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Vogel U, Beerens K, Desmet T. Nucleotide sugar dehydratases: Structure, mechanism, substrate specificity, and application potential. J Biol Chem 2022; 298:101809. [PMID: 35271853 PMCID: PMC8987622 DOI: 10.1016/j.jbc.2022.101809] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/24/2022] [Accepted: 02/28/2022] [Indexed: 11/14/2022] Open
Abstract
Nucleotide sugar (NS) dehydratases play a central role in the biosynthesis of deoxy and amino sugars, which are involved in a variety of biological functions in all domains of life. Bacteria are true masters of deoxy sugar biosynthesis as they can produce a wide range of highly specialized monosaccharides. Indeed, deoxy and amino sugars play important roles in the virulence of gram-positive and gram-negative pathogenic species and are additionally involved in the biosynthesis of diverse macrolide antibiotics. The biosynthesis of deoxy sugars relies on the activity of NS dehydratases, which can be subdivided into three groups based on their structure and reaction mechanism. The best-characterized NS dehydratases are the 4,6-dehydratases that, together with the 5,6-dehydratases, belong to the NS-short-chain dehydrogenase/reductase superfamily. The other two groups are the less abundant 2,3-dehydratases that belong to the Nudix hydrolase superfamily and 3-dehydratases, which are related to aspartame aminotransferases. 4,6-Dehydratases catalyze the first step in all deoxy sugar biosynthesis pathways, converting nucleoside diphosphate hexoses to nucleoside diphosphate-4-keto-6-deoxy hexoses, which in turn are further deoxygenated by the 2,3- and 3-dehydratases to form dideoxy and trideoxy sugars. In this review, we give an overview of the NS dehydratases focusing on the comparison of their structure and reaction mechanisms, thereby highlighting common features, and investigating differences between closely related members of the same superfamilies.
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Affiliation(s)
- Ulrike Vogel
- Centre for Synthetic Biology (CSB) - Unit for Biocatalysis and Enzyme Engineering, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - Koen Beerens
- Centre for Synthetic Biology (CSB) - Unit for Biocatalysis and Enzyme Engineering, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - Tom Desmet
- Centre for Synthetic Biology (CSB) - Unit for Biocatalysis and Enzyme Engineering, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium.
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Yeh YC, Kim HJ, Liu HW. Mechanistic Investigation of 1,2-Diol Dehydration of Paromamine Catalyzed by the Radical S-Adenosyl-l-methionine Enzyme AprD4. J Am Chem Soc 2021; 143:5038-5043. [PMID: 33784078 DOI: 10.1021/jacs.1c00076] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AprD4 is a radical S-adenosyl-l-methionine (SAM) enzyme catalyzing C3'-deoxygenation of paromamine to form 4'-oxo-lividamine. It is the only 1,2-diol dehydratase in the radical SAM enzyme superfamily that has been identified and characterized in vitro. The AprD4 catalyzed 1,2-diol dehydration is a key step in the biosynthesis of several C3'-deoxy-aminoglycosides. While the regiochemistry of the hydrogen atom abstraction catalyzed by AprD4 has been established, the mechanism of the subsequent chemical transformation remains not fully understood. To investigate the mechanism, several substrate analogues were synthesized and their fates upon incubation with AprD4 were analyzed. The results support a mechanism involving formation of a ketyl radical intermediate followed by direct elimination of the C3'-hydroxyl group rather than that of a gem-diol intermediate generated via 1,2-migration of the C3'-hydroxyl group to C4'. The stereochemistry of hydrogen atom incorporation after radical-mediated dehydration was also established.
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Affiliation(s)
- Yu-Cheng Yeh
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Hak Joong Kim
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Hung-Wen Liu
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.,Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, United States
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3
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Yu M, Luo J, Luo D, He Q, Yan Y, Ji X, Huang SX. Discovery and heterologous production of sarubicins and quinazolinone C-glycosides with protecting activity for cardiomyocytes. Org Chem Front 2021. [DOI: 10.1039/d1qo00470k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Glycosylated natural products and their derivatives are important pharmaceutical agents.
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Affiliation(s)
- Mingming Yu
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan key Laboratory of Natural Medicinal Chemistry
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650204
- China
| | - Jianying Luo
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan key Laboratory of Natural Medicinal Chemistry
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650204
- China
| | - Dan Luo
- College of Traditional Chinese Medicine
- Yunnan University of Traditional Chinese Medicine
- Kunming 650500
- China
| | - Qiang He
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan key Laboratory of Natural Medicinal Chemistry
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650204
- China
| | - Yijun Yan
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan key Laboratory of Natural Medicinal Chemistry
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650204
- China
| | - Xu Ji
- Key Laboratory of Medicinal Chemistry for Natural Resource of Ministry of Education
- Yunnan University
- Kunming 650091
- China
| | - Sheng-Xiong Huang
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan key Laboratory of Natural Medicinal Chemistry
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650204
- China
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Peltier-Pain P, Singh S, Thorson JS. Characterization of Early Enzymes Involved in TDP-Aminodideoxypentose Biosynthesis en Route to Indolocarbazole AT2433. Chembiochem 2015; 16:2141-6. [PMID: 26289554 PMCID: PMC4598305 DOI: 10.1002/cbic.201500365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Indexed: 01/29/2023]
Abstract
The characterization of TDP-α-D-glucose dehydrogenase (AtmS8), TDP-α-D-glucuronic acid decarboxylase (AtmS9), and TDP-4-keto-α-D-xylose 2,3-dehydratase (AtmS14), involved in Actinomadura melliaura AT2433 aminodideoxypentose biosynthesis, is reported. This study provides the first biochemical evidence that both deoxypentose and deoxyhexose biosynthetic pathways share common strategies for sugar 2,3-dehydration/reduction and implicates the sugar nucleotide base specificity of AtmS14 as a potential mechanism for sugar nucleotide commitment to secondary metabolism. In addition, a re-evaluation of the AtmS9 homologue involved in calicheamicin aminodeoxypentose biosynthesis (CalS9) reveals that CalS9 catalyzes UDP-4-keto-α-D-xylose as the predominant product, rather than UDP-α-D-xylose as previously reported. Cumulatively, this work provides additional fundamental insights regarding the biosynthesis of novel pentoses attached to complex bacterial secondary metabolites.
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Affiliation(s)
- Pauline Peltier-Pain
- Pharmaceutical Sciences Division, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI, 53705, USA
- Glycom A/S, Denmark
| | - Shanteri Singh
- Center for Pharmaceutical Research and Innovation, Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Jon S Thorson
- Center for Pharmaceutical Research and Innovation, Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA.
