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Abraham N, Schroeter KL, Zhu Y, Chan J, Evans N, Kimber MS, Carere J, Zhou T, Seah SYK. Structure-function characterization of an aldo-keto reductase involved in detoxification of the mycotoxin, deoxynivalenol. Sci Rep 2022; 12:14737. [PMID: 36042239 PMCID: PMC9427786 DOI: 10.1038/s41598-022-19040-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 08/23/2022] [Indexed: 11/09/2022] Open
Abstract
Deoxynivalenol (DON) is a mycotoxin, produced by filamentous fungi such as Fusarium graminearum, that causes significant yield losses of cereal grain crops worldwide. One of the most promising methods to detoxify this mycotoxin involves its enzymatic epimerization to 3-epi-DON. DepB plays a critical role in this process by reducing 3-keto-DON, an intermediate in the epimerization process, to 3-epi-DON. DepBRleg from Rhizobium leguminosarum is a member of the new aldo-keto reductase family, AKR18, and it has the unusual ability to utilize both NADH and NADPH as coenzymes, albeit with a 40-fold higher catalytic efficiency with NADPH compared to NADH. Structural analysis of DepBRleg revealed the putative roles of Lys-217, Arg-290, and Gln-294 in NADPH specificity. Replacement of these residues by site-specific mutagenesis to negatively charged amino acids compromised NADPH binding with minimal effects on NADH binding. The substrate-binding site of DepBRleg is larger than its closest structural homolog, AKR6A2, likely contributing to its ability to utilize a wide range of aldehydes and ketones, including the mycotoxin, patulin, as substrates. The structure of DepBRleg also suggests that 3-keto-DON can adopt two binding modes to facilitate 4-pro-R hydride transfer to either the re- or si-face of the C3 ketone providing a possible explanation for the enzyme's ability to convert 3-keto-DON to 3-epi-DON and DON in diastereomeric ratios of 67.2% and 32.8% respectively.
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Affiliation(s)
- Nadine Abraham
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada.,Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, ON, Canada
| | - Kurt L Schroeter
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| | - Yan Zhu
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, ON, Canada
| | - Jonathan Chan
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada.,Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, ON, Canada
| | - Natasha Evans
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada.,Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, ON, Canada
| | - Matthew S Kimber
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| | - Jason Carere
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, ON, Canada
| | - Ting Zhou
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, ON, Canada
| | - Stephen Y K Seah
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada.
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Identification and Characterization of a Novel N- and O-Glycosyltransferase from Saccharopolyspora erythraea. Molecules 2020; 25:molecules25153400. [PMID: 32727097 PMCID: PMC7435583 DOI: 10.3390/molecules25153400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/24/2020] [Accepted: 07/24/2020] [Indexed: 11/26/2022] Open
Abstract
Glycosyltransferases are important enzymes which are often used as tools to generate novel natural products. In this study, we describe the identification and characterization of an inverting N- and O-glycosyltransferase from Saccharopolyspora erythraea NRRL2338. When feeding experiments with 1,4-diaminoanthraquinone in Saccharopolyspora erythraea were performed, the formation of new compounds (U3G and U3DG) was observed by HPLC-MS. Structure elucidation by NMR revealed that U3G consists of two compounds, N1-α-glucosyl-1,4-diaminoanthraquinone and N1-β-glucosyl-1,4-diaminoanthraquinone. Based on UV and MS data, U3DG is a N1,N4-diglucosyl-1,4-diaminoanthraquinone. In order to find the responsible glycosyltransferase, gene deletion experiments were performed and we identified the glycosyltransferase Sace_3599, which belongs to the CAZy family 1. When Streptomyces albus J1074, containing the dTDP-d-glucose synthase gene oleS and the plasmid pUWL-A-sace_3599, was used as host, U3 was converted to the same compounds. Protein production in Escherichia coli and purification of Sace_3599 was carried out. The enzyme showed glycosyl hydrolase activity and was able to produce mono- and di-N-glycosylated products in vitro. When UDP-α-d-glucose was used as a sugar donor, U3 was stereoselective converted to N1-β-glucosyl-1,4-diaminoanthraquinone and N1,N4-diglucosyl-1,4-diaminoanthraquinone. The use of 1,4-dihydroxyanthraquinone as a substrate in in vitro experiments also led to the formation of mono-glucosylated and di-glucosylated products, but in lower amounts. Overall, we identified and characterized a novel glycosyltransferase which shows glycohydrolase activity and the ability to glycosylate “drug like” structures forming N- and O-glycosidic bonds.
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Dai L, Li J, Yao P, Zhu Y, Men Y, Zeng Y, Yang J, Sun Y. Exploiting the aglycon promiscuity of glycosyltransferase Bs-YjiC from Bacillus subtilis and its application in synthesis of glycosides. J Biotechnol 2017; 248:69-76. [DOI: 10.1016/j.jbiotec.2017.03.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/16/2017] [Accepted: 03/11/2017] [Indexed: 12/24/2022]
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Chiu HH, Shen MY, Liu YT, Fu YL, Chiu YA, Chen YH, Huang CP, Li YK. Diversity of sugar acceptor of glycosyltransferase 1 from Bacillus cereus and its application for glucoside synthesis. Appl Microbiol Biotechnol 2016; 100:4459-71. [PMID: 26795959 DOI: 10.1007/s00253-015-7270-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 12/08/2015] [Accepted: 12/22/2015] [Indexed: 12/31/2022]
Abstract
Glycosyltransferase 1 from Bacillus cereus (BcGT1) catalyzes the transfer of a glucosyl moiety from uridine diphosphate glucose (UDP-glucose) to various acceptors; it was expressed and characterized. The specificity of acceptors was found to be broad: more than 20 compounds classified into O-, S-, and N-linkage glucosides can be prepared with BcGT1 catalysis. Based on this work, we conclude that the corresponding acceptors of these compounds must possess the following features: (1) the acceptors must contain at least one aromatic or fused-aromatic or heteroaromatic ring; (2) the reactive hydroxyl or sulfhydryl or amino group can attach either on the aromatic ring or on its aliphatic side chain; and (3) the acceptors can be a primary, secondary, or even a tertiary amine. Four representative acceptors-fluorescein methyl ester, 17-β-estradiol, 7-mercapto-4-methylcoumarin, and 6-benzylaminopurine-were chosen as a candidate acceptor for O-, S-, and N-glucosidation, respectively. These enzymatic products were purified and the structures were confirmed with mass and NMR spectra. As all isolated glucosides are β-anomers, BcGT1 is confirmed to be an inverting enzyme. This study not only demonstrates the substrate promiscuity of BcGT1 but also showed the great application prospect of this enzyme in bioconversion of valuable bioactive molecules.
