PMID: 24271089 PMCID: PMC3946943 DOI: 10.1007/s10295-013-1375-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [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: 09/27/2013] [Accepted: 10/22/2013] [Indexed: 01/01/2023]
Abstract
Phosphonate natural products have proven to be a rich source of useful pharmaceutical, agricultural, and biotechnology products, whereas study of their biosynthetic pathways has revealed numerous intriguing enzymes that catalyze unprecedented biochemistry. Here we review the history of phosphonate natural product discovery, highlighting technological advances that have played a key role in the recent advances in their discovery. Central to these developments has been the application of genomics, which allowed discovery and development of a global phosphonate metabolic framework to guide research efforts. This framework suggests that the future of phosphonate natural products remains bright, with many new compounds and pathways yet to be discovered.
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Affiliation(s)
- Kou-San Ju
- Institute for Genomic Biology, University of Illinois, Urbana-Champaign, IL 61801
| | - James R. Doroghazi
- Institute for Genomic Biology, University of Illinois, Urbana-Champaign, IL 61801
| | - William W. Metcalf
- Institute for Genomic Biology, University of Illinois, Urbana-Champaign, IL 61801
- Department of Microbiology, University of Illinois, Urbana-Champaign, IL 61801
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32
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Gao J, Ju KS, Yu X, Velásquez JE, Mukherjee S, Lee J, Zhao C, Evans BS, Doroghazi JR, Metcalf WW, van der Donk WA. Use of a phosphonate methyltransferase in the identification of the fosfazinomycin biosynthetic gene cluster. Angew Chem Int Ed Engl 2014; 53:1334-7. [PMID: 24376039 PMCID: PMC3927463 DOI: 10.1002/anie.201308363] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [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: 09/24/2013] [Revised: 11/16/2013] [Indexed: 12/19/2022]
Abstract
Natural product discovery has been boosted by genome mining approaches, but compound purification is often still challenging. We report an enzymatic strategy for "stable isotope labeling of phosphonates in extract" (SILPE) that facilitates their purification. We used the phosphonate methyltransferase DhpI involved in dehydrophos biosynthesis to methylate a variety of phosphonate natural products in crude spent medium with a mixture of labeled and unlabeled S-adenosyl methionine. Mass-guided fractionation then allowed straightforward purification. We illustrate its utility by purifying a phosphonate that led to the identification of the fosfazinomycin biosynthetic gene cluster. This unusual natural product contains a hydrazide linker between a carboxylic acid and a phosphonic acid. Bioinformatic analysis of the gene cluster provides insights into how such a structure might be assembled.
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Affiliation(s)
- Jiangtao Gao
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West, Gregory Drive, Urbana, Illinois 61801, USA
| | - Kou-San Ju
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West, Gregory Drive, Urbana, Illinois 61801, USA
| | - Xiaomin Yu
- Department of Microbiology, 601 South Goodwin Avenue, Urbana, Illinois 61801, USA
| | - Juan E. Velásquez
- Howard Hughes Medical Institute and Department of Chemistry, University of Illinois at Urbana-Champaign, 600, South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Subha Mukherjee
- Howard Hughes Medical Institute and Department of Chemistry, University of Illinois at Urbana-Champaign, 600, South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Jaeheon Lee
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West, Gregory Drive, Urbana, Illinois 61801, USA
| | - Changming Zhao
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West, Gregory Drive, Urbana, Illinois 61801, USA
| | - Bradley S. Evans
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West, Gregory Drive, Urbana, Illinois 61801, USA
| | - James R. Doroghazi
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West, Gregory Drive, Urbana, Illinois 61801, USA
| | - William W. Metcalf
- Department of Microbiology, 601 South Goodwin Avenue, Urbana, Illinois 61801, USA
| | - Wilfred A. van der Donk
- Howard Hughes Medical Institute and Department of Chemistry, University of Illinois at Urbana-Champaign, 600, South Mathews Avenue, Urbana, Illinois 61801, USA
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33
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Benedict MN, Henriksen JR, Metcalf WW, Whitaker RJ, Price ND. ITEP: an integrated toolkit for exploration of microbial pan-genomes. BMC Genomics 2014; 15:8. [PMID: 24387194 PMCID: PMC3890548 DOI: 10.1186/1471-2164-15-8] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [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: 08/09/2013] [Accepted: 12/18/2013] [Indexed: 01/31/2023] Open
Abstract
