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Li ZR, Li R, Pasternack L, Chen P, Wong CH. Chemical Synthesis of a Keto Sugar Nucleotide. J Org Chem 2023. [PMID: 37126664 DOI: 10.1021/acs.joc.3c00553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Keto sugar nucleotides (KSNs) are common and versatile precursors to various deoxy sugar nucleotides, which are substrates for the corresponding glycosyltransferases involved in the biosynthesis of glycoproteins, glycolipids, and natural products. However, there has been no KSN synthesized chemically due to the inherent instability. Herein, the first chemical synthesis of the archetypal KSN TDP-4-keto-6-deoxy-d-glucose (1) is achieved by an efficient and optimized route, providing feasible access to other KSNs and analogues, thereby opening a new avenue for new applications.
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Affiliation(s)
- Zhong-Rui Li
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Ruofan Li
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Laura Pasternack
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Pengxi Chen
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Chi-Huey Wong
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
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2
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l-amino acid ligase: A promising alternative for the biosynthesis of l-dipeptides. Enzyme Microb Technol 2020; 136:109537. [DOI: 10.1016/j.enzmictec.2020.109537] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/25/2020] [Accepted: 02/25/2020] [Indexed: 12/12/2022]
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3
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An Z, Dai Y, Jiang Y, He J. Asymmetric Knoevenagel‐Phospha‐Michael Tandem Reaction Synergistically Catalyzed by Achiral Silanols and Grafted Chiral Amines on Mesoporous Silica. ASIAN J ORG CHEM 2019. [DOI: 10.1002/ajoc.201900217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Zhe An
- State Key Laboratory of Chemical Resource Engineering & Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical Technology Beijing 100029 China
| | - Yan Dai
- State Key Laboratory of Chemical Resource Engineering & Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical Technology Beijing 100029 China
| | - Yitao Jiang
- State Key Laboratory of Chemical Resource Engineering & Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical Technology Beijing 100029 China
| | - Jing He
- State Key Laboratory of Chemical Resource Engineering & Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical Technology Beijing 100029 China
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4
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Ren Y, Hu L, Ramström O. Multienzymatic cascade synthesis of an enantiopure (2R,5R)-1,3-oxathiolane anti-HIV agent precursor. MOLECULAR CATALYSIS 2019. [DOI: 10.1016/j.mcat.2019.02.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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5
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Brown HA, Thoden JB, Tipton PA, Holden HM. The structure of glucose-1-phosphate thymidylyltransferase from Mycobacterium tuberculosis reveals the location of an essential magnesium ion in the RmlA-type enzymes. Protein Sci 2017; 27:441-450. [PMID: 29076563 DOI: 10.1002/pro.3333] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 10/20/2017] [Accepted: 10/23/2017] [Indexed: 11/11/2022]
Abstract
Tuberculosis, caused by the bacterium Mycobacterium tuberculosis, continues to be a major threat to populations worldwide. Whereas the disease is treatable, the drug regimen is arduous at best with the use of four antimicrobials over a six-month period. There is clearly a pressing need for the development of new therapeutics. One potential target for structure-based drug design is the enzyme RmlA, a glucose-1-phosphate thymidylyltransferase. This enzyme catalyzes the first step in the biosynthesis of l-rhamnose, which is a deoxysugar critical for the integrity of the bacterium's cell wall. Here, we report the X-ray structures of M. tuberculosis RmlA in complex with either dTTP or dTDP-glucose to 1.6 Å and 1.85 Å resolution, respectively. In the RmlA/dTTP complex, two magnesium ions were observed binding to the nucleotide, both ligated in octahedral coordination spheres. In the RmlA/dTDP-glucose complex, only a single magnesium ion was observed. Importantly, for RmlA-type enzymes with known three-dimensional structures, not one model shows the position of the magnesium ion bound to the nucleotide-linked sugar. As such, this investigation represents the first direct observation of the manner in which a magnesium ion is coordinated to the RmlA product and thus has important ramifications for structure-based drug design. In the past, molecular modeling procedures have been employed to derive a three-dimensional model of the M. tuberculosis RmlA for drug design. The X-ray structures presented herein provide a superior molecular scaffold for such endeavors in the treatment of one of the world's deadliest diseases.
