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Hibi G, Shiraishi T, Umemura T, Nemoto K, Ogura Y, Nishiyama M, Kuzuyama T. Discovery of type II polyketide synthase-like enzymes for the biosynthesis of cispentacin. Nat Commun 2023; 14:8065. [PMID: 38052796 DOI: 10.1038/s41467-023-43731-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 11/18/2023] [Indexed: 12/07/2023] Open
Abstract
Type II polyketide synthases (PKSs) normally synthesize polycyclic aromatic compounds in nature, and the potential to elaborate further diverse skeletons was recently revealed by the discovery of a polyene subgroup. Here, we show a type II PKS machinery for the biosynthesis of a five-membered nonaromatic skeleton contained in the nonproteinogenic amino acid cispentacin and the plant toxin coronatine. We successfully produce cispentacin in a heterologous host and reconstruct its biosynthesis using seven recombinant proteins in vitro. Biochemical analyses of each protein reveal the unique enzymatic reactions, indicating that a heterodimer of type II PKS-like enzymes (AmcF-AmcG) catalyzes a single C2 elongation as well as a subsequent cyclization on the acyl carrier protein (AmcB) to form a key intermediate with a five-membered ring. The subsequent reactions, which are catalyzed by a collection of type II PKS-like enzymes, are also peculiar. This work further expands the definition of type II PKS and illuminates an unexplored genetic resource for natural products.
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Affiliation(s)
- Genki Hibi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Taro Shiraishi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Tatsuki Umemura
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Kenji Nemoto
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Yusuke Ogura
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Makoto Nishiyama
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Tomohisa Kuzuyama
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
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Sansinenea E, Ortiz A. The Chemistry of Cyclopropanes and New Insight in Organocatalyzed Asymmetric Cyclopropanation. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Aurelio Ortiz
- Benemerita Universidad Autonoma de Puebla Facultad de Ciencias Quimicas 14 sur y av san claudio 72570 Puebla MEXICO
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3
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Winn M, Rowlinson M, Wang F, Bering L, Francis D, Levy C, Micklefield J. Discovery, characterization and engineering of ligases for amide synthesis. Nature 2021; 593:391-398. [PMID: 34012085 DOI: 10.1038/s41586-021-03447-w] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 03/11/2021] [Indexed: 02/04/2023]
Abstract
Coronatine and related bacterial phytotoxins are mimics of the hormone jasmonyl-L-isoleucine (JA-Ile), which mediates physiologically important plant signalling pathways1-4. Coronatine-like phytotoxins disrupt these essential pathways and have potential in the development of safer, more selective herbicides. Although the biosynthesis of coronatine has been investigated previously, the nature of the enzyme that catalyses the crucial coupling of coronafacic acid to amino acids remains unknown1,2. Here we characterize a family of enzymes, coronafacic acid ligases (CfaLs), and resolve their structures. We found that CfaL can also produce JA-Ile, despite low similarity with the Jar1 enzyme that is responsible for ligation of JA and L-Ile in plants5. This suggests that Jar1 and CfaL evolved independently to catalyse similar reactions-Jar1 producing a compound essential for plant development4,5, and the bacterial ligases producing analogues toxic to plants. We further demonstrate how CfaL enzymes can be used to synthesize a diverse array of amides, obviating the need for protecting groups. Highly selective kinetic resolutions of racemic donor or acceptor substrates were achieved, affording homochiral products. We also used structure-guided mutagenesis to engineer improved CfaL variants. Together, these results show that CfaLs can deliver a wide range of amides for agrochemical, pharmaceutical and other applications.
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Affiliation(s)
- Michael Winn
- Department of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK
| | - Michael Rowlinson
- Department of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK
| | - Fanghua Wang
- Department of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Luis Bering
- Department of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK
| | - Daniel Francis
- Department of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK
| | - Colin Levy
- Department of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK
| | - Jason Micklefield
- Department of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK.