Background Comparative genomics is a powerful approach for studying variation in physiological traits as well as the evolution and ecology of microorganisms. Recent technological advances have enabled sequencing large numbers of related genomes in a single project, requiring computational tools for their integrated analysis. In particular, accurate annotations and identification of gene presence and absence are critical for understanding and modeling the cellular physiology of newly sequenced genomes. Although many tools are available to compare the gene contents of related genomes, new tools are necessary to enable close examination and curation of protein families from large numbers of closely related organisms, to integrate curation with the analysis of gain and loss, and to generate metabolic networks linking the annotations to observed phenotypes. Results We have developed ITEP, an Integrated Toolkit for Exploration of microbial Pan-genomes, to curate protein families, compute similarities to externally-defined domains, analyze gene gain and loss, and generate draft metabolic networks from one or more curated reference network reconstructions in groups of related microbial species among which the combination of core and variable genes constitute the their "pan-genomes". The ITEP toolkit consists of: (1) a series of modular command-line scripts for identification, comparison, curation, and analysis of protein families and their distribution across many genomes; (2) a set of Python libraries for programmatic access to the same data; and (3) pre-packaged scripts to perform common analysis workflows on a collection of genomes. ITEP’s capabilities include de novo protein family prediction, ortholog detection, analysis of functional domains, identification of core and variable genes and gene regions, sequence alignments and tree generation, annotation curation, and the integration of cross-genome analysis and metabolic networks for study of metabolic network evolution. Conclusions ITEP is a powerful, flexible toolkit for generation and curation of protein families. ITEP's modular design allows for straightforward extension as analysis methods and tools evolve. By integrating comparative genomics with the development of draft metabolic networks, ITEP harnesses the power of comparative genomics to build confidence in links between genotype and phenotype and helps disambiguate gene annotations when they are evaluated in both evolutionary and metabolic network contexts.
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Affiliation(s)
| | | | | | | | - Nathan D Price
- Institute for Systems Biology, 401 Terry Ave, N,, Seattle, WA 98109, USA.
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Gao J, Ju KS, Yu X, Velásquez JE, Mukherjee S, Lee J, Zhao C, Evans BS, Doroghazi JR, Metcalf WW, van der Donk WA. Use of a Phosphonate Methyltransferase in the Identification of the Fosfazinomycin Biosynthetic Gene Cluster. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201308363] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Labeda DP, Doroghazi JR, Ju KS, Metcalf WW. Taxonomic evaluation of Streptomyces albus and related species using multilocus sequence analysis and proposals to emend the description of Streptomyces albus and describe Streptomyces pathocidini sp. nov. Int J Syst Evol Microbiol 2013; 64:894-900. [PMID: 24277863 DOI: 10.1099/ijs.0.058107-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In phylogenetic analyses of the genus Streptomyces using 16S rRNA gene sequences, Streptomyces albus subsp. albus NRRL B-1811(T) forms a cluster with five other species having identical or nearly identical 16S rRNA gene sequences. Moreover, the morphological and physiological characteristics of these other species, including Streptomyces almquistii NRRL B-1685(T), Streptomyces flocculus NRRL B-2465(T), Streptomyces gibsonii NRRL B-1335(T) and Streptomyces rangoonensis NRRL B-12378(T) are quite similar. This cluster is of particular taxonomic interest because Streptomyces albus is the type species of the genus Streptomyces. The related strains were subjected to multilocus sequence analysis (MLSA) utilizing partial sequences of the housekeeping genes atpD, gyrB, recA, rpoB and trpB and confirmation of previously reported phenotypic characteristics. The five strains formed a coherent cluster supported by a 100 % bootstrap value in phylogenetic trees generated from sequence alignments prepared by concatenating the sequences of the housekeeping genes, and identical tree topology was observed using various different tree-making algorithms. Moreover, all but one strain, S. flocculus NRRL B-2465(T), exhibited identical sequences for all of the five housekeeping gene loci sequenced, but NRRL B-2465(T) still exhibited an MLSA evolutionary distance of 0.005 from the other strains, a value that is lower than the 0.007 MLSA evolutionary distance threshold proposed for species-level relatedness. These data support a proposal to reclassify S. almquistii, S. flocculus, S. gibsonii and S. rangoonensis as later heterotypic synonyms of S. albus with NRRL B-1811(T) as the type strain. The MLSA sequence database also demonstrated utility for quickly and conclusively confirming that numerous strains within the ARS Culture Collection had been previously misidentified as subspecies of S. albus and that Streptomyces albus subsp. pathocidicus should be redescribed as a novel species, Streptomyces pathocidini sp. nov., with the type strain NRRL B-24287(T).