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Affiliation(s)
- Haley A Brown
- Department of Biochemistry, University of Wisconsin, Madison, WI, 53706, USA
| | - James B Thoden
- Department of Biochemistry, University of Wisconsin, Madison, WI, 53706, USA
| | - Peter A Tipton
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin, Madison, WI, 53706, USA
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6
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Biswas A, Jasti S, Jeyakanthan J, Sekar K. Role of sequence evolution and conformational dynamics in the substrate specificity and oligomerization mode of thymidylate kinases. J Biomol Struct Dyn 2016; 35:2136-2154. [PMID: 27376462 DOI: 10.1080/07391102.2016.1207563] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Thymidylate kinase (TMK) is a key enzyme for the synthesis of DNA, making it an important target for the development of anticancer, antibacterial, and antiparasitic drugs. TMK homologs exhibit significant variations in sequence, residue conformation, substrate specificity, and oligomerization mode. However, the influence of sequence evolution and conformational dynamics on its quaternary structure and function has not been studied before. Based on extensive sequence and structure analyses, our study detected several non-conserved residues which are linked by co-evolution and are implicated in the observed variations in flexibility, oligomeric assembly, and substrate specificity among the homologs. These lead to differences in the pattern of interactions at the active site in TMKs of different specificity. The method was further tested on TMK from Sulfolobus tokodaii (StTMK) which has substantial differences in sequence and structure compared to other TMKs. Our analyses pointed to a more flexible dTMP-binding site in StTMK compared to the other homologs. Binding assays proved that the protein can accommodate both purine and pyrimidine nucleotides at the dTMP binding site with comparable affinity. Additionally, the residues responsible for the narrow specificity of Brugia malayi TMK, whose three-dimensional structure is unavailable, were detected. Our study provides a residue-level understanding of the differences observed among TMK homologs in previous experiments. It also illustrates the correlation among sequence evolution, conformational dynamics, oligomerization mode, and substrate recognition in TMKs and detects co-evolving residues that affect binding, which should be taken into account while designing novel inhibitors.
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Affiliation(s)
- Ansuman Biswas
- a Department of Physics , Indian Institute of Science , Bangalore 560012 , India
| | - Subbarao Jasti
- b Centre for Chemical Biology and Therapeutics, Institute for Stem Cell Biology and Regenerative Medicine , Bangalore 560065 , India
| | | | - Kanagaraj Sekar
- d Department of Computational and Data Sciences , Indian Institute of Science , Bangalore 560012 , India
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Chiu HT, Weng CP, Lin YC, Chen KH. Target-specific identification and characterization of the putative gene cluster for brasilinolide biosynthesis revealing the mechanistic insights and combinatorial synthetic utility of 2-deoxy-l-fucose biosynthetic enzymes. Org Biomol Chem 2016; 14:1988-2006. [DOI: 10.1039/c5ob02292d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
From Nocardia was cloned and functionally characterized a giant gene cluster for biosyntheses of brasilinolides as potent immunosuppressive and anticancer agents.
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Affiliation(s)
- Hsien-Tai Chiu
- Department of Chemistry
- National Cheng Kung University
- Tainan 701
- Taiwan
| | - Chien-Pao Weng
- Department of Chemistry
- National Cheng Kung University
- Tainan 701
- Taiwan
| | - Yu-Chin Lin
- Department of Chemistry
- National Cheng Kung University
- Tainan 701
- Taiwan
- Department of Biological Science and Technology
| | - Kuan-Hung Chen
- Department of Biological Science and Technology
- National Chiao Tung University
- Hsinchu 300
- Taiwan
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De Bruyn F, Maertens J, Beauprez J, Soetaert W, De Mey M. Biotechnological advances in UDP-sugar based glycosylation of small molecules. Biotechnol Adv 2015; 33:288-302. [PMID: 25698505 DOI: 10.1016/j.biotechadv.2015.02.005] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 12/19/2014] [Accepted: 02/09/2015] [Indexed: 01/04/2023]
Abstract
Glycosylation of small molecules like specialized (secondary) metabolites has a profound impact on their solubility, stability or bioactivity, making glycosides attractive compounds as food additives, therapeutics or nutraceuticals. The subsequently growing market demand has fuelled the development of various biotechnological processes, which can be divided in the in vitro (using enzymes) or in vivo (using whole cells) production of glycosides. In this context, uridine glycosyltransferases (UGTs) have emerged as promising catalysts for the regio- and stereoselective glycosylation of various small molecules, hereby using uridine diphosphate (UDP) sugars as activated glycosyldonors. This review gives an extensive overview of the recently developed in vivo production processes using UGTs and discusses the major routes towards UDP-sugar formation. Furthermore, the use of interconverting enzymes and glycorandomization is highlighted for the production of unusual or new-to-nature glycosides. Finally, the technological challenges and future trends in UDP-sugar based glycosylation are critically evaluated and summarized.