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Metsä-Ketelä M, Oja T, Taguchi T, Okamoto S, Ichinose K. Biosynthesis of pyranonaphthoquinone polyketides reveals diverse strategies for enzymatic carbon–carbon bond formation. Curr Opin Chem Biol 2013; 17:562-70. [DOI: 10.1016/j.cbpa.2013.06.032] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 05/30/2013] [Accepted: 06/25/2013] [Indexed: 11/26/2022]
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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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Streptomyces vietnamensis GIMV4.0001: a granaticin-producing strain that can be readily genetically manipulated. J Antibiot (Tokyo) 2011; 64:345-7. [DOI: 10.1038/ja.2011.3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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8
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Sasaki E, Ogasawara Y, Liu HW. A biosynthetic pathway for BE-7585A, a 2-thiosugar-containing angucycline-type natural product. J Am Chem Soc 2010; 132:7405-17. [PMID: 20443562 DOI: 10.1021/ja1014037] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sulfur is an essential element found ubiquitously in living systems. However, there exist only a few sulfur-containing sugars in nature and their biosyntheses have not been studied. BE-7585A produced by Amycolatopsis orientalis subsp. vinearia BA-07585 has a 2-thiosugar and is a member of the angucycline class of compounds. We report herein the results of our initial efforts to study the biosynthesis of BE-7585A. Spectroscopic analyses verified the structure of BE-7585A, which is closely related to rhodonocardin A. Feeding experiments using (13)C-labeled acetate were carried out to confirm that the angucycline core is indeed polyketide-derived. The results indicated an unusual manner of angular tetracyclic ring construction, perhaps via a Baeyer-Villiger type rearrangement. Subsequent cloning and sequencing led to the identification of the bex gene cluster spanning approximately 30 kbp. A total of 28 open reading frames, which are likely involved in BE-7585A formation, were identified in the cluster. In view of the presence of a homologue of a thiazole synthase gene (thiG), bexX, in the bex cluster, the mechanism of sulfur incorporation into the 2-thiosugar moiety could resemble that found in thiamin biosynthesis. A glycosyltransferase homologue, BexG2, was heterologously expressed in Escherichia coli. The purified enzyme successfully catalyzed the coupling of 2-thioglucose 6-phosphate and UDP-glucose to produce 2-thiotrehalose 6-phosphate, which is the precursor of the disaccharide unit in BE-7585A. On the basis of these genetic and biochemical experiments, a biosynthetic pathway for BE-7585A can now be proposed. The combined results set the stage for future biochemical studies of 2-thiosugar biosynthesis and BE-7585A assembly.
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Affiliation(s)
- Eita Sasaki
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA
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Devenish SRA, Blunt JW, Gerrard JA. NMR studies uncover alternate substrates for dihydrodipicolinate synthase and suggest that dihydrodipicolinate reductase is also a dehydratase. J Med Chem 2010; 53:4808-12. [PMID: 20503968 DOI: 10.1021/jm100349s] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Despite extensive effort, the drug target dihydrodipicolinate synthase (DHDPS) continues to evade effective inhibition. We used NMR spectroscopy to examine the substrate specificity of this enzyme and found that two pyruvate analogues previously classified as weak competitive inhibitors were turned over productively by DHDPS. Four other analogues were confirmed not to be substrates. Finally, our examination of the natural product of DHDPS and its degradation revealed that dihydrodipicolinate reductase (DHDPR) possesses previously unrecognized dehydratase activity.
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Affiliation(s)
- Sean R A Devenish
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand.
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TDP-L-megosamine biosynthesis pathway elucidation and megalomicin a production in Escherichia coli. Appl Environ Microbiol 2010; 76:3869-77. [PMID: 20418422 DOI: 10.1128/aem.03083-09] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In vivo reconstitution of the TDP-l-megosamine pathway from the megalomicin gene cluster of Micromonospora megalomicea was accomplished by the heterologous expression of its biosynthetic genes in Escherichia coli. Mass spectrometric analysis of the TDP-sugar intermediates produced from operons containing different sets of genes showed that the production of TDP-l-megosamine from TDP-4-keto-6-deoxy-d-glucose requires only five biosynthetic steps, catalyzed by MegBVI, MegDII, MegDIII, MegDIV, and MegDV. Bioconversion studies demonstrated that the sugar transferase MegDI, along with the helper protein MegDVI, catalyzes the transfer of l-megosamine to either erythromycin C or erythromycin D, suggesting two possible routes for the production of megalomicin A. Analysis in vivo of the hydroxylation step by MegK indicated that erythromycin C is the intermediate of megalomicin A biosynthesis.
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Pickens LB, Kim W, Wang P, Zhou H, Watanabe K, Gomi S, Tang Y. Biochemical analysis of the biosynthetic pathway of an anticancer tetracycline SF2575. J Am Chem Soc 2010; 131:17677-89. [PMID: 19908837 DOI: 10.1021/ja907852c] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
SF2575 1 is a tetracycline polyketide produced by Streptomyces sp. SF2575 and displays exceptionally potent anticancer activity toward a broad range of cancer cell lines. The structure of SF2575 is characterized by a highly substituted tetracycline aglycon. The modifications include methylation of the C-6 and C-12a hydroxyl groups, acylation of the 4-(S)-hydroxyl with salicylic acid, C-glycosylation of the C-9 of the D-ring with D-olivose and further acylation of the C4'-hydroxyl of D-olivose with the unusual angelic acid. Understanding the biosynthesis of SF2575 can therefore expand the repertoire of enzymes that can modify tetracyclines, and facilitate engineered biosynthesis of SF2575 analogues. In this study, we identified, sequenced, and functionally analyzed the ssf biosynthetic gene cluster which contains 40 putative open reading frames. Genes encoding enzymes that can assemble the tetracycline aglycon, as well as installing these unique structural features, are found in the gene cluster. Biosynthetic intermediates were isolated from the SF2575 culture extract to suggest the order of pendant-group addition is C-9 glycosylation, C-4 salicylation, and O-4' angelylcylation. Using in vitro assays, two enzymes that are responsible for C-4 acylation of salicylic acid were identified. These enzymes include an ATP-dependent salicylyl-CoA ligase SsfL1 and a putative GDSL family acyltransferase SsfX3, both of which were shown to have relaxed substrate specificity toward substituted benzoic acids. Since the salicylic acid moiety is critically important for the anticancer properties of SF2575, verification of the activities of SsfL1 and SsfX3 sets the stage for biosynthetic modification of the C-4 group toward structure-activity relationship studies of SF2575. Using heterologous biosynthesis in Streptomyces lividans, we also determined that biosynthesis of the SF2575 tetracycline aglycon 8 parallels that of oxytetracycline 4 and diverges after the assembly of 4-keto-anhydrotetracycline 51. The minimal ssf polyketide synthase together with the amidotransferase SsfD produced the amidated decaketide backbone that is required for the formation of 2-naphthacenecarboxamide skeleton. Additional enzymes, such as cyclases C-6 methyltransferase and C-4/C-12a dihydroxylase, were functionally reconstituted.
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Affiliation(s)
- Lauren B Pickens
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, USA
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Abstract
Many bioactive compounds contain as part of their molecules one or more deoxysugar units. Their presence in the final compound is generally necessary for biological activity. These sugars derive from common monosaccharides, like d-glucose, which have lost one or more hydroxyl groups (monodeoxysugars, dideoxysugars, trideoxysugars) during their biosynthesis. These deoxysugars are transferred to the final molecule by the action of a glycosyltransferase. Here, we first summarize the different biosynthetic steps required for the generation of the different families of deoxysugars, including those containing extra methyl or amino groups, or tailoring modifications of the glycosylated compounds. We then give examples of several strategies for modification of the glycosylation pattern of a given bioactive compound: inactivation of genes involved in the biosynthesis of deoxysugars; heterologous expression of genes for the biosynthesis or transfer of a specific deoxysugar; and combinatorial biosynthesis (including the use of gene cassette plasmids). Finally, we report techniques for the isolation and detection of the new glycosylated derivatives generated using these strategies.
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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, Oviedo, Spain
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Liu T, Kharel MK, Zhu L, Bright SA, Mattingly C, Adams VR, Rohr J. Inactivation of the ketoreductase gilU gene of the gilvocarcin biosynthetic gene cluster yields new analogues with partly improved biological activity. Chembiochem 2009; 10:278-86. [PMID: 19067453 DOI: 10.1002/cbic.200800348] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Four new analogues of the gilvocarcin-type aryl-C-glycoside antitumor compounds, namely 4'-hydroxy gilvocarcin V (4'-OH-GV), 4'-hydroxy gilvocarcin M, 4'-hydroxy gilvocarcin E and 12-demethyl-defucogilvocarcin V, were produced through inactivation of the gilU gene. The 4'-OH-analogues showed improved activity against lung cancer cell lines as compared to their parent compounds without 4'-OH group (gilvocarcins V and E). The structures of the sugar-containing new mutant products indicate that the enzyme GilU acts as an unusual ketoreductase involved in the biosynthesis of the C-glycosidically linked deoxysugar moiety of the gilvocarcins. The structures of the new gilvocarcins indicate substrate flexibility of the post-polyketide synthase modifying enzymes, particularly the C-glycosyltransferase and the enzyme responsible for the sugar ring contraction. The results also shed light into biosynthetic sequence of events in the late steps of biosynthetic pathway of gilvocarcin V.