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Affiliation(s)
- Hsi-Ho Chiu
- Department of Applied Chemistry, National Chiao Tung University, Science Building 2, 1001 Ta Hsueh Road, Hsinchu, 30010, Taiwan
| | - Mo-Yuan Shen
- Department of Applied Chemistry, National Chiao Tung University, Science Building 2, 1001 Ta Hsueh Road, Hsinchu, 30010, Taiwan
| | - Yuan-Ting Liu
- Department of Applied Chemistry, National Chiao Tung University, Science Building 2, 1001 Ta Hsueh Road, Hsinchu, 30010, Taiwan
| | - Yu-Lieh Fu
- Department of Applied Chemistry, National Chiao Tung University, Science Building 2, 1001 Ta Hsueh Road, Hsinchu, 30010, Taiwan
| | - Yu-An Chiu
- Department of Applied Chemistry, National Chiao Tung University, Science Building 2, 1001 Ta Hsueh Road, Hsinchu, 30010, Taiwan
| | - Ya-Huei Chen
- Department of Applied Chemistry, National Chiao Tung University, Science Building 2, 1001 Ta Hsueh Road, Hsinchu, 30010, Taiwan
| | - Chin-Ping Huang
- Industrial Technology Research Institute, 195, Sec. 4, Chung Hsing Rd., Chutung, Hsinchu, 31040, Taiwan
| | - Yaw-Kuen Li
- Department of Applied Chemistry, National Chiao Tung University, Science Building 2, 1001 Ta Hsueh Road, Hsinchu, 30010, Taiwan.
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Characterization of impurities in tylosin using dual liquid chromatography combined with ion trap mass spectrometry. Talanta 2013; 106:29-38. [DOI: 10.1016/j.talanta.2012.12.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Revised: 12/04/2012] [Accepted: 12/06/2012] [Indexed: 11/20/2022]
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Flores-Ramirez G, Janecek S, Miernyk JA, Skultety L. In silico biosynthesis of virenose, a methylated deoxy-sugar unique to Coxiella burnetii lipopolysaccharide. Proteome Sci 2012; 10:67. [PMID: 23150954 PMCID: PMC3539893 DOI: 10.1186/1477-5956-10-67] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 11/05/2012] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED BACKGROUND Coxiella burnetii is Gram-negative bacterium responsible for the zoonosis Q-fever. While it has an obligate intracellular growth habit, it is able to persist for extended periods outside of a host cell and can resist environmental conditions that would be lethal to most prokaryotes. It is these extracellular bacteria that are the infectious stage encountered by eukaryotic hosts. The intracellular form has evolved to grow and replicate within acidified parasitophorous vacuoles. The outer coat of C. burnetii comprises a complex lipopolysaccharide (LPS) component that includes the unique methylated-6-deoxyhexose, virenose. Although potentially important as a biomarker for C. burnetii, the pathway for its biosynthesis remains obscure. RESULTS The 6-deoxyhexoses constitute a large family integral to the LPS of many eubacteria. It is believed that precursors of the methylated-deoxyhexoses traverse common early biosynthetic steps as nucleotide-monosaccharides. As a prelude to a full biosynthetic characterization, we present herein the results from bioinformatics-based, proteomics-supported predictions of the pathway for virenose synthesis. Alternative possibilities are considered which include both GDP-mannose and TDP-glucose as precursors. CONCLUSION We propose that biosynthesis of the unique C. burnetii biomarker, virenose, involves an early pathway similar to that of other C-3'-methylated deoxysugars which then diverges depending upon the nucleotide-carrier involved. The alternatives yield either the D- or L-enantiomers of virenose. Both pathways require five enzymatic steps, beginning with either glucose-6-phosphate or mannose-6-phosphate. Our in silico results comprise a model for virenose biosynthesis that can be directly tested. Definition of this pathway should facilitate the development of therapeutic agents useful for treatment of Q fever, as well as allowing improvements in the methods for diagnosing this highly infectious disease.
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Affiliation(s)
- Gabriela Flores-Ramirez
- Department of Rickettsiology, Institute of Virology, Slovak Academy of Sciences, Dubravska cesta, 9, Bratislava, 845 05, Slovakia
| | - Stefan Janecek
- Laboratory of Protein Evolution, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, 845 51, Slovakia
| | - Ján A Miernyk
- USDA, Agricultural Research Service, Plant Genetics Research Unit, Columbia, MO, 65211, USA
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO, 65211, USA
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Ludovit Skultety
- Department of Rickettsiology, Institute of Virology, Slovak Academy of Sciences, Dubravska cesta, 9, Bratislava, 845 05, Slovakia
- Centre for Molecular Medicine, Slovak Academy of Sciences, Bratislava, 831 01, Slovakia
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Ihnatko R, Shaw E, Toman R. Proteome of Coxiella burnetii. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 984:105-30. [DOI: 10.1007/978-94-007-4315-1_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Wang G, Kharel MK, Pahari P, Rohr J. Investigating Mithramycin deoxysugar biosynthesis: enzymatic total synthesis of TDP-D-olivose. Chembiochem 2011; 12:2568-71. [PMID: 21960454 PMCID: PMC3412565 DOI: 10.1002/cbic.201100540] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Indexed: 02/04/2023]
Abstract
Mix'n'match: Enzymatic total synthesis of TDP-D-olivose was achieved, starting from TDP-4-keto-6-deoxy-D-glucose, by combining three pathway enzymes with one cofactor-regenerating enzyme. The results also revealed that MtmC is a bifunctional enzyme that can perform a 4-ketoreduction necessary for D-olivose biosynthesis besides the previously found C-methyltransfer for D-mycarose biosynthesis.
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Affiliation(s)
- Guojun Wang
- Dr. G. Wang, Prof. Dr. M. K. Kharel, Dr. P. Pahari, Prof. Dr. J. Rohr Department of Pharmaceutical Sciences, University of Kentucky 789 South Limestone Street, Lexington, KY 40536-0596 (USA)
| | - Madan K. Kharel
- Dr. G. Wang, Prof. Dr. M. K. Kharel, Dr. P. Pahari, Prof. Dr. J. Rohr Department of Pharmaceutical Sciences, University of Kentucky 789 South Limestone Street, Lexington, KY 40536-0596 (USA)
- Prof. Dr. M. K. Kharel Present address: Midway College School of Pharmacy 120 Scott Perry Drive, Paintsville, KY 41240 (USA)
| | - Pallab Pahari
- Dr. G. Wang, Prof. Dr. M. K. Kharel, Dr. P. Pahari, Prof. Dr. J. Rohr Department of Pharmaceutical Sciences, University of Kentucky 789 South Limestone Street, Lexington, KY 40536-0596 (USA)
| | - Jürgen Rohr
- Dr. G. Wang, Prof. Dr. M. K. Kharel, Dr. P. Pahari, Prof. Dr. J. Rohr Department of Pharmaceutical Sciences, University of Kentucky 789 South Limestone Street, Lexington, KY 40536-0596 (USA)
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Development of a Streptomyces venezuelae-based combinatorial biosynthetic system for the production of glycosylated derivatives of doxorubicin and its biosynthetic intermediates. Appl Environ Microbiol 2011; 77:4912-23. [PMID: 21602397 DOI: 10.1128/aem.02527-10] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Doxorubicin, one of the most widely used anticancer drugs, is composed of a tetracyclic polyketide aglycone and l-daunosamine as a deoxysugar moiety, which acts as an important determinant of its biological activity. This is exemplified by the fewer side effects of semisynthetic epirubicin (4'-epi-doxorubicin). An efficient combinatorial biosynthetic system that can convert the exogenous aglycone ε-rhodomycinone into diverse glycosylated derivatives of doxorubicin or its biosynthetic intermediates, rhodomycin D and daunorubicin, was developed through the use of Streptomyces venezuelae mutants carrying plasmids that direct the biosynthesis of different nucleotide deoxysugars and their transfer onto aglycone, as well as the postglycosylation modifications. This system improved epirubicin production from ε-rhodomycinone by selecting a substrate flexible glycosyltransferase, AknS, which was able to transfer the unnatural sugar donors and a TDP-4-ketohexose reductase, AvrE, which efficiently supported the biosynthesis of TDP-4-epi-l-daunosamine. Furthermore, a range of doxorubicin analogs containing diverse deoxysugar moieties, seven of which are novel rhodomycin D derivatives, were generated. This provides new insights into the functions of deoxysugar biosynthetic enzymes and demonstrates the potential of the S. venezuelae-based combinatorial biosynthetic system as a simple biological tool for modifying structurally complex sugar moieties attached to anthracyclines as an alternative to chemical syntheses for improving anticancer agents.