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Affiliation(s)
- Frederik De Bruyn
- Centre of Expertise-Industrial Biotechnology and Biocatalysis, Department of Biochemical and Microbial Technology, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Jo Maertens
- Centre of Expertise-Industrial Biotechnology and Biocatalysis, Department of Biochemical and Microbial Technology, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Joeri Beauprez
- Centre of Expertise-Industrial Biotechnology and Biocatalysis, Department of Biochemical and Microbial Technology, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Wim Soetaert
- Centre of Expertise-Industrial Biotechnology and Biocatalysis, Department of Biochemical and Microbial Technology, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Marjan De Mey
- Centre of Expertise-Industrial Biotechnology and Biocatalysis, Department of Biochemical and Microbial Technology, Ghent University, Coupure links 653, 9000 Ghent, Belgium.
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Ko Y, Ruszczycky MW, Choi SH, Liu HW. Mechanistic studies of the radical S-adenosylmethionine enzyme DesII with TDP-D-fucose. Angew Chem Int Ed Engl 2015; 54:860-3. [PMID: 25418063 PMCID: PMC4293265 DOI: 10.1002/anie.201409540] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Indexed: 11/06/2022]
Abstract
DesII is a radical S-adenosylmethionine (SAM) enzyme that catalyzes the C4-deamination of TDP-4-amino-4,6-dideoxyglucose through a C3 radical intermediate. However, if the C4 amino group is replaced with a hydroxy group (to give TDP-quinovose), the hydroxy group at C3 is oxidized to a ketone with no C4-dehydration. It is hypothesized that hyperconjugation between the C4 C-N/O bond and the partially filled p orbital at C3 of the radical intermediate modulates the degree to which elimination competes with dehydrogenation. To investigate this hypothesis, the reaction of DesII with the C4-epimer of TDP-quinovose (TDP-fucose) was examined. The reaction primarily results in the formation of TDP-6-deoxygulose and likely regeneration of TDP-fucose. The remainder of the substrate radical partitions roughly equally between C3-dehydrogenation and C4-dehydration. Thus, changing the stereochemistry at C4 permits a more balanced competition between elimination and dehydrogenation.
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Affiliation(s)
- Yeonjin Ko
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Mark W. Ruszczycky
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Sei-Hyun Choi
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Hung-wen Liu
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
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Ko Y, Ruszczycky MW, Choi SH, Liu HW. Mechanistic Studies of the RadicalS-Adenosylmethionine Enzyme DesII with TDP-D-Fucose. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201409540] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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12
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Le TT, Pandey RP, Gurung RB, Dhakal D, Sohng JK. Efficient enzymatic systems for synthesis of novel α-mangostin glycosides exhibiting antibacterial activity against Gram-positive bacteria. Appl Microbiol Biotechnol 2014; 98:8527-38. [PMID: 25038930 DOI: 10.1007/s00253-014-5947-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Revised: 06/18/2014] [Accepted: 07/07/2014] [Indexed: 11/26/2022]
Abstract
Two enzymatic systems were developed for the efficient synthesis of glycoside products of α-mangostin, a natural xanthonoid exhibiting anti-oxidant, antibacterial, anti-inflammatory, and anticancer activities. In these systems, one-pot reactions for the synthesis of UDP-α-D-glucose and UDP-α-D-2-deoxyglucose were modified and combined with a glycosyltransferase (GT) from Bacillus licheniformis DSM-13 to afford C-3 and C-6 position modified glucose and 2-deoxyglucose conjugated novel α-mangostin derivatives. α-Mangostin 3-O-β-D-glucopyranoside, α-mangostin 6-O-β-D-glucopyranoside, α-mangostin 3,6-di-O-β-D-glucopyranoside, α-mangostin 3-O-β-D-2-deoxyglucopyranoside, α-mangostin 6-O-β-D-2-deoxyglucopyranoside, and α-mangostin 3,6-di-O-β-D-2-deoxyglucopyranoside were successfully produced in practical quantities and characterized by high-resolution quadruple time-of-flight electrospray ionization-mass spectrometry (HR-QTOF ESI/MS), (1)H and (13)C NMR analyses. In excess of the substrate, the maximum productions of three α-mangostin glucopyranosides (4.8 mg/mL, 86.5 % overall conversion of α-mangostin) and three α-mangostin 2-deoxyglucopyronosides (4.0 mg/mL, 79 % overall conversion of α-mangostin) were achieved at 4-h incubation period. All the α-mangostin glycosides exhibited improved water solubility, and their antibacterial activity against three Gram-positive bacteria Micrococcus luteus, Bacillus subtilis, and Staphylococcus aureus was drastically enhanced by the glucosylation at C-3 position. In this study, diverse glycosylated α-mangostin were produced in significant quantities by using inexpensive starting materials and recycling co-factors within a reaction vessel without use of expensive NDP-sugars in the glycosylation reactions.
