1
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Hou X, Feng J, Franklin JL, Russo R, Guo Z, Zhou J, Gao JM, Liu HW, Wang B. Mechanistic Insights from the Crystal Structure and Computational Analysis of the Radical SAM Deaminase DesII. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2403494. [PMID: 38943270 DOI: 10.1002/advs.202403494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/06/2024] [Indexed: 07/01/2024]
Abstract
Radical S-adenosyl-L-methionine (SAM) enzymes couple the reductive cleavage of SAM to radical-mediated transformations that have proven to be quite broad in scope. DesII is one such enzyme from the biosynthetic pathway of TDP-desosamine where it catalyzes a radical-mediated deamination. Previous studies have suggested that this reaction proceeds via direct elimination of ammonia from an α-hydroxyalkyl radical or its conjugate base (i.e., a ketyl radical) rather than 1,2-migration of the amino group to form a carbinolamine radical intermediate. However, without a crystal structure, the active site features responsible for this chemistry have remained largely unknown. The crystallographic studies described herein help to fill this gap by providing a structural description of the DesII active site. Computational analyses based on the solved crystal structure are consistent with direct elimination and indicate that an active site glutamate residue likely serves as a general base to promote deprotonation of the α-hydroxyalkyl radical intermediate and elimination of the ammonia group.
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Affiliation(s)
- Xueli Hou
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi, 712100, China
- Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Jianqiang Feng
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, 361005, China
| | - Joseph Livy Franklin
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX, 78712, USA
| | - Ryan Russo
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX, 78712, USA
| | - Zhiyong Guo
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Jiahai Zhou
- Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023, China
| | - Jin-Ming Gao
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Hung-Wen Liu
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX, 78712, USA
- Department of Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, 361005, China
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2
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Prakash G, Paul N, Oliver GA, Werz DB, Maiti D. C-H deuteration of organic compounds and potential drug candidates. Chem Soc Rev 2022; 51:3123-3163. [PMID: 35320331 DOI: 10.1039/d0cs01496f] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
C-H deuteration has been intricately developed to satisfy the urgent need for site-selectively deuterated organic frameworks. Deuteration has been primarily used to study kinetic isotope effects of reactions but recently its significance in pharmaceutical chemistry has been discovered. Deuterium labelled compounds have stolen the limelight since the inception of the first FDA-approved deuterated drug, for the treatment of chorea-associated Huntington's disease, and their pharmacological importance was realised by chemists, although surprisingly very late. Various approaches were developed to carry out site-selective deuteration. However, the most common and efficient method is hydrogen isotope exchange (HIE). This review summarises deuteration methods of various organic motifs containing C(sp2)-H and C(sp3)-H bonds utilizing C-H bond functionalisation as a key step along with a variety of catalysts, and exemplifies their biological relevance.
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Affiliation(s)
- Gaurav Prakash
- Department of Chemistry, IIT Bombay, Powai, Mumbai-400076, India.
| | - Nilanjan Paul
- Department of Chemistry, IIT Bombay, Powai, Mumbai-400076, India.
| | - Gwyndaf A Oliver
- Technische Universität Braunschweig, Institute of Organic Chemistry, Hagenring 30, 38106 Braunschweig, Germany.
| | - Daniel B Werz
- Technische Universität Braunschweig, Institute of Organic Chemistry, Hagenring 30, 38106 Braunschweig, Germany.
| | - Debabrata Maiti
- Department of Chemistry, IIT Bombay, Powai, Mumbai-400076, India.
