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Kohr M, Walt C, Dastbaz J, Müller R, Kazmaier U. Total synthesis of Myxoprincomide, a secondary metabolite from Myxococcus xanthus. Org Biomol Chem 2022; 20:9609-9612. [PMID: 36416153 DOI: 10.1039/d2ob02021a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Myxoprincomide, a secondary metabolite of the myxobacterium Myxococcus xanthus DK 1622, is synthesised for the first time. The central, unusual α-ketoamide is generated at the end of the synthesis to avoid side reactions during the synthesis of this rather reactive subunit. Nevertheless, the synthetic natural product is obtained as an isomeric mixture. Detailed analytical investigations show that the identical isomeric mixture is found in the isolated natural product.
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Affiliation(s)
- Michael Kohr
- Organic Chemistry, Saarland University, D-66123 Saarbrücken, Germany.
| | - Christine Walt
- Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), and Department of Pharmacy, Saarland University, D-66123 Saarbrücken, Germany
| | - Jan Dastbaz
- Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), and Department of Pharmacy, Saarland University, D-66123 Saarbrücken, Germany
| | - Rolf Müller
- Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), and Department of Pharmacy, Saarland University, D-66123 Saarbrücken, Germany
| | - Uli Kazmaier
- Organic Chemistry, Saarland University, D-66123 Saarbrücken, Germany. .,Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), and Department of Pharmacy, Saarland University, D-66123 Saarbrücken, Germany
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2
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Kim M, Bae M, Jung Y, Kim JM, Hwang S, Song MC, Ban YH, Bae ES, Hong S, Lee SK, Cha S, Oh D, Yoon YJ. Unprecedented Noncanonical Features of the Nonlinear Nonribosomal Peptide Synthetase Assembly Line for WS9326A Biosynthesis. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Myoun‐Su Kim
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Munhyung Bae
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Ye‐Eun Jung
- Department of Chemistry and Nanoscience Ewha Womans University 52 Ewhayeodae-gil, Seodaemun-gu Seoul 03760 Republic of Korea
| | - Jung Min Kim
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Sunghoon Hwang
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Myoung Chong Song
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Yeon Hee Ban
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Eun Seo Bae
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Suckchang Hong
- Research Institute of Pharmaceutical Sciences College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Sang Kook Lee
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Sun‐Shin Cha
- Department of Chemistry and Nanoscience Ewha Womans University 52 Ewhayeodae-gil, Seodaemun-gu Seoul 03760 Republic of Korea
| | - Dong‐Chan Oh
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Yeo Joon Yoon
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
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Kim M, Bae M, Jung Y, Kim JM, Hwang S, Song MC, Ban YH, Bae ES, Hong S, Lee SK, Cha S, Oh D, Yoon YJ. Unprecedented Noncanonical Features of the Nonlinear Nonribosomal Peptide Synthetase Assembly Line for WS9326A Biosynthesis. Angew Chem Int Ed Engl 2021; 60:19766-19773. [DOI: 10.1002/anie.202103872] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/04/2021] [Indexed: 12/21/2022]
Affiliation(s)
- Myoun‐Su Kim
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Munhyung Bae
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Ye‐Eun Jung
- Department of Chemistry and Nanoscience Ewha Womans University 52 Ewhayeodae-gil, Seodaemun-gu Seoul 03760 Republic of Korea
| | - Jung Min Kim
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Sunghoon Hwang
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Myoung Chong Song
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Yeon Hee Ban
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Eun Seo Bae
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Suckchang Hong
- Research Institute of Pharmaceutical Sciences College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Sang Kook Lee
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Sun‐Shin Cha
- Department of Chemistry and Nanoscience Ewha Womans University 52 Ewhayeodae-gil, Seodaemun-gu Seoul 03760 Republic of Korea
| | - Dong‐Chan Oh
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Yeo Joon Yoon
- Natural Products Research Institute College of Pharmacy Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
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4
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Yan F, Burgard C, Popoff A, Zaburannyi N, Zipf G, Maier J, Bernauer HS, Wenzel SC, Müller R. Synthetic biology approaches and combinatorial biosynthesis towards heterologous lipopeptide production. Chem Sci 2018; 9:7510-7519. [PMID: 30319751 PMCID: PMC6180311 DOI: 10.1039/c8sc02046a] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 08/08/2018] [Indexed: 12/14/2022] Open
Abstract
Synthetic biology techniques coupled with heterologous secondary metabolite production offer opportunities for the discovery and optimisation of natural products.
