1
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Wilkens D, Simon J. Biosynthesis and function of microbial methylmenaquinones. Adv Microb Physiol 2023; 83:1-58. [PMID: 37507157 DOI: 10.1016/bs.ampbs.2023.05.002] [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: 07/30/2023]
Abstract
The membranous quinone/quinol pool is essential for the majority of life forms and its composition has been widely used as a biomarker in microbial taxonomy. The most abundant quinone is menaquinone (MK), which serves as an essential redox mediator in various electron transport chains of aerobic and anaerobic respiration. Several methylated derivatives of MK, designated methylmenaquinones (MMKs), have been reported to be present in members of various microbial phyla possessing either the classical MK biosynthesis pathway (Men) or the futalosine pathway (Mqn). Due to their low redox midpoint potentials, MMKs have been proposed to be specifically involved in appropriate electron transport chains of anaerobic respiration. The class C radical SAM methyltransferases MqnK, MenK and MenK2 have recently been shown to catalyse specific MK methylation reactions at position C-8 (MqnK/MenK) or C-7 (MenK2) to synthesise 8-MMK, 7-MMK and 7,8-dimethylmenaquinone (DMMK). MqnK, MenK and MenK2 from organisms such as Wolinella succinogenes, Adlercreutzia equolifaciens, Collinsella tanakaei, Ferrimonas marina and Syntrophus aciditrophicus have been functionally produced in Escherichia coli, enabling extensive quinone/quinol pool engineering of the native MK and 2-demethylmenaquinone (DMK). Cluster and phylogenetic analyses of available MK and MMK methyltransferase sequences revealed signature motifs that allowed the discrimination of MenK/MqnK/MenK2 family enzymes from other radical SAM enzymes and the identification of C-7-specific menaquinone methyltransferases of the MenK2 subfamily. It is envisaged that this knowledge will help to predict the methylation status of the menaquinone/menaquinol pool of any microbial species (or even a microbial community) from its (meta)genome.
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Affiliation(s)
- Dennis Wilkens
- Microbial Energy Conversion and Biotechnology, Department of Biology, Technical University of Darmstadt, Schnittspahnstraße 10, Darmstadt, Germany
| | - Jörg Simon
- Microbial Energy Conversion and Biotechnology, Department of Biology, Technical University of Darmstadt, Schnittspahnstraße 10, Darmstadt, Germany; Centre for Synthetic Biology, Technical University of Darmstadt, Darmstadt, Germany.
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2
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Sinner EK, Li R, Marous DR, Townsend CA. ThnL, a B12-dependent radical S-adenosylmethionine enzyme, catalyzes thioether bond formation in carbapenem biosynthesis. Proc Natl Acad Sci U S A 2022; 119:e2206494119. [PMID: 35969793 PMCID: PMC9407657 DOI: 10.1073/pnas.2206494119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 07/19/2022] [Indexed: 11/18/2022] Open
Abstract
Complex carbapenems are important clinical antibiotics used to treat recalcitrant infections. Their biosynthetic gene clusters contain three essential B12-dependent radical S-adenosylmethionine (rSAM) enzymes. The majority of characterized enzymes in this subfamily catalyze methyl transfer, but only one is required to sequentially install all methionine-derived carbons in complex carbapenems. Therefore, it is probable that the other two rSAM enzymes have noncanonical functions. Through a series of fermentation and in vitro experiments, we show that ThnL uses radical SAM chemistry to catalyze thioether bond formation between C2 of a carbapenam precursor and pantetheine, uniting initial bicycle assembly common to all carbapenems with later tailoring events unique to complex carbapenems. ThnL also catalyzes reversible thiol/disulfide redox on pantetheine. Neither of these functions has been observed previously in a B12-dependent radical SAM enzyme. ThnL expands the known activity of this subclass of enzymes beyond carbon-carbon bond formation or rearrangement. It is also the only radical SAM enzyme currently known to catalyze carbon-sulfur bond formation with only an rSAM Fe-S cluster and no additional auxiliary clusters.
