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Hou X, Feng J, Franklin JL, Russo R, Guo Z, Zhou J, Gao JM, Liu HW, Wang B. Mechanistic Insights from the Crystal Structure and Computational Analysis of the Radical SAM Deaminase DesII. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2403494. [PMID: 38943270 DOI: 10.1002/advs.202403494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/06/2024] [Indexed: 07/01/2024]
Abstract
Radical S-adenosyl-L-methionine (SAM) enzymes couple the reductive cleavage of SAM to radical-mediated transformations that have proven to be quite broad in scope. DesII is one such enzyme from the biosynthetic pathway of TDP-desosamine where it catalyzes a radical-mediated deamination. Previous studies have suggested that this reaction proceeds via direct elimination of ammonia from an α-hydroxyalkyl radical or its conjugate base (i.e., a ketyl radical) rather than 1,2-migration of the amino group to form a carbinolamine radical intermediate. However, without a crystal structure, the active site features responsible for this chemistry have remained largely unknown. The crystallographic studies described herein help to fill this gap by providing a structural description of the DesII active site. Computational analyses based on the solved crystal structure are consistent with direct elimination and indicate that an active site glutamate residue likely serves as a general base to promote deprotonation of the α-hydroxyalkyl radical intermediate and elimination of the ammonia group.
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Affiliation(s)
- Xueli Hou
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi, 712100, China
- Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Jianqiang Feng
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, 361005, China
| | - Joseph Livy Franklin
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX, 78712, USA
| | - Ryan Russo
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX, 78712, USA
| | - Zhiyong Guo
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Jiahai Zhou
- Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023, China
| | - Jin-Ming Gao
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Hung-Wen Liu
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX, 78712, USA
- Department of Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, 361005, China
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2
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Kamel R, Aman R, Mahfouz MM. Viperin-like proteins interfere with RNA viruses in plants. FRONTIERS IN PLANT SCIENCE 2024; 15:1385169. [PMID: 38895613 PMCID: PMC11185175 DOI: 10.3389/fpls.2024.1385169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 05/21/2024] [Indexed: 06/21/2024]
Abstract
Plant viruses cause substantial losses in crop yield and quality; therefore, devising new, robust strategies to counter viral infections has important implications for agriculture. Virus inhibitory protein endoplasmic reticulum-associated interferon-inducible (Viperin) proteins are conserved antiviral proteins. Here, we identified a set of Viperin and Viperin-like proteins from multiple species and tested whether they could interfere with RNA viruses in planta. Our data from transient and stable overexpression of these proteins in Nicotiana benthamiana reveal varying levels of interference against the RNA viruses tobacco mosaic virus (TMV), turnip mosaic virus (TuMV), and potato virus x (PVX). Harnessing the potential of these proteins represents a novel avenue in plant antiviral approaches, offering a broader and more effective spectrum for application in plant biotechnology and agriculture. Identifying these proteins opens new avenues for engineering a broad range of resistance to protect crop plants against viral pathogens.
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Affiliation(s)
| | | | - Magdy M. Mahfouz
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
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3
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Kisgeropoulos EC, Artz JH, Blahut M, Peters JW, King PW, Mulder DW. Properties of the iron-sulfur cluster electron transfer relay in an [FeFe]-hydrogenase that is tuned for H 2 oxidation catalysis. J Biol Chem 2024; 300:107292. [PMID: 38636659 PMCID: PMC11126806 DOI: 10.1016/j.jbc.2024.107292] [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] [Received: 02/12/2024] [Revised: 04/09/2024] [Accepted: 04/11/2024] [Indexed: 04/20/2024] Open
Abstract
[FeFe]-hydrogenases catalyze the reversible oxidation of H2 from electrons and protons at an organometallic active site cofactor named the H-cluster. In addition to the H-cluster, most [FeFe]-hydrogenases possess accessory FeS cluster (F-cluster) relays that function in mediating electron transfer with catalysis. There is significant variation in the structural properties of F-cluster relays among the [FeFe]-hydrogenases; however, it is unknown how this variation relates to the electronic and thermodynamic properties, and thus the electron transfer properties, of enzymes. Clostridium pasteurianum [FeFe]-hydrogenase II (CpII) exhibits a large catalytic bias for H2 oxidation (compared to H2 production), making it a notable system for examining if F-cluster properties contribute to the overall function and efficiency of the enzyme. By applying a combination of multifrequency and potentiometric electron paramagnetic resonance, we resolved two electron paramagnetic resonance signals with distinct power- and temperature-dependent properties at g = 2.058 1.931 1.891 (F2.058) and g = 2.061 1.920 1.887 (F2.061), with assigned midpoint potentials of -140 ± 18 mV and -406 ± 12 mV versus normal hydrogen electrode, respectively. Spectral analysis revealed features consistent with spin-spin coupling between the two [4Fe-4S] F-clusters, and possible functional models are discussed that account for the contribution of coupling to the electron transfer landscape. The results signify the interplay of electronic coupling and free energy properties and parameters of the FeS clusters to the electron transfer mechanism through the relay and provide new insight as to how relays functionally complement the catalytic directionality of active sites to achieve highly efficient catalysis.
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Affiliation(s)
| | - Jacob H Artz
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
| | - Matthew Blahut
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
| | - John W Peters
- Department of Chemistry and Biochemistry, The University of Oklahoma, Norman, Oklahoma, USA
| | - Paul W King
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA; Renewable and Sustainable Energy Institute, National Renewable Energy Laboratory and University of Colorado Boulder, Boulder, Colorado, USA
| | - David W Mulder
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA.
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4
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Wang XW, Zhang R, Liu LL, Li HJ, Zhu H. Expression analysis and antiviral activity of koi carp (Cyprinus carpio) viperin against carp edema virus (CEV). FISH & SHELLFISH IMMUNOLOGY 2024; 148:109519. [PMID: 38508540 DOI: 10.1016/j.fsi.2024.109519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/25/2024] [Accepted: 03/18/2024] [Indexed: 03/22/2024]
Abstract
Viperin, also known as radical S-Adenosyl methionine domain containing 2 (RSAD2), is an IFN stimulated protein that plays crucial roles in innate immunity. Here, we identified a viperin gene from the koi carp (Cyprinus carpio) (kVip). The ORF of kVip is 1047 bp in length, encoding a polypeptide of 348 amino acids with neither signal peptide nor transmembrane protein. The predicted molecular weight is 40.37 kDa and the isoelectric point is 7.7. Multiple sequence alignment indicated that putative kVip contains a radical SAM superfamily domain and a conserved C-terminal region. kVip was highly expressed in the skin and spleen of healthy koi carps, and significantly stimulated in both natural and artificial CEV-infected koi carps. In vitro immune stimulation analysis showed that both extracellular and intracellular poly (I: C) or poly (dA: dT) caused a significant increase in kVip expression of spleen cells. Furthermore, intraperitoneal injection of recombinant kVip (rkVip) not only reduced the CEV load in the gills, but also improved the survival of koi carps following CEV challenge. Additionally, rkVip administration effectively regulated inflammatory and anti-inflammatory cytokines (IL-6, IL-1β, TNF-α, IL-10) and interferon-related molecules (cGAS, STING, MyD88, IFN-γ, IFN-α, IRF3 and IRF9). Collectively, kVip effectively responded to CEV infection and exerted antiviral function against CEV partially by regulation of inflammatory and interferon responses.