Synthetic biology techniques coupled with heterologous secondary metabolite production offer opportunities for the discovery and optimisation of natural products. Here we developed a new assembly strategy based on type IIS endonucleases and elaborate synthetic DNA platforms, which could be used to seamlessly assemble and engineer biosynthetic gene clusters (BGCs). By applying this versatile tool, we designed and assembled more than thirty different artificial myxochromide BGCs, each around 30 kb in size, and established heterologous expression platforms using a derivative of Myxococcus xanthus DK1622 as a host. In addition to the five native types of myxochromides (A, B, C, D and S), novel lipopeptide structures were produced by combinatorial exchange of nonribosomal peptide synthetase (NRPS) encoding genes from different myxochromide BGCs. Inspired by the evolutionary diversification of the native myxochromide megasynthetases, the ancestral A-type NRPS was engineered by inactivation, deletion, or duplication of catalytic domains and successfully converted into functional B-, C- and D-type megasynthetases. The constructional design approach applied in this study enables combinatorial engineering of complex synthetic BGCs and has great potential for the exploitation of other natural product biosynthetic pathways.
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Affiliation(s)
- Fu Yan
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) , Helmholtz Centre for Infection Research and Department of Pharmacy at Saarland University , Saarland University Campus , Building E8.1 , 66123 Saarbrücken , Germany .
| | - Christian Burgard
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) , Helmholtz Centre for Infection Research and Department of Pharmacy at Saarland University , Saarland University Campus , Building E8.1 , 66123 Saarbrücken , Germany .
| | - Alexander Popoff
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) , Helmholtz Centre for Infection Research and Department of Pharmacy at Saarland University , Saarland University Campus , Building E8.1 , 66123 Saarbrücken , Germany .
| | - Nestor Zaburannyi
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) , Helmholtz Centre for Infection Research and Department of Pharmacy at Saarland University , Saarland University Campus , Building E8.1 , 66123 Saarbrücken , Germany .
| | - Gregor Zipf
- ATG:biosynthetics GmbH , Weberstraße 40 , 79249 Merzhausen , Germany
| | - Josef Maier
- IStLS - Information Services to Life Sciences , Härlestraße 24/1 , 78727 Oberndorf am Neckar/Boll , Germany
| | - Hubert S Bernauer
- ATG:biosynthetics GmbH , Weberstraße 40 , 79249 Merzhausen , Germany
| | - Silke C Wenzel
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) , Helmholtz Centre for Infection Research and Department of Pharmacy at Saarland University , Saarland University Campus , Building E8.1 , 66123 Saarbrücken , Germany .
| | - Rolf Müller
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) , Helmholtz Centre for Infection Research and Department of Pharmacy at Saarland University , Saarland University Campus , Building E8.1 , 66123 Saarbrücken , Germany .
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Tobias NJ, Linck A, Bode HB. Natural Product Diversification Mediated by Alternative Transcriptional Starting. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201713199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Nicholas J. Tobias
- Fachbereich Biowissenschaften; Merck Stiftungsprofessur für Molekulare Biotechnologie; Goethe-Universität Frankfurt; Frankfurt am Main Germany
| | - Annabell Linck
- Fachbereich Biowissenschaften; Merck Stiftungsprofessur für Molekulare Biotechnologie; Goethe-Universität Frankfurt; Frankfurt am Main Germany
| | - Helge B. Bode
- Fachbereich Biowissenschaften; Merck Stiftungsprofessur für Molekulare Biotechnologie; Goethe-Universität Frankfurt; Frankfurt am Main Germany
- Buchmann Institute for Molecular Life Sciences; Goethe-Universität Frankfurt; Frankfurt am Main Germany
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6
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Tobias NJ, Linck A, Bode HB. Natural Product Diversification Mediated by Alternative Transcriptional Starting. Angew Chem Int Ed Engl 2018; 57:5699-5702. [PMID: 29508935 DOI: 10.1002/anie.201713199] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Indexed: 11/08/2022]
Abstract
Photorhabdus luminescens dedicates a significant proportion of its genome to the production of natural products. These products and the structural variation in their derivatives may occur by a number of well-described mechanisms, such as module skipping or precursor promiscuity. Cappable-seq was used to identify transcriptional start sites of many of the gene clusters present in P. luminescens TTO1. We discovered that variations associated with the non-ribosomal peptide synthetase Kol, which is responsible for kolossin A production, possessed a number of internal transcripts that lead to synthesis of the smaller kolossin derivatives kolossin B and C. The data here support a new mechanism of natural product biosynthetic variation whereby mRNA may code for shorter NRPS enzymes in addition to full-length proteins, resulting in the production of smaller peptide derivatives.
