1
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Li Y, Shi H, Yin G. Synthetic techniques for thermodynamically disfavoured substituted six-membered rings. Nat Rev Chem 2024; 8:535-550. [PMID: 38822206 DOI: 10.1038/s41570-024-00612-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2024] [Indexed: 06/02/2024]
Abstract
Six-membered rings are ubiquitous structural motifs in bioactive compounds and multifunctional materials. Notably, their thermodynamically disfavoured isomers, like disubstituted cyclohexanes featuring one substituent in an equatorial position and the other in an axial position, often exhibit enhanced physical and biological activities in comparison with their opposite isomers. However, the synthesis of thermodynamically disfavoured isomers is, by its nature, challenging, with only a limited number of possible approaches. In this Review, we summarize and compare synthetic methodologies that produce substituted six-membered rings with thermodynamically disfavoured substitution patterns. We place particular emphasis on elucidating the crucial stereoinduction factors within each transformation. Our aim is to stimulate interest in the synthesis of these unique structures, while simultaneously providing synthetic chemists with a guide to approaching this synthetic challenge.
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Affiliation(s)
- Yangyang Li
- The Institute for Advanced Studies, Wuhan University, Wuhan, Hubei Province, China
| | - Hongjin Shi
- The Institute for Advanced Studies, Wuhan University, Wuhan, Hubei Province, China
| | - Guoyin Yin
- The Institute for Advanced Studies, Wuhan University, Wuhan, Hubei Province, China.
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2
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Kubiak X, Polsinelli I, Chavas LMG, Fyfe CD, Guillot A, Fradale L, Brewee C, Grimaldi S, Gerbaud G, Thureau A, Legrand P, Berteau O, Benjdia A. Structural and mechanistic basis for RiPP epimerization by a radical SAM enzyme. Nat Chem Biol 2024; 20:382-391. [PMID: 38158457 DOI: 10.1038/s41589-023-01493-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/30/2023] [Indexed: 01/03/2024]
Abstract
D-Amino acid residues, found in countless peptides and natural products including ribosomally synthesized and post-translationally modified peptides (RiPPs), are critical for the bioactivity of several antibiotics and toxins. Recently, radical S-adenosyl-L-methionine (SAM) enzymes have emerged as the only biocatalysts capable of installing direct and irreversible epimerization in RiPPs. However, the mechanism underpinning this biochemical process is ill-understood and the structural basis for this post-translational modification remains unknown. Here we report an atomic-resolution crystal structure of a RiPP-modifying radical SAM enzyme in complex with its substrate properly positioned in the active site. Crystallographic snapshots, size-exclusion chromatography-small-angle x-ray scattering, electron paramagnetic resonance spectroscopy and biochemical analyses reveal how epimerizations are installed in RiPPs and support an unprecedented enzyme mechanism for peptide epimerization. Collectively, our study brings unique perspectives on how radical SAM enzymes interact with RiPPs and catalyze post-translational modifications in natural products.
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Affiliation(s)
- Xavier Kubiak
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | - Ivan Polsinelli
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | | | - Cameron D Fyfe
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | - Alain Guillot
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | - Laura Fradale
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | - Clémence Brewee
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | | | | | - Aurélien Thureau
- Synchrotron SOLEIL, HelioBio Group, L'Orme des Merisiers, Saint-Aubin, France
| | - Pierre Legrand
- Synchrotron SOLEIL, HelioBio Group, L'Orme des Merisiers, Saint-Aubin, France
| | - Olivier Berteau
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France.
| | - Alhosna Benjdia
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France.
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3
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Walls WG, Vagstad A, Delridge T, Piel J, Broderick WE, Broderick JB. Direct Detection of the α-Carbon Radical Intermediate Formed by OspD: Mechanistic Insights into Radical S-Adenosyl-l-methionine Peptide Epimerization. J Am Chem Soc 2024; 146:5550-5559. [PMID: 38364824 PMCID: PMC11302384 DOI: 10.1021/jacs.3c13829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2024]
Abstract
OspD is a radical S-adenosyl-l-methionine (SAM) peptide epimerase that converts an isoleucine (Ile) and valine (Val) of the OspA substrate to d-amino acids during biosynthesis of the ribosomally synthesized and post-translationally modified peptide (RiPP) natural product landornamide A. OspD is proposed to carry out this reaction via α-carbon (Cα) H-atom abstraction to form a peptidyl Cα radical that is stereospecifically quenched by hydrogen atom transfer (HAT) from a conserved cysteine (Cys). Here we use site-directed mutagenesis, freeze-quench trapping, isotopic labeling, and electron paramagnetic resonance (EPR) spectroscopy to provide new insights into the OspD catalytic mechanism including the direct observation of the substrate peptide Cα radical intermediate. The putative quenching Cys334 was changed to serine to generate an OspD C334S variant impaired in HAT quenching. The reaction of reduced OspD C334S with SAM and OspA freeze-quenched at 15 s exhibits a doublet EPR signal characteristic of a Cα radical coupled to a single β-H. Using isotopologues of OspA deuterated at either Ile or Val, or both Ile and Val, reveals that the initial Cα radical intermediate forms exclusively on the Ile of OspA. Time-dependent freeze quench coupled with EPR spectroscopy provided evidence for loss of the Ile Cα radical concomitant with gain of a Val Cα radical, directly demonstrating the N-to-C directionality of epimerization by OspD. These results provide direct evidence for the aforementioned OspD-catalyzed peptide epimerization mechanism via a central Cα radical intermediate during RiPP maturation of OspA, a mechanism that may extend to other proteusin peptide epimerases.
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Affiliation(s)
- William G. Walls
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, United States
| | - Anna Vagstad
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Vladimir-Prelog-Weg 4, Zürich 8093, Switzerland
| | - Tyler Delridge
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, United States
| | - Jörn Piel
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Vladimir-Prelog-Weg 4, Zürich 8093, Switzerland
| | - William E. Broderick
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, United States
| | - Joan B. Broderick
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, United States
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4
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Bearne SL. Design and evaluation of substrate-product analog inhibitors for racemases and epimerases utilizing a 1,1-proton transfer mechanism. Methods Enzymol 2023; 690:397-444. [PMID: 37858537 DOI: 10.1016/bs.mie.2023.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
Racemases and epimerases catalyze the inversion of stereochemistry at asymmetric carbon atoms to generate stereoisomers that often play important roles in normal and pathological physiology. Consequently, there is interest in developing inhibitors of these enzymes for drug discovery. A strategy for the rational design of substrate-product analog (SPA) inhibitors of racemases and epimerases utilizing a direct 1,1-proton transfer mechanism is elaborated. This strategy assumes that two groups on the asymmetric carbon atom remain fixed at active-site binding determinants, while the hydrogen and third, motile group move during catalysis, with the latter potentially traveling between an R- and S-pocket at the active site. SPAs incorporate structural features of the substrate and product, often with geminal disubstitution on the asymmetric carbon atom to simultaneously present the motile group to both the R- and S-pockets. For racemases operating on substrates bearing three polar groups (glutamate, aspartate, and serine racemases) or with compact, hydrophobic binding pockets (proline racemase), substituent motion is limited and the design strategy furnishes inhibitors with poor or modest binding affinities. The approach is most successful when substrates have a large, motile hydrophobic group that binds at a plastic and/or capacious hydrophobic site. Potent inhibitors were developed for mandelate racemase, isoleucine epimerase, and α-methylacyl-CoA racemase using the SPA inhibitor design strategy, exhibiting binding affinities ranging from substrate-like to exceeding that of the substrate by 100-fold. This rational approach for designing inhibitors of racemases and epimerases having the appropriate active-site architectures is a useful strategy for furnishing compounds for drug development.
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Affiliation(s)
- Stephen L Bearne
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada; Department of Chemistry, Dalhousie University, Halifax, NS, Canada.
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5
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Hejna BG, Ganley JM, Shao H, Tian H, Ellefsen JD, Fastuca NJ, Houk KN, Miller SJ, Knowles RR. Catalytic Asymmetric Hydrogen Atom Transfer: Enantioselective Hydroamination of Alkenes. J Am Chem Soc 2023; 145:16118-16129. [PMID: 37432783 PMCID: PMC10544660 DOI: 10.1021/jacs.3c04591] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2023]
Abstract
We report a highly enantioselective radical-based hydroamination of enol esters with sulfonamides jointly catalyzed by an Ir photocatalyst, Brønsted base, and tetrapeptide thiol. This method is demonstrated for the formation of 23 protected β-amino-alcohol products, achieving selectivities up to 97:3 er. The stereochemistry of the product is set through selective hydrogen atom transfer from the chiral thiol catalyst to a prochiral C-centered radical. Structure-selectivity relationships derived from structural variation of both the peptide catalyst and olefin substrate provide key insights into the development of an optimal catalyst. Experimental and computational mechanistic studies indicate that hydrogen-bonding, π-π stacking, and London dispersion interactions are contributing factors for substrate recognition and enantioinduction. These findings further the development of radical-based asymmetric catalysis and contribute to the understanding of the noncovalent interactions relevant to such transformations.