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Affiliation(s)
- Xiao-Wen Wang
- Beijing Key Laboratory of Fishery Biotechnology & Fisheries Research Institute, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100068, China; National Freshwater Fisheries Engineering Technology Research Center, Beijing, 100068, China
| | - Rong Zhang
- Beijing Key Laboratory of Fishery Biotechnology & Fisheries Research Institute, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100068, China; National Freshwater Fisheries Engineering Technology Research Center, Beijing, 100068, China
| | - Li-Li Liu
- Beijing Key Laboratory of Fishery Biotechnology & Fisheries Research Institute, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100068, China; National Freshwater Fisheries Engineering Technology Research Center, Beijing, 100068, China
| | - Hui-Juan Li
- Beijing Key Laboratory of Fishery Biotechnology & Fisheries Research Institute, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100068, China; National Freshwater Fisheries Engineering Technology Research Center, Beijing, 100068, China
| | - Hua Zhu
- Beijing Key Laboratory of Fishery Biotechnology & Fisheries Research Institute, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100068, China; National Freshwater Fisheries Engineering Technology Research Center, Beijing, 100068, China.
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Ütkür K, Mayer K, Liu S, Brinkmann U, Schaffrath R. Functional Integrity of Radical SAM Enzyme Dph1•Dph2 Requires Non-Canonical Cofactor Motifs with Tandem Cysteines. Biomolecules 2024; 14:470. [PMID: 38672486 PMCID: PMC11048331 DOI: 10.3390/biom14040470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 04/05/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
The Dph1•Dph2 heterodimer from yeast is a radical SAM (RS) enzyme that generates the 3-amino-3-carboxy-propyl (ACP) precursor for diphthamide, a clinically relevant modification on eukaryotic elongation factor 2 (eEF2). ACP formation requires SAM cleavage and atypical Cys-bound Fe-S clusters in each Dph1 and Dph2 subunit. Intriguingly, the first Cys residue in each motif is found next to another ill-defined cysteine that we show is conserved across eukaryotes. As judged from structural modeling, the orientation of these tandem cysteine motifs (TCMs) suggests a candidate Fe-S cluster ligand role. Hence, we generated, by site-directed DPH1 and DPH2 mutagenesis, Dph1•Dph2 variants with cysteines from each TCM replaced individually or in combination by serines. Assays diagnostic for diphthamide formation in vivo reveal that while single substitutions in the TCM of Dph2 cause mild defects, double mutations almost entirely inactivate the RS enzyme. Based on enhanced Dph1 and Dph2 subunit instability in response to cycloheximide chases, the variants with Cys substitutions in their cofactor motifs are particularly prone to protein degradation. In sum, we identify a fourth functionally cooperative Cys residue within the Fe-S motif of Dph2 and show that the Cys-based cofactor binding motifs in Dph1 and Dph2 are critical for the structural integrity of the dimeric RS enzyme in vivo.
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Affiliation(s)
- Koray Ütkür
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, 34132 Kassel, Germany;
| | - Klaus Mayer
- Roche Pharma Research and Early Development (pRED), Large Molecule Research, Roche Innovation Center Munich, 82377 Penzberg, Germany; (K.M.); (U.B.)
| | - Shihui Liu
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA;
| | - Ulrich Brinkmann
- Roche Pharma Research and Early Development (pRED), Large Molecule Research, Roche Innovation Center Munich, 82377 Penzberg, Germany; (K.M.); (U.B.)
| | - Raffael Schaffrath
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, 34132 Kassel, Germany;
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6
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Darbyshire AL, Wolthers KR. Characterization of a Structurally Distinct ATP-Dependent Reactivating Factor of Adenosylcobalamin-Dependent Lysine 5,6-Aminomutase. Biochemistry 2024; 63:913-925. [PMID: 38471967 DOI: 10.1021/acs.biochem.3c00653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
Several anaerobic bacterial species, including the Gram-negative oral bacterium Fusobacterium nucleatum, ferment lysine to produce butyrate, acetate, and ammonia. The second step of the metabolic pathway─isomerization of β-l-lysine to erythro-3,5-diaminohexanoate─is catalyzed by the adenosylcobalamin (AdoCbl) and pyridoxal 5'-phosphate (PLP)-dependent enzyme, lysine 5,6-aminomutase (5,6-LAM). Similar to other AdoCbl-dependent enzymes, 5,6-LAM undergoes mechanism-based inactivation due to loss of the AdoCbl 5'-deoxyadenosyl moiety and oxidation of the cob(II)alamin intermediate to hydroxocob(III)alamin. Herein, we identified kamB and kamC, two genes responsible for ATP-dependent reactivation of 5,6-LAM. KamB and KamC, which are encoded upstream of the genes corresponding to α and β subunits of 5,6-LAM (kamD and kamE), co-purified following coexpression of the genes in Escherichia coli. KamBC exhibited a basal level of ATP-hydrolyzing activity that was increased 35% in a reaction mixture that facilitated 5,6-LAM turnover with β-l-lysine or d,l-lysine. Ultraviolet-visible (UV-vis) spectroscopic studies performed under anaerobic conditions revealed that KamBC in the presence of ATP/Mg2+ increased the steady-state concentration of the cob(II)alamin intermediate in the presence of excess β-l-lysine. Using a coupled UV-visible spectroscopic assay, we show that KamBC is able to reactivate 5,6-LAM through exchange of the damaged hydroxocob(III)alamin for AdoCbl. KamBC is also specific for 5,6-LAM as it had no effect on the rate of substrate-induced inactivation of the homologue, ornithine 4,5-aminomutase. Based on sequence homology, KamBC is structurally distinct from previously characterized B12 chaperones and reactivases, and correspondingly adds to the list of proteins that have evolved to maintain the cellular activity of B12 enzymes.
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Affiliation(s)
- Amanda L Darbyshire
- Department of Chemistry, University of British Columbia, Okanagan Campus, 3247 University Way, Kelowna V1V 1V7, Canada
| | - Kirsten R Wolthers
- Department of Chemistry, University of British Columbia, Okanagan Campus, 3247 University Way, Kelowna V1V 1V7, Canada
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Soualmia F, Cherrier MV, Chauviré T, Mauger M, Tatham P, Guillot A, Guinchard X, Martin L, Amara P, Mouesca JM, Daghmoum M, Benjdia A, Gambarelli S, Berteau O, Nicolet Y. Radical S-Adenosyl-l-Methionine Enzyme PylB: A C-Centered Radical to Convert l-Lysine into (3 R)-3-Methyl-d-Ornithine. J Am Chem Soc 2024; 146:6493-6505. [PMID: 38426440 DOI: 10.1021/jacs.3c03747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
PylB is a radical S-adenosyl-l-methionine (SAM) enzyme predicted to convert l-lysine into (3R)-3-methyl-d-ornithine, a precursor in the biosynthesis of the 22nd proteogenic amino acid pyrrolysine. This protein highly resembles that of the radical SAM tyrosine and tryptophan lyases, which activate their substrate by abstracting a H atom from the amino-nitrogen position. Here, combining in vitro assays, analytical methods, electron paramagnetic resonance spectroscopy, and theoretical methods, we demonstrated that instead, PylB activates its substrate by abstracting a H atom from the Cγ position of l-lysine to afford the radical-based β-scission. Strikingly, we also showed that PylB catalyzes the reverse reaction, converting (3R)-3-methyl-d-ornithine into l-lysine and using catalytic amounts of the 5'-deoxyadenosyl radical. Finally, we identified significant in vitro production of 5'-thioadenosine, an unexpected shunt product that we propose to result from the quenching of the 5'-deoxyadenosyl radical species by the nearby [Fe4S4] cluster.