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3
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Lee YH, Hou X, Chen R, Feng J, Liu X, Ruszczycky MW, Gao JM, Wang B, Zhou J, Liu HW. Radical S-Adenosyl Methionine Enzyme BlsE Catalyzes a Radical-Mediated 1,2-Diol Dehydration during the Biosynthesis of Blasticidin S. J Am Chem Soc 2022; 144:4478-4486. [PMID: 35238201 DOI: 10.1021/jacs.1c12010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The biosynthesis of blasticidin S has drawn attention due to the participation of the radical S-adenosyl methionine (SAM) enzyme BlsE. The original assignment of BlsE as a radical-mediated, redox-neutral decarboxylase is unusual because this reaction appears to serve no biosynthetic purpose and would need to be reversed by a subsequent carboxylation step. Furthermore, with the exception of BlsE, all other radical SAM decarboxylases reported to date are oxidative in nature. Careful analysis of the BlsE reaction, however, demonstrates that BlsE is not a decarboxylase but instead a lyase that catalyzes the dehydration of cytosylglucuronic acid (CGA) to form cytosyl-4'-keto-3'-deoxy-d-glucuronic acid, which can rapidly decarboxylate nonenzymatically in vitro. Analysis of substrate isotopologs, fluorinated analogues, as well as computational models based on X-ray crystal structures of the BlsE·SAM (2.09 Å) and BlsE·SAM·CGA (2.62 Å) complexes suggests that BlsE catalysis likely proceeds via direct elimination of water from the CGA C4' α-hydroxyalkyl radical as opposed to 1,2-migration of the C3'-hydroxyl prior to dehydration. Biosynthetic and mechanistic implications of the revised assignment of BlsE are discussed.
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Affiliation(s)
- Yu-Hsuan Lee
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Xueli Hou
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, Shaanxi China.,State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Ridao Chen
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, United States.,State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Jianqiang Feng
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Xiao Liu
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, United States.,School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Mark W Ruszczycky
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, United States
| | - Jin-Ming Gao
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, Shaanxi China
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Jiahai Zhou
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.,CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Hung-Wen Liu
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.,Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, United States
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4
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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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5
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Xia A, Xie X, Hu X, Xu W, Liu Y. Dehalogenative Deuteration of Unactivated Alkyl Halides Using D 2O as the Deuterium Source. J Org Chem 2019; 84:13841-13857. [PMID: 31566377 DOI: 10.1021/acs.joc.9b02026] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The general dehalogenation of alkyl halides with zinc using D2O or H2O as a deuterium or hydrogen donor has been developed. The method provides an efficient and economic protocol for deuterium-labeled derivatives with a wide substrate scope under mild reaction conditions. Mechanistic studies indicated that a radical process is involved for the formation of organozinc intermediates. The facile hydrolysis of the organozinc intermediates provides the driving force for this transformation.
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Affiliation(s)
- Aiyou Xia
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences , Chinese Academy of Sciences , 345 Lingling Lu , Shanghai 200032 , People's Republic of China
| | - Xin Xie
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences , Chinese Academy of Sciences , 345 Lingling Lu , Shanghai 200032 , People's Republic of China
| | - Xiaoping Hu
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences , Chinese Academy of Sciences , 345 Lingling Lu , Shanghai 200032 , People's Republic of China
| | - Wei Xu
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences , Chinese Academy of Sciences , 345 Lingling Lu , Shanghai 200032 , People's Republic of China
| | - Yuanhong Liu
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences , Chinese Academy of Sciences , 345 Lingling Lu , Shanghai 200032 , People's Republic of China
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6
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Ruszczycky MW, Zhong A, Liu HW. Following the electrons: peculiarities in the catalytic cycles of radical SAM enzymes. Nat Prod Rep 2019; 35:615-621. [PMID: 29485151 DOI: 10.1039/c7np00058h] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Radical SAM enzymes use S-adenosyl-l-methionine as an oxidant to initiate radical-mediated transformations that would otherwise not be possible with Lewis acid/base chemistry alone. These reactions are either redox neutral or oxidative leading to certain expectations regarding the role of SAM as either a reusable cofactor or the ultimate electron acceptor during each turnover. However, these expectations are frequently not realized resulting in fundamental questions regarding the redox handling and movement of electrons associated with these biological catalysts. Herein we provide a focused perspective on several of these questions and associated hypotheses with an emphasis on recently discovered radical SAM enzymes.
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Affiliation(s)
- Mark W Ruszczycky
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, USA.