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Affiliation(s)
- Tao Liu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 725 Rose Street, Lexington, KY 40536-0082, USA
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Pageni BB, Oh TJ, Yoo JC, Sohng JK. Functional characterization of orf6 and orf9 genes involved in the biosynthesis of L-oleandrose from Streptomyces antibioticus Tü99. BIOTECHNOL BIOPROC E 2009. [DOI: 10.1007/s12257-008-0128-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
Many biologically active bacterial natural products contain highly modified deoxysugar residues that are often critical for the activity of the parent compounds. Most of these deoxysugars are secondary metabolites that are biosynthesized in the form of nucleotide diphosphate (NDP) sugars prior to their transfer to natural product aglycones by glycosyltransferases. Over the past decade, many biosynthetic pathways that lead to the formation of these unusual sugars have been unraveled, and the mechanisms of many key enzymatic transformations involved in these pathways have been elucidated. However, obtaining workable quantities of NDP-deoxysugars for in vitro studies is often a difficult task. This limitation has hindered an in-depth investigation of the substrate specificity of deoxysugar biosynthetic enzymes, many of which are promiscuous with respect to their NDP-sugar substrates and are, thus, potentially useful catalysts for natural product glycoengineering. Presented in this review are procedures for the enzymatic synthesis and purification of a variety of NDP-deoxysugars, including some early intermediates in NDP-deoxysugar biosynthetic pathways, and highly modified NDP-deoxysugars that are late intermediates in their respective biosynthetic pathways. The procedures described herein could be used as general guidelines for the development of specific protocols for the synthesis of other NDP-deoxysugars.
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Chiu HT, Chen YL, Chen CY, Jin C, Lee MN, Lin YC. Molecular cloning, sequence analysis and functional characterization of the gene cluster for biosynthesis of K-252a and its analogs. MOLECULAR BIOSYSTEMS 2009; 5:1180-91. [DOI: 10.1039/b905293c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Thibodeaux C, Melançon C, Liu HW. Biosynthese von Naturstoffzuckern und enzymatische Glycodiversifizierung. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200801204] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Hong L, Zhao Z, Melançon CE, Zhang H, Liu HW. In vitro characterization of the enzymes involved in TDP-D-forosamine biosynthesis in the spinosyn pathway of Saccharopolyspora spinosa. J Am Chem Soc 2008; 130:4954-67. [PMID: 18345667 DOI: 10.1021/ja0771383] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Forosamine (4-dimethylamino)-2,3,4,6-tetradeoxy-beta-D-threo-hexopyranose) is a highly deoxygenated sugar component of several important natural products, including the potent yet environmentally benign insecticide spinosyns. To study D-forosamine biosynthesis, the five genes (spnO, N, Q, R, and S) from the spinosyn gene cluster thought to be involved in the conversion of TDP-4-keto-6-deoxy-D-glucose to TDP-D-forosamine were cloned and heterologously expressed, and the corresponding proteins were purified and their activities examined in vitro. Previous work demonstrated that SpnQ functions as a pyridoxamine 5'-monophosphate (PMP)-dependent 3-dehydrase which, in the presence of the cellular reductase pairs ferredoxin/ferredoxin reductase or flavodoxin/flavodoxin reductase, catalyzes C-3 deoxygenation of TDP-4-keto-2,6-dideoxy-D-glucose. It was also established that SpnR functions as a transaminase which converts the SpnQ product, TDP-4-keto-2,3,6-trideoxy-D-glucose, to TDP-4-amino-2,3,4,6-tetradeoxy-D-glucose. The results presented here provide a full account of the characterization of SpnR and SpnQ and reveal that SpnO and SpnN functions as a 2,3-dehydrase and a 3-ketoreductase, respectively. These two enzymes act sequentially to catalyze C-2 deoxygenation of TDP-4-keto-6-deoxy-D-glucose to form the SpnQ substrate, TDP-4-keto-2,6-dideoxy-D-glucose. Evidence has also been obtained to show that SpnS functions as the 4-dimethyltransferase that converts the SpnR product to TDP-D-forosamine. Thus, the biochemical functions of the five enzymes involved in TDP-D-forosamine formation have now been fully elucidated. The steady-state kinetic parameters for the SpnQ-catalyzed reaction have been determined, and the substrate specificities of SpnQ and SpnR have been explored. The implications of this work for natural product glycodiversification and comparative mechanistic analysis of SpnQ and related NDP-sugar 3-dehydrases E1 and ColD are discussed.
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Affiliation(s)
- Lin Hong
- Division of Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, USA
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Zhang X, Alemany LB, Fiedler HP, Goodfellow M, Parry RJ. Biosynthetic investigations of lactonamycin and lactonamycin z: cloning of the biosynthetic gene clusters and discovery of an unusual starter unit. Antimicrob Agents Chemother 2008; 52:574-85. [PMID: 18070976 PMCID: PMC2224763 DOI: 10.1128/aac.00717-07] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2007] [Revised: 08/20/2007] [Accepted: 11/25/2007] [Indexed: 11/20/2022] Open
Abstract
The antibiotics lactonamycin and lactonamycin Z provide attractive leads for antibacterial drug development. Both antibiotics contain a novel aglycone core called lactonamycinone. To gain insight into lactonamycinone biosynthesis, cloning and precursor incorporation experiments were undertaken. The lactonamycin gene cluster was initially cloned from Streptomyces rishiriensis. Sequencing of ca. 61 kb of S. rishiriensis DNA revealed the presence of 57 open reading frames. These included genes coding for the biosynthesis of l-rhodinose, the sugar found in lactonamycin, and genes similar to those in the tetracenomycin biosynthetic gene cluster. Since lactonamycin production by S. rishiriensis could not be sustained, additional proof for the identity of the S. rishiriensis cluster was obtained by cloning the lactonamycin Z gene cluster from Streptomyces sanglieri. Partial sequencing of the S. sanglieri cluster revealed 15 genes that exhibited a very high degree of similarity to genes within the lactonamycin cluster, as well as an identical organization. Double-crossover disruption of one gene in the S. sanglieri cluster abolished lactonamycin Z production, and production was restored by complementation. These results confirm the identity of the genetic locus cloned from S. sanglieri and indicate that the highly similar locus in S. rishiriensis encodes lactonamycin biosynthetic genes. Precursor incorporation experiments with S. sanglieri revealed that lactonamycinone is biosynthesized in an unusual manner whereby glycine or a glycine derivative serves as a starter unit that is extended by nine acetate units. Analysis of the gene clusters and of the precursor incorporation data suggested a hypothetical scheme for lactonamycinone biosynthesis.