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Affiliation(s)
- Erica K. Sinner
- Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218
| | - Rongfeng Li
- Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218
| | - Daniel R. Marous
- Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218
| | - Craig A. Townsend
- Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218
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3
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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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4
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Ye Y, Fu H, Hyster TK. Activation modes in biocatalytic radical cyclization reactions. J Ind Microbiol Biotechnol 2021; 48:6155068. [PMID: 33674826 PMCID: PMC8210684 DOI: 10.1093/jimb/kuab021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/26/2021] [Indexed: 12/17/2022]
Abstract
Radical cyclizations are essential reactions in the biosynthesis of secondary metabolites and the chemical synthesis of societally valuable molecules. In this review, we highlight the general mechanisms utilized in biocatalytic radical cyclizations. We specifically highlight cytochrome P450 monooxygenases (P450s) involved in the biosynthesis of mycocyclosin and vancomycin, nonheme iron- and α-ketoglutarate-dependent dioxygenases (Fe/αKGDs) used in the biosynthesis of kainic acid, scopolamine, and isopenicillin N, and radical S-adenosylmethionine (SAM) enzymes that facilitate the biosynthesis of oxetanocin A, menaquinone, and F420. Beyond natural mechanisms, we also examine repurposed flavin-dependent “ene”-reductases (ERED) for non-natural radical cyclization. Overall, these general mechanisms underscore the opportunity for enzymes to augment and enhance the synthesis of complex molecules using radical mechanisms.
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Affiliation(s)
- Yuxuan Ye
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Haigen Fu
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Todd K Hyster
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
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5
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Manion-Sommerhalter HR, Fedoseyenko D, Joshi S, Begley TP. Menaquinone Biosynthesis: The Mechanism of 5,8-Dihydroxy-2-naphthoate Synthase (MqnD). Biochemistry 2021; 60:1947-1951. [PMID: 34143602 DOI: 10.1021/acs.biochem.1c00257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
MqnD catalyzes the conversion of cyclic dehypoxanthine futalosine (6) to 5,8-dihydroxy-2-naphthoic acid (7) and an uncharacterized product. This study describes a chemoenzymatic synthesis of 6. This synthesis achieved a 2-fold yield enhancement by using titanium(III) citrate as the reducing agent and another 5-fold yield enhancement using a fluorinated analogue of dehypoxanthine futalosine (5) that was converted to 6 by an ipso substitution mechanism. This synthetic route enabled the synthesis of 6 in sufficient quantity to identify the second reaction product and to determine that the MqnD-catalyzed reaction proceeds by a hemiacetal ring opening-tautomerization-retroaldol sequence.
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Affiliation(s)
| | - Dmytro Fedoseyenko
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Sumedh Joshi
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Tadhg P Begley
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
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6
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Chen TY, Xue S, Tsai WC, Chien TC, Guo Y, Chang WC. Deciphering Pyrrolidine and Olefin Formation Mechanism in Kainic Acid Biosynthesis. ACS Catal 2020. [DOI: 10.1021/acscatal.0c03879] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Tzu-Yu Chen
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Shan Xue
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Wei-Chih Tsai
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Tun-Cheng Chien
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Wei-chen Chang
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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7
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Carl AG, Harris LD, Feng M, Nordstrøm LU, Gerfen GJ, Evans GB, Silakov A, Almo SC, Grove TL. Narrow-Spectrum Antibiotic Targeting of the Radical SAM Enzyme MqnE in Menaquinone Biosynthesis. Biochemistry 2020; 59:2562-2575. [DOI: 10.1021/acs.biochem.0c00070] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Ayala G. Carl
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Lawrence D. Harris
- The Ferrier Research Institute, Victoria University of Wellington, Wellington, New Zealand
- The Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 5040, New Zealand
| | - Mu Feng
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Lars U. Nordstrøm
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Gary J. Gerfen
- Department of Biophysics, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Gary B. Evans
- The Ferrier Research Institute, Victoria University of Wellington, Wellington, New Zealand
- The Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 5040, New Zealand
| | - Alexey Silakov
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Steven C. Almo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Tyler L. Grove
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, United States
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8
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Suess CJ, Martins FL, Croft AK, Jäger CM. Radical Stabilization Energies for Enzyme Engineering: Tackling the Substrate Scope of the Radical Enzyme QueE. J Chem Inf Model 2019; 59:5111-5125. [PMID: 31730347 DOI: 10.1021/acs.jcim.9b00017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Experimental assessment of catalytic reaction mechanisms and profiles of radical enzymes can be severely challenging due to the reactive nature of the intermediates and sensitivity of cofactors such as iron-sulfur clusters. Here, we present an enzyme-directed computational methodology for the assessment of thermodynamic reaction profiles and screening for radical stabilization energies (RSEs) for the assessment of catalytic turnovers in radical enzymes. We have applied this new screening method to the radical S-adenosylmethione enzyme 7-carboxy-7-deazaguanine synthase (QueE), following a detailed molecular dynamics (MD) analysis that clarifies the role of both specific enzyme residues and bound Mg2+, Ca2+, or Na+. The MD simulations provided the basis for a statistical approach to sample different conformational outcomes. RSE calculation at the M06-2X/6-31+G* level of theory provided the most computationally cost-effective assessment of enzyme-based energies, facilitated by an initial triage using semiempirical methods. The impact of intermolecular interactions on RSE was clearly established, and application to the assessment of potential alternative substrates (focusing on radical clock type rearrangements) proposes a selection of carbon-substituted analogues that would react to afford cyclopropylcarbinyl radical intermediates as candidates for catalytic turnover by QueE.