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Skultety L, Hajduch M, Flores-Ramirez G, Miernyk JA, Ciampor F, Toman R, Sekeyova Z. Proteomic comparison of virulent phase I and avirulent phase II of Coxiella burnetii, the causative agent of Q fever. J Proteomics 2011; 74:1974-84. [PMID: 21616182 DOI: 10.1016/j.jprot.2011.05.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 04/20/2011] [Accepted: 05/09/2011] [Indexed: 01/06/2023]
Abstract
Coxiella burnetii, a category B biological warfare agent, causes multiple outbreaks of the zoonotic disease Q fever world-wide, each year. The virulent phase I and avirulent phase II variants of the Nine Mile RSA 493 and 439 strains of C. burnetii were propagated in embryonated hen eggs and then purified by centrifugation through Renografin gradients. Total protein fractions were isolated from each phase and subjected to analysis by one-dimensional electrophoresis plus tandem mass spectrometry. A total of 235 and 215 non-redundant proteins were unambiguously identified from the phase I and II cells, respectively. Many of these proteins had not been previously reported in proteomic studies of C. burnetii. The newly identified proteins should provide additional insight into the pathogenesis of Q fever. Several of the identified proteins are involved in the biosynthesis and metabolism of components of the extracellular matrix. Forty-four of the proteins have been annotated as having distinct roles in the pathogenesis or survival of C. burnetii within the harsh phagolysosomal environment. We propose that nine enzymes specifically involved with lipopolysaccharide biosynthesis and metabolism, and that are distinctively present in phase I cells, are virulence-associated proteins.
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Affiliation(s)
- Ludovit Skultety
- Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovakia.
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Abstract
Polyketide natural products are among the most important microbial metabolites in human medicine and are widely used to treat both acute and degenerative diseases. The need to develop new drugs has prompted the idea of using heterologous systems for the expression of polyketide biosynthetic pathways. The basic idea behind this approach is to use heterologous bacterial systems with better growth and genetic characteristics that could support better production of a certain compound than the original host or that could allow the generation of novel analogues through combinatorial biosynthesis. Moreover, these hosts could be used to express "cryptic" secondary metabolic pathways or serve as surrogate hosts in metagenomics experiments in order to find potential new bioactive compounds. In this chapter we discuss recent advances in the heterologous production of polyketides in bacteria and describe some methodological improvements of the systems.
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Affiliation(s)
- Eduardo Rodriguez
- Instituto de Biología Molecular y Celular de Rosario (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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Karray F, Darbon E, Oestreicher N, Dominguez H, Tuphile K, Gagnat J, Blondelet-Rouault MH, Gerbaud C, Pernodet JL. Organization of the biosynthetic gene cluster for the macrolide antibiotic spiramycin in Streptomyces ambofaciens. MICROBIOLOGY-SGM 2008; 153:4111-4122. [PMID: 18048924 DOI: 10.1099/mic.0.2007/009746-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Spiramycin, a 16-membered macrolide antibiotic used in human medicine, is produced by Streptomyces ambofaciens; it comprises a polyketide lactone, platenolide, to which three deoxyhexose sugars are attached. In order to characterize the gene cluster governing the biosynthesis of spiramycin, several overlapping cosmids were isolated from an S. ambofaciens gene library, by hybridization with various probes (spiramycin resistance or biosynthetic genes, tylosin biosynthetic genes), and the sequences of their inserts were determined. Sequence analysis showed that the spiramycin biosynthetic gene cluster spanned a region of over 85 kb of contiguous DNA. In addition to the five previously described genes that encode the type I polyketide synthase involved in platenolide biosynthesis, 45 other genes have been identified. It was possible to propose a function for most of the inferred proteins in spiramycin biosynthesis, in its regulation, in resistance to the produced antibiotic or in the provision of extender units for the polyketide synthase. Two of these genes, predicted to be involved in deoxysugar biosynthesis, were inactivated by gene replacement, and the resulting mutants were unable to produce spiramycin, thus confirming their involvement in spiramycin biosynthesis. This work reveals the main features of spiramycin biosynthesis and constitutes a first step towards a detailed molecular analysis of the production of this medically important antibiotic.
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Affiliation(s)
- Fatma Karray
- CNRS UMR8621, Université Paris-Sud, Institut de Génétique et Microbiologie, Bâtiment 400, F-91405 Orsay Cedex, France
| | - Emmanuelle Darbon
- CNRS UMR8621, Université Paris-Sud, Institut de Génétique et Microbiologie, Bâtiment 400, F-91405 Orsay Cedex, France
| | - Nathalie Oestreicher
- CNRS UMR8621, Université Paris-Sud, Institut de Génétique et Microbiologie, Bâtiment 400, F-91405 Orsay Cedex, France
| | - Hélène Dominguez
- CNRS UMR8621, Université Paris-Sud, Institut de Génétique et Microbiologie, Bâtiment 400, F-91405 Orsay Cedex, France
| | - Karine Tuphile
- CNRS UMR8621, Université Paris-Sud, Institut de Génétique et Microbiologie, Bâtiment 400, F-91405 Orsay Cedex, France
| | - Josette Gagnat
- CNRS UMR8621, Université Paris-Sud, Institut de Génétique et Microbiologie, Bâtiment 400, F-91405 Orsay Cedex, France
| | | | - Claude Gerbaud
- CNRS UMR8621, Université Paris-Sud, Institut de Génétique et Microbiologie, Bâtiment 400, F-91405 Orsay Cedex, France
| | - Jean-Luc Pernodet
- CNRS UMR8621, Université Paris-Sud, Institut de Génétique et Microbiologie, Bâtiment 400, F-91405 Orsay Cedex, France
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Min Y, Lv H, Zheng Y. Fusion PCR-targeted tylCV gene deletion of Streptomyces fradiae for producing desmycosin, the direct precursor of tilmicosin. Process Biochem 2007. [DOI: 10.1016/j.procbio.2006.12.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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14
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Lamichhane J, Liou K, Lee HC, Kim CG, Sohng JK. Functional characterization of ketoreductase (rubN6) and aminotransferase (rubN4) genes in the gene cluster of Streptomyces achromogenes var. rubradiris. Biotechnol Lett 2006; 28:545-53. [PMID: 16614891 DOI: 10.1007/s10529-006-0013-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Accepted: 01/16/2006] [Indexed: 10/24/2022]
Abstract
ORF's for rubN6 and rubN4 have been annotated as thymidine diphosphate glucose 4-ketoreductase and thymidine diphosphate glucose 3-aminotransferase by sequence analysis of the rubradirin biosynthetic gene cluster cloned from Streptomyces achromogenes var. rubradiris NRRL 3061. Both ORFs were heterologously expressed in Escherichia coli as His-tagged fusion proteins. The functionalities of TDP-glucose 4-ketoreductase and TDP-glucose 3-aminotransferase were verified by in vitro enzyme assay, and a biosynthetic pathway for TDP-D: -rubranitrose is proposed.