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Affiliation(s)
- Xiujun Zhang
- Department of Chemistry, MS60, Rice University, 6100 Main St., Houston, TX 77005, USA
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Thibodeaux CJ, Melançon CE, Liu HW. Natural-product sugar biosynthesis and enzymatic glycodiversification. Angew Chem Int Ed Engl 2008; 47:9814-59. [PMID: 19058170 PMCID: PMC2796923 DOI: 10.1002/anie.200801204] [Citation(s) in RCA: 320] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Many biologically active small-molecule natural products produced by microorganisms derive their activities from sugar substituents. Changing the structures of these sugars can have a profound impact on the biological properties of the parent compounds. This realization has inspired attempts to derivatize the sugar moieties of these natural products through exploitation of the sugar biosynthetic machinery. This approach requires an understanding of the biosynthetic pathway of each target sugar and detailed mechanistic knowledge of the key enzymes. Scientists have begun to unravel the biosynthetic logic behind the assembly of many glycosylated natural products and have found that a core set of enzyme activities is mixed and matched to synthesize the diverse sugar structures observed in nature. Remarkably, many of these sugar biosynthetic enzymes and glycosyltransferases also exhibit relaxed substrate specificity. The promiscuity of these enzymes has prompted efforts to modify the sugar structures and alter the glycosylation patterns of natural products through metabolic pathway engineering and enzymatic glycodiversification. In applied biomedical research, these studies will enable the development of new glycosylation tools and generate novel glycoforms of secondary metabolites with useful biological activity.
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Affiliation(s)
- Christopher J. Thibodeaux
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX. (USA), 78712
| | - Charles E. Melançon
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX. (USA), 78712
| | - Hung-wen Liu
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX. (USA), 78712
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21
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Zhang H, White-Phillip JA, Melançon CE, Kwon HJ, Yu WL, Liu HW. Elucidation of the kijanimicin gene cluster: insights into the biosynthesis of spirotetronate antibiotics and nitrosugars. J Am Chem Soc 2007; 129:14670-83. [PMID: 17985890 DOI: 10.1021/ja0744854] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The antibiotic kijanimicin produced by the actinomycete Actinomadura kijaniata has a broad spectrum of bioactivities as well as a number of interesting biosynthetic features. To understand the molecular basis for its formation and to develop a combinatorial biosynthetic system for this class of compounds, a 107.6 kb segment of the A. kijaniata chromosome containing the kijanimicin biosynthetic locus was identified, cloned, and sequenced. The complete pathway for the formation of TDP-l-digitoxose, one of the two sugar donors used in construction of kijanimicin, was elucidated through biochemical analysis of four enzymes encoded in the gene cluster. Sequence analysis indicates that the aglycone kijanolide is formed by the combined action of a modular Type-I polyketide synthase, a conserved set of enzymes involved in formation, attachment, and intramolecular cyclization of a glycerate-derived three-carbon unit, which forms the core of the spirotetronate moiety. The genes involved in the biosynthesis of the unusual deoxysugar d-kijanose [2,3,4,6-tetradeoxy-4-(methylcarbamyl)-3-C-methyl-3-nitro-d-xylo-hexopyranose], including one encoding a flavoenzyme predicted to catalyze the formation of the nitro group, have also been identified. This work has implications for the biosynthesis of other spirotetronate antibiotics and nitrosugar-bearing natural products, as well as for future mechanistic and biosynthetic engineering efforts.
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Affiliation(s)
- Hua Zhang
- Division of Medicinal Chemistry, College of Pharmacy, Institute of Cellular and Molecular Biology, Austin, Texas 78712, USA
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22
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Peirú S, Rodríguez E, Tran CQ, Carney JR, Gramajo H. Characterization of the heterodimeric MegBIIa:MegBIIb aldo-keto reductase involved in the biosynthesis of L-mycarose from Micromonospora megalomicea. Biochemistry 2007; 46:8100-9. [PMID: 17571859 DOI: 10.1021/bi700396n] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two putative C3-ketoreductases, MegBIIa and MegBIIb (formerly MegBII and MegDVII, respectively), homologues to members of the family 12 of aldo-keto reductase (AKR12) superfamily of enzymes, were identified in the megalomicin gene cluster from Micromonospora megalomicea. Proteins from this family are involved in the metabolism of TDP-sugars by actinomycetes. MegBIIa was originally proposed to be involved in the l-mycarose biosynthetic pathway, while MegBIIb in the l-megosamine biosynthetic pathway. In this work we have investigated the role of these proteins in the biosynthesis of dTDP-l-mycarose. In vivo analysis of the dTDP-sugar intermediates indicated that neither MegBIIa nor its homologue, MegBIIb, was a fully active enzyme by itself. Surprisingly, C3-ketoreductase activity was observed only in the presence of both MegBIIa and MegBIIb, suggesting the formation of an active complex. Copurification and size exclusion chromatography experiments confirmed that MegBIIa and MegBIIb interact forming a 1:1 heterodimeric complex. Finally, a mycarose operon containing megBIIa and megBIIb together with the other biosynthetic genes of the l-mycarose pathway was constructed and tested by bioconversion experiments in Escherichia coli. High levels of mycarosyl-erythronolide B were produced under the condition tested, confirming the role of these two proteins in this metabolic pathway.
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Affiliation(s)
- Salvador Peirú
- Microbiology Division, Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias, Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Argentina
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23
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Salas JA, Méndez C. Engineering the glycosylation of natural products in actinomycetes. Trends Microbiol 2007; 15:219-32. [PMID: 17412593 DOI: 10.1016/j.tim.2007.03.004] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Revised: 03/07/2007] [Accepted: 03/22/2007] [Indexed: 11/24/2022]
Abstract
Bioactive natural products are frequently glycosylated with saccharide chains of different length, in which the sugars contribute to specific interactions with the biological target. Combinatorial biosynthesis approaches are being used in antibiotic-producing actinomycetes to generate derivatives with novel sugars in their architecture. Recent advances in this area indicate that glycosyltransferases involved in the biosynthesis of natural products have substrate flexibility regarding the sugar donor but also, less frequently, with respect to the aglycon acceptor. Therefore, the possibility exists of altering the glycosylation pattern of natural products, thus enabling an increase in the structural diversity of natural products.
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Affiliation(s)
- José A Salas
- Departamento de Biología Funcional e Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, 33006 Oviedo, Spain.
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24
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Melançon CE, Hong L, White JA, Liu YN, Liu HW. Characterization of TDP-4-keto-6-deoxy-D-glucose-3,4-ketoisomerase from the D-mycaminose biosynthetic pathway of Streptomyces fradiae: in vitro activity and substrate specificity studies. Biochemistry 2007; 46:577-90. [PMID: 17209568 PMCID: PMC2515277 DOI: 10.1021/bi061907y] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Deoxysugars are critical structural elements for the bioactivity of many natural products. Ongoing work on elucidating a variety of deoxysugar biosynthetic pathways has paved the way for manipulation of these pathways for the generation of structurally diverse glycosylated natural products. In the course of this work, the biosynthesis of d-mycaminose in the tylosin pathway of Streptomyces fradiae was investigated. Attempts to reconstitute the entire mycaminose biosynthetic machinery in a heterologous host led to the discovery of a previously overlooked gene, tyl1a, encoding an enzyme thought to convert TDP-4-keto-6-deoxy-d-glucose to TDP-3-keto-6-deoxy-d-glucose, a 3,4-ketoisomerization reaction in the pathway. Tyl1a has now been overexpressed, purified, and assayed, and its activity has been verified by product analysis. Incubation of Tyl1a and the C-3 aminotransferase TylB, the next enzyme in the pathway, produced TDP-3-amino-3,6-dideoxy-d-glucose, confirming that these two enzymes act sequentially. Steady state kinetic parameters of the Tyl1a-catalyzed reaction were determined, and the ability of Tyl1a and TylB to process a C-2 deoxygenated substrate and a CDP-linked substrate was also demonstrated. Enzymes catalyzing 3,4-ketoisomerization of hexoses represent a new class of enzymes involved in unusual sugar biosynthesis. The fact that Tyl1a exhibits a relaxed substrate specificity holds potential for future deoxysugar biosynthetic engineering endeavors.