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Affiliation(s)
- Christian J Suess
- Department of Chemical and Environmental Engineering , The University of Nottingham , University Park, Nottingham NG7 2RD , United Kingdom
| | - Floriane L Martins
- Department of Chemical and Environmental Engineering , The University of Nottingham , University Park, Nottingham NG7 2RD , United Kingdom
| | - Anna K Croft
- Department of Chemical and Environmental Engineering , The University of Nottingham , University Park, Nottingham NG7 2RD , United Kingdom
| | - Christof M Jäger
- Department of Chemical and Environmental Engineering , The University of Nottingham , University Park, Nottingham NG7 2RD , United Kingdom
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9
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Microbial production of vitamin K2: current status and future prospects. Biotechnol Adv 2019; 39:107453. [PMID: 31629792 DOI: 10.1016/j.biotechadv.2019.107453] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/24/2019] [Accepted: 09/17/2019] [Indexed: 12/18/2022]
Abstract
Vitamin K2, also called menaquinone, is an essential lipid-soluble vitamin that plays a critical role in blood clotting and prevention of osteoporosis. It has become a focus of research in recent years and has been widely used in the food and pharmaceutical industries. This review will briefly introduce the functions and applications of vitamin K2 first, after which the biosynthesis pathways and enzymes will be analyzed in-depth to highlight the bottlenecks facing the microbial vitamin K2 production on the industrial scale. Then, various strategies, including strain mutagenesis and genetic modification, different cultivation modes, fermentation and separation processes, will be summarized and discussed. The future prospects and perspectives of microbial menaquinone production will also be discussed finally.
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10
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Miller SA, Bandarian V. Analysis of Electrochemical Properties of S-Adenosyl-l-methionine and Implications for Its Role in Radical SAM Enzymes. J Am Chem Soc 2019; 141:11019-11026. [PMID: 31283208 PMCID: PMC7059804 DOI: 10.1021/jacs.9b00933] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
![]()
S-Adenosyl-l-methionine (SAM) is the
central cofactor in the radical SAM enzyme superfamily, responsible
for a vast number of transformations in primary and secondary metabolism.
In nearly all of these reactions, the reductive cleavage of SAM is
proposed to produce a reactive species, 5′-deoxyadenosyl radical,
which initiates catalysis. While the mechanistic details in many cases
are well-understood, the reductive cleavage of SAM remains elusive.
In this manuscript, we have measured the solution peak potential of
SAM to be ∼−1.4 V (v SHE) and show that under controlled
potential conditions, it undergoes irreversible fragmentation to the
5′-deoxyadenosyl radical. While the radical intermediate is
not directly observed, its presence as an initial intermediate is
inferred by the formation of 8,5′-cycloadenosine and by H atom
incorporation into 5′-deoxyadenosine from solvent exchangeable
site. Similarly, 2-aminobutyrate is also observed under electrolysis
conditions. The implications of these results in the context of the
reductive cleavage of SAM by radical SAM enzymes are discussed.