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Affiliation(s)
- Benjamin G. Hejna
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Jacob M. Ganley
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Huiling Shao
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Haowen Tian
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Jonathan D. Ellefsen
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Nicholas J. Fastuca
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - K. N. Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Scott J. Miller
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Robert R. Knowles
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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6
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Hazra S, Begley TP. Alkylcysteine Sulfoxide C-S Monooxygenase Uses a Flavin-Dependent Pummerer Rearrangement. J Am Chem Soc 2023; 145:11933-11938. [PMID: 37229602 PMCID: PMC10863075 DOI: 10.1021/jacs.3c03545] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Indexed: 05/27/2023]
Abstract
Flavoenzymes are highly versatile and participate in the catalysis of a wide range of reactions, including key reactions in the metabolism of sulfur-containing compounds. S-Alkyl cysteine is formed primarily by the degradation of S-alkyl glutathione generated during electrophile detoxification. A recently discovered S-alkyl cysteine salvage pathway uses two flavoenzymes (CmoO and CmoJ) to dealkylate this metabolite in soil bacteria. CmoO catalyzes a stereospecific sulfoxidation, and CmoJ catalyzes the cleavage of one of the sulfoxide C-S bonds in a new reaction of unknown mechanism. In this paper, we investigate the mechanism of CmoJ. We provide experimental evidence that eliminates carbanion and radical intermediates and conclude that the reaction proceeds via an unprecedented enzyme-mediated modified Pummerer rearrangement. The elucidation of the mechanism of CmoJ adds a new motif to the flavoenzymology of sulfur-containing natural products and demonstrates a new strategy for the enzyme-catalyzed cleavage of C-S bonds.
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Affiliation(s)
- Sohan Hazra
- Department of Chemistry, Texas A&M University, College
Station, Texas 77843, United States
| | - Tadhg P. Begley
- Department of Chemistry, Texas A&M University, College
Station, Texas 77843, United States
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7
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Li X, Yu F, Wang F, Wang S, Han R, Cheng Y, Zhao M, Sun J, Xue Z. Point mutation of V252 in neomycin C epimerase enlarges substrate-binding pocket and improves neomycin B accumulation in Streptomyces fradiae. BIORESOUR BIOPROCESS 2022; 9:123. [PMID: 38647873 PMCID: PMC10991966 DOI: 10.1186/s40643-022-00613-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/19/2022] [Indexed: 12/09/2022] Open
Abstract
Neomycin, an aminoglycoside antibiotic with broad-spectrum antibacterial resistance, is widely used in pharmaceutical and agricultural fields. However, separation and purification of neomycin B as an active substance from Streptomyces fradiae are complicated. Although NeoN can catalyze conversion of neomycin C to neomycin B, the underlying catalytic mechanism is still unclear. In this study, the genomic information of high-yielding mutant S. fradiae SF-2 was elucidated using whole-genome sequencing. Subsequently, the mechanism of NeoN in catalyzing conversion of neomycin C to neomycin B was resolved based on NeoN-SAM-neomycin C ternary complex. Mutant NeoNV252A showed improved NeoN activity, and the recombinant strain SF-2-NeoNV252A accumulated 16,766.6 U/mL neomycin B, with a decrease in neomycin C ratio from 16.1% to 6.28%, when compared with the parental strain SF-2. In summary, this study analyzed the catalytic mechanism of NeoN, providing significant reference for rational design of NeoN to improve neomycin B production and weaken the proportion of neomycin C.
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Affiliation(s)
- Xiangfei Li
- Engineering Laboratory for Industrial Microbiology Molecular Beeding of Anhui Province, College of Biologic and Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu, 241000, China
| | - Fei Yu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Fang Wang
- Engineering Laboratory for Industrial Microbiology Molecular Beeding of Anhui Province, College of Biologic and Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu, 241000, China
| | - Sang Wang
- Engineering Laboratory for Industrial Microbiology Molecular Beeding of Anhui Province, College of Biologic and Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu, 241000, China
| | - Rumeng Han
- Engineering Laboratory for Industrial Microbiology Molecular Beeding of Anhui Province, College of Biologic and Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu, 241000, China
| | - Yihan Cheng
- Engineering Laboratory for Industrial Microbiology Molecular Beeding of Anhui Province, College of Biologic and Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu, 241000, China
| | - Ming Zhao
- Engineering Laboratory for Industrial Microbiology Molecular Beeding of Anhui Province, College of Biologic and Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu, 241000, China
| | - Junfeng Sun
- Engineering Laboratory for Industrial Microbiology Molecular Beeding of Anhui Province, College of Biologic and Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu, 241000, China
| | - Zhenglian Xue
- Engineering Laboratory for Industrial Microbiology Molecular Beeding of Anhui Province, College of Biologic and Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu, 241000, China.
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8
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Abstract
Creating, conserving and modifying the stereochemistry of organic compounds has been the subject of significant research efforts in synthetic chemistry. Most synthetic routes are designed according to the stereoselectivity-determining step. Stereochemical editing is an alternative strategy, wherein the chiral-defining or geometry-defining steps are independent of the construction of the major scaffold or complexity. It enables late-stage alterations of stereochemistry and can generate isomers from a single compound. However, in many instances, stereochemical editing processes are contra-thermodynamic, meaning the transformation is unfavourable. To overcome this barrier, photocatalysis uses photogenerated radical species and introduces thermochemical biases. A range of synthetically valuable contra-thermodynamic stereochemical editing processes have been invented, including deracemization of chiral molecules, positional alkene isomerization and dynamic epimerization of sugars and diols. In this Review, we highlight the fundamental mechanisms of visible-light photocatalysis and the general reactivity modes of the photogenerated radical intermediates towards contra-thermodynamic stereochemical editing processes.
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9
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Exploiting photoredox catalysis for carbohydrate modification through C–H and C–C bond activation. Nat Rev Chem 2022; 6:782-805. [PMID: 37118094 DOI: 10.1038/s41570-022-00422-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2022] [Indexed: 11/09/2022]
Abstract
Photoredox catalysis has recently emerged as a powerful synthetic platform for accessing complex chemical structures through non-traditional bond disconnection strategies that proceed through free-radical intermediates. Such synthetic strategies have been used for a range of organic transformations; however, in carbohydrate chemistry they have primarily been applied to the generation of oxocarbenium ion intermediates in the ubiquitous glycosylation reaction. In this Review, we present more intricate light-induced synthetic strategies to modify native carbohydrates through homolytic C-H and C-C bond cleavage. These strategies allow access to glycans and glycoconjugates with profoundly altered carbohydrate skeletons, which are challenging to obtain through conventional synthetic means. Carbohydrate derivatives with such structural motifs represent a broad class of natural products integral to numerous biochemical processes and can be found in active pharmaceutical substances. Here we present progress made in C-H and C-C bond activation of carbohydrates through photoredox catalysis, focusing on the operational mechanisms and the scope of the described methodologies.
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10
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Chen Z, Sato S, Geng Y, Zhang J, Liu HW. Identification of the Early Steps in Herbicidin Biosynthesis Reveals an Atypical Mechanism of C-Glycosylation. J Am Chem Soc 2022; 144:15653-15661. [PMID: 35981300 DOI: 10.1021/jacs.2c05728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Herbicidins are adenosine-derived nucleoside antibiotics with an unusual tricyclic core structure. Deletion of the genes responsible for formation of the tricyclic skeleton in Streptomyces sp. L-9-10 reveals the in vivo importance of Her4, Her5, and Her6 in the early stages of herbicidin biosynthesis. In vitro characterization of Her4 and Her5 demonstrates their involvement in an initial, two-stage C-C coupling reaction that results in net C5'-glycosylation of ADP/ATP by UDP/TDP-glucuronic acid. Biochemical analyses and intermediate trapping experiments imply a noncanonical mechanism of C-glycosylation reminiscent of NAD-dependent S-adenosylhomocysteine (SAH)-hydrolase catalysis. Structural characterization of the isolated metabolites suggests possible reactions catalyzed by Her6 and Her7. An overall herbicidin biosynthetic pathway is proposed based on these observations.
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Affiliation(s)
- Zhang Chen
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Shusuke Sato
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Yujie Geng
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jiawei Zhang
- 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, The University of Texas at Austin, Austin, Texas 78712, United States
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11
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Kudo F, Eguchi T. Biosynthesis of cyclitols. Nat Prod Rep 2022; 39:1622-1642. [PMID: 35726901 DOI: 10.1039/d2np00024e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Review covering up to 2021Cyclitols derived from carbohydrates are naturally stable hydrophilic substances under ordinary physiological conditions, increasing the water solubility of whole molecules in cells. The stability of cyclitols is derived from their carbocyclic structures bearing no acetal groups, in contrast to sugar molecules. Therefore, carbocycle-forming reactions are critical for the biosynthesis of cyclitols. Herein, we review naturally occurring cyclitols that have been identified to date and categorize them according to the type of carbocycle-forming enzymatic reaction. Furthermore, the cyclitol-forming enzymatic reaction mechanisms and modification pathways of the initially generated cyclitols are reviewed.
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Affiliation(s)
- Fumitaka Kudo
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-Okayama, Meguro-ku, Tokyo, Japan.
| | - Tadashi Eguchi
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-Okayama, Meguro-ku, Tokyo, Japan.
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12
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Characterization of the cobalamin-dependent radical S-adenosyl-l-methionine enzyme C-methyltransferase Fom3 in fosfomycin biosynthesis. Methods Enzymol 2022; 669:45-70. [PMID: 35644180 DOI: 10.1016/bs.mie.2021.11.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fosfomycin is a clinically used broad-spectrum antibiotic that has the structure of an oxirane ring with a phosphonic acid substituent and a methyl substituent. In nature, fosfomycin is produced by Streptomyces spp. and Pseudomonas sp., but biosynthesis of fosfomycin significantly differs between the two bacteria, especially in the incorporation mechanism of the methyl group. It has been proposed that the cobalamin-dependent radical S-adenosyl-l-methionine (SAM) enzyme Fom3 is responsible for the methyl-transfer reaction in Streptomyces fosfomycin biosynthesis. In this chapter, we describe the experimental methods to characterize Fom3. We performed the methylation reaction with the purified recombinant Fom3, revealing that Fom3 recognizes a cytidylylated 2-hydroxyethylphosphonate as a substrate and catalyzes stereoselective methylation of the sp3 carbon at the C2 position to afford cytidylylated (S)-2-hydroxypropylphosphonate. Reaction analysis using deuterium-labeled substrates showed that the 5'-deoxyadenosyl radical generated by reductive cleavage of SAM stereoselectively abstracts the pro-R hydrogen atom of the CH bond at the C2 position of cytidylylated 2-hydroxyethylphosphonate. Therefore, the C-methylation reaction catalyzed by Fom3 proceeds with inversion of the configuration at the C2 position. Experimental methods to elucidate the chemical structures of the substrate and products and the stereochemical course in the Fom3-catalyzed reaction could give information to progress investigation of cobalamin-dependent radical SAM C-methyltransferases.