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Affiliation(s)
- Janardan Lamichhane
- Department of Pharmaceutical Engineering, Institute of Biomolecule Reconstruction, IBR, SunMoon University, Tangjeonmyun, 336-708, Asan-si, Chung-nam, Republic of Korea
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Dürr C, Schnell HJ, Luzhetskyy A, Murillo R, Weber M, Welzel K, Vente A, Bechthold A. Biosynthesis of the Terpene Phenalinolactone in Streptomyces sp. Tü6071: Analysis of the Gene Cluster and Generation of Derivatives. ACTA ACUST UNITED AC 2006; 13:365-77. [PMID: 16632249 DOI: 10.1016/j.chembiol.2006.01.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2005] [Revised: 01/12/2006] [Accepted: 01/27/2006] [Indexed: 11/16/2022]
Abstract
Phenalinolactones are terpene glycosides with antibacterial activity. A striking structural feature is a highly oxidized gamma-butyrolactone of elusive biosynthetic origin. To investigate the genetic basis of the phenalinolactones biosynthesis, we cloned and sequenced the corresponding gene cluster from the producer strain Streptomyces sp. Tü6071. Spanning a 42 kbp region, 35 candidate genes could be assigned to putatively encode biosynthetic, regulatory, and resistance-conferring functions. Targeted gene inactivations were carried out to specifically manipulate the phenalinolactones pathway. The inactivation of a sugar methyltransferase gene and a cytochrome P450 monoxygenase gene led to the production of modified phenalinolactone derivatives. The inactivation of a Fe(II)/alpha-ketoglutarate-dependent dioxygenase gene disrupted the biosynthetic pathway within gamma-butyrolactone formation. The structure elucidation of the accumulating intermediate indicated that pyruvate is the biosynthetic precursor of the gamma butyrolactone moiety.
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Affiliation(s)
- Clemens Dürr
- Albert-Ludwigs-Universität, Institut für Pharmazeutische Wissenschaften, Stefan-Meier-Strasse 19, 79104 Freiburg, Germany
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Hill AM. The biosynthesis, molecular genetics and enzymology of the polyketide-derived metabolites. Nat Prod Rep 2005; 23:256-320. [PMID: 16572230 DOI: 10.1039/b301028g] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This review covers the biosynthesis of aliphatic and aromatic polyketides as well as mixed polyketide/NRPS metabolites, and discusses the molecular genetics and enzymology of the proteins responsible for their formation.
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Elling L, Rupprath C, Günther N, Römer U, Verseck S, Weingarten P, Dräger G, Kirschning A, Piepersberg W. An enzyme module system for the synthesis of dTDP-activated deoxysugars from dTMP and sucrose. Chembiochem 2005; 6:1423-30. [PMID: 15977277 DOI: 10.1002/cbic.200500037] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A flexible enzyme module system is presented that allows preparative access to important dTDP-activated deoxyhexoses from dTMP and sucrose. The strategic combination of the recombinant enzymes dTMP-kinase and sucrose synthase (SuSy), and the enzymes RmlB (4,6-dehydratase), RmlC (3,5-epimerase) and RmlD (4-ketoreductase) from the biosynthetic pathway of dTDP-beta-L-rhamnose was optimized. The SuSy module (dTMP-kinase, SuSy, +/-RmlB) yielded the precursor dTDP-alpha-D-glucose (2) or the biosynthetic intermediate dTDP-6-deoxy-4-keto-alpha-D-glucose (3) on a 0.2-0.6 g scale with overall yields of 62 % and 72 %, respectively. A two-step strategy in which the SuSy module was followed by the deoxysugar module (RmlC and RmlD) resulted in the synthesis of dTDP-beta-L-rhamnose (4; 24.1 micromol, overall yield: 35.9 %). Substitution of RmlC by DnmU from the dTDP-beta-L-daunosamine pathway of Streptomyces peucetius in this module demonstrated that DnmU acts in vitro as a 3,5-epimerase with 3 as substrate to yield 4 (32.2 mumol, overall yield: 44.7 %). Chemical reduction of 3 with NaBH4 gave a mixture of the C-4 epimers dTDP-alpha-D-quinovose (6) and dTDP-alpha-D-fucose (7) in a ratio of 2:1. In summary, the modular character of the presented enzyme system provides valuable compounds for the biochemical characterization of deoxysugar pathways playing a major role in microbial producers of antibiotic and antitumour agents.
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Affiliation(s)
- Lothar Elling
- Department of Biotechnology/Biomaterial Sciences and Helmholtz Institute for Biomedical Engineering, RWTH Aachen, Worringerweg 1, 52056 Aachen, Germany.
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Affiliation(s)
- Leonard Katz
- Kosan Biosciences, Incorporated, 3832 Bay Center Place, Hayward, California 94545, USA.
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Abstract
Control of tylosin production in Streptomyces fradiae features interplay between a repressor, TylQ, and an activator, TylS, during regulation of tylR. The latter encodes a pathway-specific activator that controls most of the tylosin-biosynthetic (tyl) genes that are subject to regulation. This was established by targeted gene disruption applied separately to tylR and tylS together with transcript analysis involving reverse transcription polymerase chain reaction (RT-PCR). TylR controls multiple genes that encode the synthesis or addition of all three tylosin sugars, plus polyketide ring oxidation, and at least one of the polyketide synthase (PKS) megagenes, tylGI. (Expression of a few tyl genes, plus the resistance determinants tlrB and tlrD, together with some ancillary or unassigned genes, is not apparently regulated during fermentation, consistent with constitutive expression.) In contrast, the only gene known for sure to be directly controlled by TylS is tylR, and there are very few additional candidates. These include the mycinose-biosynthetic gene, tylJ, and two previously unassigned genes, ORF12* (tylU) plus ORF11* (tylV). TylS also controls the PKS genes [tylGIII-tylGIV-tylGV] although not in obligatory fashion. These genes can be transcribed (i.e. tylosin can be produced) in a tylS-KO strain by forcing overexpression of tylR using a foreign promoter. We therefore suspect that TylS might control the PKS genes indirectly, although this remains to be established unequivocally. Conceivably, the direct effects of TylS are exerted exclusively on other regulators. Tylosin production levels were elevated when tylS or (especially) tylR was overexpressed in S. fradiae wild-type and yield increments of industrial significance were generated by similar manipulation of an enhanced production strain.