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Affiliation(s)
- Sven A Miller
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112 , United States
| | - Vahe Bandarian
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112 , United States
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11
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Abstract
Enzyme-mediated cascade reactions are widespread in biosynthesis. To facilitate comparison with the mechanistic categorizations of cascade reactions by synthetic chemists and delineate the common underlying chemistry, we discuss four types of enzymatic cascade reactions: those involving nucleophilic, electrophilic, pericyclic, and radical reactions. Two subtypes of enzymes that generate radical cascades exist at opposite ends of the oxygen abundance spectrum. Iron-based enzymes use O2 to generate high valent iron-oxo species to homolyze unactivated C-H bonds in substrates to initiate skeletal rearrangements. At anaerobic end, enzymes reversibly cleave S-adenosylmethionine (SAM) to generate the 5'-deoxyadenosyl radical as a powerful oxidant to initiate C-H bond homolysis in bound substrates. The latter enzymes are termed radical SAM enzymes. We categorize the former as "thwarted oxygenases".
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Affiliation(s)
- Christopher T Walsh
- Stanford University Chemistry, Engineering, and Medicine for Human Health (CheM-H), Stanford University, Stanford, CA, 94305, USA
| | - Bradley S Moore
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
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12
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Erbilgin O, Rübel O, Louie KB, Trinh M, Raad MD, Wildish T, Udwary D, Hoover C, Deutsch S, Northen TR, Bowen BP. MAGI: A Method for Metabolite Annotation and Gene Integration. ACS Chem Biol 2019; 14:704-714. [PMID: 30896917 DOI: 10.1021/acschembio.8b01107] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Metabolomics is a widely used technology for obtaining direct measures of metabolic activities from diverse biological systems. However, ambiguous metabolite identifications are a common challenge and biochemical interpretation is often limited by incomplete and inaccurate genome-based predictions of enzyme activities (that is, gene annotations). Metabolite Annotation and Gene Integration (MAGI) generates a metabolite-gene association score using a biochemical reaction network. This is calculated by a method that emphasizes consensus between metabolites and genes via biochemical reactions. To demonstrate the potential of this method, we applied MAGI to integrate sequence data and metabolomics data collected from Streptomyces coelicolor A3(2), an extensively characterized bacterium that produces diverse secondary metabolites. Our findings suggest that coupling metabolomics and genomics data by scoring consensus between the two increases the quality of both metabolite identifications and gene annotations in this organism. MAGI also made biochemical predictions for poorly annotated genes that were consistent with the extensive literature on this important organism. This limited analysis suggests that using metabolomics data has the potential to improve annotations in sequenced organisms and also provides testable hypotheses for specific biochemical functions. MAGI is freely available for academic use both as an online tool at https://magi.nersc.gov and with source code available at https://github.com/biorack/magi .
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Affiliation(s)
- Onur Erbilgin
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Oliver Rübel
- Data Analytics and Visualization Group, Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Katherine B. Louie
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Matthew Trinh
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Markus de Raad
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Tony Wildish
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- National Energy Research Scientific Computing Center, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Daniel Udwary
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- National Energy Research Scientific Computing Center, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Cindi Hoover
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Samuel Deutsch
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Trent R. Northen
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Benjamin P. Bowen
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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13
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Mahanta N, Hicks KA, Naseem S, Zhang Y, Fedoseyenko D, Ealick SE, Begley TP. Menaquinone Biosynthesis: Biochemical and Structural Studies of Chorismate Dehydratase. Biochemistry 2019; 58:1837-1840. [DOI: 10.1021/acs.biochem.9b00105] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Nilkamal Mahanta
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Katherine A. Hicks
- Department of Chemistry, The State University of New York Cortland, Cortland, New York 13045, United States
| | - Saad Naseem
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Yang Zhang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Dmytro Fedoseyenko
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Steven E. Ealick
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Tadhg P. Begley
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
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14
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Searching for potent and specific antibiotics against pathogenic Helicobacter and Campylobacter strains. ACTA ACUST UNITED AC 2019; 46:409-414. [DOI: 10.1007/s10295-018-2108-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 11/08/2018] [Indexed: 12/14/2022]
Abstract
Abstract
Menaquinone is an obligatory component of the electron-transfer pathway in microorganisms. Its biosynthetic pathway was established by pioneering studies with Escherichia coli and it was revealed to be derived from chorismate by Men enzymes. However, we identified an alternative pathway, the futalosine pathway, operating in some microorganisms including Helicobacter pylori and Campylobacter jejuni, which cause gastric carcinoma and diarrhea, respectively. Because some useful intestinal bacteria, such as lactobacilli, use the canonical pathway, the futalosine pathway is an attractive target for development of chemotherapeutics for the abovementioned pathogens. In this mini-review, we summarize compounds that inhibit Mqn enzymes involved in the futalosine pathway discovered to date.