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13
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Zhang J, Hou X, Chen Z, Ko Y, Ruszczycky MW, Chen Y, Zhou J, Liu HW. Dioxane Bridge Formation during the Biosynthesis of Spectinomycin Involves a Twitch Radical S-Adenosyl Methionine Dehydrogenase That May Have Evolved from an Epimerase. J Am Chem Soc 2022; 144:9910-9919. [PMID: 35622017 DOI: 10.1021/jacs.2c02676] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Spectinomycin is a dioxane-bridged, tricyclic aminoglycoside produced by Streptomyces spectabilis ATCC 27741. While the spe biosynthetic gene cluster for spectinomycin has been reported, the chemistry underlying construction of the dioxane ring is unknown. The twitch radical SAM enzyme SpeY from the spe cluster is shown here to catalyze dehydrogenation of the C2' alcohol of (2'R,3'S)-tetrahydrospectinomycin to yield (3'S)-dihydrospectinomycin as a likely biosynthetic intermediate. This reaction is radical-mediated and initiated via H atom abstraction from C2' of the substrate by the 5'-deoxyadenosyl radical equivalent generated upon reductive cleavage of SAM. Crystallographic analysis of the ternary Michaelis complex places serine-183 adjacent to C2' of the bound substrate opposite C5' of SAM. Mutation of this residue to cysteine converts SpeY to the corresponding C2' epimerase mirroring the opposite phenomenon observed in the homologous twitch radical SAM epimerase HygY from the hygromycin B biosynthetic pathway. Phylogenetic analysis suggests a relatively recent evolutionary branching of putative twitch radical SAM epimerases bearing homologous cysteine residues to generate the SpeY clade of enzymes.
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Affiliation(s)
- Jiawei Zhang
- 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
| | - Zhang Chen
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Yeonjin Ko
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Mark W Ruszczycky
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, United States
| | - Yutian Chen
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, United States
| | - 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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14
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Song Y, Hou J, Kwok JSL, Weng H, Tang MF, Wang MH, Leung ASY, Tao KP, Wong GWK, Chan RWY, Tsui SKW, Leung TF. Whole-Genome Shotgun Sequencing for Nasopharyngeal Microbiome in Pre-school Children With Recurrent Wheezing. Front Microbiol 2022; 12:792556. [PMID: 35250904 PMCID: PMC8889122 DOI: 10.3389/fmicb.2021.792556] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 12/21/2021] [Indexed: 12/20/2022] Open
Abstract
Microbiome mediates early life immune deviation in asthma development. Recurrent wheeze (RW) in pre-school years is a risk factor for asthma diagnosis in school-age children. Dysbiosis exists in asthmatic airways, while its origin in pre-school years and relationship to RW is not clearly defined. This study investigated metagenomics of nasopharyngeal microbiome in pre-school children with RW. We applied whole-genome shotgun sequencing and human rhinovirus (HRV) detection on nasopharyngeal samples collected from three groups of pre-school children: (i) RW group: 16 children at-risk for asthma who were hospitalized for RW, (ii) inpatient control (IC): 18 subjects admitted for upper respiratory infection, and (iii) community control (CC): 36 children without respiratory syndromes. Sequence reads were analyzed by MetaPhlAn2 and HUMAnN2 algorithm for taxonomic and functional identification. Linear discriminant analysis effect size (LEfSe) analysis was used to identify discriminative features. We identified that Moraxella catarrhalis and Dolosigranulum pigrum were predominant species in nasopharynx. RW had lower alpha diversity (Shannon diversity index) than CC (0.48 vs. 1.07; Padj = 0.039), characterized by predominant Proteobacteria. LEfSe analysis revealed D. pigrum was the only discriminative species across groups (LDA = 5.57, P = 0.002), with its relative abundance in RW, IC, and CC being 9.6, 14.2, and 37.3%, respectively (P < 0.05). LEfSe identified five (ribo)nucleotides biosynthesis pathways to be group discriminating. Adjusting for HRV status, pre-school children with RW have lower nasopharyngeal biodiversity, which is associated with Proteobacteria predominance and lower abundance of D. pigrum. Along with discriminative pathways found in RW and CC, these microbial biomarkers help to understand RW pathogenesis.
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Affiliation(s)
- Yuping Song
- Department of Pediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
| | - Jinpao Hou
- School of Biomedical Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
| | - Jamie Sui Lam Kwok
- School of Biomedical Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
| | - Haoyi Weng
- Jockey Club School of Public Health and Primary Care, Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
| | - Man Fung Tang
- Department of Pediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China.,Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
| | - Maggie Haitian Wang
- Jockey Club School of Public Health and Primary Care, Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
| | - Agnes Sze Yin Leung
- Department of Pediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
| | - Kin Pong Tao
- Department of Pediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China.,The Chinese University of Hong Kong-University Medical Center Utrecht Joint Research Laboratory of Respiratory Virus and Immunobiology, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
| | - Gary Wing Kin Wong
- Department of Pediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
| | - Renee Wan Yi Chan
- Department of Pediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China.,Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China.,The Chinese University of Hong Kong-University Medical Center Utrecht Joint Research Laboratory of Respiratory Virus and Immunobiology, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
| | - Stephen Kwok Wing Tsui
- School of Biomedical Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
| | - Ting Fan Leung
- Department of Pediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China.,Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China.,The Chinese University of Hong Kong-University Medical Center Utrecht Joint Research Laboratory of Respiratory Virus and Immunobiology, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
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15
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Yu F, Zhang M, Sun J, Wang F, Li X, Liu Y, Wang Z, Zhao X, Li J, Chen J, Du G, Xue Z. Improved Neomycin Sulfate Potency in Streptomyces fradiae Using Atmospheric and Room Temperature Plasma (ARTP) Mutagenesis and Fermentation Medium Optimization. Microorganisms 2022; 10:microorganisms10010094. [PMID: 35056543 PMCID: PMC8780280 DOI: 10.3390/microorganisms10010094] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 12/29/2021] [Accepted: 12/31/2021] [Indexed: 12/04/2022] Open
Abstract
To improve the screening efficiency of high-yield neomycin sulfate (NM) Streptomyces fradiae strains after mutagenesis, a high-throughput screening method using streptomycin resistance prescreening (8 μg/mL) and a 24-deep well plates/microplate reader (trypan blue spectrophotometry) rescreening strategy was developed. Using this approach, we identified a high-producing NM mutant strain, Sf6-2, via six rounds of atmospheric and room temperature plasma (ARTP) mutagenesis and screening. The mutant displayed a NM potency of 7780 ± 110 U/mL and remarkably stable genetic properties over six generations. Furthermore, the key components (soluble starch, peptone, and (NH4)2SO4) affecting NM potency in fermentation medium were selected using Plackett-Burman and optimized by Box-Behnken designs. Finally, the NM potency of Sf6-2 was increased to 10,849 ± 141 U/mL at the optimal concentration of each factor (73.98 g/L, 9.23 g/L, and 5.99 g/L, respectively), and it exhibited about a 40% and 100% enhancement when compared with before optimization conditions and the wild-type strain, respectively. In this study, we provide a new S. fradiae NM production strategy and generate valuable insights for the breeding and screening of other microorganisms.
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Affiliation(s)
- Fei Yu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (F.Y.); (X.L.); (X.Z.); (J.L.); (J.C.)
- Microorganism Fermentation Engineering and Technology Research Center of Anhui Province, College of Biologic & Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China; (M.Z.); (J.S.); (F.W.); (Y.L.); (Z.W.)
- Anhui Engineering Laboratory for Industrial Microbiology Molecular Breeding, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China
| | - Min Zhang
- Microorganism Fermentation Engineering and Technology Research Center of Anhui Province, College of Biologic & Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China; (M.Z.); (J.S.); (F.W.); (Y.L.); (Z.W.)
- Anhui Engineering Laboratory for Industrial Microbiology Molecular Breeding, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China
| | - Junfeng Sun
- Microorganism Fermentation Engineering and Technology Research Center of Anhui Province, College of Biologic & Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China; (M.Z.); (J.S.); (F.W.); (Y.L.); (Z.W.)
- Anhui Engineering Laboratory for Industrial Microbiology Molecular Breeding, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China
| | - Fang Wang
- Microorganism Fermentation Engineering and Technology Research Center of Anhui Province, College of Biologic & Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China; (M.Z.); (J.S.); (F.W.); (Y.L.); (Z.W.)
- Anhui Engineering Laboratory for Industrial Microbiology Molecular Breeding, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China
| | - Xiangfei Li
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (F.Y.); (X.L.); (X.Z.); (J.L.); (J.C.)
| | - Yan Liu
- Microorganism Fermentation Engineering and Technology Research Center of Anhui Province, College of Biologic & Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China; (M.Z.); (J.S.); (F.W.); (Y.L.); (Z.W.)