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Affiliation(s)
- Tuoi Thi Le
- Institute of Biomolecule Reconstruction (iBR), Department of Pharmaceutical Engineering, Sun Moon University, #100, Kalsan-ri, Tangjeong-myeon, Asan-si, Chungnam, 336-708, Republic of Korea
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Al-Mestarihi A, Romo A, Liu HW, Bachmann BO. Nitrososynthase-triggered oxidative carbon-carbon bond cleavage in baumycin biosynthesis. J Am Chem Soc 2013; 135:11457-60. [PMID: 23885759 DOI: 10.1021/ja404987r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Baumycins are coproduced with the clinically important anticancer secondary metabolites daunorubicin and doxorubicin, which are glycosylated anthracyclines isolated from Streptomyces peucetius. The distinguishing feature of baumycins is the presence of an unusual acetal moiety appended to daunosamine, which is hydrolyzed during acidic extraction of daunorubicin from fermentation broth. The structure of the baumycin acetal suggests that it is likely derived from an unknown C3″-methyl deoxysugar cleaved between the C3″ and C4″ positions. This is supported by analysis of the baumycin/daunorubicin biosynthetic gene cluster (dox), which also encodes putative proteins consistent with production of an anthracycline dissacharide containing a branched sugar. Notably, the dnmZ gene in the dox gene cluster possesses high translated sequence similarity to nitrososynthases, which are flavin-dependent amine monooxygenases involved in the four-electron oxidation of amino sugars to nitroso sugars. Herein we demonstrate that DnmZ is an amino sugar nitrososynthase that initiates the conversion of thymidine-5'-diphosphate-l-epi-vancosamine to a ring-opened product via a previously uncharacterized retro oxime-aldol reaction.
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Affiliation(s)
- Ahmad Al-Mestarihi
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA
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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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Yang S, He J. Heterogeneous asymmetric Henry–Michael one-pot reaction synergically catalyzed by grafted chiral bases and inherent achiral hydroxyls on mesoporous silica surface. Chem Commun (Camb) 2012; 48:10349-51. [DOI: 10.1039/c2cc35110b] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Romo AJ, Liu HW. Mechanisms and structures of vitamin B(6)-dependent enzymes involved in deoxy sugar biosynthesis. BIOCHIMICA ET BIOPHYSICA ACTA 2011; 1814:1534-47. [PMID: 21315852 PMCID: PMC3115481 DOI: 10.1016/j.bbapap.2011.02.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 01/08/2011] [Accepted: 02/01/2011] [Indexed: 10/18/2022]
Abstract
PLP is well-regarded for its role as a coenzyme in a number of diverse enzymatic reactions. Transamination, deoxygenation, and aldol reactions mediated by PLP-dependent enzymes enliven and enrich deoxy sugar biosynthesis, endowing these compounds with unique structures and contributing to their roles as determinants of biological activity in many natural products. The importance of deoxy aminosugars in natural product biosynthesis has spurred several recent structural investigations of sugar aminotransferases. The structure of a PMP-dependent enzyme catalyzing the C-3 deoxygenation reaction in the biosynthesis of ascarylose was also determined. These studies, and the crystal structures they have provided, offer a wealth of new insights regarding the enzymology of PLP/PMP-dependent enzymes in deoxy sugar biosynthesis. In this review, we consider these recent achievements in the structural biology of deoxy sugar biosynthetic enzymes and the important implications they hold for understanding enzyme catalysis and natural product biosynthesis in general. This article is part of a Special Issue entitled: Pyridoxal Phosphate Enzymology.