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Affiliation(s)
- Feryel Soualmia
- Université Paris-Saclay, Micalis Institute, ChemSyBio, Université Paris-Saclay, INRAE, AgroParisTech, 78350 Jouy-en-Josas, France
| | - Mickael V Cherrier
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit, F-38000 Grenoble, France
| | - Timothée Chauviré
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-DIESE-SyMMES-CAMPE, F-38000 Grenoble, France
| | - Mickaël Mauger
- Université Paris-Saclay, Micalis Institute, ChemSyBio, Université Paris-Saclay, INRAE, AgroParisTech, 78350 Jouy-en-Josas, France
| | - Philip Tatham
- Université Paris-Saclay, Micalis Institute, ChemSyBio, Université Paris-Saclay, INRAE, AgroParisTech, 78350 Jouy-en-Josas, France
| | - Alain Guillot
- Université Paris-Saclay, Micalis Institute, ChemSyBio, Université Paris-Saclay, INRAE, AgroParisTech, 78350 Jouy-en-Josas, France
| | - Xavier Guinchard
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France
| | - Lydie Martin
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit, F-38000 Grenoble, France
| | - Patricia Amara
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit, F-38000 Grenoble, France
| | - Jean-Marie Mouesca
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-DIESE-SyMMES-CAMPE, F-38000 Grenoble, France
| | - Meriem Daghmoum
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France
| | - Alhosna Benjdia
- Université Paris-Saclay, Micalis Institute, ChemSyBio, Université Paris-Saclay, INRAE, AgroParisTech, 78350 Jouy-en-Josas, France
| | - Serge Gambarelli
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-DIESE-SyMMES-CAMPE, F-38000 Grenoble, France
| | - Olivier Berteau
- Université Paris-Saclay, Micalis Institute, ChemSyBio, Université Paris-Saclay, INRAE, AgroParisTech, 78350 Jouy-en-Josas, France
| | - Yvain Nicolet
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit, F-38000 Grenoble, France
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8
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Walls WG, Vagstad AL, 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 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, Montana 59717, United States
| | - Anna L 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, Montana 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, Montana 59717, United States
| | - Joan B Broderick
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, Montana 59717, United States
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9
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Johnson BA, Clark KA, Bushin LB, Spolar CN, Seyedsayamdost MR. Expanding the Landscape of Noncanonical Amino Acids in RiPP Biosynthesis. J Am Chem Soc 2024; 146:3805-3815. [PMID: 38316431 DOI: 10.1021/jacs.3c10824] [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: 02/07/2024]
Abstract
Advancements in DNA sequencing technologies and bioinformatics have enabled the discovery of new metabolic reactions from overlooked microbial species and metagenomic sequences. Using a bioinformatic co-occurrence strategy, we previously generated a network of ∼600 uncharacterized quorum-sensing-regulated biosynthetic gene clusters that code for ribosomally synthesized and post-translationally modified peptide (RiPP) natural products and are tailored by radical S-adenosylmethionine (RaS) enzymes in streptococci. The most complex of these is the GRC subfamily, named after a conserved motif in the precursor peptide and found exclusively in Streptococcus pneumoniae, the causative agent of bacterial pneumonia. In this study, using both in vivo and in vitro approaches, we have elucidated the modifications installed by the grc biosynthetic enzymes, including a ThiF-like adenylyltransferase/cyclase that generates a C-terminal Glu-to-Cys thiolactone macrocycle, and two RaS enzymes, which selectively epimerize the β-carbon of threonine and desaturate histidine to generate the first instances of l-allo-Thr and didehydrohistidine in RiPP biosynthesis. RaS-RiPPs that have been discovered thus far have stood out for their exotic macrocycles. The product of the grc cluster breaks this trend by generating two noncanonical residues rather than an unusual macrocycle in the peptide substrate. These modifications expand the landscape of nonproteinogenic amino acids in RiPP natural product biosynthesis and motivate downstream biocatalytic applications of the corresponding enzymes.
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Affiliation(s)
- Brooke A Johnson
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Kenzie A Clark
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Leah B Bushin
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Calvin N Spolar
- 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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10
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Zhang C, Seyedsayamdost MR. Widespread Peptide Surfactants with Post-translational C-methylations Promote Bacterial Development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.23.576971. [PMID: 38328144 PMCID: PMC10849626 DOI: 10.1101/2024.01.23.576971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Bacteria produce a variety of peptides to mediate nutrient acquisition, microbial interactions, and other physiological processes. Of special interest are surface-active peptides that aid in growth and development. Herein, we report the structure and characterization of clavusporins, unusual and hydrophobic ribosomal peptides with multiple C-methylations at unactivated carbon centers, which help drastically reduce the surface tension of water and thereby aid in Streptomyces development. The peptides are synthesized by a previously uncharacterized protein superfamily, termed DUF5825, in conjunction with a vitamin B12-dependent radical S-adenosylmethionine metalloenzyme. The operon encoding clavusporin is wide-spread among actinomycete bacteria, suggesting a prevalent role for clavusporins as morphogens in erecting aerial hyphae and thereby advancing sporulation and proliferation.
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Affiliation(s)
- Chen Zhang
- Department of Chemistry, Princeton University, Princeton, NJ 08544, United States
| | - Mohammad R. Seyedsayamdost
- Department of Chemistry, Princeton University, Princeton, NJ 08544, United States
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, United States
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11
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Lachowicz J, Lee J, Sagatova A, Jew K, Grove TL. The new epoch of structural insights into radical SAM enzymology. Curr Opin Struct Biol 2023; 83:102720. [PMID: 37862762 DOI: 10.1016/j.sbi.2023.102720] [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] [Received: 07/13/2023] [Revised: 09/21/2023] [Accepted: 09/22/2023] [Indexed: 10/22/2023]
Abstract
The Radical SAM (RS) superfamily of enzymes catalyzes a wide array of enzymatic reactions. The majority of these enzymes employ an electron from a reduced [4Fe-4S]+1 cluster to facilitate the reductive cleavage of S-adenosyl-l-methionine, thereby producing a highly reactive 5'-deoxyadenosyl radical (5'-dA⋅) and l-methionine. Typically, RS enzymes use this 5'-dA⋅ to extract a hydrogen atom from the target substrate, starting the cascade of an expansive and impressive variety of chemical transformations. While a great deal of understanding has been gleaned for 5'-dA⋅ formation, because of the chemical diversity within this superfamily, the subsequent chemical transformations have only been fully elucidated in a few examples. In addition, with the advent of new sequencing technology, the size of this family now surpasses 700,000 members, with the number of uncharacterized enzymes and domains also rapidly expanding. In this review, we outline the history of RS enzyme characterization in what we term "epochs" based on advances in technology designed for stably producing these enzymes in an active state. We propose that the state of the field has entered the fourth epoch, which we argue should commence with a protein structure initiative focused solely on RS enzymes to properly tackle this unique superfamily and uncover more novel chemical transformations that likely exist.
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Affiliation(s)
- Jake Lachowicz
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - James Lee
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Alia Sagatova
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kristen Jew
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Tyler L Grove
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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12
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Lundahl MN, Yang H, Broderick WE, Hoffman BM, Broderick JB. Pyruvate formate-lyase activating enzyme: The catalytically active 5'-deoxyadenosyl radical caught in the act of H-atom abstraction. Proc Natl Acad Sci U S A 2023; 120:e2314696120. [PMID: 37956301 PMCID: PMC10665898 DOI: 10.1073/pnas.2314696120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 10/03/2023] [Indexed: 11/15/2023] Open
Abstract
Enzymes of the radical S-adenosyl-l-methionine (radical SAM, RS) superfamily, the largest in nature, catalyze remarkably diverse reactions initiated by H-atom abstraction. Glycyl radical enzyme activating enzymes (GRE-AEs) are a growing class of RS enzymes that generate the catalytically essential glycyl radical of GREs, which in turn catalyze essential reactions in anaerobic metabolism. Here, we probe the reaction of the GRE-AE pyruvate formate-lyase activating enzyme (PFL-AE) with the peptide substrate RVSG734YAV, which mimics the site of glycyl radical formation on the native substrate, pyruvate formate-lyase. Time-resolved freeze-quench electron paramagnetic resonance spectroscopy shows that at short mixing times reduced PFL-AE + SAM reacts with RVSG734YAV to form the central organometallic intermediate, Ω, in which the adenosyl 5'C is covalently bound to the unique iron of the [4Fe-4S] cluster. Freeze-trapping the reaction at longer times reveals the formation of the peptide G734• glycyl radical product. Of central importance, freeze-quenching at intermediate times reveals that the conversion of Ω to peptide glycyl radical is not concerted. Instead, homolysis of the Ω Fe-C5' bond generates the nominally "free" 5'-dAdo• radical, which is captured here by freeze-trapping. During cryoannealing at 77 K, the 5'-dAdo• directly abstracts an H-atom from the peptide to generate the G734• peptide radical trapped in the PFL-AE active site. These observations reveal the 5'-dAdo• radical to be a well-defined intermediate, caught in the act of substrate H-atom abstraction, providing new insights into the mechanistic steps of radical initiation by RS enzymes.