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Reeves CD, Ward SL, Revill WP, Suzuki H, Marcus M, Petrakovsky OV, Marquez S, Fu H, Dong SD, Katz L. Production of hybrid 16-membered macrolides by expressing combinations of polyketide synthase genes in engineered Streptomyces fradiae hosts. ACTA ACUST UNITED AC 2005; 11:1465-72. [PMID: 15489173 DOI: 10.1016/j.chembiol.2004.08.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2004] [Revised: 08/06/2004] [Accepted: 08/10/2004] [Indexed: 11/28/2022]
Abstract
Combinations of the five polyketide synthase (PKS) genes for biosynthesis of tylosin in Streptomyces fradiae (tylG), spiramycin in Streptomyces ambofaciens (srmG), or chalcomycin in Streptomyces bikiniensis (chmG) were expressed in engineered hosts derived from a tylosin-producing strain of S. fradiae. Surprisingly efficient synthesis of compounds predicted from the expressed hybrid PKS was obtained. The post-PKS tailoring enzymes of tylosin biosynthesis acted efficiently on the hybrid intermediates with the exception of TylH-catalyzed hydroxylation of the methyl group at C14, which was efficient if C4 bore a methyl group, but inefficient if a methoxyl was present. Moreover, for some compounds, oxidation of the C6 ethyl side chain to an unprecedented carboxylic acid was observed. By also expressing chmH, a homolog of tylH from the chalcomycin gene cluster, efficient hydroxylation of the 14-methyl group was restored.
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Lombó F, Gibson M, Greenwell L, Braña AF, Rohr J, Salas JA, Méndez C. Engineering Biosynthetic Pathways for Deoxysugars: Branched-Chain Sugar Pathways and Derivatives from the Antitumor Tetracenomycin. ACTA ACUST UNITED AC 2004; 11:1709-18. [PMID: 15610855 DOI: 10.1016/j.chembiol.2004.10.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Revised: 10/04/2004] [Accepted: 10/07/2004] [Indexed: 10/26/2022]
Abstract
Sugar biosynthesis cassette genes have been used to construct plasmids directing the biosynthesis of branched-chain deoxysugars: pFL942 (NDP-L-mycarose), pFL947 (NDP-4-deacetyl-L-chromose B), and pFL946/pFL954 (NDP-2,3,4-tridemethyl-L-nogalose). Expression of pFL942 and pFL947 in S. lividans 16F4, which harbors genes for elloramycinone biosynthesis and the flexible ElmGT glycosyltransferase of the elloramycin biosynthetic pathway, led to the formation of two compounds: 8-alpha-L-mycarosyl-elloramycinone and 8-demethyl-8-(4-deacetyl)-alpha-L-chromosyl-tetracenomycin C, respectively. Expression of pFL946 or pFL954 failed to produce detectable amounts of a novel glycosylated tetracenomycin derivative. Formation of these two compounds represents examples of the sugar cosubstrate flexibility of the ElmGT glycosyltransferase. The use of these cassette plasmids also provided insights into the substrate flexibility of deoxysugar biosynthesis enzymes as the C-methyltransferases EryBIII and MtmC, the epimerases OleL and EryBVII, and the 4-ketoreductases EryBIV and OleU.
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Affiliation(s)
- Felipe Lombó
- Departamento de Biología Funcional and Instituto Universitario de Oncología, del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, 33006 Oviedo, Spain
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Bruheim P, Borgos SEF, Tsan P, Sletta H, Ellingsen TE, Lancelin JM, Zotchev SB. Chemical diversity of polyene macrolides produced by Streptomyces noursei ATCC 11455 and recombinant strain ERD44 with genetically altered polyketide synthase NysC. Antimicrob Agents Chemother 2004; 48:4120-9. [PMID: 15504830 PMCID: PMC525400 DOI: 10.1128/aac.48.11.4120-4129.2004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2004] [Revised: 03/29/2004] [Accepted: 07/11/2004] [Indexed: 11/20/2022] Open
Abstract
The gram-positive bacterium Streptomyces noursei ATCC 11455 produces a complex mixture of polyene macrolides generally termed nystatins. Although the structures for nystatins A(1) and A(3) have been reported, the identities of other components of the nystatin complex remain obscure. Analyses of the culture extract from the S. noursei wild type revealed the presence of several nystatin-related compounds for which chemical structures could be suggested on the basis of their molecular weights, their UV spectra, and knowledge of the nystatin biosynthetic pathway. Nuclear magnetic resonance (NMR) studies with one of these polyene macrolides identified it as a nystatin analogue containing a mycarose moiety at C-35. A similar investigation was performed with the culture extract of the ERD44 mutant, which has a genetically altered polyketide synthase (PKS) NysC and which was previously shown to produce a heptaene nystatin analogue. The latter compound, tentatively named S44HP, and its derivative, which contains two deoxysugar moieties, were purified; and their structures were confirmed by NMR analysis. Nystatin analogues with an expanded macrolactone ring were also observed in the extract of the ERD44 mutant, suggesting that the altered PKS can "stutter" during the polyketide chain assembly. These data provide new insights into the biosynthesis of polyene macrolide antibiotics and the functionalities of PKSs and post-PKS modification enzymes.
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Affiliation(s)
- Per Bruheim
- Department of Biotechnology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
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23
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Ogasawara Y, Katayama K, Minami A, Otsuka M, Eguchi T, Kakinuma K. Cloning, sequencing, and functional analysis of the biosynthetic gene cluster of macrolactam antibiotic vicenistatin in Streptomyces halstedii. ACTA ACUST UNITED AC 2004; 11:79-86. [PMID: 15112997 DOI: 10.1016/j.chembiol.2003.12.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2003] [Revised: 10/13/2003] [Accepted: 10/30/2003] [Indexed: 11/25/2022]
Abstract
Vicenistatin, an antitumor antibiotic isolated from Streptomyces halstedii, is a unique 20-membered macrocyclic lactam with a novel aminosugar vicenisamine. The vicenistatin biosynthetic gene cluster (vin) spanning approximately 64 kbp was cloned and sequenced. The cluster contains putative genes for the aglycon biosynthesis including four modular polyketide synthases (PKSs), glutamate mutase, acyl CoA-ligase, and AMP-ligase. Also found in the cluster are genes of NDP-hexose 4,6-dehydratase and aminotransferase for vicenisamine biosynthesis. For the functional confirmation of the cluster, a putative glycosyltransferase gene product, VinC, was heterologously expressed, and the vicenisamine transfer reaction to the aglycon was chemically proved. A unique feature of the vicenistatin PKS is that the loading module contains only an acyl carrier protein domain, in contrast to other known PKS-loading modules containing certain activation domains. Activation of the starter acyl group by separate polypeptides is postulated as well.
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Affiliation(s)
- Yasushi Ogasawara
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1, O-okayama, Meguro-ku, Tokyo 152-8551, Japan
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Haydock SF, Mironenko T, Ghoorahoo HI, Leadlay PF. The putative elaiophylin biosynthetic gene cluster in Streptomyces sp. DSM4137 is adjacent to genes encoding adenosylcobalamin-dependent methylmalonyl CoA mutase and to genes for synthesis of cobalamin. J Biotechnol 2004; 113:55-68. [PMID: 15380647 DOI: 10.1016/j.jbiotec.2004.03.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2003] [Revised: 01/09/2004] [Accepted: 03/04/2004] [Indexed: 12/30/2022]
Abstract
A type I PKS gene probe obtained from RAPB of the rapamycin producer Streptomyces hygroscopicus, strongly hybridised to 92 out of 1120 cosmids from a genomic library of the elaiophylin-producing strain Streptomyces sp. DSM4137. Partial cosmid sequencing suggested the presence of 10 separate sequences encoding type I PKS genes. One entire DNA sequence was obtained and found exactly to match the gene organisation expected for the biosynthesis of the unusual macrodiolide polyketide elaiophylin. The putative elaiophylin gene cluster contains five large open-reading frames encoding typical modular polyketide synthases, which together catalyse the synthesis of the octaketide monomer of elaiophylin. Other genes were identified that would be required for provision of the ethylmalonate extender unit, for the synthesis and attachment of 2-deoxy-L-fucose and in regulation, or in export of the product. Immediately adjacent to the putative elaiophylin biosynthetic gene cluster is a 30-kbp region containing the gene for adenosylcobalamin-dependent methylmalonyl CoA mutase and also genes involved in the biosynthesis of the cobalamin cofactor. Analysis of the latter gene set confirms the view that cbiD of the anaerobic pathway and cobF in the aerobic pathway catalyse the same methylation of precorrin-5. The proximity of these genes to the putative elaiophylin gene cluster can best be rationalised if in this organism succinyl-CoA is a significant source of the methylmalonate units for complex polyketide biosynthesis.