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15
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Affiliation(s)
- Christopher T. Walsh
- Stanford University Chemistry, Engineering, and Medicine for Human Health (CheM-H)Stanford University Stanford CA 94305 USA
| | - Bradley S. Moore
- Center for Marine Biotechnology and BiomedicineScripps Institution of OceanographyUniversity of California, San Diego La Jolla CA 92093 USA
- Skaggs School of Pharmacy and Pharmaceutical SciencesUniversity of California, San Diego La Jolla CA 92093 USA
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16
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Chang WC, Yang ZJ, Tu YH, Chien TC. Reaction Mechanism of a Nonheme Iron Enzyme Catalyzed Oxidative Cyclization via C-C Bond Formation. Org Lett 2018; 21:228-232. [PMID: 30550285 DOI: 10.1021/acs.orglett.8b03670] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A complementary study including design of mechanistic probes, biochemical assays, model analysis, and liquid chromatography coupled mass spectrometry was conducted to establish the reaction mechanism for a nonheme iron enzyme catalyzed (-)-podophyllotoxin formation. Our results indicate that the originally proposed hydroxylated intermediate is unlikely to be involved in this reaction. Instead, the formation of benzylic radical/carbocation intermediate can be utilized to trigger the C-C bond formation to construct the C-ring of (-)-podophyllotoxin.
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Affiliation(s)
- Wei-Chen Chang
- Department of Chemistry , North Carolina State University , Raleigh , North Carolina 27695 , United States
| | - Zhi-Jie Yang
- Department of Chemistry , National Taiwan Normal University , Taipei 11677 , Taiwan
| | - Yueh-Hua Tu
- Department of Chemistry , National Taiwan Normal University , Taipei 11677 , Taiwan
| | - Tun-Cheng Chien
- Department of Chemistry , National Taiwan Normal University , Taipei 11677 , Taiwan
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17
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Novel enzymology in futalosine-dependent menaquinone biosynthesis. Curr Opin Chem Biol 2018; 47:134-141. [DOI: 10.1016/j.cbpa.2018.09.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 09/13/2018] [Accepted: 09/20/2018] [Indexed: 12/12/2022]
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18
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Abstract
Transition state theory teaches that chemically stable mimics of enzymatic transition states will bind tightly to their cognate enzymes. Kinetic isotope effects combined with computational quantum chemistry provides enzymatic transition state information with sufficient fidelity to design transition state analogues. Examples are selected from various stages of drug development to demonstrate the application of transition state theory, inhibitor design, physicochemical characterization of transition state analogues, and their progress in drug development.
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Affiliation(s)
- Vern L. Schramm
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
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19
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Iterative Methylations Resulting in the Biosynthesis of the t-Butyl Group Catalyzed by a B 12-Dependent Radical SAM Enzyme in Cystobactamid Biosynthesis. Methods Enzymol 2018; 606:199-216. [PMID: 30097093 DOI: 10.1016/bs.mie.2018.05.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
B12-dependent radical SAM enzymes that can perform methylations on sp3 carbon centers are important for functional diversity and regulation of biological activity in several nonribosomal peptides. Detailed studies on these enzymes are hindered by the complexity of the substrates and low levels of expression of active enzymes. CysS can catalyze iterative methylations of a methoxybenzene moiety during the biosynthesis of the cystobactamids. Here, we describe the overexpression, purification, substrate identification, and mechanism of this enzyme.