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Affiliation(s)
- Maike N. Lundahl
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT59717
| | - Hao Yang
- Department of Chemistry, Northwestern University, Evanston, IL60208
| | - William E. Broderick
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT59717
| | - Brian M. Hoffman
- Department of Chemistry, Northwestern University, Evanston, IL60208
| | - Joan B. Broderick
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT59717
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13
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Ütkür K, Schmidt S, Mayer K, Klassen R, Brinkmann U, Schaffrath R. DPH1 Gene Mutations Identify a Candidate SAM Pocket in Radical Enzyme Dph1•Dph2 for Diphthamide Synthesis on EF2. Biomolecules 2023; 13:1655. [PMID: 38002337 PMCID: PMC10669111 DOI: 10.3390/biom13111655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 11/10/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
In eukaryotes, the Dph1•Dph2 dimer is a non-canonical radical SAM enzyme. Using iron-sulfur (FeS) clusters, it cleaves the cosubstrate S-adenosyl-methionine (SAM) to form a 3-amino-3-carboxy-propyl (ACP) radical for the synthesis of diphthamide. The latter decorates a histidine residue on elongation factor 2 (EF2) conserved from archaea to yeast and humans and is important for accurate mRNA translation and protein synthesis. Guided by evidence from archaeal orthologues, we searched for a putative SAM-binding pocket in Dph1•Dph2 from Saccharomyces cerevisiae. We predict an SAM-binding pocket near the FeS cluster domain that is conserved across eukaryotes in Dph1 but not Dph2. Site-directed DPH1 mutagenesis and functional characterization through assay diagnostics for the loss of diphthamide reveal that the SAM pocket is essential for synthesis of the décor on EF2 in vivo. Further evidence from structural modeling suggests particularly critical residues close to the methionine moiety of SAM. Presumably, they facilitate a geometry specific for SAM cleavage and ACP radical formation that distinguishes Dph1•Dph2 from classical radical SAM enzymes, which generate canonical 5'-deoxyadenosyl (dAdo) radicals.
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Affiliation(s)
- Koray Ütkür
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, 34132 Kassel, Germany; (K.Ü.); (S.S.); (R.K.)
| | - Sarina Schmidt
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, 34132 Kassel, Germany; (K.Ü.); (S.S.); (R.K.)
| | - Klaus Mayer
- Roche Pharma Research and Early Development (pRED), Large Molecule Research, Roche Innovation Center Munich, 82377 Penzberg, Germany; (K.M.); (U.B.)
| | - Roland Klassen
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, 34132 Kassel, Germany; (K.Ü.); (S.S.); (R.K.)
| | - Ulrich Brinkmann
- Roche Pharma Research and Early Development (pRED), Large Molecule Research, Roche Innovation Center Munich, 82377 Penzberg, Germany; (K.M.); (U.B.)
| | - Raffael Schaffrath
- Roche Pharma Research and Early Development (pRED), Large Molecule Research, Roche Innovation Center Munich, 82377 Penzberg, Germany; (K.M.); (U.B.)
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14
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Ma S, Xi W, Wang S, Chen H, Guo S, Mo T, Chen W, Deng Z, Chen F, Ding W, Zhang Q. Substrate-Controlled Catalysis in the Ether Cross-Link-Forming Radical SAM Enzymes. J Am Chem Soc 2023; 145:22945-22953. [PMID: 37769281 DOI: 10.1021/jacs.3c04355] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
Darobactin is a heptapeptide antibiotic featuring an ether cross-link and a C-C cross-link, and both cross-links are installed by a radical S-adenosylmethionine (rSAM) enzyme DarE. How a single DarE enzyme affords the two chemically distinct cross-links remains largely obscure. Herein, by mapping the biosynthetic landscape for darobactin-like RiPP (daropeptide), we identified and characterized two novel daropeptides that lack the C-C cross-link present in darobactin and instead are solely composed of ether cross-links. Phylogenetic and mutagenesis analyses reveal that the daropeptide maturases possess intrinsic multifunctionality, catalyzing not only the formation of ether cross-link but also C-C cross-linking and Ser oxidation. Intriguingly, the different chemical outcomes are controlled by the exact substrate motifs. Our work not only provides a roadmap for the discovery of new daropeptide natural products but also offers insights into the regulatory mechanisms that govern these remarkably versatile ether cross-link-forming rSAM enzymes.
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Affiliation(s)
- Suze Ma
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Wenhui Xi
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Shu Wang
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Heng Chen
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Sijia Guo
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tianlu Mo
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Wenxue Chen
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Fener Chen
- Department of Chemistry, Fudan University, Shanghai 200433, China
- National Engineering Research Center for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang 330022, China
| | - Wei Ding
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qi Zhang
- Department of Chemistry, Fudan University, Shanghai 200433, China
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15
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Fix I, Heidinger L, Friedrich T, Layer G. The Radical SAM Heme Synthase AhbD from Methanosarcina barkeri Contains Two Auxiliary [4Fe-4S] Clusters. Biomolecules 2023; 13:1268. [PMID: 37627333 PMCID: PMC10452713 DOI: 10.3390/biom13081268] [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] [Received: 07/11/2023] [Revised: 08/11/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
In archaea and sulfate-reducing bacteria, heme is synthesized via the siroheme-dependent pathway. The last step of this route is catalyzed by the Radical SAM enzyme AhbD and consists of the conversion of iron-coproporphyrin III into heme. AhbD belongs to the subfamily of Radical SAM enzymes containing a SPASM/Twitch domain carrying either one or two auxiliary iron-sulfur clusters in addition to the characteristic Radical SAM cluster. In previous studies, AhbD was reported to contain one auxiliary [4Fe-4S] cluster. In this study, the amino acid sequence motifs containing conserved cysteine residues in AhbD proteins from different archaea and sulfate-reducing bacteria were reanalyzed. Amino acid sequence alignments and computational structural models of AhbD suggested that a subset of AhbD proteins possesses the full SPASM motif and might contain two auxiliary iron-sulfur clusters (AuxI and AuxII). Therefore, the cluster content of AhbD from Methanosarcina barkeri was studied using enzyme variants lacking individual clusters. The purified enzymes were analyzed using UV/Visible absorption and EPR spectroscopy as well as iron/sulfide determinations showing that AhbD from M. barkeri contains two auxiliary [4Fe-4S] clusters. Heme synthase activity assays suggested that the AuxI cluster might be involved in binding the reaction intermediate and both clusters potentially participate in electron transfer.