- Anhui Engineering Laboratory for Industrial Microbiology Molecular Breeding, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China
| | - Zhou Wang
- Microorganism Fermentation Engineering and Technology Research Center of Anhui Province, College of Biologic & Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China; (M.Z.); (J.S.); (F.W.); (Y.L.); (Z.W.)
- Anhui Engineering Laboratory for Industrial Microbiology Molecular Breeding, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China
| | - Xinrui Zhao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (F.Y.); (X.L.); (X.Z.); (J.L.); (J.C.)
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Jianghua Li
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (F.Y.); (X.L.); (X.Z.); (J.L.); (J.C.)
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Jian Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (F.Y.); (X.L.); (X.Z.); (J.L.); (J.C.)
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Guocheng Du
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (F.Y.); (X.L.); (X.Z.); (J.L.); (J.C.)
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
- Correspondence: (G.D.); (Z.X.)
| | - Zhenglian Xue
- Microorganism Fermentation Engineering and Technology Research Center of Anhui Province, College of Biologic & Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China; (M.Z.); (J.S.); (F.W.); (Y.L.); (Z.W.)
- Anhui Engineering Laboratory for Industrial Microbiology Molecular Breeding, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China
- Correspondence: (G.D.); (Z.X.)
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16
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Suh CE, Carder HM, Wendlandt AE. Selective Transformations of Carbohydrates Inspired by Radical-Based Enzymatic Mechanisms. ACS Chem Biol 2021; 16:1814-1828. [PMID: 33988380 DOI: 10.1021/acschembio.1c00190] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Enzymes are a longstanding source of inspiration for synthetic reaction development. However, enzymatic reactivity and selectivity are frequently untenable in a synthetic context, as the principles that govern control in an enzymatic setting often do not translate to small molecule catalysis. Recent synthetic methods have revealed the viability of using small molecule catalysts to promote highly selective radical-mediated transformations of minimally protected sugar substrates. These transformations share conceptual similarities with radical SAM enzymes found in microbial carbohydrate biosynthesis and present opportunities for synthetic chemists to access microbial and unnatural carbohydrate building blocks without the need for protecting groups or lengthy synthetic sequences. Here, we highlight strategies through which radical reaction pathways can enable the site-, regio-, and diastereoselective transformation of minimally protected carbohydrates in both synthetic and enzymatic systems.
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Affiliation(s)
- Carolyn E. Suh
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Hayden M. Carder
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alison E. Wendlandt
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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17
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McLean JT, Benny A, Nolan MD, Swinand G, Scanlan EM. Cysteinyl radicals in chemical synthesis and in nature. Chem Soc Rev 2021; 50:10857-10894. [PMID: 34397045 DOI: 10.1039/d1cs00254f] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nature harnesses the unique properties of cysteinyl radical intermediates for a diverse range of essential biological transformations including DNA biosynthesis and repair, metabolism, and biological photochemistry. In parallel, the synthetic accessibility and redox chemistry of cysteinyl radicals renders them versatile reactive intermediates for use in a vast array of synthetic applications such as lipidation, glycosylation and fluorescent labelling of proteins, peptide macrocyclization and stapling, desulfurisation of peptides and proteins, and development of novel therapeutics. This review provides the reader with an overview of the role of cysteinyl radical intermediates in both chemical synthesis and biological systems, with a critical focus on mechanistic details. Direct insights from biological systems, where applied to chemical synthesis, are highlighted and potential avenues from nature which are yet to be explored synthetically are presented.
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Affiliation(s)
- Joshua T McLean
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
| | - Alby Benny
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
| | - Mark D Nolan
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
| | - Glenna Swinand
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
| | - Eoin M Scanlan
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
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18
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Sato S, Kudo F, Rohmer M, Eguchi T. Biochemical and Mutational Analysis of Radical S-Adenosyl-L-Methionine Adenosylhopane Synthase HpnH from Zymomonas mobilis Reveals that the Conserved Residue Cysteine-106 Reduces a Radical Intermediate and Determines the Stereochemistry. Biochemistry 2021; 60:2865-2874. [PMID: 34506710 DOI: 10.1021/acs.biochem.1c00536] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Adenosylhopane is a crucial precursor of C35 hopanoids, which are believed to modulate the fluidity and permeability of bacterial cell membranes. Adenosylhopane is formed by a crosslinking reaction between diploptene and a 5'-deoxyadenosyl radical that is generated by the radical S-adenosyl-L-methionine (SAM) enzyme HpnH. We previously showed that HpnH from Streptomyces coelicolor A3(2) (ScHpnH) converts diploptene to (22R)-adenosylhopane. However, the mechanism of the stereoselective C-C bond formation was unclear. Thus, here, we performed biochemical and mutational analysis of another HpnH, from the ethanol-producing bacterium Zymomonas mobilis (ZmHpnH). Similar to ScHpnH, wild-type ZmHpnH afforded (22R)-adenosylhopane. Conserved cysteine and tyrosine residues were suggested as possible hydrogen sources to quench the putative radical reaction intermediate. A Cys106Ala mutant of ZmHpnH had one-fortieth the activity of the wild-type enzyme and yielded both (22R)- and (22S)-adenosylhopane along with some related byproducts. Radical trapping experiments with a spin-trapping agent supported the generation of a radical intermediate in the ZmHpnH-catalyzed reaction. We propose that the thiol of Cys106 stereoselectively reduces the radical intermediate generated at the C22 position by the addition of the 5'-deoxadenosyl radical to diploptene, to complete the reaction.
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Affiliation(s)
- Shusuke Sato
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Fumitaka Kudo
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Michel Rohmer
- Institut de Chimie de Strasbourg, Université de Strasbourg/CNRS, 4 rue Blaise Pascal, Strasbourg Cedex 67070, France
| | - Tadashi Eguchi
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8551, Japan
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19
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Besandre RA, Chen Z, Davis I, Zhang J, Ruszczycky MW, Liu A, Liu HW. HygY Is a Twitch Radical SAM Epimerase with Latent Dehydrogenase Activity Revealed upon Mutation of a Single Cysteine Residue. J Am Chem Soc 2021; 143:15152-15158. [PMID: 34491039 DOI: 10.1021/jacs.1c05727] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
HygY is a SPASM/twitch radical SAM enzyme hypothesized to catalyze the C2'-epimerization of galacamine during the biosynthesis of hygromycin B. This activity is confirmed via biochemical and structural analysis of the derivatized reaction products using chemically synthesized deuterated substrate, high-resolution mass spectrometry and 1H NMR. Electron paramagnetic resonance spectroscopy of the reduced enzyme is consistent with ligation of two [Fe4S4] clusters characteristic of the twitch radical SAM subgroup. HygY catalyzed epimerization proceeds with incorporation of a single solvent Hydron into the talamine product facilitated by the catalytic cysteine-183 residue. Mutation of this cysteine to alanine converts HygY from a C2'-epimerase to an C2'-dehydrogenase with comparable activity. The SPASM/twitch radical SAM enzymes often serve as anaerobic oxidases making the redox-neutral epimerases in this class rather interesting. The discovery of latent dehydrogenase activity in a twitch epimerase may therefore offer new insights into the mechanistic features that distinguish oxidative versus redox-neutral SPASM/twitch enzymes and lead to the evolution of new enzyme activities.
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Affiliation(s)
- Ronald A Besandre
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, United States
| | - Zhang Chen
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, United States
| | - Ian Davis
- Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249, United States
| | - Jiawei Zhang
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, United States
| | - Mark Walter Ruszczycky
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX 78712, United States
| | - Aimin Liu
- Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249, United States
| | - Hung-Wen Liu
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, United States.,Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX 78712, United States
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20
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Lloyd MD, Yevglevskis M, Nathubhai A, James TD, Threadgill MD, Woodman TJ. Racemases and epimerases operating through a 1,1-proton transfer mechanism: reactivity, mechanism and inhibition. Chem Soc Rev 2021; 50:5952-5984. [PMID: 34027955 PMCID: PMC8142540 DOI: 10.1039/d0cs00540a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Indexed: 12/12/2022]
Abstract
Racemases and epimerases catalyse changes in the stereochemical configurations of chiral centres and are of interest as model enzymes and as biotechnological tools. They also occupy pivotal positions within metabolic pathways and, hence, many of them are important drug targets. This review summarises the catalytic mechanisms of PLP-dependent, enolase family and cofactor-independent racemases and epimerases operating by a deprotonation/reprotonation (1,1-proton transfer) mechanism and methods for measuring their catalytic activity. Strategies for inhibiting these enzymes are reviewed, as are specific examples of inhibitors. Rational design of inhibitors based on substrates has been extensively explored but there is considerable scope for development of transition-state mimics and covalent inhibitors and for the identification of inhibitors by high-throughput, fragment and virtual screening approaches. The increasing availability of enzyme structures obtained using X-ray crystallography will facilitate development of inhibitors by rational design and fragment screening, whilst protein models will facilitate development of transition-state mimics.
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Affiliation(s)
- Matthew D Lloyd
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK.
| | - Maksims Yevglevskis
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK. and CatSci Ltd., CBTC2, Capital Business Park, Wentloog, Cardiff CF3 2PX, UK
| | - Amit Nathubhai
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK. and University of Sunderland, School of Pharmacy & Pharmaceutical Sciences, Sciences Complex, Sunderland SR1 3SD, UK
| | - Tony D James
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK and School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, People's Republic of China
| | - Michael D Threadgill
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK. and Institute of Biological, Environmental & Rural Sciences, Aberystwyth University, Aberystwyth SY23 3BY, UK
| | - Timothy J Woodman
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK.