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Affiliation(s)
- D P Labeda
- National Center for Agricultural Utilization Research, USDA-ARS, Peoria, IL 61604, USA
| | - J R Doroghazi
- Department of Microbiology and Institute for Genomic Biology at University of Illinois, Urbana-Champaign, IL 61801, USA
| | - K-S Ju
- Department of Microbiology and Institute for Genomic Biology at University of Illinois, Urbana-Champaign, IL 61801, USA
| | - W W Metcalf
- Department of Microbiology and Institute for Genomic Biology at University of Illinois, Urbana-Champaign, IL 61801, USA
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36
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Albright JC, Goering AW, Doroghazi JR, Metcalf WW, Kelleher NL. Strain-specific proteogenomics accelerates the discovery of natural products via their biosynthetic pathways. J Ind Microbiol Biotechnol 2013; 41:451-9. [PMID: 24242000 DOI: 10.1007/s10295-013-1373-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [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] [Received: 08/25/2013] [Accepted: 10/18/2013] [Indexed: 11/27/2022]
Abstract
The use of proteomics for direct detection of expressed pathways producing natural products has yielded many new compounds, even when used in a screening mode without a bacterial genome sequence available. Here we quantify the advantages of having draft DNA-sequence available for strain-specific proteomics using the latest in ultrahigh-resolution mass spectrometry for both proteins and the small molecules they generate. Using the draft sequence of Streptomyces lilacinus NRRL B-1968, we show a >tenfold increase in the number of peptide identifications vs. using publicly available databases. Detected in this strain were six expressed gene clusters with varying homology to those known. To date, we have identified three of these clusters as encoding for the production of griseobactin (known), rakicidin D (an orphan NRPS/PKS hybrid cluster), and a putative thr and DHB-containing siderophore produced by a new non-ribosomal peptide sythetase gene cluster. The remaining three clusters show lower homology to those known, and likely encode enzymes for production of novel compounds. Using an interpreted strain-specific DNA sequence enables deep proteomics for the detection of multiple pathways and their encoded natural products in a single cultured bacterium.
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Affiliation(s)
- Jessica C Albright
- Departments of Chemistry, Molecular Biosciences, and the Feinberg School of Medicine, Northwestern University, 2170 Campus Drive, Evanston, IL, 60208, USA
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Doroghazi JR, Metcalf WW. Comparative genomics of actinomycetes with a focus on natural product biosynthetic genes. BMC Genomics 2013; 14:611. [PMID: 24020438 PMCID: PMC3848822 DOI: 10.1186/1471-2164-14-611] [Citation(s) in RCA: 136] [Impact Index Per Article: 12.4] [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: 04/02/2013] [Accepted: 09/04/2013] [Indexed: 01/15/2023] Open
Abstract
Background Actinomycetes are a diverse group of medically, industrially and ecologically important bacteria, studied as much for the diseases they cause as for the cures they hold. The genomes of actinomycetes revealed that these bacteria have a large number of natural product gene clusters, although many of these are difficult to tie to products in the laboratory. Large scale comparisons of these clusters are difficult to perform due to the presence of highly similar repeated domains in the most common biosynthetic machinery: polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs). Results We have used comparative genomics to provide an overview of the genomic features of a set of 102 closed genomes from this important group of bacteria with a focus on natural product biosynthetic genes. We have focused on well-represented genera and determine the occurrence of gene cluster families therein. Conservation of natural product gene clusters within Mycobacterium, Streptomyces and Frankia suggest crucial roles for natural products in the biology of each genus. The abundance of natural product classes is also found to vary greatly between genera, revealing underlying patterns that are not yet understood. Conclusions A large-scale analysis of natural product gene clusters presents a useful foundation for hypothesis formulation that is currently underutilized in the field. Such studies will be increasingly necessary to study the diversity and ecology of natural products as the number of genome sequences available continues to grow.