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7
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Kincannon WM, Bruender NA, Bandarian V. A Radical Clock Probe Uncouples H Atom Abstraction from Thioether Cross-Link Formation by the Radical S-Adenosyl-l-methionine Enzyme SkfB. Biochemistry 2018; 57:4816-4823. [PMID: 29965747 PMCID: PMC6094349 DOI: 10.1021/acs.biochem.8b00537] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Sporulation
killing factor (SKF) is a ribosomally synthesized and
post-translationally modified peptide (RiPP) produced by Bacillus. SKF contains a thioether cross-link between the α-carbon
at position 40 and the thiol of Cys32, introduced by a member of the
radical S-adenosyl-l-methionine (SAM) superfamily,
SkfB. Radical SAM enzymes employ a 4Fe–4S cluster to bind and
reductively cleave SAM to generate a 5′-deoxyadenosyl radical.
SkfB utilizes this radical intermediate to abstract the α-H
atom at Met40 to initiate cross-linking. In addition to the cluster
that binds SAM, SkfB also has an auxiliary cluster, the function of
which is not known. We demonstrate that a substrate analogue with
a cyclopropylglycine (CPG) moiety replacing the wild-type Met40 side
chain forgoes thioether cross-linking for an alternative radical ring
opening of the CPG side chain. The ring opening reaction also takes
place with a catalytically inactive SkfB variant in which the auxiliary
Fe–S cluster is absent. Therefore, the CPG-containing peptide
uncouples H atom abstraction from thioether bond formation, limiting
the role of the auxiliary cluster to promoting thioether cross-link
formation. CPG proves to be a valuable tool for uncoupling H atom
abstraction from peptide modification in RiPP maturases and demonstrates
potential to leverage RS enzyme reactivity to create noncanonical
amino acids.
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Affiliation(s)
- William M Kincannon
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112 , United States
| | - Nathan A Bruender
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112 , United States
| | - Vahe Bandarian
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112 , United States
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8
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Ko Y, Lin GM, Ruszczycky MW, Liu HW. Mechanistic Implications of the Deamination of TDP-4-amino-4-deoxy-d-fucose Catalyzed by the Radical SAM Enzyme DesII. Biochemistry 2018; 57:3130-3133. [PMID: 29473739 DOI: 10.1021/acs.biochem.8b00110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DesII is a radical SAM lyase that catalyzes a deamination reaction during the biosynthesis of desosamine in Streptomyces venezuelae. Competing mechanistic hypotheses for this radical-mediated reaction are differentiated according to whether a 1,2-migration takes place and the timing of proton abstraction following generation of a substrate α-hydroxyalkyl radical intermediate. In this study, the deuterated C4 epimer of the natural substrate, TDP-4-amino-4-deoxy-d-[3-2H]fucose, was prepared and shown to be a substrate for DesII undergoing deamination alone with a specific activity that is only marginally reduced (∼3-fold) with respect to that of deamination of the natural substrate. Furthermore, pH titration of the deamination reaction implicates the presence of a hydron acceptor that facilitates catalysis but does not appear to be necessary. On the basis of these as well as previously reported results, a mechanism involving direct elimination of ammonium with concerted proton transfer to the nucleofuge from the adjacent α-hydroxyalkyl radical is proposed.
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9
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Kim HJ, Liu YN, McCarty RM, Liu HW. Reaction Catalyzed by GenK, a Cobalamin-Dependent Radical S-Adenosyl-l-methionine Methyltransferase in the Biosynthetic Pathway of Gentamicin, Proceeds with Retention of Configuration. J Am Chem Soc 2017; 139:16084-16087. [PMID: 29091410 DOI: 10.1021/jacs.7b09890] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Many cobalamin (Cbl)-dependent radical S-adenosyl-l-methionine (SAM) methyltransferases have been identified through sequence alignment and/or genetic analysis; however, few have been studied in vitro. GenK is one such enzyme that catalyzes methylation of the 6'-carbon of gentamicin X2 (GenX2) to produce G418 during the biosynthesis of gentamicins. Reported herein, several alternative substrates and fluorinated substrate analogs were prepared to investigate the mechanism of methyl transfer from Cbl to the substrate as well as the substrate specificity of GenK. Experiments with deuterated substrates are also shown here to demonstrate that the 6'-pro-R-hydrogen atom of GenX2 is stereoselectively abstracted by the 5'-dAdo· radical and that methylation occurs with retention of configuration at C6'. Based on these observations, a model of GenK catalysis is proposed wherein free rotation of the radical-bearing carbon is prevented and the radical SAM machinery sits adjacent rather than opposite to the Me-Cbl cofactor with respect to the substrate in the enzyme active site.