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4
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Kang WJ, Pan HX, Wang S, Yu B, Hua H, Tang GL. Identification of the Amipurimycin Gene Cluster Yields Insight into the Biosynthesis of C9 Sugar Nucleoside Antibiotics. Org Lett 2019; 21:3148-3152. [PMID: 30990701 DOI: 10.1021/acs.orglett.9b00840] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Feeding studies indicate a possible synthetic pattern for the N-terminal cis-aminocyclopentane carboxylic acid (ACPC) and suggest an unusual source of the high-carbon sugar skeleton of amipurimycin (APM). The biosynthetic gene cluster of APM was identified and confirmed by in vivo experiments. A C9 core intermediate was discovered from null mutants of ACPC pathway, and an ATP-grasp enzyme (ApmA8) was reconstituted in vitro for ACPC loading. Our observations allow a first proposal of the APM biosynthetic pathway.
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Affiliation(s)
- Wen-Jia Kang
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education , Shenyang Pharmaceutical University , Shenyang 110016 , China
| | - Hai-Xue Pan
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis , Shanghai Institute of Organic Chemistry , University of Chinese Academy of Sciences (CAS), CAS, Shanghai 200032 , China
| | - Shengyang Wang
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis , Shanghai Institute of Organic Chemistry , University of Chinese Academy of Sciences (CAS), CAS, Shanghai 200032 , China
| | - Biao Yu
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis , Shanghai Institute of Organic Chemistry , University of Chinese Academy of Sciences (CAS), CAS, Shanghai 200032 , China
| | - Huiming Hua
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education , Shenyang Pharmaceutical University , Shenyang 110016 , China
| | - Gong-Li Tang
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis , Shanghai Institute of Organic Chemistry , University of Chinese Academy of Sciences (CAS), CAS, Shanghai 200032 , China
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5
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Bignell DRD, Cheng Z, Bown L. The coronafacoyl phytotoxins: structure, biosynthesis, regulation and biological activities. Antonie van Leeuwenhoek 2018; 111:649-666. [PMID: 29307013 DOI: 10.1007/s10482-017-1009-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/19/2017] [Indexed: 12/11/2022]
Abstract
Phytotoxins are secondary metabolites that contribute to the development and/or severity of diseases caused by various plant pathogenic microorganisms. The coronafacoyl phytotoxins are an important family of plant toxins that are known or suspected to be produced by several phylogenetically distinct plant pathogenic bacteria, including the gammaproteobacterium Pseudomonas syringae and the actinobacterium Streptomyces scabies. At least seven different family members have been identified, of which coronatine was the first to be described and is the best-characterized. Though nonessential for disease development, coronafacoyl phytotoxins appear to enhance the severity of disease symptoms induced by pathogenic microbes during host infection. In addition, the identification of coronafacoyl phytotoxin biosynthetic genes in organisms not known to be plant pathogens suggests that these metabolites may have additional roles other than as virulence factors. This review focuses on our current understanding of the structures, biosynthesis, regulation, biological activities and evolution of coronafacoyl phytotoxins as well as the different methods that are used to detect these metabolites and the organisms that produce them.
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Affiliation(s)
- Dawn R D Bignell
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1B 3X9, Canada.
| | - Zhenlong Cheng
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1B 3X9, Canada
| | - Luke Bown
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1B 3X9, Canada
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6
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Gemperlein K, Hoffmann M, Huo L, Pilak P, Petzke L, Müller R, Wenzel SC. Synthetic biology approaches to establish a heterologous production system for coronatines. Metab Eng 2017; 44:213-222. [DOI: 10.1016/j.ymben.2017.09.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 08/19/2017] [Accepted: 09/18/2017] [Indexed: 11/28/2022]
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Strieter ER, Koglin A, Aron ZD, Walsh CT. Cascade reactions during coronafacic acid biosynthesis: elongation, cyclization, and functionalization during Cfa7-catalyzed condensation. J Am Chem Soc 2009; 131:2113-5. [PMID: 19199623 PMCID: PMC2662718 DOI: 10.1021/ja8077945] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herein, the biogenesis of the hydrindane ring system within coronafacic acid (CFA) has been investigated. These studies reveal that in addition to the canonical polyketide chain elongation and functionalization encoded by type I polyketide synthase (PKSs), cascade reactions can take place during assembly line-like biosynthesis. Indeed, upon Cfa7-catalyzed Claisen condensation between enzyme-bound malonate and an N-acetylcysteamine (SNAC) thioester, latent reactivity within the elongated enzyme-bound intermediate is unveiled. This reactivity translates into an intramolecular cyclization, which can proceed in a facile manner as observed by the enzyme-independent cyclization of a linear beta-ketothioester intermediate.