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Affiliation(s)
- James R Doroghazi
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, IL 61801, USA.
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Evans BS, Zhao C, Gao J, Evans CM, Ju KS, Doroghazi JR, van der Donk WA, Kelleher NL, Metcalf WW. Discovery of the antibiotic phosacetamycin via a new mass spectrometry-based method for phosphonic acid detection. ACS Chem Biol 2013; 8:908-13. [PMID: 23474169 DOI: 10.1021/cb400102t] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Naturally occurring phosphonates such as phosphinothricin (Glufosinate, a commercially used herbicide) and fosfomycin (Monurol, a clinically used antibiotic) have proved to be potent and useful biocides. Yet this class of natural products is still an under explored family of secondary metabolites. Discovery of the biosynthetic pathways responsible for the production of these compounds has been simplified by using gene based screening approaches, but detection and identification of the natural products the genes produce have been hampered by a lack of high-throughput methods for screening potential producers under various culture conditions. Here, we present an efficient mass-spectrometric method for the selective detection of natural products containing phosphonate and phosphinate functional groups. We have used this method to identify a new phosphonate metabolite, phosacetamycin, whose structure, biological activity, and biosynthetic gene cluster are reported.
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Affiliation(s)
| | | | | | | | | | | | | | - Neil L. Kelleher
- Northwestern University, Evanston, Illinois 60208, United States
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Gonnerman MC, Benedict MN, Feist AM, Metcalf WW, Price ND. Genomically and biochemically accurate metabolic reconstruction of Methanosarcina barkeri Fusaro, iMG746. Biotechnol J 2013; 8:1070-9. [PMID: 23420771 DOI: 10.1002/biot.201200266] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [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: 11/26/2012] [Revised: 01/15/2013] [Accepted: 02/13/2013] [Indexed: 11/11/2022]
Abstract
Methanosarcina barkeri is an Archaeon that produces methane anaerobically as the primary byproduct of its metabolism. M. barkeri can utilize several substrates for ATP and biomass production including methanol, acetate, methyl amines, and a combination of hydrogen and carbon dioxide. In 2006, a metabolic reconstruction of M. barkeri, iAF692, was generated based on a draft genome annotation. The iAF692 reconstruction enabled the first genome-Scale simulations for Archaea. Since the publication of the first metabolic reconstruction of M. barkeri, additional genomic, biochemical, and phenotypic data have clarified several metabolic pathways. We have used this newly available data to improve the M. barkeri metabolic reconstruction. Modeling simulations using the updated model, iMG746, have led to increased accuracy in predicting gene knockout phenotypes and simulations of batch growth behavior. We used the model to examine knockout lethality data and make predictions about metabolic regulation under different growth conditions. Thus, the updated metabolic reconstruction of M. barkeri metabolism is a useful tool for predicting cellular behavior, studying the methanogenic lifestyle, guiding experimental studies, and making predictions relevant to metabolic engineering applications.
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Affiliation(s)
- Matthew C Gonnerman
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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40
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Metcalf WW, Griffin BM, Cicchillo RM, Gao J, Janga SC, Cooke HA, Circello BT, Evans BS, Martens-Habbena W, Stahl DA, van der Donk WA. Synthesis of methylphosphonic acid by marine microbes: a source for methane in the aerobic ocean. Science 2012; 337:1104-7. [PMID: 22936780 DOI: 10.1126/science.1219875] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Relative to the atmosphere, much of the aerobic ocean is supersaturated with methane; however, the source of this important greenhouse gas remains enigmatic. Catabolism of methylphosphonic acid by phosphorus-starved marine microbes, with concomitant release of methane, has been suggested to explain this phenomenon, yet methylphosphonate is not a known natural product, nor has it been detected in natural systems. Further, its synthesis from known natural products would require unknown biochemistry. Here we show that the marine archaeon Nitrosopumilus maritimus encodes a pathway for methylphosphonate biosynthesis and that it produces cell-associated methylphosphonate esters. The abundance of a key gene in this pathway in metagenomic data sets suggests that methylphosphonate biosynthesis is relatively common in marine microbes, providing a plausible explanation for the methane paradox.