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21
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Zhu W, Klinman JP. Biogenesis of the peptide-derived redox cofactor pyrroloquinoline quinone. Curr Opin Chem Biol 2020; 59:93-103. [PMID: 32731194 PMCID: PMC7736144 DOI: 10.1016/j.cbpa.2020.05.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/04/2020] [Accepted: 05/06/2020] [Indexed: 12/15/2022]
Abstract
Pyrroloquinoline quinone (PQQ) is a peptide-derived redox cofactor produced by prokaryotes that also plays beneficial roles in organisms from other kingdoms. We review recent developments on the pathway of PQQ biogenesis, focusing on the mechanisms of PqqE, PqqF/G, and PqqB. These advances may shed light on other, uncharacterized biosynthetic pathways.
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Affiliation(s)
- Wen Zhu
- California Institute for Quantitative Biosciences and Department of Chemistry, University of California, Berkeley, CA, 94720-3220, USA
| | - Judith P Klinman
- California Institute for Quantitative Biosciences and Department of Chemistry, University of California, Berkeley, CA, 94720-3220, USA; Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720-3220, USA.
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22
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Zheng J, Li Y, Guan H, Li J, Li D, Zhang J, Tan H. Component Optimization of Neomycin Biosynthesis via the Reconstitution of a Combinatorial Mini-Gene-Cluster in Streptomyces fradiae. ACS Synth Biol 2020; 9:2493-2501. [PMID: 32864952 DOI: 10.1021/acssynbio.0c00281] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Neomycin, a multicomponent aminoglycoside antibiotic, is mainly utilized in livestock husbandry and feed additives in animals. The antimicrobial potency of the main product neomycin B is higher than that of its stereoisomer neomycin C. However, the content of neomycin C as an impurity in the high-producing strain is relatively high, and its isolation or removal from neomycin B is quite difficult, which influences the widespread application of neomycin. In this work, the essential genes responsible for neomycin biosynthesis were evaluated and overexpressed to reduce the content of neomycin C. Among them, neoG and neoH are two novel regulatory genes for neomycin biosynthesis, aphA is a resistance gene, neoN encoding a radical SAM-dependent epimerase is responsible for the conversion of neomycin C to B using SAM as the cofactor, and metK is a SAM synthetase coding gene. We demonstrated that the reconstitution and overexpression of a mini-gene-cluster (PkasO*-neoN-metK-PkasO*-neoGH-aphA) could effectively reduce the accumulation of neomycin C from 19.1 to 12.7% and simultaneously increase neomycin B by ∼13.1% in the engineered strain Sf/pKCZ04 compared with the wild-type strain (Sf). Real-time quantitative polymerase chain reaction analysis revealed the remarkable up-regulation of the neoE, neoH, neoN, and metK genes situated in the mini-gene-cluster. The findings will pave a new path for component optimization and the large-scale industrial production of significant commercial antibiotics.
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Affiliation(s)
- Jiazhen Zheng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hanye Guan
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Junyue Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Dong Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jihui Zhang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Huarong Tan
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
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23
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Bearne SL. Through the Looking Glass: Chiral Recognition of Substrates and Products at the Active Sites of Racemases and Epimerases. Chemistry 2020; 26:10367-10390. [DOI: 10.1002/chem.201905826] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/09/2020] [Indexed: 12/18/2022]
Affiliation(s)
- Stephen L. Bearne
- Department of Biochemistry & Molecular BiologyDepartment of ChemistryDalhousie University Halifax, Nova Scotia B3H 4R2 Canada
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24
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Li S, Liu Q, Zhong Z, Deng Z, Sun Y. Exploration of Hygromycin B Biosynthesis Utilizing CRISPR-Cas9-Associated Base Editing. ACS Chem Biol 2020; 15:1417-1423. [PMID: 32275383 DOI: 10.1021/acschembio.0c00071] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Hygromycin B is an aminoglycoside antibiotic widely used in industry and biological research. However, most of its biosynthetic pathway has not been completely identified due to the immense difficulty in genetic manipulation of the producing strain. To address this problem, we developed an efficient system that combines clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9-associated base editing and site-specific recombination instead of conventional double-crossover-based homologous recombination. This strategy was successfully applied to the in vivo inactivation of five candidate genes involved in the biosynthesis of hygromycin B by generating stop codons or mutating conserved residues within the encoding region. The results revealed that HygJ, HygL, and HygD are responsible for successive dehydrogenation, transamination, and transglycosylation of nucleoside diphosphate (NDP)-heptose. Notably, HygY acts as an unusual radical S-adenosylmethionine (SAM)-dependent epimerase for hydroxyl carbons, and HygM serves as a versatile methyltransferase in multiple parallel metabolic networks. Based on in vivo and in vitro evidence, the biosynthetic pathway for hygromycin B is proposed.
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Affiliation(s)
- Sicong Li
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, People’s Republic of China
| | - Qian Liu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, People’s Republic of China
| | - Zhiyu Zhong
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, People’s Republic of China
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, People’s Republic of China
| | - Yuhui Sun
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, People’s Republic of China
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25
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Ushimaru R, Chen Z, Zhao H, Fan P, Liu H. Identification of the Enzymes Mediating the Maturation of the Seryl‐tRNA Synthetase Inhibitor SB‐217452 during the Biosynthesis of Albomycins. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201915275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Richiro Ushimaru
- Department of Chemistry, and Division of Chemical Biology and Medicinal ChemistryCollege of PharmacyUniversity of Texas at Austin Austin TX 78712 USA
| | - Zhang Chen
- Department of Chemistry, and Division of Chemical Biology and Medicinal ChemistryCollege of PharmacyUniversity of Texas at Austin Austin TX 78712 USA
| | - Houyuan Zhao
- Department of Chemistry, and Division of Chemical Biology and Medicinal ChemistryCollege of PharmacyUniversity of Texas at Austin Austin TX 78712 USA
| | - Po‐hsun Fan
- Department of Chemistry, and Division of Chemical Biology and Medicinal ChemistryCollege of PharmacyUniversity of Texas at Austin Austin TX 78712 USA
| | - Hung‐wen Liu
- Department of Chemistry, and Division of Chemical Biology and Medicinal ChemistryCollege of PharmacyUniversity of Texas at Austin Austin TX 78712 USA
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26
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Ushimaru R, Chen Z, Zhao H, Fan PH, Liu HW. Identification of the Enzymes Mediating the Maturation of the Seryl-tRNA Synthetase Inhibitor SB-217452 during the Biosynthesis of Albomycins. Angew Chem Int Ed Engl 2020; 59:3558-3562. [PMID: 31863717 DOI: 10.1002/anie.201915275] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 12/17/2019] [Indexed: 12/21/2022]
Abstract
Albomycin δ2 is a sulfur-containing sideromycin natural product that shows potent antibacterial activity against clinically important pathogens. The l-serine-thioheptose dipeptide partial structure, known as SB-217452, has been found to be the active seryl-tRNA synthetase inhibitor component of albomycin δ2 . Herein, it is demonstrated that AbmF catalyzes condensation between the 6'-amino-4'-thionucleoside with the d-ribo configuration and seryl-adenylate supplied by the serine adenylation activity of AbmK. Formation of the dipeptide is followed by C3'-epimerization to produce SB-217452 with the d-xylo configuration, which is catalyzed by the radical S-adenosyl-l-methionine enzyme AbmJ. Gene deletion suggests that AbmC is involved in peptide assembly linking SB-217452 with the siderophore moiety. This study establishes how the albomycin biosynthetic machinery generates its antimicrobial component SB-217452.
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Affiliation(s)
- Richiro Ushimaru
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX, 78712, USA
| | - Zhang Chen
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX, 78712, USA
| | - Houyuan Zhao
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX, 78712, USA
| | - Po-Hsun Fan
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX, 78712, USA
| | - Hung-Wen Liu
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX, 78712, USA
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27
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Wang Y, Carder HM, Wendlandt AE. Synthesis of rare sugar isomers through site-selective epimerization. Nature 2020; 578:403-408. [DOI: 10.1038/s41586-020-1937-1] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 01/03/2020] [Indexed: 12/22/2022]
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28
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Ban YH, Song MC, Park JW, Yoon YJ. Minor components of aminoglycosides: recent advances in their biosynthesis and therapeutic potential. Nat Prod Rep 2020; 37:301-311. [DOI: 10.1039/c9np00041k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
This Highlight covers the recent advances in the biosynthetic pathways of aminoglycosides including their minor components, together with the therapeutic potential for minor aminoglycoside components and semi-synthetic aminoglycosides.