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Affiliation(s)
- Isabelle Fix
- Institut für Pharmazeutische Wissenschaften, Pharmazeutische Biologie, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Str. 19, 79104 Freiburg, Germany
| | - Lorenz Heidinger
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany; (L.H.); (T.F.)
| | - Thorsten Friedrich
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany; (L.H.); (T.F.)
| | - Gunhild Layer
- Institut für Pharmazeutische Wissenschaften, Pharmazeutische Biologie, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Str. 19, 79104 Freiburg, Germany
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16
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Oberg N, Zallot R, Gerlt JA. EFI-EST, EFI-GNT, and EFI-CGFP: Enzyme Function Initiative (EFI) Web Resource for Genomic Enzymology Tools. J Mol Biol 2023; 435:168018. [PMID: 37356897 PMCID: PMC10291204 DOI: 10.1016/j.jmb.2023.168018] [Citation(s) in RCA: 63] [Impact Index Per Article: 63.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 02/04/2023] [Accepted: 02/13/2023] [Indexed: 02/19/2023]
Abstract
The Enzyme Function Initiative (EFI) provides a web resource with "genomic enzymology" web tools to leverage the protein (UniProt) and genome (European Nucleotide Archive; ENA; https://www.ebi.ac.uk/ena/) databases to assist the assignment of in vitro enzymatic activities and in vivo metabolic functions to uncharacterized enzymes (https://efi.igb.illinois.edu/). The tools enable (1) exploration of sequence-function space in enzyme families using sequence similarity networks (SSNs; EFI-EST), (2) easy access to genome context for bacterial, archaeal, and fungal proteins in the SSN clusters so that isofunctional families can be identified and their functions inferred from genome context (EFI-GNT); and (3) determination of the abundance of SSN clusters in NIH Human Metagenome Project metagenomes using chemically guided functional profiling (EFI-CGFP). We describe enhancements that enable SSNs to be generated from taxonomy categories, allowing higher resolution analyses of sequence-function space; we provide examples of the generation of taxonomy category-specific SSNs.
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Affiliation(s)
- Nils Oberg
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, IL 61801, United States
| | - Rémi Zallot
- Department of Chemistry, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK; Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
| | - John A Gerlt
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, IL 61801, United States; Department of Biochemistry, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, IL 61801, United States; Department of Chemistry, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, IL 61801, United States.
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17
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Moody JD, Hill S, Lundahl MN, Saxton AJ, Galambas A, Broderick WE, Lawrence CM, Broderick JB. Computational engineering of previously crystallized pyruvate formate-lyase activating enzyme reveals insights into SAM binding and reductive cleavage. J Biol Chem 2023; 299:104791. [PMID: 37156396 PMCID: PMC10267522 DOI: 10.1016/j.jbc.2023.104791] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/21/2023] [Accepted: 04/23/2023] [Indexed: 05/10/2023] Open
Abstract
Radical S-adenosyl-l-methionine (SAM) enzymes are ubiquitous in nature and carry out a broad variety of difficult chemical transformations initiated by hydrogen atom abstraction. Although numerous radical SAM (RS) enzymes have been structurally characterized, many prove recalcitrant to crystallization needed for atomic-level structure determination using X-ray crystallography, and even those that have been crystallized for an initial study can be difficult to recrystallize for further structural work. We present here a method for computationally engineering previously observed crystallographic contacts and employ it to obtain more reproducible crystallization of the RS enzyme pyruvate formate-lyase activating enzyme (PFL-AE). We show that the computationally engineered variant binds a typical RS [4Fe-4S]2+/+ cluster that binds SAM, with electron paramagnetic resonance properties indistinguishable from the native PFL-AE. The variant also retains the typical PFL-AE catalytic activity, as evidenced by the characteristic glycyl radical electron paramagnetic resonance signal observed upon incubation of the PFL-AE variant with reducing agent, SAM, and PFL. The PFL-AE variant was also crystallized in the [4Fe-4S]2+ state with SAM bound, providing a new high-resolution structure of the SAM complex in the absence of substrate. Finally, by incubating such a crystal in a solution of sodium dithionite, the reductive cleavage of SAM is triggered, providing us with a structure in which the SAM cleavage products 5'-deoxyadenosine and methionine are bound in the active site. We propose that the methods described herein may be useful in the structural characterization of other difficult-to-resolve proteins.
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Affiliation(s)
- James D Moody
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, USA; Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Sarah Hill
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Maike N Lundahl
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Aubrianna J Saxton
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, USA
| | - Amanda Galambas
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - William E Broderick
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - C Martin Lawrence
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Joan B Broderick
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA.
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18
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Brimberry M, Corrigan P, Silakov A, Lanzilotta WN. Evidence for Porphyrin-Mediated Electron Transfer in the Radical SAM Enzyme HutW. Biochemistry 2023; 62:1191-1196. [PMID: 36877586 PMCID: PMC10035031 DOI: 10.1021/acs.biochem.2c00474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
Bacteria that infect the human gut must compete for essential nutrients, including iron, under a variety of different metabolic conditions. Several enteric pathogens, including Vibrio cholerae and Escherichia coli O157:H7, have evolved mechanisms to obtain iron from heme in an anaerobic environment. Our laboratory has demonstrated that a radical S-adenosylmethionine (SAM) methyltransferase is responsible for the opening of the heme porphyrin ring and release of iron under anaerobic conditions. Furthermore, the enzyme in V. cholerae, HutW, has recently been shown to accept electrons from NADPH directly when SAM is utilized to initiate the reaction. However, how NADPH, a hydride donor, catalyzes the single electron reduction of a [4Fe-4S] cluster, and/or subsequent electron/proton transfer reactions, was not addressed. In this work, we provide evidence that the substrate, in this case, heme, facilitates electron transfer from NADPH to the [4Fe-4S] cluster. This study uncovers a new electron transfer pathway adopted by radical SAM enzymes and further expands our understanding of these enzymes in bacterial pathogens.
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Affiliation(s)
- Marley Brimberry
- Department of Biochemistry and Molecular Biology & Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602, United States
| | - Patrick Corrigan
- Department of Chemistry, Penn State University, University Park, Pennsylvania 16802, United States
| | - Alexey Silakov
- Department of Chemistry, Penn State University, University Park, Pennsylvania 16802, United States
| | - William N Lanzilotta
- Department of Biochemistry and Molecular Biology & Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602, United States
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19
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Bak DW, Weerapana E. Monitoring Fe-S cluster occupancy across the E. coli proteome using chemoproteomics. Nat Chem Biol 2023; 19:356-366. [PMID: 36635565 PMCID: PMC9992348 DOI: 10.1038/s41589-022-01227-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 11/17/2022] [Indexed: 01/13/2023]
Abstract
Iron-sulfur (Fe-S) clusters are ubiquitous metallocofactors involved in redox chemistry, radical generation and gene regulation. Common methods to monitor Fe-S clusters include spectroscopic analysis of purified proteins and autoradiographic visualization of radiolabeled iron distribution in proteomes. Here, we report a chemoproteomic strategy that monitors changes in the reactivity of Fe-S cysteine ligands to inform on Fe-S cluster occupancy. We highlight the utility of this platform in Escherichia coli by (1) demonstrating global disruptions in Fe-S incorporation in cells cultured under iron-depleted conditions, (2) determining Fe-S client proteins reliant on five scaffold, carrier and chaperone proteins within the Isc Fe-S biogenesis pathway and (3) identifying two previously unannotated Fe-S proteins, TrhP and DppD. In summary, the chemoproteomic strategy described herein is a powerful tool that reports on Fe-S cluster incorporation directly within a native proteome, enabling the interrogation of Fe-S biogenesis pathways and the identification of previously uncharacterized Fe-S proteins.
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Affiliation(s)
- Daniel W Bak
- Department of Chemistry, Boston College, Chestnut Hill, MA, USA.