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Affiliation(s)
- William W Metcalf
- Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA.
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Abstract
The discovery of the third domain of life, the Archaea, is one of the most exciting findings of the last century. These remarkable prokaryotes are well known for their adaptations to extreme environments; however, Archaea have also conquered moderate environments. Many of the archaeal biochemical processes, such as methane production, are unique in nature and therefore of great scientific interest. Although formerly restricted to biochemical and physiological studies, sophisticated systems for genetic manipulation have been developed during the last two decades for methanogenic archaea, halophilic archaea and thermophilic, sulfur-metabolizing archaea. The availability of these tools has allowed for more complete studies of archaeal physiology and metabolism and most importantly provides the basis for the investigation of gene expression, regulation and function. In this review we provide an overview of methods for genetic manipulation of Methanosarcina spp., a group of methanogenic archaea that are key players in the global carbon cycle and which can be found in a variety of anaerobic environments.
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Affiliation(s)
- Petra R A Kohler
- Department of Microbiology, B103 Chemical and Life Science Laboratory, University of Illinois at Urbana-Champaign Urbana, IL, USA
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42
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Hung JE, Fogle EJ, Christman HD, Johannes TW, Zhao H, Metcalf WW, van der Donk WA. Investigation of the role of Arg301 identified in the X-ray structure of phosphite dehydrogenase. Biochemistry 2012; 51:4254-62. [PMID: 22564138 PMCID: PMC3361975 DOI: 10.1021/bi201691w] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [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: 12/12/2022]
Abstract
![]()
Phosphite dehydrogenase (PTDH) from Pseudomonas
stutzeri catalyzes the nicotinamide adenine dinucleotide-dependent
oxidation
of phosphite to phosphate. The enzyme belongs to the family of d-hydroxy acid dehydrogenases (DHDHs). A search of the protein
databases uncovered many additional putative phosphite dehydrogenases.
The genes encoding four diverse candidates were cloned and expressed,
and the enzymes were purified and characterized. All oxidized phosphite
to phosphate and had similar kinetic parameters despite a low level
of pairwise sequence identity (39–72%). A recent crystal structure
identified Arg301 as a residue in the active site that has not been
investigated previously. Arg301 is fully conserved in the enzymes
shown here to be PTDHs, but the residue is not conserved in other
DHDHs. Kinetic analysis of site-directed mutants of this residue shows
that it is important for efficient catalysis, with an ∼100-fold
decrease in kcat and an almost 700-fold
increase in Km,phosphite for the R301A
mutant. Interestingly, the R301K mutant displayed a slightly higher kcat than the parent PTDH, and a more modest
increase in Km for phosphite (nearly 40-fold).
Given these results, Arg301 may be involved in the binding and orientation
of the phosphite substrate and/or play a catalytic role via electrostatic
interactions. Three other residues in the active site region that
are conserved in the PTDH orthologs but not DHDHs were identified
(Trp134, Tyr139, and Ser295). The importance of these residues was
also investigated by site-directed mutagenesis. All of the mutants
had kcat values similar to that of the
wild-type enzyme, indicating these residues are not important for
catalysis.