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20
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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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21
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Abstract
The Immucillins are chemically stable analogues that mimic the ribocation and leaving-group features of N-ribosyltransferase transition states. Infectious disease agents often rely on ribosyltransferase chemistry in pathways involving precursor synthesis for nucleic acids, salvage of nucleic acid precursors, or synthetic pathways with nucleoside intermediates. Here, we review three infectious agents and the use of the Immucillins to taget enzymes essential to the parasites. First, DADMe-Immucillin-G is a purine nucleoside phosphorylase (PNP) inhibitor that blocks purine salvage and shows clinical potential for treatment for the malaria parasite Plasmodium falciparum, a purine auxotroph requiring hypoxanthine for purine nucleotide synthesis. Inhibition of the PNPs in the host and in parasite cells leads to apurinic starvation and death. Second, Helicobacter pylori, a causative agent of human ulcers, synthesizes menaquinone, an essential electron transfer agent, in a pathway requiring aminofutalosine nucleoside hydrolysis. Inhibitors of the H. pylori methylthioadenosine nucleosidase (MTAN) are powerful antibiotics for this organism. Synthesis of menaquinone by the aminofutalosine pathway does not occur in most bacteria populating the human gut microbiome. Thus, MTAN inhibitors provide high-specificity antibiotics for H. pylori and are not expected to disrupt the normal gut bacterial flora. Third, Immucillin-A was designed as a transition state analogue of the atypical PNP from Trichomonas vaginalis. In antiviral screens, Immucillin-A was shown to act as a prodrug. It is active against filoviruses and flaviviruses. In virus-infected cells, Immucillin-A is converted to the triphosphate, is incorporated into the viral transcript, and functions as an atypical chain-terminator for RNA-dependent RNA polymerases. Immucillin-A has entered clinical trials for use as an antiviral. We also summarize other Immucillins that have been characterized in successful clinical trials for T-cell lymphoma and gout. The human trials support the potential development of the Immucillins in infectious diseases.
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Affiliation(s)
- Gary B. Evans
- Ferrier Research
Institute, Victoria University of Wellington, 69 Gracefield Road, Gracefield, Lower Hutt, 5010, New Zealand
| | - Peter C. Tyler
- Ferrier Research
Institute, Victoria University of Wellington, 69 Gracefield Road, Gracefield, Lower Hutt, 5010, New Zealand
| | - Vern L. Schramm
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
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22
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Schramma KR, Forneris CC, Caruso A, Seyedsayamdost MR. Mechanistic Investigations of Lysine-Tryptophan Cross-Link Formation Catalyzed by Streptococcal Radical S-Adenosylmethionine Enzymes. Biochemistry 2018; 57:461-468. [PMID: 29320164 DOI: 10.1021/acs.biochem.7b01147] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Streptide is a ribosomally synthesized and post-translationally modified peptide with a unique cyclization motif consisting of an intramolecular lysine-tryptophan cross-link. Three radical S-adenosylmethionine enzymes, StrB, AgaB, and SuiB from different species of Streptococcus, have been shown to install this modification onto their respective precursor peptides in a leader-dependent fashion. Herein, we conduct detailed investigations to differentiate among several plausible mechanistic proposals, specifically addressing radical versus electrophilic addition to the indole during cross-link formation, the role of substrate side chains in binding in the enzyme active site, and the identity of the catalytic base in the reaction cycle. Our results are consistent with a radical electrophilic aromatic substitution mechanism for the key carbon-carbon bond-forming step. They also elaborate on other mechanistic features that underpin this unique and synthetically challenging post-translational modification.
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Affiliation(s)
- Kelsey R Schramma
- Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States
| | - Clarissa C Forneris
- Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States
| | - Alessio Caruso
- Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States
| | - Mohammad R Seyedsayamdost
- Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States.,Department of Molecular Biology, Princeton University , Princeton, New Jersey 08544, United States
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23
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Aminofutalosine Synthase (MqnE): A New Catalytic Motif in Radical SAM Enzymology. Methods Enzymol 2018; 606:179-198. [DOI: 10.1016/bs.mie.2018.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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24
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Bame J, Hoeck C, Carrington MJ, Butts CP, Jäger CM, Croft AK. Improved NOE fitting for flexible molecules based on molecular mechanics data – a case study with S-adenosylmethionine. Phys Chem Chem Phys 2018; 20:7523-7531. [DOI: 10.1039/c7cp07265a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using the important biomolecule S-adenosyl methionine as an exemplar, we provide a new, enhanced approach for fitting MD data to high-accuracy NOE data, providing improvements in structure determination.