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20
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Luo X, Wang X, Zhang L, Du A, Deng Z, Jiang M, He X. Importance of aspartic acid side chain carboxylate-arginine interaction in substrate selection of arginine 2,3-aminomutase BlsG. Protein Sci 2023; 32:e4584. [PMID: 36721314 PMCID: PMC9926467 DOI: 10.1002/pro.4584] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 02/02/2023]
Abstract
The fungicide nucleoside blasticidin S features a β-arginine, a moiety seldom revealed in the structure of natural products. BlsG, a radical SAM arginine-2,3-aminomutase from the blasticidin S biosynthetic pathway, displayed promiscuous activity to three basic amino acids. Here in this study, we demonstrated that BlsG showed high preference toward its natural substrate arginine. The combined structural modeling, steady-state kinetics, and mutational analyses lead to the detailed understanding of the substrate recognition of BlsG. A single mutation of T340D changed the substrate preference of BlsG leading to a little more preference to lysine than arginine. On the basis of our understanding of the substrate selection of BlsG and bioinformatic analysis, we propose that the D…D motif locationally corresponding to D293 and D330 of KAM is characteristic of lysine 2,3-aminomutase while the corresponding D…T motif is characteristic of arginine 2,3-aminomutase. The study may provide a simple way to discern the arginine 2,3-aminomutase and thus lead to the discovery of new natural compounds with β-arginine moiety.
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Affiliation(s)
- Xiangkun Luo
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences & BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
| | - Xiankun Wang
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences & BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
| | - Lina Zhang
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences & BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
| | - Aiqin Du
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences & BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences & BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
- Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
| | - Ming Jiang
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences & BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
- Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
| | - Xinyi He
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences & BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
- Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
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21
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Walsh CT. Tailoring enzyme strategies and functional groups in biosynthetic pathways. Nat Prod Rep 2023; 40:326-386. [PMID: 36268810 DOI: 10.1039/d2np00048b] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Covering: 2000 to 2022Secondary metabolites are assembled by drawing off and committing some of the flux of primary metabolic building blocks to sets of enzymes that tailor the maturing scaffold to increase architectural and framework complexity, often balancing hydrophilic and hydrophobic surfaces. In this review we examine the small number of chemical strategies that tailoring enzymes employ in maturation of scaffolds. These strategies depend both on the organic functional groups present at each metabolic stage and one of two tailoring enzyme strategies. Nonoxidative tailoring enzymes typically transfer electrophilic fragments, acyl, alkyl and glycosyl groups, from a small set of thermodynamically activated but kinetically stable core metabolites. Oxidative tailoring enzymes can be oxygen-independent or oxygen-dependent. The oxygen independent oxidoreductases are often reversible nicotinamide-utilizing redox catalysts, flipping the nucleophilicity and electrophilicity of functional groups in pathway intermediates. O2-dependent oxygenases, both mono- and dioxygenases, act by orthogonal, one electron strategies, generating carbon radical species. At sp3 substrate carbons, product alcohols may then behave as nucleophiles for subsequent waves of enzymatic tailoring. At sp2 carbons in olefins, electrophilic epoxides have opposite reactivity and often function as "disappearing groups", opened by intramolecular nucleophiles during metabolite maturation. "Thwarted" oxygenases generate radical intermediates that rearrange internally and are not captured oxygenatively.
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22
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Alvarez-Morezuelas A, Barandalla L, Ritter E, Ruiz de Galarreta JI. Genome-Wide Association Study of Agronomic and Physiological Traits Related to Drought Tolerance in Potato. PLANTS (BASEL, SWITZERLAND) 2023; 12:734. [PMID: 36840081 PMCID: PMC9963855 DOI: 10.3390/plants12040734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/02/2023] [Accepted: 02/04/2023] [Indexed: 06/18/2023]
Abstract
Potato (Solanum tuberosum L.) is often considered a water-sensitive crop and its production can be threatened by drought events, making water stress tolerance a trait of increasing interest. In this study, a panel of 144 tetraploid potato genotypes was evaluated for two consecutive years (2019 and 2020) to observe the variation of several physiological traits such as chlorophyll content and fluorescence, stomatal conductance, NDVI, and leaf area and circumference. In addition, agronomic parameters such as yield, tuber fresh weight, tuber number, starch content, dry matter and reducing sugars were determined. GGP V3 Potato array was used to genotype the population, obtaining a total of 18,259 high-quality SNP markers. Marker-trait association was performed using GWASpoly package in R software and Q + K linear mixed models were considered. This approach allowed us to identify eighteen SNP markers significantly associated with the studied traits in both treatments and years, which were related to genes with known functions. Markers related to chlorophyll content and number of tubers under control and stress conditions, and related to stomatal conductance, NDVI, yield and reducing sugar content under water stress, were identified. Although these markers were distributed throughout the genome, the SNPs associated with the traits under control conditions were found mainly on chromosome 11, while under stress conditions they were detected on chromosome 4. These results contribute to the knowledge of the mechanisms of potato tolerance to water stress and are useful for future marker-assisted selection programs.
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23
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Yang W, Chen H, Chen Y, Chen A, Feng X, Zhao B, Zheng F, Fang H, Zhang C, Zeng Z. Thermophilic archaeon orchestrates temporal expression of GDGT ring synthases in response to temperature and acidity stress. Environ Microbiol 2023; 25:575-587. [PMID: 36495168 DOI: 10.1111/1462-2920.16301] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 12/04/2022] [Indexed: 12/14/2022]
Abstract
Glycerol dibiphytanyl glycerol tetraethers (GDGTs) are unique archaeal membrane-spanning lipids with 0-8 cyclopentane rings on the biphytanyl chains. The cyclization pattern of GDGTs is affected by many environmental factors, such as temperature and pH, but the underlying molecular mechanism remains elusive. Here, we find that the expression regulation of GDGT ring synthase genes grsA and grsB in thermophilic archaeon Sulfolobus acidocaldarius is temperature- and pH-dependent. Moreover, the presence of functional GrsA protein, or more likely its products cyclic GDGTs rather than the accumulation of GrsA protein itself, is required to induce grsB expression, resulting in temporal regulation of grsA and grsB expression. Our findings establish a molecular model of GDGT cyclization regulated by environment factors in a thermophilic ecosystem, which could be also relevant to that in mesophilic marine archaea. Our study will help better understand the biological basis for GDGT-based paleoclimate proxies. Archaea inhabit a wide range of terrestrial and marine environments. In response to environment fluctuations, archaea modulate their unique membrane GDGTs lipid composition with different strategies, in particular GDGTs cyclization significantly alters membrane permeability. However, the regulation details of archaeal GDGTs cyclization in response to different environmental factor changes remain unknown. We demonstrated, for the first time, thermophilic archaea orchestrate the temporal expression of GDGT ring synthases, leading to delicate control of GDGTs cyclization to respond environmental temperature and acidity stress. Our study provides insight into the regulation of archaea membrane plasticity, and the survival strategy of archaea in fluctuating environments.