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Affiliation(s)
- John E Hung
- Department of Chemistry, University of Illinois, 600 South Mathews Avenue, Urbana, IL 61801, USA
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Agarwal V, Borisova SA, Metcalf WW, van der Donk WA, Nair SK. Structural and mechanistic insights into C-P bond hydrolysis by phosphonoacetate hydrolase. ACTA ACUST UNITED AC 2012; 18:1230-40. [PMID: 22035792 DOI: 10.1016/j.chembiol.2011.07.019] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [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: 05/18/2011] [Revised: 06/24/2011] [Accepted: 07/15/2011] [Indexed: 11/18/2022]
Abstract
Bacteria have evolved pathways to metabolize phosphonates as a nutrient source for phosphorus. In Sinorhizobium meliloti 1021, 2-aminoethylphosphonate is catabolized to phosphonoacetate, which is converted to acetate and inorganic phosphate by phosphonoacetate hydrolase (PhnA). Here we present detailed biochemical and structural characterization of PhnA that provides insights into the mechanism of C-P bond cleavage. The 1.35 Å resolution crystal structure reveals a catalytic core similar to those of alkaline phosphatases and nucleotide pyrophosphatases but with notable differences, such as a longer metal-metal distance. Detailed structure-guided analysis of active site residues and four additional cocrystal structures with phosphonoacetate substrate, acetate, phosphonoformate inhibitor, and a covalently bound transition state mimic provide insight into active site features that may facilitate cleavage of the C-P bond. These studies expand upon the array of reactions that can be catalyzed by enzymes of the alkaline phosphatase superfamily.
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Affiliation(s)
- Vinayak Agarwal
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Chen Y, Ntai I, Ju KS, Unger M, Zamdborg L, Robinson SJ, Doroghazi JR, Labeda DP, Metcalf WW, Kelleher NL. A proteomic survey of nonribosomal peptide and polyketide biosynthesis in actinobacteria. J Proteome Res 2011; 11:85-94. [PMID: 21978092 DOI: 10.1021/pr2009115] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Actinobacteria such as streptomycetes are renowned for their ability to produce bioactive natural products including nonribosomal peptides (NRPs) and polyketides (PKs). The advent of genome sequencing has revealed an even larger genetic repertoire for secondary metabolism with most of the small molecule products of these gene clusters still unknown. Here, we employed a "protein-first" method called PrISM (Proteomic Investigation of Secondary Metabolism) to screen 26 unsequenced actinomycetes using mass spectrometry-based proteomics for the targeted detection of expressed nonribosomal peptide synthetases or polyketide synthases. Improvements to the original PrISM screening approach (Nat. Biotechnol. 2009, 27, 951-956), for example, improved de novo peptide sequencing, have enabled the discovery of 10 NRPS/PKS gene clusters from 6 strains. Taking advantage of the concurrence of biosynthetic enzymes and the secondary metabolites they generate, two natural products were associated with their previously "orphan" gene clusters. This work has demonstrated the feasibility of a proteomics-based strategy for use in screening for NRP/PK production in actinomycetes (often >8 Mbp, high GC genomes) versus the bacilli (2-4 Mbp genomes) used previously.
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Affiliation(s)
- Yunqiu Chen
- Department of Chemistry, Northwestern University, Evanston, Illinois, 60208, United States
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Evans BS, Chen Y, Metcalf WW, Zhao H, Kelleher NL. Directed evolution of the nonribosomal peptide synthetase AdmK generates new andrimid derivatives in vivo. Chem Biol 2011; 18:601-7. [PMID: 21609841 PMCID: PMC3102229 DOI: 10.1016/j.chembiol.2011.03.008] [Citation(s) in RCA: 96] [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] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Revised: 02/02/2011] [Accepted: 03/07/2011] [Indexed: 11/17/2022]
Abstract
Many lead compounds in the search for new drugs derive from peptides and polyketides whose similar biosynthetic enzymes have been difficult to engineer for production of new derivatives. Problems with generating multiple analogs in a single experiment along with lack of high-throughput methods for structure-based screening have slowed progress in this area. Here, we use directed evolution and a multiplexed assay to screen a library of >14,000 members to generate three derivatives of the antibacterial compound, andrimid. Another limiting factor in reengineering these mega-enzymes of secondary metabolism has been that commonly used hosts such as Escherichia coli often give lower product titers, so our reengineering was performed in the native producer, Pantoea agglomerans. This integrated in vivo approach can be extended to larger enzymes to create analogs of natural products for bioactivity testing.