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Affiliation(s)
- Charles E. Melançon
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - Lin Hong
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - Jessica A. White
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
| | - Yung-nan Liu
- Division of Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712
| | - Hung-wen Liu
- Division of Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
- To whom correspondence and reprint requests should be addressed. Phone: 512-232-7811, Fax: 512-471-2746. E-mail:
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25
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Anthracycline Biosynthesis: Genes, Enzymes and Mechanisms. ANTHRACYCLINE CHEMISTRY AND BIOLOGY I 2007. [DOI: 10.1007/128_2007_14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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26
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Gao Q, Zhang C, Blanchard S, Thorson JS. Deciphering indolocarbazole and enediyne aminodideoxypentose biosynthesis through comparative genomics: insights from the AT2433 biosynthetic locus. ACTA ACUST UNITED AC 2006; 13:733-43. [PMID: 16873021 DOI: 10.1016/j.chembiol.2006.05.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Revised: 04/28/2006] [Accepted: 05/04/2006] [Indexed: 11/19/2022]
Abstract
AT2433, an indolocarbazole antitumor antibiotic, is structurally distinguished by its aminodideoxypentose-containing disaccharide and asymmetrically halogenated N-methylated aglycon. Cloning and sequence analysis of AT2433 gene cluster and comparison of this locus with that encoding for rebeccamycin and the gene cluster encoding calicheamicin present an opportunity to study the aminodideoxypentose biosynthesis via comparative genomics. The locus was confirmed via in vitro biochemical characterization of two methyltransferases--one common to AT2433 and rebeccamycin, the other unique to AT2433--as well as via heterologous expression and in vivo bioconversion experiments using the AT2433 N-glycosyltransferase. Preliminary studies of substrate tolerance for these three enzymes reveal the potential to expand upon the enzymatic diversification of indolocarbazoles. Moreover, this work sets the stage for future studies regarding the origins of the indolocarbazole maleimide nitrogen and indolocarbazole asymmetry.
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Affiliation(s)
- Qunjie Gao
- Laboratory for Biosynthetic Chemistry, Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin, Madison, 53705, USA
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27
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Pérez M, Lombó F, Baig I, Braña AF, Rohr J, Salas JA, Méndez C. Combinatorial biosynthesis of antitumor deoxysugar pathways in Streptomyces griseus: Reconstitution of "unnatural natural gene clusters" for the biosynthesis of four 2,6-D-dideoxyhexoses. Appl Environ Microbiol 2006; 72:6644-52. [PMID: 17021216 PMCID: PMC1610316 DOI: 10.1128/aem.01266-06] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Combinatorial biosynthesis was applied to Streptomyces deoxysugar biosynthesis genes in order to reconstitute "unnatural natural gene clusters" for the biosynthesis of four D-deoxysugars (D-olivose, D-oliose, D-digitoxose, and D-boivinose). Expression of these gene clusters in Streptomyces albus 16F4 was used to prove the functionality of the designed clusters through the generation of glycosylated tetracenomycins. Three glycosylated tetracenomycins were generated and characterized, two of which (D-digitoxosyl-tetracenomycin C and D-boivinosyl-tetracenocmycin C) were novel compounds. The constructed gene clusters may be used to increase the capabilities of microorganisms to synthesize new deoxysugars and therefore to produce new glycosylated bioactive compounds.
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Affiliation(s)
- María Pérez
- Departamento de Biología Funcional e Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, Oviedo, Spain
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28
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Bihlmaier C, Welle E, Hofmann C, Welzel K, Vente A, Breitling E, Müller M, Glaser S, Bechthold A. Biosynthetic gene cluster for the polyenoyltetramic acid alpha-lipomycin. Antimicrob Agents Chemother 2006; 50:2113-21. [PMID: 16723573 PMCID: PMC1479109 DOI: 10.1128/aac.00007-06] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The gram-positive bacterium Streptomyces aureofaciens Tü117 produces the acyclic polyene antibiotic alpha-lipomycin. The entire biosynthetic gene cluster (lip gene cluster) was cloned and characterized. DNA sequence analysis of a 74-kb region revealed the presence of 28 complete open reading frames (ORFs), 22 of them belonging to the biosynthetic gene cluster. Central to the cluster is a polyketide synthase locus that encodes an eight-module system comprised of four multifunctional proteins. In addition, one ORF shows homology to those for nonribosomal peptide synthetases, indicating that alpha-lipomycin belongs to the classification of hybrid peptide-polyketide natural products. Furthermore, the lip cluster includes genes responsible for the formation and attachment of d-digitoxose as well as ORFs that resemble those for putative regulatory and export functions. We generated biosynthetic mutants by insertional gene inactivation. By analysis of culture extracts of these mutants, we could prove that, indeed, the genes involved in the biosynthesis of lipomycin had been cloned, and additionally we gained insight into an unusual biosynthesis pathway.
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Affiliation(s)
- C Bihlmaier
- Albert-Ludwigs-Universität Freiburg, Institut für Pharmazeutische Wissenschaften, Pharmazeutische Biologie und Biotechnologie, Freiburg, Germany
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29
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Shao L, Qu XD, Jia XY, Zhao QF, Tian ZH, Wang M, Tang GL, Liu W. Cloning and characterization of a bacterial iterative type I polyketide synthase gene encoding the 6-methylsalicyclic acid synthase. Biochem Biophys Res Commun 2006; 345:133-9. [PMID: 16677607 DOI: 10.1016/j.bbrc.2006.04.069] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2006] [Accepted: 04/10/2006] [Indexed: 11/28/2022]
Abstract
Unusual polyketide synthases (PKSs), that are structurally type I but act in an iterative manner for aromatic polyketide biosynthesis, are a new family found in bacteria. Here we report the cloning of the iterative type I PKS gene chlB1 from the chlorothricin (CHL) producer Streptomyces antibioticus DSM 40725 by a rapid PCR approach, and characterization of the function of the gene product as a 6-methylsalicyclic acid synthase (6-MSAS). Sequence analysis of various iterative type I PKSs suggests that the resulting aromatic or aliphatic structure of the products might be intrinsically determined by a catalytic feature of the paired KR-DH domains in the control of the double bond geometry. The finding of ChlB1 as a 6-MSAS not only enriches the current knowledge of aromatic polyketide biosynthesis in bacteria, but will also contribute to the generation of novel polyketide analogs via combinatorial biosynthesis with engineered PKSs.
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Affiliation(s)
- Lei Shao
- School of Life Science and Technology, Chinese Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China
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30
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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: 65] [Impact Index Per Article: 3.6] [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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31
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Takahashi H, Liu YN, Liu HW. A two-stage one-pot enzymatic synthesis of TDP-L-mycarose from thymidine and glucose-1-phosphate. J Am Chem Soc 2006; 128:1432-3. [PMID: 16448097 PMCID: PMC2502060 DOI: 10.1021/ja0562144] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This report describes a procedure combining six enzymes native to Escherichia coli or Salmonella typhi, such as thymidine kinase (TK), thymidylate kinase (TMK), nucleoside diphosphate kinase (NDK), pyruvate kinase (PK; for ATP regeneration), TDP-glucose synthetase (RfbA), and TDP-glucose 4,6-dehydratase (RfbB), with five enzymes from Streptomyces fradiae, such as TylX3, TylC1, TylC3, TylK, and TylC2, that resulted in the biosynthesis of TDP-l-mycarose from glucose-1-phosphate and thymidine. This two-stage one-pot approach can be readily applied to the synthesis of other unusual sugars.