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Affiliation(s)
- Yeon Hee Ban
- Department of Chemistry and Nanoscience
- Ewha Womans University
- Seoul 03760
- Republic of Korea
| | - Myoung Chong Song
- Department of Chemistry and Nanoscience
- Ewha Womans University
- Seoul 03760
- Republic of Korea
| | - Je Won Park
- School of Biosystems and Biomedical Sciences
- Korea University
- Seoul 02841
- Republic of Korea
| | - Yeo Joon Yoon
- Department of Chemistry and Nanoscience
- Ewha Womans University
- Seoul 03760
- Republic of Korea
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29
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Sato S, Kudo F, Rohmer M, Eguchi T. Characterization of Radical SAM Adenosylhopane Synthase, HpnH, which Catalyzes the 5
′
‐Deoxyadenosyl Radical Addition to Diploptene in the Biosynthesis of C
35
Bacteriohopanepolyols. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201911584] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Shusuke Sato
- Department of Chemistry Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku Tokyo 152-8551 Japan
| | - Fumitaka Kudo
- Department of Chemistry Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku Tokyo 152-8551 Japan
| | - Michel Rohmer
- Institut Le Bel Université de Strasbourg/CNRS 4 rue Blaise Pascal 67070 Strasbourg Cedex France
| | - Tadashi Eguchi
- Department of Chemistry Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku Tokyo 152-8551 Japan
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30
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Sato S, Kudo F, Rohmer M, Eguchi T. Characterization of Radical SAM Adenosylhopane Synthase, HpnH, which Catalyzes the 5
′
‐Deoxyadenosyl Radical Addition to Diploptene in the Biosynthesis of C
35
Bacteriohopanepolyols. Angew Chem Int Ed Engl 2019; 59:237-241. [DOI: 10.1002/anie.201911584] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/15/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Shusuke Sato
- Department of Chemistry Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku Tokyo 152-8551 Japan
| | - Fumitaka Kudo
- Department of Chemistry Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku Tokyo 152-8551 Japan
| | - Michel Rohmer
- Institut Le Bel Université de Strasbourg/CNRS 4 rue Blaise Pascal 67070 Strasbourg Cedex France
| | - Tadashi Eguchi
- Department of Chemistry Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku Tokyo 152-8551 Japan
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31
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Kudo F, Zhang J, Sato S, Hirayama A, Eguchi T. Functional Characterization of 3-Aminobenzoic Acid Adenylation Enzyme PctU and UDP-N-Acetyl-d-Glucosamine: 3-Aminobenzoyl-ACP Glycosyltransferase PctL in Pactamycin Biosynthesis. Chembiochem 2019; 20:2458-2462. [PMID: 31059166 DOI: 10.1002/cbic.201900239] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Indexed: 12/27/2022]
Abstract
Pactamycin is an antibiotic produced by Streptomyces pactum with antitumor and antimalarial properties. Pactamycin has a unique aminocyclitol core that is decorated with 3-aminoacetophenone, 6-methylsaliciate, and an N,N-dimethylcarbamoyl group. Herein, we show that the adenylation enzyme PctU activates 3-aminobenzoic acid (3ABA) with adenosine triphosphate and ligates it to the holo form of the discrete acyl carrier protein PctK to yield 3ABA-PctK. Then, 3ABA-PctK is N-glycosylated with uridine diphosphate-N-acetyl-d-glucosamine (UDP-GlcNAc) by the glycosyltransferase PctL to yield GlcNAc-3ABA-PctK. Because 3ABA is known to be a precursor of the 3-aminoacetophenone moiety, PctU appears to be a gatekeeper that selects the appropriate 3-aminobenzoate starter unit. Overall, we propose that acyl carrier protein-bound glycosylated 3ABA derivatives are biosynthetic intermediates of pactamycin biosynthesis.
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Affiliation(s)
- Fumitaka Kudo
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Jiahao Zhang
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Shusuke Sato
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Akane Hirayama
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Tadashi Eguchi
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan
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32
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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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33
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Abstract
ABSTRACT
Peptides, biologically occurring oligomers of amino acids linked by amide bonds, are essential for living organisms. Many peptides isolated as natural products have biological functions such as antimicrobial, antivirus and insecticidal activities. Peptides often possess structural features or modifications not found in proteins, including the presence of nonproteinogenic amino acids, macrocyclic ring formation, heterocyclization, N-methylation and decoration by sugars or acyl groups. Nature employs various strategies to increase the structural diversity of peptides. Enzymes that modify peptides to yield mature natural products are of great interest for discovering new enzyme chemistry and are important for medicinal chemistry applications. We have discovered novel peptide modifying enzymes and have identified: (i) a new class of amide bond forming-enzymes; (ii) a pathway to biosynthesize a carbonylmethylene-containing pseudodipeptide structure; and (iii) two distinct peptide epimerases. In this review, an overview of our findings on peptide modifying enzymes is presented.
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34
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Ushimaru R, Liu HW. Biosynthetic Origin of the Atypical Stereochemistry in the Thioheptose Core of Albomycin Nucleoside Antibiotics. J Am Chem Soc 2019; 141:2211-2214. [PMID: 30673214 DOI: 10.1021/jacs.8b12565] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Albomycins are peptidyl thionucleoside natural products that display antimicrobial activity against clinically important pathogens. Their structures are characterized by a thioheptose with atypical stereochemistry including a d-xylofuranose ring modified with a d-amino acid moiety. Herein it is demonstrated that AbmH is a pyridoxal 5'-phosphate (PLP)-dependent transaldolase that catalyzes a threo-selective aldol-type reaction to generate the thioheptose core with a d-ribofuranose ring and an l-amino acid moiety. The conversion of l-to d-amino acid configuration is catalyzed by the PLP-dependent epimerase AbmD. The d- ribo to d- xylo conversion of the thiofuranose ring appears according to gene deletion experiments to be mediated by AbmJ, which is annotated as a radical S-adenosyl-l-methionine (SAM) enzyme. These studies establish several key steps in the assembly of the thioheptose core during the biosynthesis of albomycins.
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Affiliation(s)
- Richiro Ushimaru
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy , University of Texas at Austin , Austin , Texas 78712 , United States
| | - Hung-Wen Liu
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy , University of Texas at Austin , Austin , Texas 78712 , United States
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35
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Enhancement of neomycin production by engineering the entire biosynthetic gene cluster and feeding key precursors in Streptomyces fradiae CGMCC 4.576. Appl Microbiol Biotechnol 2019; 103:2263-2275. [DOI: 10.1007/s00253-018-09597-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/18/2018] [Accepted: 12/20/2018] [Indexed: 01/20/2023]
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36
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Wang Y, Hu X, Morales-Rivera CA, Li GX, Huang X, He G, Liu P, Chen G. Epimerization of Tertiary Carbon Centers via Reversible Radical Cleavage of Unactivated C(sp 3)-H Bonds. J Am Chem Soc 2018; 140:9678-9684. [PMID: 29983059 DOI: 10.1021/jacs.8b05753] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Reversible cleavage of C(sp3)-H bonds can enable racemization or epimerization, offering a valuable tool to edit the stereochemistry of organic compounds. While epimerization reactions operating via cleavage of acidic C(sp3)-H bonds, such as the Cα-H of carbonyl compounds, have been widely used in organic synthesis and enzyme-catalyzed biosynthesis, epimerization of tertiary carbons bearing a nonacidic C(sp3)-H bond is much more challenging with few practical methods available. Herein, we report the first synthetically useful protocol for the epimerization of tertiary carbons via reversible radical cleavage of unactivated C(sp3)-H bonds with hypervalent iodine reagent benziodoxole azide and H2O under mild conditions. These reactions exhibit excellent reactivity and selectivity for unactivated 3° C-H bonds of various cycloalkanes and offer a powerful strategy for editing the stereochemical configurations of carbon scaffolds intractable to conventional methods. Mechanistic study suggests that the unique ability of N3• to serve as a catalytic H atom shuttle is critical to reversibly break and reform 3° C-H bonds with high efficiency and selectivity.
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Affiliation(s)
- Yaxin Wang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Xiafei Hu
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Cristian A Morales-Rivera
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Guo-Xing Li
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Xin Huang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Gang He
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071 , China
| | - Peng Liu
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Gong Chen
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071 , China.,Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
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37
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Yokoyama K, Lilla EA. C-C bond forming radical SAM enzymes involved in the construction of carbon skeletons of cofactors and natural products. Nat Prod Rep 2018; 35:660-694. [PMID: 29633774 PMCID: PMC6051890 DOI: 10.1039/c8np00006a] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Covering: up to the end of 2017 C-C bond formations are frequently the key steps in cofactor and natural product biosynthesis. Historically, C-C bond formations were thought to proceed by two electron mechanisms, represented by Claisen condensation in fatty acids and polyketide biosynthesis. These types of mechanisms require activated substrates to create a nucleophile and an electrophile. More recently, increasing number of C-C bond formations catalyzed by radical SAM enzymes are being identified. These free radical mediated reactions can proceed between almost any sp3 and sp2 carbon centers, allowing introduction of C-C bonds at unconventional positions in metabolites. Therefore, free radical mediated C-C bond formations are frequently found in the construction of structurally unique and complex metabolites. This review discusses our current understanding of the functions and mechanisms of C-C bond forming radical SAM enzymes and highlights their important roles in the biosynthesis of structurally complex, naturally occurring organic molecules. Mechanistic consideration of C-C bond formation by radical SAM enzymes identifies the significance of three key mechanistic factors: radical initiation, acceptor substrate activation and radical quenching. Understanding the functions and mechanisms of these characteristic enzymes will be important not only in promoting our understanding of radical SAM enzymes, but also for understanding natural product and cofactor biosynthesis.
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Affiliation(s)
- Kenichi Yokoyama
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
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38
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Parent A, Benjdia A, Guillot A, Kubiak X, Balty C, Lefranc B, Leprince J, Berteau O. Mechanistic Investigations of PoyD, a Radical S-Adenosyl-l-methionine Enzyme Catalyzing Iterative and Directional Epimerizations in Polytheonamide A Biosynthesis. J Am Chem Soc 2018; 140:2469-2477. [PMID: 29253341 PMCID: PMC5824343 DOI: 10.1021/jacs.7b08402] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a growing family of bioactive peptides. Among RiPPs, the bacterial toxin polytheonamide A is characterized by a unique set of post-translational modifications catalyzed by novel radical S-adenosyl-l-methionine (SAM) enzymes. Here we show that the radical SAM enzyme PoyD catalyzes in vitro polytheonamide epimerization in a C-to-N directional manner. By combining mutagenesis experiments with labeling studies and investigating the enzyme substrate promiscuity, we deciphered in detail the mechanism of PoyD. We notably identified a critical cysteine residue as a likely key H atom donor and demonstrated that PoyD belongs to a distinct family of radical SAM peptidyl epimerases. In addition, our study shows that the core peptide directly influences the epimerization pattern allowing for production of peptides with unnatural epimerization patterns.