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Affiliation(s)
- Eric R Strieter
- Harvard Medical School, Department of Biological Chemistry and Molecular Pharmacology, 240 Longwood Avenue, Boston, Massachusetts 02115, USA
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8
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Seidle H, Rangaswamy V, Couch R, Bender CL, Parry RJ. Characterization of Cfa1, a monofunctional acyl carrier protein involved in the biosynthesis of the phytotoxin coronatine. J Bacteriol 2004; 186:2499-503. [PMID: 15060056 PMCID: PMC412169 DOI: 10.1128/jb.186.8.2499-2503.2004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cfa1 was overproduced in Escherichia coli and Pseudomonas syringae, and the degree of 4'-phosphopantetheinylation was determined. The malonyl-coenzyme A:acyl carrier protein transacylase (FabD) of P. syringae was overproduced and shown to catalyze malonylation of Cfa1, suggesting that FabD plays a role in coronatine biosynthesis. Highly purified Cfa1 did not exhibit self-malonylation activity.
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Affiliation(s)
- Heather Seidle
- Department of Chemistry, Rice University, Houston, Texas 77005, USA
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9
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Couch R, O'Connor SE, Seidle H, Walsh CT, Parry R. Characterization of CmaA, an adenylation-thiolation didomain enzyme involved in the biosynthesis of coronatine. J Bacteriol 2004; 186:35-42. [PMID: 14679222 PMCID: PMC303444 DOI: 10.1128/jb.186.1.35-42.2004] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several pathovars of Pseudomonas syringae produce the phytotoxin coronatine (COR), which contains an unusual amino acid, the 1-amino-2-ethylcyclopropane carboxylic acid called coronamic acid (CMA), which is covalently linked to a polyketide-derived carboxylic acid, coronafacic acid, by an amide bond. The region of the COR biosynthetic gene cluster proposed to be responsible for CMA biosynthesis was resequenced, and errors in previously deposited cmaA sequences were corrected. These efforts allowed overproduction of P. syringae pv. glycinea PG4180 CmaA in P. syringae pv. syringae FF5 as a FLAG-tagged protein and overproduction of P. syringae pv. tomato CmaA in Escherichia coli as a His-tagged protein; both proteins were in an enzymatically active form. Sequence analysis of CmaA indicated that there were two domains, an adenylation domain (A domain) and a thiolation domain (T domain). ATP-(32)PP(i) exchange assays showed that the A domain of CmaA catalyzes the conversion of branched-chain L-amino acids and ATP into the corresponding aminoacyl-AMP derivatives, with a kinetic preference for L-allo-isoleucine. Additional experiments demonstrated that the T domain of CmaA, which is posttranslationally modified with a 4'-phosphopantetheinyl group, reacts with the AMP derivative of L-allo-isoleucine to produce an aminoacyl thiolester intermediate. This covalent species was detected by incubating CmaA with ATP and L-[G-(3)H]allo-isoleucine, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. It is postulated that the L-allo-isoleucine covalently tethered to CmaA serves as the substrate for additional enzymes in the CMA biosynthetic pathway that catalyze cyclopropane ring formation, which is followed by thiolester hydrolysis, yielding free CMA. The availability of catalytically active CmaA should facilitate elucidation of the details of the subsequent steps in the formation of this novel cyclopropyl amino acid.