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Affiliation(s)
- Nicholas J Tobias
- Fachbereich Biowissenschaften, Merck Stiftungsprofessur für Molekulare Biotechnologie, Goethe-Universität Frankfurt, Frankfurt am Main, Germany
| | - Annabell Linck
- Fachbereich Biowissenschaften, Merck Stiftungsprofessur für Molekulare Biotechnologie, Goethe-Universität Frankfurt, Frankfurt am Main, Germany
| | - Helge B Bode
- Fachbereich Biowissenschaften, Merck Stiftungsprofessur für Molekulare Biotechnologie, Goethe-Universität Frankfurt, Frankfurt am Main, Germany.,Buchmann Institute for Molecular Life Sciences, Goethe-Universität Frankfurt, Frankfurt am Main, Germany
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7
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Pistorius D, Müller R. Discovery of the Rhizopodin Biosynthetic Gene Cluster in Stigmatella aurantiaca Sg a15 by Genome Mining. Chembiochem 2012; 13:416-26. [DOI: 10.1002/cbic.201100575] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Indexed: 11/06/2022]
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Cortina NS, Krug D, Plaza A, Revermann O, Müller R. Myxoprincomid: Entdeckung eines Naturstoffs mithilfe einer umfassenden Analyse des sekundären Metaboloms von Myxococcusxanthus. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201106305] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Cortina NS, Krug D, Plaza A, Revermann O, Müller R. Myxoprincomide: A Natural Product from Myxococcus xanthus Discovered by Comprehensive Analysis of the Secondary Metabolome. Angew Chem Int Ed Engl 2011; 51:811-6. [DOI: 10.1002/anie.201106305] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 10/17/2011] [Indexed: 11/07/2022]
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Bode HB, Ring MW, Schwär G, Altmeyer MO, Kegler C, Jose IR, Singer M, Müller R. Identification of additional players in the alternative biosynthesis pathway to isovaleryl-CoA in the myxobacterium Myxococcus xanthus. Chembiochem 2009; 10:128-40. [PMID: 18846531 DOI: 10.1002/cbic.200800219] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Isovaleryl-CoA (IV-CoA) is usually derived from the degradation of leucine by using the Bkd (branched-chain keto acid dehydrogenase) complex. We have previously identified an alternative pathway for IV-CoA formation in myxobacteria that branches from the well-known mevalonate-dependent isoprenoid biosynthesis pathway. We identified 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase (MvaS) to be involved in this pathway in Myxococcus xanthus, which is induced in mutants with impaired leucine degradation (e.g., bkd(-)) or during myxobacterial fruiting-body formation. Here, we show that the proteins required for leucine degradation are also involved in the alternative IV-CoA biosynthesis pathway through the efficient catalysis of the reverse reactions. Moreover, we conducted a global gene-expression experiment and compared vegetative wild-type cells with bkd mutants, and identified a five-gene operon that is highly up-regulated in bkd mutants and contains mvaS and other genes that are directly involved in the alternative pathway. Based on our experiments, we assigned roles to the genes required for the formation of IV-CoA from HMG-CoA. Additionally, several genes involved in outer-membrane biosynthesis and a plethora of genes encoding regulatory proteins were decreased in expression levels in the bkd(-) mutant; this explains the complex phenotype of bkd mutants including a lack of adhesion in developmental submerse culture.
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Affiliation(s)
- Helge B Bode
- Institut für Pharmazeutische Biotechnologie, Universität des Saarlandes, Saarbrücken, Germany
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Ohlendorf B, Kehraus S, König GM. Myxochromide B3, a new member of the myxochromide family of secondary metabolites. JOURNAL OF NATURAL PRODUCTS 2008; 71:1708-1713. [PMID: 18803421 DOI: 10.1021/np800319v] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Myxochromides are cyclic depsipeptides with an unsaturated polyketide side chain, which have been reported from different myxobacterial species, e.g., Myxococcus xanthus and Stigmatella aurantiaca. To date, myxochromides are subdivided into the groups A and S, according to their peptidic core structure. The peptide moiety of the new myxochromide B3 (1), which was isolated from a myxobacterial strain of the genus Myxococcus, differs from that of myxochromides A and S. Compound 1 thus is the first representative of a new group of myxochromides. For myxochromide A3 (2) the complete and assigned spectroscopic data are described. For the structure elucidation one- and two-dimensional NMR spectroscopy as well as mass spectrometry have been applied. Configurational analysis has been accomplished by chiral GC-MS and HPLC.