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Affiliation(s)
- Wei Yang
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Huahui Chen
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Yufei Chen
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Aiping Chen
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Xi Feng
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Bo Zhao
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Fengfeng Zheng
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Hongwei Fang
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Changyi Zhang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Zhirui Zeng
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
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24
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Domán A, Dóka É, Garai D, Bogdándi V, Balla G, Balla J, Nagy P. Interactions of reactive sulfur species with metalloproteins. Redox Biol 2023; 60:102617. [PMID: 36738685 PMCID: PMC9926313 DOI: 10.1016/j.redox.2023.102617] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/23/2023] [Accepted: 01/24/2023] [Indexed: 01/28/2023] Open
Abstract
Reactive sulfur species (RSS) entail a diverse family of sulfur derivatives that have emerged as important effector molecules in H2S-mediated biological events. RSS (including H2S) can exert their biological roles via widespread interactions with metalloproteins. Metalloproteins are essential components along the metabolic route of oxygen in the body, from the transport and storage of O2, through cellular respiration, to the maintenance of redox homeostasis by elimination of reactive oxygen species (ROS). Moreover, heme peroxidases contribute to immune defense by killing pathogens using oxygen-derived H2O2 as a precursor for stronger oxidants. Coordination and redox reactions with metal centers are primary means of RSS to alter fundamental cellular functions. In addition to RSS-mediated metalloprotein functions, the reduction of high-valent metal centers by RSS results in radical formation and opens the way for subsequent per- and polysulfide formation, which may have implications in cellular protection against oxidative stress and in redox signaling. Furthermore, recent findings pointed out the potential role of RSS as substrates for mitochondrial energy production and their cytoprotective capacity, with the involvement of metalloproteins. The current review summarizes the interactions of RSS with protein metal centers and their biological implications with special emphasis on mechanistic aspects, sulfide-mediated signaling, and pathophysiological consequences. A deeper understanding of the biological actions of reactive sulfur species on a molecular level is primordial in H2S-related drug development and the advancement of redox medicine.
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Affiliation(s)
- Andrea Domán
- Department of Molecular Immunology and Toxicology and the National Tumor Biology Laboratory, National Institute of Oncology, 1122, Budapest, Hungary
| | - Éva Dóka
- Department of Molecular Immunology and Toxicology and the National Tumor Biology Laboratory, National Institute of Oncology, 1122, Budapest, Hungary
| | - Dorottya Garai
- Department of Molecular Immunology and Toxicology and the National Tumor Biology Laboratory, National Institute of Oncology, 1122, Budapest, Hungary,Kálmán Laki Doctoral School, University of Debrecen, 4012, Debrecen, Hungary
| | - Virág Bogdándi
- Department of Molecular Immunology and Toxicology and the National Tumor Biology Laboratory, National Institute of Oncology, 1122, Budapest, Hungary
| | - György Balla
- Kálmán Laki Doctoral School, University of Debrecen, 4012, Debrecen, Hungary,Department of Pediatrics, Faculty of Medicine, University of Debrecen, 4032, Debrecen, Hungary,ELKH-UD Vascular Pathophysiology Research Group, 11003, University of Debrecen, 4012, Debrecen, Hungary
| | - József Balla
- Kálmán Laki Doctoral School, University of Debrecen, 4012, Debrecen, Hungary,ELKH-UD Vascular Pathophysiology Research Group, 11003, University of Debrecen, 4012, Debrecen, Hungary,Department of Nephrology, Institute of Internal Medicine, Faculty of Medicine, University of Debrecen, 4012, Debrecen, Hungary
| | - Péter Nagy
- Department of Molecular Immunology and Toxicology and the National Tumor Biology Laboratory, National Institute of Oncology, 1122, Budapest, Hungary; Department of Anatomy and Histology, ELKH Laboratory of Redox Biology, University of Veterinary Medicine, 1078, Budapest, Hungary; Chemistry Institute, University of Debrecen, 4012, Debrecen, Hungary.
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25
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Broderick JB, Broderick WE, Hoffman BM. Radical SAM enzymes: Nature's choice for radical reactions. FEBS Lett 2023; 597:92-101. [PMID: 36251330 PMCID: PMC9894703 DOI: 10.1002/1873-3468.14519] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 10/05/2022] [Indexed: 02/04/2023]
Abstract
Enzymes that use a [4Fe-4S]1+ cluster plus S-adenosyl-l-methionine (SAM) to initiate radical reactions (radical SAM) form the largest enzyme superfamily, with over half a million members across the tree of life. This review summarizes recent work revealing the radical SAM reaction pathway, which ultimately liberates the 5'-deoxyadenosyl (5'-dAdo•) radical to perform extremely diverse, highly regio- and stereo-specific, transformations. Most surprising was the discovery of an organometallic intermediate Ω exhibiting an Fe-C5'-adenosyl bond. Ω liberates 5'-dAdo• through homolysis of the Fe-C5' bond, in analogy to Co-C5' bond homolysis in B12 , previously viewed as biology's paradigmatic radical generator. The 5'-dAdo• has been trapped and characterized in radical SAM enzymes via a recently discovered photoreactivity of the [4Fe-4S]+ /SAM complex, and has been confirmed as a catalytically active intermediate in enzyme catalysis. The regioselective SAM S-C bond cleavage to produce 5'-dAdo• originates in the Jahn-Teller effect. The simplicity of SAM as a radical precursor, and the exquisite control of 5'-dAdo• reactivity in radical SAM enzymes, may be why radical SAM enzymes pervade the tree of life, while B12 enzymes are only a few.
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Affiliation(s)
- Joan B. Broderick
- Department of Chemistry & Biochemistry, 103 CBB, Montana State University, Bozeman, MT 59717
| | - William E. Broderick
- Department of Chemistry & Biochemistry, 103 CBB, Montana State University, Bozeman, MT 59717
| | - Brian M. Hoffman
- Department of Chemistry, 2145 Sheridan Rd, Northwestern University, Evanston, IL. 60208
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26
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Li X, Ma S, Zhang Q. Chemical Synthesis and Biosynthesis of Darobactin. Tetrahedron Lett 2023. [DOI: 10.1016/j.tetlet.2023.154337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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27
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Booker SJ, Lloyd CT. Twenty Years of Radical SAM! The Genesis of the Superfamily. ACS BIO & MED CHEM AU 2022; 2:538-547. [PMID: 37101427 PMCID: PMC10114671 DOI: 10.1021/acsbiomedchemau.2c00078] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Indexed: 12/10/2022]
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28
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Nie L, Wei T, Cao M, Lyu Y, Wang S, Feng Z. Biosynthesis of coelulatin for the methylation of anthraquinone featuring HemN-like radical S-adenosyl-L-methionine enzyme. Front Microbiol 2022; 13:1040900. [DOI: 10.3389/fmicb.2022.1040900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 10/26/2022] [Indexed: 11/19/2022] Open
Abstract
Bacterial aromatic polyketides are usually biosynthesized by the type II polyketide synthase (PKS-II) system. Advances in deoxyribonucleic acid (DNA) sequencing, informatics, and biotechnologies have broadened opportunities for the discovery of aromatic polyketides. Meanwhile, metagenomics is a biotechnology that has been considered as a promising approach for the discovery of novel natural products from uncultured bacteria. Here, we cloned a type II polyketide biosynthetic gene cluster (BGC) from the soil metagenome, and the heterologous expression of this gene cluster in Streptomyces coelicolor M1146 resulted in the production of three anthraquinones, two of which (coelulatins 2 and 3) had special hydroxymethyl and methyloxymethyl modifications at C2 of the polyketide scaffold. Gene deletion and in vitro biochemical characterization indicated that the HemN-like radical S-adenosyl-L-methionine (SAM) enzyme CoeI exhibits methylation and is involved in C2 modification.