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Affiliation(s)
- Anthony J. Romo
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - Hung-wen Liu
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
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Gantt RW, Peltier-Pain P, Cournoyer WJ, Thorson JS. Using simple donors to drive the equilibria of glycosyltransferase-catalyzed reactions. Nat Chem Biol 2011; 7:685-91. [PMID: 21857660 PMCID: PMC3177962 DOI: 10.1038/nchembio.638] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 06/24/2011] [Indexed: 12/17/2022]
Abstract
We report that simple glycoside donors can drastically shift the equilibria of glycosyltransferase-catalyzed reactions, transforming NDP-sugar formation from an endothermic to an exothermic process. To demonstrate the utility of this thermodynamic adaptability, we highlight the glycosyltransferase-catalyzed synthesis of 22 sugar nucleotides from simple aromatic sugar donors, as well as the corresponding in situ formation of sugar nucleotides as a driving force in the context of glycosyltransferase-catalyzed reactions for small-molecule glycodiversification. These simple aromatic donors also enabled a general colorimetric assay for glycosyltransfer, applicable to drug discovery, protein engineering and other fundamental sugar nucleotide-dependent investigations. This study directly challenges the general notion that NDP-sugars are 'high-energy' sugar donors when taken out of their traditional biological context.
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Affiliation(s)
- Richard W. Gantt
- Pharmaceutical Sciences Division, School of Pharmacy, Wisconsin Center for Natural Products Research, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705-2222, USA
| | - Pauline Peltier-Pain
- Pharmaceutical Sciences Division, School of Pharmacy, Wisconsin Center for Natural Products Research, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705-2222, USA
| | - William J. Cournoyer
- Pharmaceutical Sciences Division, School of Pharmacy, Wisconsin Center for Natural Products Research, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705-2222, USA
| | - Jon S. Thorson
- Pharmaceutical Sciences Division, School of Pharmacy, Wisconsin Center for Natural Products Research, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705-2222, USA
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Kharel MK, Lian H, Rohr J. Characterization of the TDP-D-ravidosamine biosynthetic pathway: one-pot enzymatic synthesis of TDP-D-ravidosamine from thymidine-5-phosphate and glucose-1-phosphate. Org Biomol Chem 2011; 9:1799-808. [PMID: 21264378 PMCID: PMC4482361 DOI: 10.1039/c0ob00854k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ravidomycin V and related compounds, e.g., FE35A-B, exhibit potent anticancer activities against various cancer cell lines in the presence of visible light. The amino sugar moieties (D-ravidosamine and its analogues, respectively) in these molecules contribute to the higher potencies of ravidomycin and analogues when compared to closely related compounds with neutral or branched sugars. Within the ravidomycin V biosynthetic gene cluster, five putative genes encoding NDP-D-ravidosamine biosynthetic enzymes were identified. Through the activities of the isolated enzymes in vitro, it is demonstrated that ravD, ravE, ravIM, ravAMT and ravNMT encode TDP-D-glucose synthase, TDP-4-keto-6-deoxy-D-glucose-4,6-dehydratase, TDP-4-keto-6-deoxy-D-glucose-3,4-ketoisomerase, TDP-3-keto-6-deoxy-D-galactose-3-aminotransferase, and TDP-3-amino-3,6-dideoxy-D-galactose-N,N-dimethyl-transferase, respectively. A protocol for a one-pot enzymatic synthesis of TDP-D-ravidosamine has been developed. The results presented here now set the stage to produce TDP-D-ravidosamine routinely for glycosylation studies.