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Affiliation(s)
- Bradley S. Evans
- Department of Biochemistry, University of Illinois, Urbana, IL 61801
- Institute for Genomic Biology, University of Illinois, Urbana, IL 61801
| | - Yunqiu Chen
- Department of Chemistry, Northwestern University, Evanston, IL 60208
- The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208
| | - William W. Metcalf
- Institute for Genomic Biology, University of Illinois, Urbana, IL 61801
- Department of Microbiology, University of Illinois, Urbana, IL 61801
| | - Huimin Zhao
- Institute for Genomic Biology, University of Illinois, Urbana, IL 61801
- Department of Chemical and Biomolecular Engineering, University of Illinois, Urbana, IL 61801
| | - Neil L. Kelleher
- Department of Chemistry, Northwestern University, Evanston, IL 60208
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
- The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208
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Borisova SA, Christman HD, Metcalf MEM, Zulkepli NA, Zhang JK, van der Donk WA, Metcalf WW. Genetic and biochemical characterization of a pathway for the degradation of 2-aminoethylphosphonate in Sinorhizobium meliloti 1021. J Biol Chem 2011; 286:22283-90. [PMID: 21543322 DOI: 10.1074/jbc.m111.237735] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A variety of microorganisms have the ability to use phosphonic acids as sole sources of phosphorus. Here, a novel pathway for degradation of 2-aminoethylphosphonate in the bacterium Sinorhizobium meliloti 1021 is proposed based on the analysis of the genome sequence. Gene deletion experiments confirmed the involvement of the locus containing phnW, phnA, and phnY genes in the conversion of 2-aminoethylphosphonate to inorganic phosphate. Biochemical studies of the recombinant PhnY and PhnA proteins verified their roles as phosphonoacetaldehyde dehydrogenase and phosphonoacetate hydrolase, respectively. This pathway is likely not limited to S. meliloti as suggested by the presence of homologous gene clusters in other bacterial genomes.
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Affiliation(s)
- Svetlana A Borisova
- Institute for Genomic Biology, Howard Hughes Medical Institute University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Simeonova DD, Wilson MM, Metcalf WW, Schink B. Identification and heterologous expression of genes involved in anaerobic dissimilatory phosphite oxidation by Desulfotignum phosphitoxidans. J Bacteriol 2010; 192:5237-44. [PMID: 20622064 PMCID: PMC2944520 DOI: 10.1128/jb.00541-10] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [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] [Received: 05/11/2010] [Accepted: 06/28/2010] [Indexed: 12/20/2022] Open
Abstract
Desulfotignum phosphitoxidans is a strictly anaerobic, Gram-negative bacterium that utilizes phosphite as the sole electron source for homoacetogenic CO2 reduction or sulfate reduction. A genomic library of D. phosphitoxidans, constructed using the fosmid vector pJK050, was screened for clones harboring the genes involved in phosphite oxidation via PCR using primers developed based on the amino acid sequences of phosphite-induced proteins. Sequence analysis of two positive clones revealed a putative operon of seven genes predicted to be involved in phosphite oxidation. Four of these genes (ptxD-ptdFCG) were cloned and heterologously expressed in Desulfotignum balticum, a related strain that cannot use phosphite as either an electron donor or as a phosphorus source. The ptxD-ptdFCG gene cluster was sufficient to confer phosphite uptake and oxidation ability to the D. balticum host strain but did not allow use of phosphite as an electron donor for chemolithotrophic growth. Phosphite oxidation activity was measured in cell extracts of D. balticum transconjugants, suggesting that all genes required for phosphite oxidation were cloned. Genes of the phosphite gene cluster were assigned putative functions on the basis of sequence analysis and enzyme assays.