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Affiliation(s)
- Stephen F Haydock
- Department of Biochemistry, University of Cambridge, Tennis Court Road, CB2 1TN, UK.
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Rodriguez E, Ward S, Fu H, Revill WP, McDaniel R, Katz L. Engineered biosynthesis of 16-membered macrolides that require methoxymalonyl-ACP precursors in Streptomyces fradiae. Appl Microbiol Biotechnol 2004; 66:85-91. [PMID: 15179529 DOI: 10.1007/s00253-004-1658-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2004] [Revised: 04/26/2004] [Accepted: 05/07/2004] [Indexed: 11/30/2022]
Abstract
Development of host microorganisms for heterologous expression of polyketide synthases (PKS) that possess the intrinsic capacity to overproduce polyketides with a broad spectrum of precursors supports the current demand for new tools to create novel chemical structures by combinatorial engineering of modular and other classes of PKS. Streptomyces fradiae is an ideal host for development of generic polyketide-overproducing strains because it contains three of the most common precursors--malonyl-CoA, methylmalonyl-CoA and ethylmalonyl-CoA--used by modular PKS, and is a host that is amenable to genetic manipulation. We have expanded the utility of an overproducing S. fradiae strain for engineered biosynthesis of polyketides by engineering a biosynthetic pathway for methoxymalonyl-ACP, a fourth precursor used by many 16-membered macrolide PKS. This was achieved by introducing a set of five genes, fkbG-K from Streptomyces hygroscopicus, putatively encoding the methoxymalonyl-ACP biosynthetic pathway, into the S. fradiae chromosome. Heterologous expression of the midecamycin PKS genes in this strain resulted in 1 g/l production of a midecamycin analog. These results confirm the ability to engineer unusual precursor pathways to support high levels of polyketide production, and validate the use of S. fradiae for overproduction of 16-membered macrolides derived from heterologous PKS that require a broad range of precursors.
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Walsh C, Freel Meyers CL, Losey HC. Antibiotic glycosyltransferases: antibiotic maturation and prospects for reprogramming. J Med Chem 2003; 46:3425-36. [PMID: 12877577 DOI: 10.1021/jm030257i] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christopher Walsh
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
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Thompson HA, Hoover TA, Vodkin MH, Shaw EI. Do chromosomal deletions in the lipopolysaccharide biosynthetic regions explain all cases of phase variation in Coxiella burnetii strains? An update. Ann N Y Acad Sci 2003; 990:664-70. [PMID: 12860704 DOI: 10.1111/j.1749-6632.2003.tb07441.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- H A Thompson
- Viral and Rickettsial Zoonoses Branch, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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Remsing LL, González AM, Nur-e-Alam M, Fernández-Lozano MJ, Braña AF, Rix U, Oliveira MA, Méndez C, Salas JA, Rohr J. Mithramycin SK, a novel antitumor drug with improved therapeutic index, mithramycin SA, and demycarosyl-mithramycin SK: three new products generated in the mithramycin producer Streptomyces argillaceus through combinatorial biosynthesis. J Am Chem Soc 2003; 125:5745-53. [PMID: 12733914 PMCID: PMC4480629 DOI: 10.1021/ja034162h] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To gain initial structure-activity relationships regarding the highly functionalized pentyl side chain attached at C-3 of mithramycin (MTM), we focused on a post-polyketide synthase (post-PKS) tailoring step of the MTM biosynthesis by Streptomyces argillaceus ATCC 12956, which was proposed to be catalyzed by ketoreductase (KR) MtmW. In this last step of the MTM biosynthesis, a keto group of the pentyl side chain is reduced to a secondary alcohol, and we anticipated the generation of an MTM derivative with an additional keto group in the 3-side chain. Insertional inactivation of mtmW, a gene located ca. 8 kb downstream of the mithramycin-PKS genes, yielded an S. argillaceus mutant, which accumulated three new mithramycin analogues, namely mithramycin SA, demycarosyl-mithramycin SK, and mithramycin SK (MTM-SK). The structures of these three compounds confirmed indirectly the proposed role of MtmW in MTM biosynthesis. However, the new mithramycin derivatives bear unexpectedly shorter 3-side chains (ethyl or butyl) than MTM, presumably caused by nonenzymatic rearrangement or cleavage reactions of the initially formed pentyl side chain with a reactive beta-dicarbonyl functional group. The major product, MTM-SK, was tested in vitro against a variety of human cancer cell lines, as well as in an in vitro toxicity assay, and showed an improved therapeutic index, in comparison to the parent drug, MTM.
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Hoover TA, Culp DW, Vodkin MH, Williams JC, Thompson HA. Chromosomal DNA deletions explain phenotypic characteristics of two antigenic variants, phase II and RSA 514 (crazy), of the Coxiella burnetii nine mile strain. Infect Immun 2002; 70:6726-33. [PMID: 12438347 PMCID: PMC132984 DOI: 10.1128/iai.70.12.6726-2733.2002] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
After repeated passages through embyronated eggs, the Nine Mile strain of Coxiella burnetii exhibits antigenic variation, a loss of virulence characteristics, and transition to a truncated lipopolysaccharide (LPS) structure. In two independently derived strains, Nine Mile phase II and RSA 514, these phenotypic changes were accompanied by a large chromosomal deletion (M. H. Vodkin and J. C. Williams, J. Gen. Microbiol. 132:2587-2594, 1986). In the work reported here, additional screening of a cosmid bank prepared from the wild-type strain was used to map the deletion termini of both mutant strains and to accumulate all the segments of DNA that comprise the two deletions. The corresponding DNAs were then sequenced and annotated. The Nine Mile phase II deletion was completely nested within the deletion of the RSA 514 strain. Basic alignment and homology studies indicated that a large group of LPS biosynthetic genes, arranged in an apparent O-antigen cluster, was deleted in both variants. Database homologies identified, in particular, mannose pathway genes and genes encoding sugar methylases and nucleotide sugar epimerase-dehydratase proteins. Candidate genes for addition of sugar units to the core oligosaccharide for synthesis of the rare sugar 6-deoxy-3-C-methylgulose (virenose) were identified in the deleted region. Repeats, redundancies, paralogous genes, and two regions with reduced G+C contents were found within the deletions.