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Affiliation(s)
- Hak Joong Kim
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, and Department of Chemistry, University of Texas at Austin , Austin, Texas 78712, United States
| | - Yung-Nan Liu
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, and Department of Chemistry, University of Texas at Austin , Austin, Texas 78712, United States
| | - Reid M McCarty
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, and Department of Chemistry, University of Texas at Austin , Austin, Texas 78712, United States
| | - Hung-Wen Liu
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, and Department of Chemistry, University of Texas at Austin , Austin, Texas 78712, United States
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10
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Michelotti A, Rodrigues F, Roche M. Development and Scale-Up of Stereoretentive α-Deuteration of Amines. Org Process Res Dev 2017. [DOI: 10.1021/acs.oprd.7b00227] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
| | - Fabien Rodrigues
- CortecNet, 15-17 Rue des Tilleuls, 78960 Voisins-le-Bretonneux, France
| | - Maxime Roche
- CortecNet, 15-17 Rue des Tilleuls, 78960 Voisins-le-Bretonneux, France
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11
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Liu L, Ji X, Li Y, Ji W, Mo T, Ding W, Zhang Q. A mechanistic study of the non-oxidative decarboxylation catalyzed by the radical S-adenosyl-l-methionine enzyme BlsE involved in blasticidin S biosynthesis. Chem Commun (Camb) 2017; 53:8952-8955. [DOI: 10.1039/c7cc04286h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BlsE-catalyzed non-oxidative decarboxylation is initiated by a hydrogen abstraction from a sugar carbon of the substrate cytosylglucuronic acid (CGA).
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Affiliation(s)
- Lei Liu
- College of Life Science & Biotechnology
- Mianyang Normal University
- Mianyang 621000
- P. R. China
- Department of Chemistry
| | - Xinjian Ji
- Department of Chemistry
- Fudan University
- Shanghai
- China
| | - Yongzhen Li
- Department of Chemistry
- Fudan University
- Shanghai
- China
- Medical College of Qinghai University
| | - Wenjuan Ji
- Department of Chemistry
- Fudan University
- Shanghai
- China
| | - Tianlu Mo
- Department of Chemistry
- Fudan University
- Shanghai
- China
| | - Wei Ding
- Department of Chemistry
- Fudan University
- Shanghai
- China
| | - Qi Zhang
- Department of Chemistry
- Fudan University
- Shanghai
- China
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12
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Bodea S, Funk MA, Balskus EP, Drennan CL. Molecular Basis of C-N Bond Cleavage by the Glycyl Radical Enzyme Choline Trimethylamine-Lyase. Cell Chem Biol 2016; 23:1206-1216. [PMID: 27642068 DOI: 10.1016/j.chembiol.2016.07.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 07/07/2016] [Accepted: 07/25/2016] [Indexed: 01/16/2023]
Abstract
Deamination of choline catalyzed by the glycyl radical enzyme choline trimethylamine-lyase (CutC) has emerged as an important route for the production of trimethylamine, a microbial metabolite associated with both human disease and biological methane production. Here, we have determined five high-resolution X-ray structures of wild-type CutC and mechanistically informative mutants in the presence of choline. Within an unexpectedly polar active site, CutC orients choline through hydrogen bonding with a putative general base, and through close interactions between phenolic and carboxylate oxygen atoms of the protein scaffold and the polarized methyl groups of the trimethylammonium moiety. These structural data, along with biochemical analysis of active site mutants, support a mechanism that involves direct elimination of trimethylamine. This work broadens our understanding of radical-based enzyme catalysis and will aid in the rational design of inhibitors of bacterial trimethylamine production.