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Affiliation(s)
- Robin Couch
- Department of Chemistry, Rice University, Houston, Texas 77005, USA
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10
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Reichenbach-Klinke R, Kruppa M, König B. NADH model systems functionalized with Zn(II)-cyclen as flavin binding site-structure dependence of the redox reaction within reversible aggregates. J Am Chem Soc 2002; 124:12999-3007. [PMID: 12405826 DOI: 10.1021/ja026719j] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The relative positions and conformations of the prosthetic group FAD and the cofactor NADH have been remarkably conserved within the structurally diverse group of flavin enzymes. To provide a chemical rational for such an obviously optimal relative disposition of the redox partners for efficient reaction we have synthesized NADH models with Zn(II)-cyclen substituents for reversible flavin binding in water. Altogether, four of these model systems with systematically varying spacer length between the recognition site and the redox active dihydronicotinamide were prepared. The binding of these model systems to riboflavin tetraacetate was confirmed by potentiometric pH titration in water and their reaction with flavin was followed by UV-vis spectroscopy in aqueous media under physiological conditions. The measurements reveal a significant rate enhancement of up to 175 times that of an intermolecular reaction. Moreover, a strong dependence of the reaction rate on the spacer length was observed, which clearly shows that within the dynamic reversible assembly only the optimal relative disposition of the redox partners ensures an efficient redox reaction.
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11
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Tao T, Parry RJ. Determination by enantioselective synthesis of the absolute configuration of CPE, a potential intermediate in coronatine biosynthesis. Org Lett 2001; 3:3045-7. [PMID: 11554839 DOI: 10.1021/ol0165037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The first enantioselective synthesis of the methyl ester of CPE, a potential intermediate in coronatine (COR) biosynthesis, is described. Comparison of the specific rotation of the synthetic ester with that of the methyl ester of natural CPE established that the latter possesses the (R) configuration. This configuration is the same as that found at the corresponding asymmetric center of coronatine. Structure: see text.
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Affiliation(s)
- T Tao
- Department of Chemistry MS60, Rice University, Houston, Texas 77251-1892, USA
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12
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Jiralerspong S, Rangaswamy V, Bender CL, Parry RJ. Analysis of the enzymatic domains in the modular portion of the coronafacic acid polyketide synthase. Gene 2001; 270:191-200. [PMID: 11404016 DOI: 10.1016/s0378-1119(01)00476-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Coronafacic acid (CFA) is the polyketide component of coronatine (COR), a phytotoxin produced by the plant pathogen Pseudomonas syringae. The CFA polyketide synthase (PKS) consists of two open reading frames (ORFs) that encode type I multifunctional proteins and several ORFs that encode monofunctional proteins. Sequence comparisons of the modular portions of the CFA PKS with other prokaryotic, modular PKSs elucidated the boundaries of the domains that are involved in the individual stages of polyketide assembly. The two beta-ketoacyl:acyl carrier protein synthase (KS) domains in the modular portion of the CFA PKS exhibit a high degree of similarity to each other (53%), but are even more similar to the KS domains of DEBS, RAPS, and RIF. Cfa6 possesses two acyltransferases- AT0, which is associated with a loading domain, and AT1, which uses ethylmalonyl-CoA (eMCoA) as a substrate for chain extension. Cfa7 contains an AT that uses malonyl-CoA as a substrate for chain extension. The Cfa6 AT0 shows 35 and 32% similarity to the DEBS1 and NidA1 AT0s, respectively, and 32 and 36% similarity to the Cfa6 and Cfa7 AT1s. Sequence motifs have previously been identified that correlate with AT substrates. The motifs in Cfa6 AT1 were found to correlate reasonably well with those predicted for methylmalonyl-CoA (mMCoA) ATs. The motifs in the AT of Cfa7 correlated more poorly with those predicted for MCoA ATs. Three ACP domains occur in the modular proteins of the COR PKS. The loading domain-associated ACP0 showed 38% similarity to the loading domain ACP0s of DEBS1 and NidA1 and 32-36% similarity to the two module-associated ACPs of the COR PKS. It exhibited a higher degree of similarity to the module-associated ACPs of RAPS. The two module-associated ACPs show 39% similarity to each other, but appear more closely related to module-associated ACP domains in RAPS and RIFS. Furthermore, the DH and KR domains of Cfa6 and Cfa7 show greater similarity to DH and KR domains in RAPS and RIFS than to each other. The CFA PKS includes a thioesterase domain (TE I) that resides at the C-terminus of Cfa7 and a second thioesterase, which exists as a separate ORF (Cfa9, a TE II). Analysis of a Cfa7 thioesterase mutant demonstrated that the TE domain is required for the production of CFA. The co-existence of TE domains within modular PKSs along with physically separated, monofunctional TEs (TE IIs) has been reported for a number of modular polyketide and non-ribosomal peptide synthases (NRPS). An analysis of the two types of thioesterases using Clustal X yielded a dendrogram showing that TE IIs from PKSs and NRPSs are more closely related to each other than to domain TEs from either PKSs or NRPSs. Furthermore, the dendrogram indicates that both types of TE IIs are more closely related to TE domains associated with PKSs than to TE domains in NRPSs. Finally, the overall % G+C content and the % G+C content at the third codon for all of the PKS genes in the COR cluster suggest that these genes may have been recruited from a gram-positive bacterium.