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Affiliation(s)
- Jessica Bame
- University of Bristol
- School of Chemistry
- Clifton
- Bristol BS8 1TS
- UK
| | - Casper Hoeck
- University of Bristol
- School of Chemistry
- Clifton
- Bristol BS8 1TS
- UK
| | - Matthew J. Carrington
- University of Nottingham
- Department of Chemical and Environmental Engineering
- University Park
- Nottingham
- UK
| | - Craig P. Butts
- University of Bristol
- School of Chemistry
- Clifton
- Bristol BS8 1TS
- UK
| | - Christof M. Jäger
- University of Nottingham
- Department of Chemical and Environmental Engineering
- University Park
- Nottingham
- UK
| | - Anna K. Croft
- University of Nottingham
- Department of Chemical and Environmental Engineering
- University Park
- Nottingham
- UK
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25
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Joshi S, Mahanta N, Fedoseyenko D, Williams H, Begley TP. Aminofutalosine Synthase: Evidence for Captodative and Aryl Radical Intermediates Using β-Scission and SRN1 Trapping Reactions. J Am Chem Soc 2017; 139:10952-10955. [DOI: 10.1021/jacs.7b04209] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Sumedh Joshi
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Nilkamal Mahanta
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Dmytro Fedoseyenko
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Howard Williams
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Tadhg P. Begley
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
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26
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Abstract
Oxidative cyclizations are important transformations that occur widely during natural product biosynthesis. The transformations from acyclic precursors to cyclized products can afford morphed scaffolds, structural rigidity, and biological activities. Some of the most dramatic structural alterations in natural product biosynthesis occur through oxidative cyclization. In this Review, we examine the different strategies used by nature to create new intra(inter)molecular bonds via redox chemistry. This Review will cover both oxidation- and reduction-enabled cyclization mechanisms, with an emphasis on the former. Radical cyclizations catalyzed by P450, nonheme iron, α-KG-dependent oxygenases, and radical SAM enzymes are discussed to illustrate the use of molecular oxygen and S-adenosylmethionine to forge new bonds at unactivated sites via one-electron manifolds. Nonradical cyclizations catalyzed by flavin-dependent monooxygenases and NAD(P)H-dependent reductases are covered to show the use of two-electron manifolds in initiating cyclization reactions. The oxidative installations of epoxides and halogens into acyclic scaffolds to drive subsequent cyclizations are separately discussed as examples of "disappearing" reactive handles. Last, oxidative rearrangement of rings systems, including contractions and expansions, will be covered.
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Affiliation(s)
- Man-Cheng Tang
- Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, 420 Westwood Plaza, Los Angeles, CA 90095, USA
| | - Yi Zou
- Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, 420 Westwood Plaza, Los Angeles, CA 90095, USA
| | - Kenji Watanabe
- Department of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Christopher T. Walsh
- Stanford University Chemistry, Engineering, and Medicine for Human Health (ChEM-H), Stanford University, 443 Via Ortega, Stanford, CA 94305
| | - Yi Tang
- Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, 420 Westwood Plaza, Los Angeles, CA 90095, USA
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27
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Jäger CM, Croft AK. Radical Reaction Control in the AdoMet Radical Enzyme CDG Synthase (QueE): Consolidate, Destabilize, Accelerate. Chemistry 2017; 23:953-962. [PMID: 27859789 PMCID: PMC5347944 DOI: 10.1002/chem.201604719] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Indexed: 12/29/2022]
Abstract
Controlling radical intermediates and thus catalysing and directing complex radical reactions is a central feature of S-adensosylmethionine (SAM)-dependent radical enzymes. We report ab initio and DFT calculations highlighting the specific influence of ion complexation, including Mg2+ , identified as a key catalytic component on radical stability and reaction control in 7-carboxy-7-deazaguanine synthase (QueE). Radical stabilisation energies (RSEs) of key intermediates and radical clock-like model systems of the enzyme-catalysed rearrangement of 6-carboxytetrahydropterin (CPH4), reveals a directing role of Mg2+ in destabilising both the substrate-derived radical and corresponding side reactions, with the effect that the experimentally-observed rearrangement becomes dominant over possible alternatives. Importantly, this is achieved with minimal disruption of the thermodynamics of the substrate itself, affording a novel mechanism for an enzyme to both maintain binding potential and accelerate the rearrangement step. Other mono and divalent ions were probed with only dicationic species achieving the necessary radical conformation to facilitate the reaction.