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Affiliation(s)
- Smaranda Bodea
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA
| | - Michael A Funk
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts, Avenue 68-680, Cambridge, MA 02139, USA
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
| | - Catherine L Drennan
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts, Avenue 68-680, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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13
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Lv M, Ji X, Zhao J, Li Y, Zhang C, Su L, Ding W, Deng Z, Yu Y, Zhang Q. Characterization of a C3 Deoxygenation Pathway Reveals a Key Branch Point in Aminoglycoside Biosynthesis. J Am Chem Soc 2016; 138:6427-35. [PMID: 27120352 DOI: 10.1021/jacs.6b02221] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Apramycin is a clinically interesting aminoglycoside antibiotic (AGA) containing a highly unique bicyclic octose moiety, and this octose is deoxygenated at the C3 position. Although the biosynthetic pathways for most 2-deoxystreptamine-containing AGAs have been well characterized, the pathway for apramycin biosynthesis, including the C3 deoxygenation process, has long remained unknown. Here we report detailed investigation of apramycin biosynthesis by a series of genetic, biochemical and bioinformatical studies. We show that AprD4 is a novel radical S-adenosyl-l-methionine (SAM) enzyme, which uses a noncanonical CX3CX3C motif for binding of a [4Fe-4S] cluster and catalyzes the dehydration of paromamine, a pseudodisaccharide intermediate in apramycin biosynthesis. We also show that AprD3 is an NADPH-dependent reductase that catalyzes the reduction of the dehydrated product from AprD4-catalyzed reaction to generate lividamine, a C3' deoxygenated product of paromamine. AprD4 and AprD3 do not form a tight catalytic complex, as shown by protein complex immunoprecipitation and other assays. The AprD4/AprD3 enzyme system acts on different pseudodisaccharide substrates but does not catalyze the deoxygenation of oxyapramycin, an apramycin analogue containing a C3 hydroxyl group on the octose moiety, suggesting that oxyapramycin and apramycin are partitioned into two parallel pathways at an early biosynthetic stage. Functional dissection of the C6 dehydrogenase AprQ shows the crosstalk between different AGA biosynthetic gene clusters from the apramycin producer Streptomyces tenebrarius, and reveals the remarkable catalytic versatility of AprQ. Our study highlights the intriguing chemistry in apramycin biosynthesis and nature's ingenuity in combinatorial biosynthesis of natural products.
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Affiliation(s)
- Meinan Lv
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University , Wuhan, 430071, China
| | - Xinjian Ji
- Department of Chemistry, Fudan University , Shanghai, 200433, China
| | - Junfeng Zhao
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University , Wuhan, 430071, China.,Department of Chemistry, Fudan University , Shanghai, 200433, China
| | - Yongzhen Li
- Department of Chemistry, Fudan University , Shanghai, 200433, China
| | - Chen Zhang
- Department of Chemistry, Fudan University , Shanghai, 200433, China
| | - Li Su
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University , Wuhan, 430071, China
| | - Wei Ding
- Department of Chemistry, Fudan University , Shanghai, 200433, China
| | - Zixin Deng
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University , Wuhan, 430071, China
| | - Yi Yu
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University , Wuhan, 430071, China
| | - Qi Zhang
- Department of Chemistry, Fudan University , Shanghai, 200433, China
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14
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Kim HJ, LeVieux J, Yeh YC, Liu HW. C3'-Deoxygenation of Paromamine Catalyzed by a Radical S-Adenosylmethionine Enzyme: Characterization of the Enzyme AprD4 and Its Reductase Partner AprD3. Angew Chem Int Ed Engl 2016; 55:3724-8. [PMID: 26879038 PMCID: PMC4943880 DOI: 10.1002/anie.201510635] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Indexed: 11/06/2022]
Abstract
C3'-deoxygenation of aminoglycosides results in their decreased susceptibility to phosphorylation thereby increasing their efficacy as antibiotics. However, the biosynthetic mechanism of C3'-deoxygenation is unknown. To address this issue, aprD4 and aprD3 genes from the apramycin gene cluster in Streptomyces tenebrarius were expressed in E. coli and the resulting gene products were characterized in vitro. AprD4 is shown to be a radical S-adenosylmethionine (SAM) enzyme, catalyzing homolysis of SAM to 5'-deoxyadenosine (5'-dAdo) in the presence of paromamine. [4'-(2) H]-Paromamine was prepared and used to show that its C4'-H is transferred to 5'-dAdo by AprD4, during which the substrate is dehydrated to a product consistent with 4'-oxolividamine. In contrast, paromamine is reduced to a deoxy product when incubated with AprD4/AprD3/NADPH. These results show that AprD4 is the first radical SAM diol-dehydratase and, along with AprD3, is responsible for 3'-deoxygenation in aminoglycoside biosynthesis.