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Affiliation(s)
- S Jiralerspong
- Department of Chemistry MS60, Rice University, Houston, TX 77251-1892, USA
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Du L, Sánchez C, Shen B. Hybrid peptide-polyketide natural products: biosynthesis and prospects toward engineering novel molecules. Metab Eng 2001; 3:78-95. [PMID: 11162234 DOI: 10.1006/mben.2000.0171] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The structural and catalytic similarities between modular nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) inspired us to search for hybrid NRPS-PKS systems. By examining the biochemical and genetic data known to date for the biosynthesis of hybrid peptide-polyketide natural products, we show (1) that the same catalytic sites are conserved between the hybrid NRPS-PKS and normal NRPS or PKS systems, although the ketoacyl synthase domain in NRPS/PKS hybrids is unique, and (2) that specific interpolypeptide linkers exist at both the C- and N-termini of the NRPS and PKS proteins, which presumably play a critical role in facilitating the transfer of the growing peptide or polyketide intermediate between NRPS and PKS modules in hybrid NRPS-PKS systems. These findings provide new insights for intermodular communications in hybrid NRPS-PKS systems and should now be taken into consideration in engineering hybrid peptide-polyketide biosynthetic pathways for making novel "unnatural" natural products.
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Affiliation(s)
- L Du
- Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, USA
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Bender CL, Alarcón-Chaidez F, Gross DC. Pseudomonas syringae phytotoxins: mode of action, regulation, and biosynthesis by peptide and polyketide synthetases. Microbiol Mol Biol Rev 1999; 63:266-92. [PMID: 10357851 PMCID: PMC98966 DOI: 10.1128/mmbr.63.2.266-292.1999] [Citation(s) in RCA: 516] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Coronatine, syringomycin, syringopeptin, tabtoxin, and phaseolotoxin are the most intensively studied phytotoxins of Pseudomonas syringae, and each contributes significantly to bacterial virulence in plants. Coronatine functions partly as a mimic of methyl jasmonate, a hormone synthesized by plants undergoing biological stress. Syringomycin and syringopeptin form pores in plasma membranes, a process that leads to electrolyte leakage. Tabtoxin and phaseolotoxin are strongly antimicrobial and function by inhibiting glutamine synthetase and ornithine carbamoyltransferase, respectively. Genetic analysis has revealed the mechanisms responsible for toxin biosynthesis. Coronatine biosynthesis requires the cooperation of polyketide and peptide synthetases for the assembly of the coronafacic and coronamic acid moieties, respectively. Tabtoxin is derived from the lysine biosynthetic pathway, whereas syringomycin, syringopeptin, and phaseolotoxin biosynthesis requires peptide synthetases. Activation of phytotoxin synthesis is controlled by diverse environmental factors including plant signal molecules and temperature. Genes involved in the regulation of phytotoxin synthesis have been located within the coronatine and syringomycin gene clusters; however, additional regulatory genes are required for the synthesis of these and other phytotoxins. Global regulatory genes such as gacS modulate phytotoxin production in certain pathovars, indicating the complexity of the regulatory circuits controlling phytotoxin synthesis. The coronatine and syringomycin gene clusters have been intensively characterized and show potential for constructing modified polyketides and peptides. Genetic reprogramming of peptide and polyketide synthetases has been successful, and portions of the coronatine and syringomycin gene clusters could be valuable resources in developing new antimicrobial agents.