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Affiliation(s)
- Madan K. Kharel
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Hui Lian
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Jürgen Rohr
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
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Gantt RW, Peltier-Pain P, Thorson JS. Enzymatic methods for glyco(diversification/randomization) of drugs and small molecules. Nat Prod Rep 2011; 28:1811-53. [DOI: 10.1039/c1np00045d] [Citation(s) in RCA: 194] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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20
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Vey JL, Al-Mestarihi A, Hu Y, Funk MA, Bachmann BO, Iverson TM. Structure and mechanism of ORF36, an amino sugar oxidizing enzyme in everninomicin biosynthesis . Biochemistry 2010; 49:9306-17. [PMID: 20866105 DOI: 10.1021/bi101336u] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Everninomicin is a highly modified octasaccharide that belongs to the orthosomycin family of antibiotics and possesses potent Gram-positive antibiotic activity, including broad-spectrum efficacy against multidrug resistant enterococci and Staphylococcus aureus. Among its distinctive structural features is a nitro sugar, l-evernitrose, analogues of which decorate a variety of natural products. Recently, we identified a nitrososynthase enzyme encoded by orf36 from Micromonospora carbonacea var. africana that mediates the flavin-dependent double oxidation of synthetically generated thymidine diphosphate (TDP)-l-epi-vancosamine to the corresponding nitroso sugar. Herein, we utilize a five-enzyme in vitro pathway both to verify that ORF36 catalyzes oxidation of biogenic TDP-l-epi-vancosamine and to determine whether ORF36 exhibits catalytic competence for any of its biosynthetic progenitors, which are candidate substrates for nitrososynthases in vivo. Progenitors solely undergo single-oxidation reactions and terminate in the hydroxylamine oxidation state. Performing the in vitro reactions in the presence of (18)O(2) establishes that molecular oxygen, rather than oxygen from water, is incorporated into ORF36-generated intermediates and products and identifies an off-pathway product that correlates with the oxidation product of a progenitor substrate. The 3.15 Å resolution X-ray crystal structure of ORF36 reveals a tetrameric enzyme that shares a fold with acyl-CoA dehydrogenases and class D flavin-containing monooxygenases, including the nitrososynthase KijD3. However, ORF36 and KijD3 have unusually open active sites in comparison to these related enzymes. Taken together, these studies map substrate determinants and allow the proposal of a minimal monooxygenase mechanism for amino sugar oxidation by ORF36.
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Affiliation(s)
- Jessica L Vey
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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21
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Kalaitzakis D, Smonou I. A Two-Step, One-Pot Enzymatic Synthesis of 2-Substituted 1,3-Diols. J Org Chem 2010; 75:8658-61. [DOI: 10.1021/jo101519t] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Ioulia Smonou
- Department of Chemistry, University of Crete, Heraklion 71003, Crete, Greece
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22
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Kharel MK, Pahari P, Lian H, Rohr J. Enzymatic total synthesis of rabelomycin, an angucycline group antibiotic. Org Lett 2010; 12:2814-7. [PMID: 20486694 DOI: 10.1021/ol1009009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A one-pot enzymatic total synthesis of angucycline antibiotic rabelomycin was accomplished, starting from acetyl-CoA and malonyl-CoA, using a mixture of polyketide synthase (PKS) enzymes of the gilvocarcin, ravidomycin, and jadomycin biosynthetic pathways. The in vitro results were compared to in vivo catalysis using analogous sets of enzymes.