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Affiliation(s)
- Haruko Takahashi
- Division of Medicinal Chemistry, College of Pharmacy and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA
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32
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Salas JA, Méndez C. Biosynthesis Pathways for Deoxysugars in Antibiotic-Producing Actinomycetes: Isolation, Characterization and Generation of Novel Glycosylated Derivatives. J Mol Microbiol Biotechnol 2005; 9:77-85. [PMID: 16319497 DOI: 10.1159/000088838] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Many bioactive natural products synthesized by actinomycetes are glycosylated compounds in which the appended sugars contribute to specific interactions with their biological target. Most of these sugars are 6-deoxyhexoses, of which more than 70 different forms have been identified, and an increasing number of gene clusters involved in 6-deoxyhexoses biosynthesis are being characterized from antibiotic-producing actinomycetes. Novel glycosylated compounds have been generated by modifying natural deoxysugar biosynthesis pathways in the producer organisms, and/or the simultaneous expression in these strains of selected deoxysugar biosynthesis genes from other strains. Non-producing strains endowed with the capacity to synthesize novel deoxysugars through the expression of engineered deoxysugar biosynthesis clusters can also be used as alternative hosts. Transfer of these deoxysugars to a multiplicity of aglycones relies upon the existence of glycosyltransferases with an inherent degree of 'relaxed substrate specificity'. In this review, we analyze how the knowledge coming out from isolation and characterization of deoxysugar biosynthesis pathways from actinomycetes is being used to produce novel glycosylated derivatives of natural products.
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Affiliation(s)
- José A Salas
- Departamento de Biología Funcional e Instituto Universitario de Oncología de Asturias (IUOPA), Universidad de Oviedo, Oviedo, Spain.
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33
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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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34
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Méndez C, Salas JA. Engineering glycosylation in bioactive compounds by combinatorial biosynthesis. ERNST SCHERING RESEARCH FOUNDATION WORKSHOP 2005:127-46. [PMID: 15645719 DOI: 10.1007/3-540-27055-8_6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Affiliation(s)
- C Méndez
- Departamento de Biologia Funcional e Instituto Universitario de Oncologia (I.U.O.P.A.), Universidad de Oviedo, Spain
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35
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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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Menéndez N, Nur-e-Alam M, Braña AF, Rohr J, Salas JA, Méndez C. Biosynthesis of the antitumor chromomycin A3 in Streptomyces griseus: analysis of the gene cluster and rational design of novel chromomycin analogs. ACTA ACUST UNITED AC 2004; 11:21-32. [PMID: 15112992 DOI: 10.1016/j.chembiol.2003.12.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2003] [Revised: 10/10/2003] [Accepted: 10/14/2003] [Indexed: 11/25/2022]
Abstract
The biosynthetic gene cluster of the aureolic acid type antitumor drug chromomycin A3 from S. griseus subsp. griseus has been identified and characterized. It spans 43 kb and contains 36 genes involved in polyketide biosynthesis and modification, deoxysugar biosynthesis and sugar transfer, pathway regulation and resistance. The organization of the cluster clearly differs from that of the closely related mithramycin. Involvement of the cluster in chromomycin A3 biosynthesis was demonstrated by disrupting the cmmWI gene encoding a polyketide reductase involved in side chain reduction. Three novel chromomycin derivatives were obtained, named chromomycin SK, chromomycin SA, and chromomycin SDK, which show antitumor activity and differ with respect to their 3-side chains. A pathway for the biosynthesis of chromomycin A3 and its deoxysugars is proposed.
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Affiliation(s)
- Nuria Menéndez
- Departamento de Biología Funcional e Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, 33006 Oviedo, Spain
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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: 37] [Impact Index Per Article: 1.9] [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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Abstract
Carbohydrates are highly abundant biomolecules found extensively in nature. Besides playing important roles in energy storage and supply, they often serve as essential biosynthetic precursors or structural elements needed to sustain all forms of life. A number of unusual sugars that have certain hydroxyl groups replaced by a hydrogen, an amino group, or an alkyl side chain play crucial roles in determining the biological activity of the parent natural products in bacterial lipopolysaccharides or secondary metabolite antibiotics. Recent investigation of the biosynthesis of these monosaccharides has led to the identification of the gene clusters whose protein products facilitate the unusual sugar formation from the ubiquitous NDP-glucose precursors. This review summarizes the mechanistic studies of a few enzymes crucial to the biosynthesis of C-2, C-3, C-4, and C-6 deoxysugars, the characterization and mutagenesis of nucleotidyl transferases that can recognize and couple structural analogs of their natural substrates and the identification of glycosyltransferases with promiscuous substrate specificity. Information gleaned from these studies has allowed pathway engineering, resulting in the creation of new macrolides with unnatural deoxysugar moieties for biological activity screening. This represents a significant progress toward our goal of searching for more potent agents against infectious diseases and malignant tumors.
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Affiliation(s)
- Xuemei M He
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, USA.
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Räty K, Hautala A, Torkkell S, Kantola J, Mäntsälä P, Hakala J, Ylihonko K. Characterization of mutations in aclacinomycin A-non-producing Streptomyces galilaeus strains with altered glycosylation patterns. MICROBIOLOGY (READING, ENGLAND) 2002; 148:3375-3384. [PMID: 12427929 DOI: 10.1099/00221287-148-11-3375] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this study a set of Streptomyces galilaeus ATCC 31615 mutants was characterized, which are incapable of synthesizing some or all of the deoxyhexose sugars of aclacinomycin A. Complementation experiments with the the mutant strains H026, H038, H039, H054, H063, H065 and H075 were carried out with glycosylation genes previously derived from the wild-type S. galilaeus. Mutations in strains H038, H063 and H075 were complemented with single PCR-amplified genes. Furthermore, amplification and sequencing of the corresponding genes from the mutant strains revealed single point mutations in the sequences. First, in H038 a transition mutation in aknQ, encoding a putative dTDP-hexose 3-ketoreductase, causes an amino acid substitution from glycine to aspartate, suppressing the biosynthesis of both 2-deoxyfucose and rhodinose and thus leading to the accumulation of aclacinomycin T with rhodosamine as its only sugar. Second, in H063, which accumulates aklavinone without a sugar moiety, amino acid substitution occurs, with threonine being substituted by isoleucine in dTDP-glucose synthase, the first enzyme participating in deoxyhexose biosynthesis, encoded by aknY. Third, a nonsense mutation in aknP leads to truncated dTDP-hexose 3-dehydratase in H075, which is incapable of synthesizing rhodinose. In addition, mutants H054 and H065, which accumulate aclacinomycins without aminosugars, were complemented by a gene for an aminotransferase, aknZ. Characterization of the nature of the mutations adds to the usefulness and value of the mutants in the analysis of gene function and in the creation of novel compounds by combinatorial biosynthesis. Furthermore, these results strengthen the assignments of akn gene products and enlighten the biosynthetic pathway for deoxyhexoses.
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Affiliation(s)
- Kaj Räty
- Department of Biochemistry and Food Chemistry, University of Turku, Vatselankatu 2,FIN-20014, Turku, Finland1
| | - Anne Hautala
- Galilaeus Oy, PO Box 113, FIN-20781, Kaarina, Finland2
| | - Sirke Torkkell
- Department of Biochemistry and Food Chemistry, University of Turku, Vatselankatu 2,FIN-20014, Turku, Finland1
| | - Jaana Kantola
- Galilaeus Oy, PO Box 113, FIN-20781, Kaarina, Finland2
| | - Pekka Mäntsälä
- Department of Biochemistry and Food Chemistry, University of Turku, Vatselankatu 2,FIN-20014, Turku, Finland1
| | - Juha Hakala
- Galilaeus Oy, PO Box 113, FIN-20781, Kaarina, Finland2
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Abstract
In the past few years, significant progress has been made in our understanding of the biosynthesis of deoxyhexoses. Mechanistic studies have revealed how enzymes can cleave CbondO bonds of a hexose substrate to make unusual sugars. The increasing amount of knowledge about the biosynthesis of deoxysugars may allow the assembly of a repertoire of novel sugar structures through recruitment and collaborative action of genes from a variety of biosynthetic pathways to create diverse secondary metabolites in our search for novel antibiotic/antitumour agents.