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Affiliation(s)
- C L Bender
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, Oklahoma 74078-3032, USA.
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Bender CL, Rangaswamy V, Loper J. POLYKETIDE PRODUCTION BY PLANT-ASSOCIATED PSEUDOMONADS. ANNUAL REVIEW OF PHYTOPATHOLOGY 1999; 37:175-196. [PMID: 11701821 DOI: 10.1146/annurev.phyto.37.1.175] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Polyketides constitute a huge family of structurally diverse natural products including antibiotics, chemotherapeutic compounds, and antiparasitics. Most of the research on polyketide synthesis in bacteria has focused on compounds synthesized by Streptomyces or other actinomycetes; however, plant-associated pseudomonads also produce a variety of compounds via the polyketide pathway including the phytotoxin coronatine, the antibiotic mupirocin, and the antifungal compounds pyoluteorin and 2,4-diacetylphloroglucinol. This review focuses on the mode of action, regulation, biosynthesis, and genetics of these four compounds and the potential use of Pseudomonas-derived polyketide synthases in the generation of novel compounds with unique activities.
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Affiliation(s)
- CL Bender
- Department of Entomology and Plant Pathology, 110 Noble Research Center, Oklahoma State University, Stillwater, Oklahoma 74078-3032; e-mail: ;
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16
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Rangaswamy V, Jiralerspong S, Parry R, Bender CL. Biosynthesis of the Pseudomonas polyketide coronafacic acid requires monofunctional and multifunctional polyketide synthase proteins. Proc Natl Acad Sci U S A 1998; 95:15469-74. [PMID: 9860992 PMCID: PMC28066 DOI: 10.1073/pnas.95.26.15469] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Coronafacic acid (CFA) is the polyketide component of the phytotoxin coronatine, a virulence factor of the plant pathogen Pseudomonas syringae. Our current knowledge of polyketide biosynthesis largely is based on the analysis of polyketide synthases (PKSs) in actinomycetes and other Gram-positive bacteria. Consequently, the cloning and characterization of the CFA biosynthetic gene cluster will contribute significantly to our knowledge of polyketide synthesis in Pseudomonas. In this report, we describe two genes in the CFA biosynthetic gene cluster that encode PKSs that are structurally and functionally similar to the multifunctional modular PKSs, which catalyze the synthesis of macrolide antibiotics. The CFA PKS genes were overproduced in Escherichia coli and shown to cross-react with antisera made to a modular PKS involved in erythromycin synthesis. A scheme for CFA biosynthesis is presented that incorporates the activities of all proteins in the CFA PKS. In this report a gene cluster encoding a pseudomonad polyketide has been completely sequenced and the deduced gene functions have been used to develop a biosynthetic scheme.
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Affiliation(s)
- V Rangaswamy
- Department of Entomology and Plant Pathology, 110 Noble Research Center, Oklahoma State University, Stillwater, OK 74078, USA
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17
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Investigations of coronatine biosynthesis. Overexpression and assay of CmaT, a thioesterase involved in coronamic acid biosynthesis. Tetrahedron 1998. [DOI: 10.1016/s0040-4020(98)01002-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Rangaswamy V, Mitchell R, Ullrich M, Bender C. Analysis of genes involved in biosynthesis of coronafacic acid, the polyketide component of the phytotoxin coronatine. J Bacteriol 1998; 180:3330-8. [PMID: 9642184 PMCID: PMC107286 DOI: 10.1128/jb.180.13.3330-3338.1998] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Coronafacic acid (CFA) is the polyketide component of coronatine (COR), a phytotoxin produced by the plant-pathogenic bacterium Pseudomonas syringae. The genes involved in CFA biosynthesis are encoded by a single transcript which encompasses 19 kb of the COR gene cluster. In the present study, the nucleotide sequence was determined for a 4-kb region located at the 3' end of the CFA biosynthetic gene cluster. Three open reading frames were identified and designated cfa8, cfa9, and tnp1; the predicted translation products of these genes showed relatedness to oxidoreductases, thioesterases, and transposases, respectively. The translational products of cfa8 and cfa9 were overproduced in Escherichia coli BL21; however, tnp1 was not translated in these experiments. Mutagenesis and complementation analysis indicated that cfa8 is required for the production of CFA and COR. Analysis of a cfa9 mutant indicated that this gene is dispensable for CFA and COR production but may increase the release of enzyme-bound products from the COR pathway; tnp1, however, had no obvious function in CFA or COR biosynthesis. A genetic strategy was used to produce CFA in a P. syringae strain which lacks the COR gene cluster; this approach will be useful in future studies designed to investigate biosynthetic products of the CFA gene cluster.