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Affiliation(s)
- T A Hoover
- Bacteriology Division, USAMRIID, Ft. Detrick, Frederick, Maryland 21701, USA
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Abstract
The aldo-keto reductases (AKR) are a superfamily of enzymes with diverse functions in the reduction of aldehydes and ketones. AKR enzymes are found in a wide range of microorganisms, and many open reading frames encoding related putative enzymes have been identified through genome sequencing projects. Established microbial members of the superfamily include the xylose reductases, 2,5-diketo-D-gluconic acid reductases and beta-keto ester reductases. The AKR enzymes share a common (alpha/beta)(8) structure, and conserved catalytic mechanism, although there is considerable variation in the substrate-binding pocket. The physiological function of many of these enzymes is unknown, but a variety of methods including gene disruptions, heterologous expression systems and expression profiling are being employed to deduce the roles of these enzymes in cell metabolism. Several microbial AKR are already being exploited in biotransformation reactions and there is potential for other novel members of this important superfamily to be identified, studied and utilized in this way.
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Affiliation(s)
- Elizabeth M Ellis
- Departments of Bioscience and Pharmaceutical Sciences, University of Strathclyde, 204 George Street, G1 1XW, Glasgow, UK.
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Li SM, Westrich L, Schmidt J, Kuhnt C, Heide L. Methyltransferase genes in Streptomyces rishiriensis: new coumermycin derivatives from gene-inactivation experiments. MICROBIOLOGY (READING, ENGLAND) 2002; 148:3317-3326. [PMID: 12368465 DOI: 10.1099/00221287-148-10-3317] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The coumarin antibiotic coumermycin A(1) contains at least eight methyl groups, presumably derived from S-adenosylmethionine. Two putative methyltransferase genes, couO and couP, of the coumermycin A(1) biosynthetic gene cluster were inactivated by in-frame deletion. In the resulting mutants, coumermycin A(1) production was abolished. New coumermycin derivatives were accumulated instead, and were identified by HPLC-MS using selected reaction monitoring via electrospray ionization. couO mutants accumulated a coumermycin derivative lacking the methyl groups at C-8 of the characteristic aminocoumarin rings, whereas in the couP mutant a coumermycin derivative lacking the methyl groups at the 4-hydroxyl groups of the two deoxysugar moieties was identified. These results provided evidence that couO encodes a C-methyltransferase responsible for the transfer of a methyl group to C-8 of the aminocoumarin ring, and couP an O-methyltransferase for methylation of 4-OH of the sugar in the biosynthesis of coumermycin A(1), respectively. C-methylation of the aminocoumarin ring is considered as an early step of coumermycin biosynthesis. Nevertheless, the intermediates with the non-methylated aminocoumarin ring were accepted by the enzymes catalysing the subsequent steps of the pathway. The new, demethylated secondary metabolites were produced in an amount at least as high as that of coumermycin A(1) in the wild-type.
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Affiliation(s)
- Shu-Ming Li
- Eberhard-Karls-Universität Tübingen, Pharmazeutische Biologie, Auf der Morgenstelle 8,D-72076 Tübingen, Germany1
| | - Lucia Westrich
- Eberhard-Karls-Universität Tübingen, Pharmazeutische Biologie, Auf der Morgenstelle 8,D-72076 Tübingen, Germany1
| | - Jürgen Schmidt
- Institut für Pflanzenbiochemie, Weinberg 3, 06120 Halle (Saale), Germany2
| | - Christine Kuhnt
- Institut für Pflanzenbiochemie, Weinberg 3, 06120 Halle (Saale), Germany2
| | - Lutz Heide
- Eberhard-Karls-Universität Tübingen, Pharmazeutische Biologie, Auf der Morgenstelle 8,D-72076 Tübingen, Germany1
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Remsing LL, Garcia-Bernardo J, Gonzalez A, Künzel E, Rix U, Braña AF, Bearden DW, Méndez C, Salas JA, Rohr J. Ketopremithramycins and ketomithramycins, four new aureolic acid-type compounds obtained upon inactivation of two genes involved in the biosynthesis of the deoxysugar moieties of the antitumor drug mithramycin by Streptomyces argillaceus, reveal novel insights into post-PKS tailoring steps of the mithramycin biosynthetic pathway. J Am Chem Soc 2002; 124:1606-14. [PMID: 11853433 PMCID: PMC4480631 DOI: 10.1021/ja0105156] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mithramycin is an aureolic acid-type antimicrobial and antitumor agent produced by Streptomyces argillaceus. Modifying post-polyketide synthase (PKS) tailoring enzymes involved in the production of mithramycin is an effective way of gaining further information regarding the late steps of its biosynthetic pathway. In addition, new "unnatural" natural products of the aureolic acid-type class are likely to be produced. The role of two such post-PKS tailoring enzymes, encoded by mtmC and mtmTIII, was investigated, and four novel aureolic acid class drugs, two premithramycin-type molecules and two mithramycin derivatives, were isolated from mutant strains constructed by insertional gene inactivation of either of these two genes. From data bank comparisons, the corresponding proteins MtmC and MtmTIII were believed to act as a C-methyltransferase involved in the production of the D-mycarose (sugar E) of mithramycin and as a ketoreductase seemingly involved in the biosynthesis of the mithramycin aglycon, respectively. However, gene inactivation and analysis of the accumulated products revealed that both genes encode enzymes participating in the biosynthesis of the D-mycarose building block. Furthermore, the inactivation of MtmC seems to affect the ketoreductase responsible for 4-ketoreduction of sugar C, a D-olivose. Instead of obtaining premithramycin and mithramycin derivatives with a modified E-sugar upon inactivation of mtmC, compounds were obtained that completely lack the E-sugar moiety and that possess an unexpected 4-ketosugar moiety instead of the D-olivose at the beginning of the lower deoxysaccharide chain. The inactivation of mtmTIII led to the accumulation of 4E-ketomithramycin, showing that this ketoreductase is responsible for the 4-ketoreduction of the D-mycarose moiety. The new compounds of the mutant strains, 4A-ketopremithramycin A2, 4A-keto-9-demethylpremithramycin A2, 4C-keto-demycarosylmithramycin, and 4E-ketomithramycin, indicate surprising substrate flexibility of post-PKS enzymes of the mithramycin biosynthetic pathway. Although the glycosyltransferase responsible for the attachment of D-mycarose cannot transfer the unmethylated sugar to the existing lower disaccharide chain, it can transfer the 4-ketoform of sugar E. In addition, the glycosyltransferase MtmGIV, which is responsible for the linkage of sugar C, is also able to transfer an activated 4-ketosugar. The oxygenase MtmOIV, normally responsible for the oxidative cleavage of the tetracyclic premithramycin B into the tricyclic immediate precursor of mithramycin, can act on a substrate analogue with a modified or even incomplete trisaccharide chain. The same is true for glycosyltransferases MtmGI and MtmGII, both of which partake in the formation and attachment of the A-B disaccharide in mithramycin.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Jose A. Salas
- To whom correspondence should be addressed. Tel: (843) 876 5091. Fax: (843) 792 0759. J.R., ; J.A.S.,
| | - Jürgen Rohr
- To whom correspondence should be addressed. Tel: (843) 876 5091. Fax: (843) 792 0759. J.R., ; J.A.S.,
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Weitnauer G, Gaisser S, Kellenberger L, Leadlay PF, Bechthold A. Analysis of a C-methyltransferase gene (aviG1) involved in avilamycin biosynthesis in Streptomyces viridochromogenes Tü57 and complementation of a Saccharopolyspora erythraea eryBIII mutant by aviG1. MICROBIOLOGY (READING, ENGLAND) 2002; 148:373-379. [PMID: 11832501 DOI: 10.1099/00221287-148-2-373] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Streptomyces viridochromogenes Tü57 is the principal producer of avilamycin A. aviG1, a putative methyltransferase gene, was detected in the avilamycin biosynthetic gene cluster. To determine the function of aviG1, a targeted gene inactivation experiment was performed. The resulting chromosomal mutant, carrying an in-frame deletion in aviG1, was deficient in avilamycin production. aviG1 was used to complement an eryBIII mutant of the erythromycin A producer Saccharopolyspora erythraea [Gaisser, S., Bohm, G. A., Doumith, M., Raynal, M. C., Dhillon, N., Cortes, J. & Leadlay, P. F. (1998). Mol Gen Genet 258, 78-88]. The presence of erythromycin A in the culture supernatant of the complemented mutant indicated that L-mycarose biosynthesis could be restored and that AviG1 could take over the function of the C-methyltransferase EryBIII.