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Affiliation(s)
- Xuemei He
- Division of Medicinal Chemistry, College of Pharmacy, Department of Chemistry and Biochemistry, University of Texas, Austin 78712, USA
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Wang L, White RL, Vining LC. Biosynthesis of the dideoxysugar component of jadomycin B: genes in the jad cluster of Streptomyces venezuelae ISP5230 for L-digitoxose assembly and transfer to the angucycline aglycone. MICROBIOLOGY (READING, ENGLAND) 2002; 148:1091-1103. [PMID: 11932454 DOI: 10.1099/00221287-148-4-1091] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Eight additional genes, jadX, O, P, Q, S, T, U and V, in the jad cluster of Streptomyces venezuelae ISP5230, were located immediately downstream of jadN by chromosome walking. Sequence analyses and comparisons implicated them in biosynthesis of the 2,6-dideoxysugar in jadomycin B. The genes were cloned in Escherichia coli, inactivated by inserting an apramycin resistance cassette with a promoter driving transcription of downstream genes, and transferred into Streptomyces venezuelae by intergeneric conjugation. Analysis by HPLC and NMR of intermediates accumulated by cultures of the insertionally inactivated Streptomyces venezuelae mutants indicated that jadO, P, Q, S, T, U and V mediate formation of the dideoxysugar moiety of jadomycin B and its attachment to the aglycone. Based on these results and sequence similarities to genes described in other species producing deoxysugar derivatives, a biosynthetic pathway is proposed in which the jadQ product (glucose-1-phosphate nucleotidyltransferase) activates glucose to its nucleotide diphosphate (NDP) derivative, and the jadT product (a 4,6-dehydratase) converts this to NDP-4-keto-6-deoxy-D-glucose. An NDP-hexose 2,3-dehydratase and an oxidoreductase, encoded by jadO and jadP, respectively, catalyse ensuing reactions that produce an NDP-2,6-dideoxy-D-threo-4-hexulose. The product of jadU (NDP-4-keto-2,6-dideoxy-5-epimerase) converts this intermediate to its L-erythro form and the jadV product (NDP-4-keto-2,6-dideoxyhexose 4-ketoreductase) reduces the keto group of the NDP-4-hexulose to give an activated form of the L-digitoxose moiety in jadomycin B. Finally, a glycosyltransferase encoded by jadS transfers the activated sugar to jadomycin aglycone. The function of jadX is unclear; the gene is not essential for jadomycin B biosynthesis, but its presence ensures complete conversion of the aglycone to the glycoside. The deduced amino acid sequence of a 612 bp ORF (jadR*) downstream of the dideoxysugar biosynthesis genes resembles many TetR-family transcriptional regulator sequences.
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Affiliation(s)
- Liru Wang
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, CanadaB3H 4J11
| | - Robert L White
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, CanadaB3H 4J32
| | - Leo C Vining
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, CanadaB3H 4J11
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Taguchi T, Ebizuka Y, Hopwood DA, Ichinose K. A new mode of stereochemical control revealed by analysis of the biosynthesis of dihydrogranaticin in Streptomyces violaceoruber Tü22. J Am Chem Soc 2001; 123:11376-80. [PMID: 11707113 DOI: 10.1021/ja015981+] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A class of Streptomyces aromatic polyketide antibiotics, the benzoisochromanequinones, all shows trans stereochemistry at C-3 and C-15 in the pyran ring. The opposite stereochemical control found in actinorhodin (3S, 15R, ACT) from S. coelicolor A3(2) and dihydrogranaticin (3R, 15S, DHGRA) from S. violaceoruber Tü22 was studied by functional expression of the potentially relevant ketoreductase genes, actIII, actVI-ORF1, gra-ORF5, and gra-ORF6. A common bicyclic intermediate was postulated to undergo stereospecific reduction to provide either the 3-(S) or the 3-(R) configuration of an advanced intermediate, 4-dihydro-9-hydroxy-1-methyl-10-oxo-3-H-naphtho[2,3-c]pyran-3-acetic acid (DNPA). Combinations of the four ketoreductase genes were coexpressed with the early biosynthetic genes encoding a type II minimal polyketide synthase, aromatase, and cyclase. gra-ORF6 was essential to produce (R)-DNPA in DHGRA biosynthesis. Out of the various recombinants carrying the relevant ketoreductases, the set of gra-ORF5 and -ORF6 under translational coupling (on pIK191) led to the most efficient production of (R)-DNPA as a single product, implying a possible unique cooperative function whereby gra-ORF6 might encode a "guiding" protein to control the regio- and stereochemical course of reduction at C-3 catalyzed by the gra-ORF5 protein. Updated BLAST-based database analysis suggested that the gra-ORF6 product, a putative short-chain dehydrogenase, has virtually no sequence homology with the actVI-ORF1 protein, which was previously shown to determine the 3-(S) configuration of DNPA in ACT biosynthesis. This demonstrates an example of opposite stereochemical control in antibiotic biosynthesis, providing a key branch point to afford diverse chiral metabolic pools.
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Affiliation(s)
- T Taguchi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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de Koning CB, Green IR, Michael JP, Oliveira JR. The synthesis of isochroman-4-ols and isochroman-3-ols: models for naturally occurring benzo[g]isochromanols. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(01)00963-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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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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Amann S, Dräger G, Rupprath C, Kirschning A, Elling L. (Chemo)enzymatic synthesis of dTDP-activated 2,6-dideoxysugars as building blocks of polyketide antibiotics. Carbohydr Res 2001; 335:23-32. [PMID: 11553351 DOI: 10.1016/s0008-6215(01)00195-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The flexible substrate spectrum of the recombinant enzymes from the biosynthetic pathway of dTDP-beta-L-rhamnose in Salmonella enterica, serovar typhimurium (LT2), was exploited for the chemoenzymatic synthesis of deoxythymidine diphosphate- (dTDP-) activated 2,6-dideoxyhexoses. The enzymatic synthesis strategy yielded dTDP-2-deoxy-alpha-D-glucose and dTDP-2,6-dideoxy-4-keto-alpha-D-glucose (13) in a 40-60 mg scale. The nucleotide deoxysugar 13 was further used for the enzymatic synthesis of dTDP-2,6-dideoxy-beta-L-arabino-hexose (dTDP-beta-L-olivose) (15) in a 30-mg scale. The chemical reduction of 13 gave dTDP-2,6-dideoxy-alpha-D-arabino-hexose (dTDP-alpha-D-olivose) (1) as the main isomer after product isolation in a 10-mg scale. With 13 as an important key intermediate, the in vitro characterization of enzymes involved in the biosynthesis of dTDP-activated 2,6-dideoxy-, 2,3,6-trideoxy-D- and L-hexoses can now be addressed. Most importantly, compounds 1 and 15 are donor substrates for the in vitro characterization of glycosyltransferases involved in the biosynthesis of polyketides and other antibiotic/antitumor drugs. Their synthetic access may contribute to the evaluation of the glycosylation potential of bacterial glycosyltransferases to generate hybrid antibiotics.