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Affiliation(s)
- Diliana Dancheva Simeonova
- Laboratory of Microbial Ecology, University of Konstanz, Germany, Department of Microbiology and Institute for Genomic Biology, University of Illinois, Urbana, Illinois
| | - Marlena Marie Wilson
- Laboratory of Microbial Ecology, University of Konstanz, Germany, Department of Microbiology and Institute for Genomic Biology, University of Illinois, Urbana, Illinois
| | - William W. Metcalf
- Laboratory of Microbial Ecology, University of Konstanz, Germany, Department of Microbiology and Institute for Genomic Biology, University of Illinois, Urbana, Illinois
| | - Bernhard Schink
- Laboratory of Microbial Ecology, University of Konstanz, Germany, Department of Microbiology and Institute for Genomic Biology, University of Illinois, Urbana, Illinois
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Circello BT, Eliot AC, Lee JH, van der Donk WA, Metcalf WW. Molecular cloning and heterologous expression of the dehydrophos biosynthetic gene cluster. ACTA ACUST UNITED AC 2010; 17:402-11. [PMID: 20416511 DOI: 10.1016/j.chembiol.2010.03.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 03/10/2010] [Accepted: 03/12/2010] [Indexed: 10/19/2022]
Abstract
Dehydrophos is a vinyl phosphonate tripeptide produced by Streptomyces luridus with demonstrated broad-spectrum antibiotic activity. To identify genes necessary for biosynthesis of this unusual compound we screened a fosmid library of S. luridus for the presence of the phosphoenolpyruvate mutase gene, which is required for biosynthesis of most phosphonates. Integration of one such fosmid clone into the chromosome of S. lividans led to heterologous production of dehydrophos. Deletion analysis of this clone allowed identification of the minimal contiguous dehydrophos cluster, which contained 17 open reading frames (ORFs). Bioinformatic analyses of these ORFs are consistent with a proposed biosynthetic pathway that generates dehydrophos from phosphoenolpyruvate. The early steps of this pathway are supported by analysis of intermediates accumulated by blocked mutants and in vitro biochemical experiments.
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Affiliation(s)
- Benjamin T Circello
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Borisova SA, Circello BT, Zhang JK, van der Donk WA, Metcalf WW. Biosynthesis of rhizocticins, antifungal phosphonate oligopeptides produced by Bacillus subtilis ATCC6633. ACTA ACUST UNITED AC 2010; 17:28-37. [PMID: 20142038 DOI: 10.1016/j.chembiol.2009.11.017] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 11/23/2009] [Accepted: 11/30/2009] [Indexed: 11/16/2022]
Abstract
Rhizocticins are phosphonate oligopeptide antibiotics containing the C-terminal nonproteinogenic amino acid (Z)-l-2-amino-5-phosphono-3-pentenoic acid (APPA). Here we report the identification and characterization of the rhizocticin biosynthetic gene cluster (rhi) in Bacillus subtilis ATCC6633. Rhizocticin B was heterologously produced in the nonproducer strain Bacillus subtilis 168. A biosynthetic pathway is proposed on the basis of bioinformatics analysis of the rhi genes. One of the steps during the biosynthesis of APPA is an unusual aldol reaction between phosphonoacetaldehyde and oxaloacetate catalyzed by an aldolase homolog RhiG. Recombinant RhiG was prepared, and the product of an in vitro enzymatic conversion was characterized. Access to this intermediate allows for biochemical characterization of subsequent steps in the pathway.
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Affiliation(s)
- Svetlana A Borisova
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Johannes TW, DeSieno MA, Griffin BM, Thomas PM, Kelleher NL, Metcalf WW, Zhao H. Deciphering the late biosynthetic steps of antimalarial compound FR-900098. ACTA ACUST UNITED AC 2010; 17:57-64. [PMID: 20142041 DOI: 10.1016/j.chembiol.2009.12.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 12/01/2009] [Accepted: 12/09/2009] [Indexed: 11/17/2022]
Abstract
FR-900098 is a potent chemotherapeutic agent for the treatment of malaria. Here we report the heterologous production of this compound in Escherichia coli by reconstructing the entire biosynthetic pathway using a three-plasmid system. Based on this system, whole-cell feeding assays in combination with in vitro enzymatic activity assays reveal an unusual functional role of nucleotide conjugation and lead to the complete elucidation of the previously unassigned late biosynthetic steps. These studies also suggest a biosynthetic route to a second phosphonate antibiotic, FR-33289. A thorough understanding of the FR-900098 biosynthetic pathway now opens possibilities for metabolic engineering in E. coli to increase production of the antimalarial antibiotic and combinatorial biosynthesis to generate novel derivatives of FR-900098.
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Affiliation(s)
- Tyler W Johannes
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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