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Affiliation(s)
- G Weitnauer
- Albert-Ludwigs-Universität Freiburg, Institut für Pharmazeutische Biologie, Stefan-Meier Str. 19, 79104 Freiburg, Germany1
| | - S Gaisser
- Cambridge Centre for Molecular Recognition and Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK2
| | - L Kellenberger
- Cambridge Centre for Molecular Recognition and Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK2
| | - P F Leadlay
- Cambridge Centre for Molecular Recognition and Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK2
| | - A Bechthold
- Albert-Ludwigs-Universität Freiburg, Institut für Pharmazeutische Biologie, Stefan-Meier Str. 19, 79104 Freiburg, Germany1
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Stratigopoulos G, Cundliffe E. Expression analysis of the tylosin-biosynthetic gene cluster: pivotal regulatory role of the tylQ product. CHEMISTRY & BIOLOGY 2002; 9:71-8. [PMID: 11841940 DOI: 10.1016/s1074-5521(01)00095-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Expression analysis by RT-PCR, applied to the entire tyl cluster, revealed that the pattern of transcription is more complex than expected. For example, the five tylG polyketide synthase genes are not necessarily cotranscribed or even coregulated. Among the regulatory genes, tylQ has emerged as a key factor. Although several genes (including the positive regulator, tylS) were possibly expressed constitutively, only tylQ was silent during secondary metabolism. Analysis of engineered strains, in which tylQ was disrupted or overexpressed, showed that the TylQ protein is a transcriptional repressor that blocks tylosin biosynthesis by controlling expression of the activator, tylR. Before tylosin production can be triggered, tylQ must be switched off, or at least downregulated.
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Affiliation(s)
- George Stratigopoulos
- Department of Biochemistry, University of Leicester, LE1 7RH, Leicester, United Kingdom
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Abstract
Many bioactive natural products are glycosylated compounds in which the sugars are important or essential for biological activity. The isolation of several sugar biosynthesis gene clusters and glycosyltransferases from different antibiotic-producing organisms, and the increasing knowledge about these biosynthetic pathways opens up the possibility of generating novel bioactive compounds through combinatorial biosynthesis in the near future. Recent advances in this area indicate that antibiotic glycosyltransferases show some substrate flexibility that might allow us to alter the types of sugar transferred to the different aglycons or, less frequently, to change the position of its attachment.
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Affiliation(s)
- C Méndez
- Dept Biologia Funcional e Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Universidad de Oviedo, 33006 Oviedo, Spain
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Weitnauer G, Mühlenweg A, Trefzer A, Hoffmeister D, Süssmuth RD, Jung G, Welzel K, Vente A, Girreser U, Bechthold A. Biosynthesis of the orthosomycin antibiotic avilamycin A: deductions from the molecular analysis of the avi biosynthetic gene cluster of Streptomyces viridochromogenes Tü57 and production of new antibiotics. CHEMISTRY & BIOLOGY 2001; 8:569-81. [PMID: 11410376 DOI: 10.1016/s1074-5521(01)00040-0] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Streptomyces viridochromogenes Tü57 is the producer of avilamycin A. The antibiotic consists of a heptasaccharide side chain and a polyketide-derived dichloroisoeverninic acid as aglycone. Molecular cloning and characterization of the genes governing the avilamycin A biosynthesis is of major interest as this information might set the direction for the development of new antimicrobial agents. RESULTS A 60-kb section of the S. viridochromogenes Tü57 chromosome containing genes involved in avilamycin biosynthesis was sequenced. Analysis of the DNA sequence revealed 54 open reading frames. Based on the putative function of the gene products a model for avilamycin biosynthesis is proposed. Inactivation of aviG4 and aviH, encoding a methyltransferase and a halogenase, respectively, prevented the mutant strains from producing the complete dichloroisoeverninic acid moiety resulting in the accumulation of new antibiotics named gavibamycins. CONCLUSIONS The avilamycin A biosynthetic gene cluster represents an interesting system to study the formation and attachment of unusual deoxysugars. Several enzymes putatively responsible for specific steps of this pathway could be assigned. Two genes encoding enzymes involved in post-PKS tailoring reactions were deleted allowing the production of new analogues of avilamycin A.
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Affiliation(s)
- G Weitnauer
- Albert-Ludwigs-Universität Freiburg, Institut für Pharmazeutische Biologie, Germany
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Butler AR, Flint SA, Cundliffe E. Feedback control of polyketide metabolism during tylosin production. MICROBIOLOGY (READING, ENGLAND) 2001; 147:795-801. [PMID: 11283275 DOI: 10.1099/00221287-147-4-795] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Tylosin is produced by Streptomyces fradiae via a combination of polyketide metabolism and synthesis of three deoxyhexose sugars, of which mycaminose is the first to be added to the polyketide aglycone, tylactone (protylonolide). Previously, disruption of the gene (tylMII) encoding attachment of mycaminose to the aglycone unexpectedly abolished accumulation of the latter, raising the possibility of a link between polyketide metabolism and deoxyhexose biosynthesis in S. fradiae. However, at that time, it was not possible to eliminate an alternative explanation, namely, that downstream effects on the expression of other genes, not involved in mycaminose metabolism, might have contributed to this phenomenon. Here, it is shown that disruption of any of the four genes (tylMI--III and tylB) specifically involved in mycaminose biosynthesis elicits a similar response, confirming that production of mycaminosyl-tylactone directly influences polyketide metabolism in S. fradiae. Under similar conditions, when mycaminose biosynthesis was specifically blocked by gene disruption, accumulation of tylactone could be restored by exogenous addition of glycosylated tylosin precursors. Moreover, certain other macrolides, not of the tylosin pathway, were also found to elicit qualitatively similar effects. Comparison of the structures of stimulatory macrolides will facilitate studies of the stimulatory mechanism.
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Affiliation(s)
- Andrew R Butler
- Department of Biochemistry, University of Leicester, Leicester LE1 7RH, UK1
| | - Simon A Flint
- Department of Biochemistry, University of Leicester, Leicester LE1 7RH, UK1
| | - Eric Cundliffe
- Department of Biochemistry, University of Leicester, Leicester LE1 7RH, UK1
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