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Affiliation(s)
- S Amann
- Institute of Enzyme Technology, Heinrich-Heine-University, Düsseldorf Research Center Jülich, D-52426 Jülich, Germany
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Waldron C, Matsushima P, Rosteck PR, Broughton MC, Turner J, Madduri K, Crawford KP, Merlo DJ, Baltz RH. Cloning and analysis of the spinosad biosynthetic gene cluster of Saccharopolyspora spinosa. ACTA ACUST UNITED AC 2001; 8:487-99. [PMID: 11358695 DOI: 10.1016/s1074-5521(01)00029-1] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Spinosad is a mixture of novel macrolide secondary metabolites produced by Saccharopolyspora spinosa. It is used in agriculture as a potent insect control agent with exceptional safety to non-target organisms. The cloning of the spinosyn biosynthetic gene cluster provides the starting materials for the molecular genetic manipulation of spinosad yields, and for the production of novel derivatives containing alterations in the polyketide core or in the attached sugars. RESULTS We cloned the spinosad biosynthetic genes by molecular probing, complementation of blocked mutants, and cosmid walking, and sequenced an 80 kb region. We carried out gene disruptions of some of the genes and analyzed the mutants for product formation and for the bioconversion of intermediates in the spinosyn pathway. The spinosyn gene cluster contains five large open reading frames that encode a multifunctional, multi-subunit type I polyketide synthase (PKS). The PKS cluster is flanked on one side by genes involved in the biosynthesis of the amino sugar forosamine, in O-methylations of rhamnose, in sugar attachment to the polyketide, and in polyketide cross-bridging. Genes involved in the early common steps in the biosynthesis of forosamine and rhamnose, and genes dedicated to rhamnose biosynthesis, were not located in the 80 kb cluster. CONCLUSIONS Most of the S. spinosa genes involved in spinosyn biosynthesis are found in one 74 kb cluster, though it does not contain all of the genes required for the essential deoxysugars. Characterization of the clustered genes suggests that the spinosyns are synthesized largely by mechanisms similar to those used to assemble complex macrolides in other actinomycetes. However, there are several unusual genes in the spinosyn cluster that could encode enzymes that generate the most striking structural feature of these compounds, a tetracyclic polyketide aglycone nucleus.
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Affiliation(s)
- C Waldron
- Dow AgroSciences, Indianapolis, IN 46268, USA.
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Rodríguez L, Rodríguez D, Olano C, Braña AF, Méndez C, Salas JA. Functional analysis of OleY L-oleandrosyl 3-O-methyltransferase of the oleandomycin biosynthetic pathway in Streptomyces antibioticus. J Bacteriol 2001; 183:5358-63. [PMID: 11514520 PMCID: PMC95419 DOI: 10.1128/jb.183.18.5358-5363.2001] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Oleandomycin, a macrolide antibiotic produced by Streptomyces antibioticus, contains two sugars attached to the aglycon: L-oleandrose and D-desosamine. oleY codes for a methyltransferase involved in the biosynthesis of L-oleandrose. This gene was overexpressed in Escherichia coli to form inclusion bodies and in Streptomyces lividans, producing a soluble protein. S. lividans overexpressing oleY was used as a biotransformation host, and it converted the precursor L-olivosyl-erythronolide B into its 3-O-methylated derivative, L-oleandrosyl-erythronolide B. Two other monoglycosylated derivatives were also substrates for the OleY methyltransferase: L-rhamnosyl- and L-mycarosyl-erythronolide B. OleY methyltransferase was purified yielding a 43-kDa single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The native enzyme showed a molecular mass of 87 kDa by gel filtration chromatography, indicating that the enzyme acts as a dimer. It showed a narrow pH range for optimal activity, and its activity was clearly stimulated by the presence of several divalent cations, being maximal with Co(2+). The S. antibioticus OleG2 glycosyltransferase is proposed to transfer L-olivose to the oleandolide aglycon, which is then converted into L-oleandrose by the OleY methyltransferase. This represents an alternative route for L-oleandrose biosynthesis from that in the avermectin producer Streptomyces avermitilis, in which L-oleandrose is transferred to the aglycon by a glycosyltransferase.
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Affiliation(s)
- L Rodríguez
- Departamento de Biología Funcional e Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, 33006 Oviedo, Spain
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Agnihotri G, Liu HW. PLP and PMP Radicals: A New Paradigm in Coenzyme B6 Chemistry. Bioorg Chem 2001; 29:234-57. [PMID: 16256695 DOI: 10.1006/bioo.2001.1211] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2000] [Indexed: 11/22/2022]
Abstract
Enzymes frequently rely on a broad repertoire of cofactors to perform chemically challenging transformations. The B6 coenzymes, composed of pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate (PMP), are used by many transaminases, racemases, decarboxylases, and enzymes catalyzing alpha,beta and beta,gamma-eliminations. Despite the variety of reactions catalyzed by B6-dependent enzymes, the mechanism of almost all such enzymes is based on their ability to stabilize high-energy anionic intermediates in their reaction pathways by the pyridinium moiety of PLP/PMP. However, there are two notable exceptions to this model, which are discussed in this article. The first enzyme, lysine 2,3-aminomutase, is a PLP-dependent enzyme that catalyzes the interconversion of L-lysine to L-beta-lysine using a one-electron-based mechanism utilizing a [4Fe-4S] cluster and S-adenosylmethionine. The second enzyme, CDP-6-deoxy-L-threo-D-glycero-4-hexulose-3-dehydrase, is a PMP-dependent enzyme involved in the formation of 3,6-dideoxysugars in bacteria. This enzyme also contains an iron-sulfur cluster and uses a one-electron based mechanism to catalyze removal of a C-3 hydroxy group from a 4-hexulose. In both cases, the participation of free radicals in the reaction pathway has been established, placing these two B6-dependent enzymes in an exclusive class by themselves.
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Affiliation(s)
- G Agnihotri
- Division of Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, Texas 78712, USA
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Wohlert S, Lomovskaya N, Kulowski K, Fonstein L, Occi JL, Gewain KM, MacNeil DJ, Hutchinson CR. Insights about the biosynthesis of the avermectin deoxysugar L-oleandrose through heterologous expression of Streptomyces avermitilis deoxysugar genes in Streptomyces lividans. CHEMISTRY & BIOLOGY 2001; 8:681-700. [PMID: 11451669 DOI: 10.1016/s1074-5521(01)00043-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The avermectins, produced by Streptomyces avermitilis, are potent anthelminthic agents with a polyketide-derived macrolide skeleton linked to a disaccharide composed of two alpha-linked L-oleandrose units. Eight contiguous genes, avrBCDEFGHI (also called aveBI-BVIII), are located within the avermectin-producing gene cluster and have previously been mapped to the biosynthesis and attachment of thymidinediphospho-oleandrose to the avermectin aglycone. This gene cassette provides a convenient way to study the biosynthesis of 2,6-dideoxysugars, namely that of L-oleandrose, and to explore ways to alter the biosynthesis and structures of the avermectins by combinatorial biosynthesis. RESULTS A Streptomyces lividans strain harboring a single plasmid with the avrBCDEFGHI genes in which avrBEDC and avrIHGF were expressed under control of the actI and actIII promoters, respectively, correctly glycosylated exogenous avermectin A1a aglycone with identical oleandrose units to yield avermectin A1a. Modified versions of this minimal gene set produced novel mono- and disaccharide avermectins. The results provide further insight into the biosynthesis of L-oleandrose. CONCLUSIONS The plasmid-based reconstruction of the avr deoxysugar genes for expression in a heterologous system combined with biotransformation has led to new information about the mechanism of 2,6-deoxysugar biosynthesis. The structures of the di-demethyldeoxysugar avermectins accumulated indicate that in the oleandrose pathway the stereochemistry at C-3 is ultimately determined by the 3-O-methyltransferase and not by the 3-ketoreductase or a possible 3,5-epimerase. The AvrF protein is therefore a 5-epimerase and not a 3,5-epimerase. The ability of the AvrB (mono-)glycosyltransferase to accommodate different deoxysugar intermediates is evident from the structures of the novel avermectins produced.
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Affiliation(s)
- S Wohlert
- School of Pharmacy, University of Wisconsin, Madison, WI 53706, USA
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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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