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Affiliation(s)
- Birgit Ohlendorf
- Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, D-53115 Bonn, Germany
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Meiser P, Müller R. Two Functionally Redundant Sfp‐Type 4′‐Phosphopantetheinyl Transferases Differentially Activate Biosynthetic Pathways inMyxococcus xanthus. Chembiochem 2008; 9:1549-53. [DOI: 10.1002/cbic.200800077] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Stein DB, Linne U, Hahn M, Marahiel MA. Impact of Epimerization Domains on the Intermodular Transfer of Enzyme-Bound Intermediates in Nonribosomal Peptide Synthesis. Chembiochem 2006; 7:1807-14. [PMID: 16952189 DOI: 10.1002/cbic.200600192] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Assembly of bioactive natural compounds through the action of nonribosomal peptide synthetases (NRPSs) relies on the specific interplay of modules and domains along these multiple mega-enzymes. As the C termini of several bacterial NRPSs often harbor epimerization (E) domains that generate D-amino acids, these seem to facilitate the ordered intermolecular enzymatic interaction and the directed transfer of intermediates. To elucidate this bifunctional role, E domains in recombinant bimodular proteins derived from the tyrocidine synthetase B were investigated. By utilizing sequent tryptic proteolysis and HPLC Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS), we could directly interrogate and determine the formation of intermediates attached to the TycB(3)-PCP domain of wild-type TycB(2-3) and to the E domain exchange enzyme TycB(2-3)-ATCAT/E(tycA). In addition, the two proteins and a version of TycB(2-3) fused to the communication-mediating (COM) domain of TycA were applied in product formation assays with TycB(1) to corroborate E domain impact on intermodular NRPS interaction. Significant functional differences between the C-terminal aminoacyl- and peptidyl-E domains were observed in terms of in trans interaction and misinitiation. E domains originating from elongation modules (peptidyl-E domains) seem to be optimized for regulation of the progression of peptide bond formation, epimerization, and intermediate transfer to the downstream module, whereas E domains of initiation modules (aminoacyl-E domains) impair upstream condensation and cause misinitiation. The selection of E domains is therefore decisive for successful application in biocombinatorial engineering of nonribosomal peptides.
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Affiliation(s)
- Daniel B Stein
- Fachbereich Chemie/Biochemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35032 Marburg, Germany
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Simunovic V, Zapp J, Rachid S, Krug D, Meiser P, Müller R. Myxovirescin A Biosynthesis is Directed by Hybrid Polyketide Synthases/Nonribosomal Peptide Synthetase, 3-Hydroxy-3-Methylglutaryl-CoA Synthases, and trans-Acting Acyltransferases. Chembiochem 2006; 7:1206-20. [PMID: 16835859 DOI: 10.1002/cbic.200600075] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Myxococcus xanthus DK1622 is shown to be a producer of myxovirescin (antibiotic TA) antibiotics. The myxovirescin biosynthetic gene cluster spans at least 21 open reading frames (ORFs) and covers a chromosomal region of approximately 83 kb. In silico analysis of myxovirescin ORFs in conjunction with genetic studies suggests the involvement of four type I polyketide synthases (PKSs; TaI, TaL, TaO, and TaP), one major hybrid PKS/NRPS (Ta-1), and a number of monofunctional enzymes similar to the ones involved in type II fatty-acid biosynthesis (FAB). Whereas deletion of either taI or taL causes a dramatic drop in myxovirescin production, deletion of both genes (DeltataIL) leads to the complete loss of myxovirescin production. These results suggest that both TaI and TaL PKSs might act in conjunction with a methyltransferase, reductases, and a monooxygenase to produce the 2-hydroxyvaleryl-S-ACP starter that is proposed to act as the biosynthetic primer in the initial condensation reaction with glycine. Polymerization of the remaining 11 acetates required for lactone formation is directed by 12 modules of Ta-1, TaO, and TaP megasynthetases. All modules, except for the first module of TaL, lack cognate acyltransferase (AT) domains. Furthermore, deletion of a discrete tandem AT-encoded by taV-blocks myxovirescin production; this suggests an "in trans" mode of action. To embellish the macrocycle with methyl and ethyl moieties, assembly of the myxovirescin scaffold is proposed to switch twice from PKS to 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA)-like biochemistry during biosynthesis. Disruption of the S-adenosylmethionine (SAM)-dependent methyltransferase, TaQ, shifts production toward two novel myxovirescin analogues, designated myxovirescin Q(a) and myxovirescin Q(c). NMR analysis of purified myxovirescin Q(a) revealed the loss of the methoxy carbon atom. This novel analogue lacks bioactivity against E. coli.
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Affiliation(s)
- Vesna Simunovic
- Pharmaceutical Biotechnology, Saarland University, Im Stadtwald, 66123 Saarbrücken, Germany
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