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Affiliation(s)
- Aubérie Parent
- Micalis Institute, ChemSyBio, INRA, AgroParisTech, Université Paris-Saclay , 78350 Jouy-en-Josas, France
| | - Alhosna Benjdia
- Micalis Institute, ChemSyBio, INRA, AgroParisTech, Université Paris-Saclay , 78350 Jouy-en-Josas, France
| | - Alain Guillot
- Micalis Institute, ChemSyBio, INRA, AgroParisTech, Université Paris-Saclay , 78350 Jouy-en-Josas, France
| | - Xavier Kubiak
- Micalis Institute, ChemSyBio, INRA, AgroParisTech, Université Paris-Saclay , 78350 Jouy-en-Josas, France
| | - Clémence Balty
- Micalis Institute, ChemSyBio, INRA, AgroParisTech, Université Paris-Saclay , 78350 Jouy-en-Josas, France
| | - Benjamin Lefranc
- Inserm U1239, PRIMACEN, University of Rouen Normandy , 76000 Rouen, France
| | - Jérôme Leprince
- Inserm U1239, PRIMACEN, University of Rouen Normandy , 76000 Rouen, France
| | - Olivier Berteau
- Micalis Institute, ChemSyBio, INRA, AgroParisTech, Université Paris-Saclay , 78350 Jouy-en-Josas, France
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39
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Radical S-Adenosylmethionine Peptide Epimerases: Detection of Activity and Characterization of d-Amino Acid Products. Methods Enzymol 2018; 604:237-257. [DOI: 10.1016/bs.mie.2018.01.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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40
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Holliday GL, Brown SD, Akiva E, Mischel D, Hicks MA, Morris JH, Huang CC, Meng EC, Pegg SCH, Ferrin TE, Babbitt PC. Biocuration in the structure-function linkage database: the anatomy of a superfamily. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2017; 2017:3074783. [PMID: 28365730 PMCID: PMC5467563 DOI: 10.1093/database/bax006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/23/2017] [Indexed: 12/11/2022]
Abstract
With ever-increasing amounts of sequence data available in both the primary literature and sequence repositories, there is a bottleneck in annotating molecular function to a sequence. This article describes the biocuration process and methods used in the structure-function linkage database (SFLD) to help address some of the challenges. We discuss how the hierarchy within the SFLD allows us to infer detailed functional properties for functionally diverse enzyme superfamilies in which all members are homologous, conserve an aspect of their chemical function and have associated conserved structural features that enable the chemistry. Also presented is the Enzyme Structure-Function Ontology (ESFO), which has been designed to capture the relationships between enzyme sequence, structure and function that underlie the SFLD and is used to guide the biocuration processes within the SFLD. Database URL:http://sfld.rbvi.ucsf.edu/
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Affiliation(s)
- Gemma L Holliday
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143, USA
| | - Shoshana D Brown
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143, USA
| | - Eyal Akiva
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143, USA
| | - David Mischel
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143, USA
| | - Michael A Hicks
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143, USA.,Human Longevity, Inc, San Diego, CA 92121, USA
| | - John H Morris
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, CA 94143, USA
| | - Conrad C Huang
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, CA 94143, USA
| | - Elaine C Meng
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, CA 94143, USA
| | | | - Thomas E Ferrin
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, CA 94143, USA.,California Institute for Quantitative Biosciences, University of California, San Francisco, CA 94158, USA
| | - Patricia C Babbitt
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143, USA.,Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, CA 94143, USA.,California Institute for Quantitative Biosciences, University of California, San Francisco, CA 94158, USA
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41
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Benjdia A, Balty C, Berteau O. Radical SAM Enzymes in the Biosynthesis of Ribosomally Synthesized and Post-translationally Modified Peptides (RiPPs). Front Chem 2017; 5:87. [PMID: 29167789 PMCID: PMC5682303 DOI: 10.3389/fchem.2017.00087] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 10/11/2017] [Indexed: 11/13/2022] Open
Abstract
Ribosomally-synthesized and post-translationally modified peptides (RiPPs) are a large and diverse family of natural products. They possess interesting biological properties such as antibiotic or anticancer activities, making them attractive for therapeutic applications. In contrast to polyketides and non-ribosomal peptides, RiPPs derive from ribosomal peptides and are post-translationally modified by diverse enzyme families. Among them, the emerging superfamily of radical SAM enzymes has been shown to play a major role. These enzymes catalyze the formation of a wide range of post-translational modifications some of them having no counterparts in living systems or synthetic chemistry. The investigation of radical SAM enzymes has not only illuminated unprecedented strategies used by living systems to tailor peptides into complex natural products but has also allowed to uncover novel RiPP families. In this review, we summarize the current knowledge on radical SAM enzymes catalyzing RiPP post-translational modifications and discuss their mechanisms and growing importance notably in the context of the human microbiota.
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Affiliation(s)
- Alhosna Benjdia
- Micalis Institute, ChemSyBio, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Clémence Balty
- Micalis Institute, ChemSyBio, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Olivier Berteau
- Micalis Institute, ChemSyBio, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
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42
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Sato S, Kudo F, Kim SY, Kuzuyama T, Eguchi T. Methylcobalamin-Dependent Radical SAM C-Methyltransferase Fom3 Recognizes Cytidylyl-2-hydroxyethylphosphonate and Catalyzes the Nonstereoselective C-Methylation in Fosfomycin Biosynthesis. Biochemistry 2017; 56:3519-3522. [PMID: 28678474 DOI: 10.1021/acs.biochem.7b00472] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A methylcobalamin (MeCbl)-dependent radical S-adenosyl-l-methionine (SAM) methyltransferase Fom3 was found to catalyze the C-methylation of cytidylyl-2-hydroxyethylphosphonate (HEP-CMP) to give cytidylyl-2-hydroxypropylphosphonate (HPP-CMP), although it was originally proposed to catalyze the C-methylation of 2-hydroxyethylphosphonate to give 2-hydroxypropylphosphonate in the biosynthesis of a unique C-P bond containing antibiotic fosfomycin in Streptomyces. Unexpectedly, the Fom3 reaction product from HEP-CMP was almost a 1:1 diastereomeric mixture of HPP-CMP, indicating that the C-methylation is not stereoselective. Presumably, only the CMP moiety of HEP-CMP is critical for substrate recognition; on the other hand, the enzyme does not fix the 2-hydroxy group of the substrate and either of the prochiral hydrogen atoms at the C2 position can be abstracted by the 5'-deoxyadenosyl radical generated from SAM to form the substrate radical intermediates, which react with MeCbl to afford the corresponding products. This strict substrate recognition mechanism with no stereoselectivity of a MeCbl-dependent radical SAM methyltransferase is remarkable in natural product biosynthetic chemistry, because such a hidden clue for selective substrate recognition is likely to be found in the other biosynthetic pathways.
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Affiliation(s)
- Shusuke Sato
- Department of Chemistry, Tokyo Institute of Technology , 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Fumitaka Kudo
- Department of Chemistry, Tokyo Institute of Technology , 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Seung-Young Kim
- Biotechnology Research Center, The University of Tokyo , 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tomohisa Kuzuyama
- Biotechnology Research Center, The University of Tokyo , 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tadashi Eguchi
- Department of Chemistry, Tokyo Institute of Technology , 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8551, Japan
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43
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Park JW, Ban YH, Nam SJ, Cha SS, Yoon YJ. Biosynthetic pathways of aminoglycosides and their engineering. Curr Opin Biotechnol 2017; 48:33-41. [PMID: 28365471 DOI: 10.1016/j.copbio.2017.03.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 02/27/2017] [Accepted: 03/15/2017] [Indexed: 11/30/2022]
Abstract
Despite decades long clinical usage, aminoglycosides still remain a valuable pharmaceutical source for fighting Gram-negative bacterial pathogens, and their newly identified bioactivities are also renewing interest in this old class of antibiotics. As Nature's gift, some aminoglycosides possess natural defensive structural elements that can circumvent drug resistance mechanisms. Thus, a detailed understanding of aminoglycoside biosynthesis will enable us to apply Nature's biosynthetic strategy towards expanding structural diversity in order to produce novel and more robust aminoglycoside analogs. The engineered biosynthesis of novel aminoglycosides is required not only to develop effective therapeutics against the emerging 'superbugs' but also to reinvigorate antibiotic lead discovery in readiness for the emerging post-antibiotic era.
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Affiliation(s)
- Je Won Park
- School of Biosystem and Biomedical Science, Korea University, Seoul 02841, Republic of Korea
| | - Yeon Hee Ban
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Sang-Jip Nam
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Sun-Shin Cha
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Yeo Joon Yoon
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Republic of Korea.
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44
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Post-translational modification of ribosomally synthesized peptides by a radical SAM epimerase in Bacillus subtilis. Nat Chem 2017. [PMID: 28644475 DOI: 10.1038/nchem.2714] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ribosomally synthesized peptides are built out of L-amino acids, whereas D-amino acids are generally the hallmark of non-ribosomal synthetic processes. Here we show that the model bacterium Bacillus subtilis is able to produce a novel type of ribosomally synthesized and post-translationally modified peptide that contains D-amino acids, and which we propose to call epipeptides. We demonstrate that a two [4Fe-4S]-cluster radical S-adenosyl-L-methionine (SAM) enzyme converts L-amino acids into their D-counterparts by catalysing Cα-hydrogen-atom abstraction and using a critical cysteine residue as the hydrogen-atom donor. Unexpectedly, these D-amino acid residues proved to be essential for the activity of a peptide that induces the expression of LiaRS, a major component of the bacterial cell envelope stress-response system. Present in B. subtilis and in several members of the human microbiome, these epipeptides and radical SAM epimerases broaden the landscape of peptidyl structures accessible to living organisms.