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Affiliation(s)
- V Rangaswamy
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater 74078-3032, USA
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Bender CL, Palmer DA, Peñaloza-Vázquez A, Rangaswamy V, Ullrich M. Biosynthesis and regulation of coronatine, a non-host-specific phytotoxin produced by Pseudomonas syringae. Subcell Biochem 1998; 29:321-41. [PMID: 9594652 DOI: 10.1007/978-1-4899-1707-2_10] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Many P. syringae pathovars are known to produce low-molecular-weight, diffusible toxins in infected host plants. These phytotoxins reproduce some of the symptoms of the relevant bacterial disease and are effective at very low concentrations. Phytotoxins generally enhance the virulence of the P. syringae pathovar which produces them, but are not required for pathogenesis. Genes encoding phytotoxin production have been identified and cloned from several P. syringae pathovars. With the exception of coronatine, toxin biosynthetic gene clusters are generally chromosomally encoded. In several pathovars, the toxin biosynthetic gene cluster also contains a resistance gene which functions to protect the producing strain from the biocidal effects of the toxin. In the case of phaseolotoxin, a resistance gene (argK) has been utilized to engineer phaseolotoxin-resistant tobacco plants. Although P. syringae phytotoxins can induce very similar effects in plants (chlorosis and necrosis), their biosynthesis and mode of action can be quite different. Knowledge of the biosynthetic pathways to these toxins and the cloning of the structural genes for their biosynthesis has relevance to the development of new bioactive compounds with altered specificity. For example, polyketides constitute a huge family of structurally diverse natural products including antibiotics, chemotherapeutic compounds, and antiparasitics. Most of the research on polyketide synthesis in bacteria has focused on compounds synthesized by Streptomyces or other actinomycetes. It is also important to note that it is now possible to utilize a genetic rather than synthetic approach to biosynthesize novel polyketides with altered biological properties (Hutchinson and Fujii, 1995; Kao et al., 1994; Donadio et al., 1993; Katz and Donadio, 1993). Most of the reprogramming or engineering of novel polyketides has been done using actinomycete PKSs, but much of this technology could also be applied to polyketides synthesized by Pseudomonas when sufficient sequence information is available. It is important to note that Pseudomonas produces a variety of antimicrobial compounds from the polyketide pathway, including mupirocin (pseudomonic acid) (Feline et al., 1977), pyoluteorin (Cuppels et al., 1986), and 2-4 diacetylphloroglucinol (Phl) (Bangera and Thomashow, 1996). Pseudomonic acid is valued for its pharmaceutical properties as an antibiotic (Aldridge, 1992), whereas pyoluteorin and Phl have antifungal properties (Howell and Stipanovic, 1980; Keel et al., 1992). A thorough understanding of the biosynthetic pathway to polyketide phytotoxins such as coronatine may ultimately lead to the development of novel compounds with altered biological properties. Thus, specific genes in the biosynthetic pathways of P. syringae phytotoxins could be deployed in other systems to develop new compounds with a wide range of activities.
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Affiliation(s)
- C L Bender
- Department of Plant Pathology, Oklahoma State University, Stillwater 74078-3032, USA
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