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Affiliation(s)
- Madan Kumar Kharel
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky 40536, USA
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23
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Ruszczycky MW, Choi SH, Liu HW. Stoichiometry of the redox neutral deamination and oxidative dehydrogenation reactions catalyzed by the radical SAM enzyme DesII. J Am Chem Soc 2010; 132:2359-69. [PMID: 20121093 DOI: 10.1021/ja909451a] [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
DesII from Streptomyces venezuelae is a radical SAM (S-adenosyl-l-methionine) enzyme that catalyzes the deamination of TDP-4-amino-4,6-dideoxy-d-glucose to form TDP-3-keto-4,6-dideoxy-d-glucose in the biosynthesis of TDP-d-desosamine. DesII also catalyzes the dehydrogenation of the nonphysiological substrate TDP-D-quinovose to TDP-3-keto-6-deoxy-d-glucose. These properties prompted an investigation of how DesII handles SAM in the redox neutral deamination versus the oxidative dehydrogenation reactions. This work was facilitated by the development of an enzymatic synthesis of TDP-4-amino-4,6-dideoxy-d-glucose that couples a transamination equilibrium to the thermodynamically favorable oxidation of formate. In this study, DesII is found to consume SAM versus TDP-sugar with stoichiometries of 0.96 +/- 0.05 and 1.01 +/- 0.05 in the deamination and dehydrogenation reactions, respectively, using Na(2)S(2)O(4) as the reductant. Importantly, no significant change in stoichiometry is observed when the flavodoxin/flavodoxin NADP(+) oxidoreductase/NADPH reducing system is used in place of Na(2)S(2)O(4). Moreover, there is no evidence of an uncoupled or abortive process in the deamination reaction, as indicated by the observation that dehydrogenation can take place in the absence of an external source of reductant whereas deamination cannot. Mechanistic and biochemical implications of these results are discussed.
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Affiliation(s)
- Mark W Ruszczycky
- 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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Szu PH, Ruszczycky MW, Choi SH, Yan F, Liu HW. Characterization and mechanistic studies of DesII: a radical S-adenosyl-L-methionine enzyme involved in the biosynthesis of TDP-D-desosamine. J Am Chem Soc 2009; 131:14030-42. [PMID: 19746907 PMCID: PMC2780582 DOI: 10.1021/ja903354k] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
D-desosamine (1) is a 3-(N,N-dimethylamino)-3,4,6-trideoxyhexose found in a number of macrolide antibiotics including methymycin (2), neomethymycin (3), pikromycin (4), and narbomycin (5) produced by Streptomyces venezuelae . It plays an essential role in conferring biological activities to its parent aglycones. Previous genetic and biochemical studies of the biosynthesis of desosamine in S. venezuelae showed that the conversion of TDP-4-amino-4,6-dideoxy-D-glucose (8) to TDP-3-keto-4,6-dideoxy-D-glucose (9) is catalyzed by DesII, which is a member of the radical S-adenosyl-L-methionine (SAM) enzyme superfamily. Here, we report the purification and reconstitution of His(6)-tagged DesII, characterization of its [4Fe-4S] cluster using UV-vis and EPR spectroscopies, and the capability of flavodoxin, flavodoxin reductase, and NADPH to reduce the [4Fe-4S](2+) cluster. Also included are a steady-state kinetic analysis of DesII-catalyzed reaction and an investigation of the substrate flexibility of DesII. Studies of deuterium incorporation into SAM using TDP-[3-(2)H]-4-amino-4,6-dideoxy-D-glucose as the substrate provides strong evidence for direct hydrogen atom transfer to a 5'-deoxyadenosyl radical in the catalytic cycle. The fact that hydrogen atom abstraction occurs at C-3 also sheds light on the mechanism of this intriguing deamination reaction.
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Affiliation(s)
- Ping-Hui Szu
- 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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25
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Wu Q, Xu JM, Xia L, Wang JL, Lin XF. Promiscuous Zinc-Dependent Acylase-Mediated One-Pot Synthesis of Monosaccharide-Containing Pyrimidine Derivatives in Organic Medium. Adv Synth Catal 2009. [DOI: 10.1002/adsc.200900161] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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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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27
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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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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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29
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Thibodeaux CJ, Melançon CE, Liu HW. Natural-product sugar biosynthesis and enzymatic glycodiversification. Angew Chem Int Ed Engl 2008. [PMID: 19058170 DOI: 10.1002/anie] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
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 78712, USA
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30
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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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31
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Zhang C, Fu Q, Albermann C, Li L, Thorson JS. The in vitro characterization of the erythronolide mycarosyltransferase EryBV and its utility in macrolide diversification. Chembiochem 2007; 8:385-90. [PMID: 17262863 DOI: 10.1002/cbic.200600509] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Changsheng Zhang
- Laboratory for Biosynthetic Chemistry, University of Wisconsin, National Cooperative Drug Discovery Group, Pharmaceutical Sciences Division, School of Pharmacy, Madison, WI 53705, USA
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32
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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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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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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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