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45
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He N, Wu P, Lei Y, Xu B, Zhu X, Xu G, Gao Y, Qi J, Deng Z, Tang G, Chen W, Xiao Y. Construction of an octosyl acid backbone catalyzed by a radical S-adenosylmethionine enzyme and a phosphatase in the biosynthesis of high-carbon sugar nucleoside antibiotics. Chem Sci 2017; 8:444-451. [PMID: 28451191 PMCID: PMC5365060 DOI: 10.1039/c6sc01826b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/17/2016] [Indexed: 01/26/2023] Open
Abstract
Unique bicyclic octosyl uronic acid nucleosides include ezomycin, malayamycin, and octosyl acid (OA). They are structurally characterized by OA, an unusual 8-carbon furanosyl nucleoside core proposed to be the precursor to polyoxin and nikkomycin. Despite the well-known bioactivity of these nucleoside antibiotics, the biosynthesis of OA has not been elucidated yet. Here we report the two pivotal enzymatic steps in the polyoxin biosynthetic pathway leading to the identification of OA as a key intermediate. Our data suggest that this intermediate is formed via a free radical reaction catalyzed by the radical S-adenosylmethionine (SAM) enzyme, PolH, and using 3'-enolpyruvyl uridine 5'-monophosphate (3'-EUMP) as a substrate. Subsequent dephosphorylation catalyzed by phosphatase PolJ converts the resulting octosyl acid 5'-phosphate (OAP) to OA. These results provide, for the first time, significant in vitro evidence for the biosynthetic origins of the C8 backbone of OA.
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Affiliation(s)
- Nisha He
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery , Ministry of Education , School of Pharmaceutical Sciences , Wuhan University , Wuhan 430071 , China .
- CAS Key Laboratory of Synthetic Biology , CAS Center for Excellence in Molecular Plant Sciences , Institute of Plant Physiology and Ecology , Shanghai Institutes for Biological Sciences , Chinese Academy of Sciences , 300 FengLin Road , Shanghai 200032 , China .
- University of Chinese Academy of Sciences , Beijing 100039 , China
| | - Pan Wu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery , Ministry of Education , School of Pharmaceutical Sciences , Wuhan University , Wuhan 430071 , China .
| | - Yongxing Lei
- CAS Key Laboratory of Synthetic Biology , CAS Center for Excellence in Molecular Plant Sciences , Institute of Plant Physiology and Ecology , Shanghai Institutes for Biological Sciences , Chinese Academy of Sciences , 300 FengLin Road , Shanghai 200032 , China .
- University of Chinese Academy of Sciences , Beijing 100039 , China
| | - Baofu Xu
- CAS Key Laboratory of Synthetic Biology , CAS Center for Excellence in Molecular Plant Sciences , Institute of Plant Physiology and Ecology , Shanghai Institutes for Biological Sciences , Chinese Academy of Sciences , 300 FengLin Road , Shanghai 200032 , China .
- University of Chinese Academy of Sciences , Beijing 100039 , China
| | - Xiaochen Zhu
- CAS Key Laboratory of Synthetic Biology , CAS Center for Excellence in Molecular Plant Sciences , Institute of Plant Physiology and Ecology , Shanghai Institutes for Biological Sciences , Chinese Academy of Sciences , 300 FengLin Road , Shanghai 200032 , China .
| | - Gudan Xu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery , Ministry of Education , School of Pharmaceutical Sciences , Wuhan University , Wuhan 430071 , China .
| | - Yaojie Gao
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery , Ministry of Education , School of Pharmaceutical Sciences , Wuhan University , Wuhan 430071 , China .
| | - Jianzhao Qi
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery , Ministry of Education , School of Pharmaceutical Sciences , Wuhan University , Wuhan 430071 , China .
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery , Ministry of Education , School of Pharmaceutical Sciences , Wuhan University , Wuhan 430071 , China .
| | - Gongli Tang
- State Key Laboratory of Bio-organic and Natural Products Chemistry , Shanghai Institute of Organic Chemistry , Chinese Academy of Sciences , 345 Lingling Road , Shanghai 200032 , China
| | - Wenqing Chen
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery , Ministry of Education , School of Pharmaceutical Sciences , Wuhan University , Wuhan 430071 , China .
| | - Youli Xiao
- CAS Key Laboratory of Synthetic Biology , CAS Center for Excellence in Molecular Plant Sciences , Institute of Plant Physiology and Ecology , Shanghai Institutes for Biological Sciences , Chinese Academy of Sciences , 300 FengLin Road , Shanghai 200032 , China .
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46
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Morinaka BI, Verest M, Freeman MF, Gugger M, Piel J. An Orthogonal D
2
O‐Based Induction System that Provides Insights into
d
‐Amino Acid Pattern Formation by Radical S‐Adenosylmethionine Peptide Epimerases. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201609469] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Brandon I. Morinaka
- Institute of Microbiology Eigenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 1-5/10 8093 Zurich Switzerland
| | - Marjan Verest
- Institute of Microbiology Eigenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 1-5/10 8093 Zurich Switzerland
| | - Michael F. Freeman
- Institute of Microbiology Eigenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 1-5/10 8093 Zurich Switzerland
| | - Muriel Gugger
- Insitut Pasteur, Collection des Cyanobactéries Département de Microbiologie 75015 Paris France
| | - Jörn Piel
- Institute of Microbiology Eigenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 1-5/10 8093 Zurich Switzerland
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47
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Morinaka BI, Verest M, Freeman MF, Gugger M, Piel J. An Orthogonal D
2
O‐Based Induction System that Provides Insights into
d
‐Amino Acid Pattern Formation by Radical S‐Adenosylmethionine Peptide Epimerases. Angew Chem Int Ed Engl 2016; 56:762-766. [DOI: 10.1002/anie.201609469] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Brandon I. Morinaka
- Institute of Microbiology Eigenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 1-5/10 8093 Zurich Switzerland
| | - Marjan Verest
- Institute of Microbiology Eigenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 1-5/10 8093 Zurich Switzerland
| | - Michael F. Freeman
- Institute of Microbiology Eigenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 1-5/10 8093 Zurich Switzerland
| | - Muriel Gugger
- Insitut Pasteur, Collection des Cyanobactéries Département de Microbiologie 75015 Paris France
| | - Jörn Piel
- Institute of Microbiology Eigenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 1-5/10 8093 Zurich Switzerland
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48
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Carbon extension in peptidylnucleoside biosynthesis by radical SAM enzymes. Nat Chem Biol 2016; 12:905-907. [PMID: 27642865 PMCID: PMC5069167 DOI: 10.1038/nchembio.2187] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 08/16/2016] [Indexed: 01/04/2023]
Abstract
Nikkomycins and polyoxins are antifungal peptidylnucleoside antibiotics active against human and plant pathogens. Here we report that during peptidylnucleoside biosynthesis in Streptomyces cacaoi and S. tendae, the C5' extension of the nucleoside essential for downstream structural diversification is catalyzed by a conserved radical S-adenosyl-L-methionine (SAM) enzyme, PolH or NikJ. This is distinct from the nucleophilic mechanism reported for antibacterial nucleosides and represents a new mechanism of nucleoside natural product biosynthesis.
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49
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Kudo F, Tokumitsu T, Eguchi T. Substrate specificity of radical S-adenosyl-l-methionine dehydratase AprD4 and its partner reductase AprD3 in the C3'-deoxygenation of aminoglycoside antibiotics. J Antibiot (Tokyo) 2016; 70:423-428. [PMID: 27599765 DOI: 10.1038/ja.2016.110] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 07/29/2016] [Accepted: 08/05/2016] [Indexed: 02/02/2023]
Abstract
A radical S-adenosyl-l-methionine dehydratase AprD4 and an NADPH-dependent reductase AprD3 are responsible for the C3'-deoxygenation of pseudodisaccharide paromamine in the biosynthesis of apramycin. These enzymes are involved in the construction of the characteristic structural motif that is not modified by 3'-phosphotransferase in aminoglycoside-resistant bacterial strains. AprD4 catalyzes the C3'-dehydration of paromamine via a radical-mediated reaction mechanism to give 4'-oxolividamine, which is then reduced by AprD3 with NADPH to afford lividamine. In the present study, the substrate specificity of this unique combination of enzymes has been investigated. AprD4 was found to recognize paromamine, neamine, kanamycin C, and kanamycin B to afford 5'-deoxyadenosine as one of products during the C3'-dehydration of aminoglycosides, but not 2'-N-acetylparomamine and paromomycin. Only paromamine and kanamycin C were converted to the corresponding C3'-deoxygenated compounds by AprD4 and AprD3. AprD3 recognizes the 4'-oxolividamine moiety, including the pseudotrisaccharide kanamycin C, and seems to reject the amino group at C6' of neamine and kanamycin B. Chirally deuterium-labeled NADPH was used to identify that that AprD3 transfers the pro-S hydrogen atom of NADPH when reducing 4'-oxolividamine to give lividamine.
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Affiliation(s)
- Fumitaka Kudo
- Department of Chemistry, Tokyo Institute of Technology, Tokyo, Japan
| | | | - Tadashi Eguchi
- Department of Chemistry, Tokyo Institute of Technology, Tokyo, Japan
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50
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Polytheonamide biosynthesis showcasing the metabolic potential of sponge-associated uncultivated ‘Entotheonella’ bacteria. Curr Opin Chem Biol 2016; 31:8-14. [DOI: 10.1016/j.cbpa.2015.11.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 10/12/2015] [Accepted: 11/01/2015] [Indexed: 01/14/2023]
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