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Affiliation(s)
- Christof M. Jäger
- The University of NottinghamDepartment of Chemical and Environmental EngineeringUniversity ParkNottinghamNG7 2RDUnited Kingdom
| | - Anna K. Croft
- The University of NottinghamDepartment of Chemical and Environmental EngineeringUniversity ParkNottinghamNG7 2RDUnited Kingdom
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28
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Bhandari DM, Fedoseyenko D, Begley TP. Tryptophan Lyase (NosL): A Cornucopia of 5′-Deoxyadenosyl Radical Mediated Transformations. J Am Chem Soc 2016; 138:16184-16187. [DOI: 10.1021/jacs.6b06139] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dhananjay M. Bhandari
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Dmytro Fedoseyenko
- 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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29
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Mehta AP, Abdelwahed SH, Mahanta N, Fedoseyenko D, Philmus B, Cooper LE, Liu Y, Jhulki I, Ealick SE, Begley TP. Radical S-adenosylmethionine (SAM) enzymes in cofactor biosynthesis: a treasure trove of complex organic radical rearrangement reactions. J Biol Chem 2014; 290:3980-6. [PMID: 25477515 DOI: 10.1074/jbc.r114.623793] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this minireview, we describe the radical S-adenosylmethionine enzymes involved in the biosynthesis of thiamin, menaquinone, molybdopterin, coenzyme F420, and heme. Our focus is on the remarkably complex organic rearrangements involved, many of which have no precedent in organic or biological chemistry.
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Affiliation(s)
- Angad P Mehta
- From the Department of Chemistry, Texas A&M University, College Station, Texas 77843 and
| | - Sameh H Abdelwahed
- From the Department of Chemistry, Texas A&M University, College Station, Texas 77843 and
| | - Nilkamal Mahanta
- From the Department of Chemistry, Texas A&M University, College Station, Texas 77843 and
| | - Dmytro Fedoseyenko
- From the Department of Chemistry, Texas A&M University, College Station, Texas 77843 and
| | - Benjamin Philmus
- From the Department of Chemistry, Texas A&M University, College Station, Texas 77843 and
| | - Lisa E Cooper
- From the Department of Chemistry, Texas A&M University, College Station, Texas 77843 and
| | - Yiquan Liu
- From the Department of Chemistry, Texas A&M University, College Station, Texas 77843 and
| | - Isita Jhulki
- From the Department of Chemistry, Texas A&M University, College Station, Texas 77843 and
| | - Steven E Ealick
- the Department of Chemistry, Cornell University, Ithaca, New York 14850
| | - Tadhg P Begley
- From the Department of Chemistry, Texas A&M University, College Station, Texas 77843 and
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30
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Broderick JB, Duffus B, Duschene KS, Shepard EM. Radical S-adenosylmethionine enzymes. Chem Rev 2014; 114:4229-317. [PMID: 24476342 PMCID: PMC4002137 DOI: 10.1021/cr4004709] [Citation(s) in RCA: 576] [Impact Index Per Article: 57.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Indexed: 12/22/2022]
Affiliation(s)
- Joan B. Broderick
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Benjamin
R. Duffus
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Kaitlin S. Duschene
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Eric M. Shepard
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
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31
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Mahanta N, Fedoseyenko D, Dairi T, Begley TP. Menaquinone biosynthesis: formation of aminofutalosine requires a unique radical SAM enzyme. J Am Chem Soc 2013; 135:15318-21. [PMID: 24083939 PMCID: PMC3855536 DOI: 10.1021/ja408594p] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Menaquinone (MK, vitamin K2) is a lipid-soluble molecule that participates in the bacterial electron transport chain. In mammalian cells, MK functions as an essential vitamin for the activation of various proteins involved in blood clotting and bone metabolism. Recently, a new pathway for the biosynthesis of this cofactor was discovered in Streptomyces coelicolor A3(2) in which chorismate is converted to aminofutalosine in a reaction catalyzed by MqnA and an unidentified enzyme. Here, we reconstitute the biosynthesis of aminofutalosine and demonstrate that the missing enzyme (aminofutalosine synthase, MqnE) is a radical SAM enzyme that catalyzes the addition of the adenosyl radical to the double bond of 3-[(1-carboxyvinyl)oxy]benzoic acid. This is a new reaction type in the radical SAM superfamily.
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Affiliation(s)
- Nilkamal Mahanta
- Department of Chemistry, Texas A&M University , College Station, Texas 77843, United States
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