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Affiliation(s)
- Hak Joong Kim
- Division of Medicinal Chemistry, College of Pharmacy and Department of Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
| | - Jake LeVieux
- Division of Medicinal Chemistry, College of Pharmacy and Department of Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
| | - Yu-Cheng Yeh
- Division of Medicinal Chemistry, College of Pharmacy and Department of Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
| | - Hung-Wen Liu
- Division of Medicinal Chemistry, College of Pharmacy and Department of Chemistry, University of Texas at Austin, Austin, TX, 78712, USA.
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15
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Ji X, Li Y, Jia Y, Ding W, Zhang Q. Mechanistic Insights into the RadicalS-adenosyl-l-methionine Enzyme NosL From a Substrate Analogue and the Shunt Products. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201509900] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Xinjian Ji
- Department of Chemistry; Fudan University; Shanghai 200433 China
| | - Yongzhen Li
- Department of Chemistry; Fudan University; Shanghai 200433 China
| | - Youli Jia
- Department of Chemistry; Fudan University; Shanghai 200433 China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering; Gansu Province Lanzhou 730000 China
| | - Wei Ding
- Department of Chemistry; Fudan University; Shanghai 200433 China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering; Gansu Province Lanzhou 730000 China
| | - Qi Zhang
- Department of Chemistry; Fudan University; Shanghai 200433 China
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16
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Ji X, Li Y, Jia Y, Ding W, Zhang Q. Mechanistic Insights into the RadicalS-adenosyl-l-methionine Enzyme NosL From a Substrate Analogue and the Shunt Products. Angew Chem Int Ed Engl 2016; 55:3334-7. [DOI: 10.1002/anie.201509900] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Indexed: 01/17/2023]
Affiliation(s)
- Xinjian Ji
- Department of Chemistry; Fudan University; Shanghai 200433 China
| | - Yongzhen Li
- Department of Chemistry; Fudan University; Shanghai 200433 China
| | - Youli Jia
- Department of Chemistry; Fudan University; Shanghai 200433 China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering; Gansu Province Lanzhou 730000 China
| | - Wei Ding
- Department of Chemistry; Fudan University; Shanghai 200433 China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering; Gansu Province Lanzhou 730000 China
| | - Qi Zhang
- Department of Chemistry; Fudan University; Shanghai 200433 China
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17
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Ji X, Liu WQ, Yuan S, Yin Y, Ding W, Zhang Q. Mechanistic study of the radical SAM-dependent amine dehydrogenation reactions. Chem Commun (Camb) 2016; 52:10555-8. [DOI: 10.1039/c6cc05661j] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Radical SAM-dependent amine dehydrogenation of tryptophan andl–tyrosine has resulted from the 5′-deoxyadenosyl radical-mediated hydrogen abstraction from the Cα of the substrates.
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Affiliation(s)
- Xinjian Ji
- Department of Chemistry
- Fudan University
- Shanghai
- China
| | - Wan-Qiu Liu
- Department of Chemistry
- Fudan University
- Shanghai
- China
- School of Life Sciences
| | - Shuguang Yuan
- Institute of Chemical Sciences and Engineering
- Ecole Polytechnique Fédérale de Lausanne (EPFL)
- Lausanne
- Switzerland
| | - Yue Yin
- Department of Chemistry
- Fudan University
- Shanghai
- China
| | - Wei Ding
- Department of Chemistry
- Fudan University
- Shanghai
- China
- School of Life Sciences
| | - Qi Zhang
- Department of Chemistry
- Fudan University
- Shanghai
- China
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