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29
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Warui D, Sil D, Lee KH, Neti SS, Esakova OA, Knox HL, Krebs C, Booker SJ. In Vitro Demonstration of Human Lipoyl Synthase Catalytic Activity in the Presence of NFU1. ACS BIO & MED CHEM AU 2022; 2:456-468. [PMID: 36281303 PMCID: PMC9585516 DOI: 10.1021/acsbiomedchemau.2c00020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lipoyl synthase (LS) catalyzes the last step in the biosynthesis of the lipoyl cofactor, which is the attachment of sulfur atoms at C6 and C8 of an n-octanoyllysyl side chain of a lipoyl carrier protein (LCP). The protein is a member of the radical S-adenosylmethionine (SAM) superfamily of enzymes, which use SAM as a precursor to a 5'-deoxyadenosyl 5'-radical (5'-dA·). The role of the 5'-dA· in the LS reaction is to abstract hydrogen atoms from C6 and C8 of the octanoyl moiety of the substrate to initiate subsequent sulfur attachment. All radical SAM enzymes have at least one [4Fe-4S] cluster that is used in the reductive cleavage of SAM to generate the 5'-dA·; however, LSs contain an additional auxiliary [4Fe-4S] cluster from which sulfur atoms are extracted during turnover, leading to degradation of the cluster. Therefore, these enzymes catalyze only 1 turnover in the absence of a system that restores the auxiliary cluster. In Escherichia coli, the auxiliary cluster of LS can be regenerated by the iron-sulfur (Fe-S) cluster carrier protein NfuA as fast as catalysis takes place, and less efficiently by IscU. NFU1 is the human ortholog of E. coli NfuA and has been shown to interact directly with human LS (i.e., LIAS) in yeast two-hybrid analyses. Herein, we show that NFU1 and LIAS form a tight complex in vitro and that NFU1 can efficiently restore the auxiliary cluster of LIAS during turnover. We also show that BOLA3, previously identified as being critical in the biosynthesis of the lipoyl cofactor in humans and Saccharomyces cerevisiae, has no direct effect on Fe-S cluster transfer from NFU1 or GLRX5 to LIAS. Further, we show that ISCA1 and ISCA2 can enhance LIAS turnover, but only slightly.
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Affiliation(s)
- Douglas
M. Warui
- Department
of Chemistry and Biochemistry and Molecular Biology and the Howard Hughes
Medical Institute, The Pennsylvania State
University, University
Park, Pennsylvania 16802, United States
| | - Debangsu Sil
- Department
of Chemistry and Biochemistry and Molecular Biology and the Howard Hughes
Medical Institute, The Pennsylvania State
University, University
Park, Pennsylvania 16802, United States
| | - Kyung-Hoon Lee
- Department
of Chemistry and Biochemistry and Molecular Biology and the Howard Hughes
Medical Institute, The Pennsylvania State
University, University
Park, Pennsylvania 16802, United States
| | - Syam Sundar Neti
- Department
of Chemistry and Biochemistry and Molecular Biology and the Howard Hughes
Medical Institute, The Pennsylvania State
University, University
Park, Pennsylvania 16802, United States
| | - Olga A. Esakova
- Department
of Chemistry and Biochemistry and Molecular Biology and the Howard Hughes
Medical Institute, The Pennsylvania State
University, University
Park, Pennsylvania 16802, United States
| | - Hayley L. Knox
- Department
of Chemistry and Biochemistry and Molecular Biology and the Howard Hughes
Medical Institute, The Pennsylvania State
University, University
Park, Pennsylvania 16802, United States
| | - Carsten Krebs
- Department
of Chemistry and Biochemistry and Molecular Biology and the Howard Hughes
Medical Institute, The Pennsylvania State
University, University
Park, Pennsylvania 16802, United States
| | - Squire J. Booker
- Department
of Chemistry and Biochemistry and Molecular Biology and the Howard Hughes
Medical Institute, The Pennsylvania State
University, University
Park, Pennsylvania 16802, United States
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30
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Fan PH, Geng Y, Romo AJ, Zhong A, Zhang J, Yeh YC, Lee YH, Liu HW. Two Radical SAM Enzymes Are Necessary and Sufficient for the In Vitro Production of the Oxetane Nucleoside Antiviral Agent Albucidin. Angew Chem Int Ed Engl 2022; 61:e202210362. [PMID: 36064953 PMCID: PMC9561071 DOI: 10.1002/anie.202210362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Indexed: 11/09/2022]
Abstract
Oxetanocin A and albucidin are two oxetane natural products. While the biosynthesis of oxetanocin A has been described, less is known about albucidin. In this work, the albucidin biosynthetic gene cluster is identified in Streptomyces. Heterologous expression in a nonproducing strain demonstrates that the genes alsA and alsB are necessary and sufficient for albucidin biosynthesis confirming a previous study (Myronovskyi et al. Microorganisms 2020, 8, 237). A two-step construction of albucidin 4'-phosphate from 2'-deoxyadenosine monophosphate (2'-dAMP) is shown to be catalyzed in vitro by the cobalamin dependent radical S-adenosyl-l-methionine (SAM) enzyme AlsB, which catalyzes a ring contraction, and the radical SAM enzyme AlsA, which catalyzes elimination of a one-carbon fragment. Isotope labelling studies show that AlsB catalysis begins with stereospecific H-atom transfer of the C2'-pro-R hydrogen from 2'-dAMP to 5'-deoxyadenosine, and that the eliminated one-carbon fragment originates from C3' of 2'-dAMP.
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Affiliation(s)
- Po-Hsun Fan
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Yujie Geng
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, United States
| | - Anthony J. Romo
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, United States
| | - Aoshu Zhong
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, 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
| | - Yu-Cheng Yeh
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Yu-Hsuan Lee
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Hung-wen Liu
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, United States
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31
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Ho MB, Jodts RJ, Kim Y, McSkimming A, Suess DLM, Hoffman BM. Characterization by ENDOR Spectroscopy of the Iron–Alkyl Bond in a Synthetic Counterpart of Organometallic Intermediates in Radical SAM Enzymes. J Am Chem Soc 2022; 144:17642-17650. [DOI: 10.1021/jacs.2c07155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Madeline B. Ho
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Richard J. Jodts
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Youngsuk Kim
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alex McSkimming
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Daniel L. M. Suess
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Brian M. Hoffman
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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32
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Fan PH, Geng Y, Romo AJ, Zhong A, Zhang J, Yeh YC, Lee YH, Liu HW. Two Radical SAM Enzymes Are Necessary and Sufficient for the In Vitro Production of the Oxetane Nucleoside Antiviral Agent Albucidin. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202210362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Po-Hsun Fan
- The University of Texas at Austin Chemistry The University of Texas at Austin 78712-1139 Austin UNITED STATES
| | - Yujie Geng
- The University of Texas at Austin College of Pharmacy College of Pharmacy 78712-1139 Austin UNITED STATES
| | - Anthony J Romo
- The University of Texas at Austin College of Pharmacy College of Pharmacy 78712-1139 Austin UNITED STATES
| | - Aoshu Zhong
- The University of Texas at Austin College of Pharmacy College of Pharmacy 78712-1139 Austin UNITED STATES
| | - Jiawei Zhang
- The University of Texas at Austin Chemistry The University of Texas at Austin 78712-1139 Austin UNITED STATES
| | - Yu-Cheng Yeh
- UT Austin: The University of Texas at Austin Chemistry The University of Texas at Austin 78712-1139 Austin UNITED STATES
| | - Yu-Hsuan Lee
- UT Austin: The University of Texas at Austin Chemistry The University of Texas at Austin 78712-1139 Austin UNITED STATES
| | - Hung-wen Liu
- University of Texas at Austin Phar-Med Chem/3.206 1 University Station A1935PHR 3.206B 78712-0128 Austin UNITED STATES
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33
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Steward KF, Payne D, Kincannon W, Johnson C, Lensing M, Fausset H, Németh B, Shepard EM, Broderick WE, Broderick JB, Dubois J, Bothner B. Proteomic Analysis of Methanococcus voltae Grown in the Presence of Mineral and Nonmineral Sources of Iron and Sulfur. Microbiol Spectr 2022; 10:e0189322. [PMID: 35876569 PMCID: PMC9431491 DOI: 10.1128/spectrum.01893-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 06/17/2022] [Indexed: 11/28/2022] Open
Abstract
Iron sulfur (Fe-S) proteins are essential and ubiquitous across all domains of life, yet the mechanisms underpinning assimilation of iron (Fe) and sulfur (S) and biogenesis of Fe-S clusters are poorly understood. This is particularly true for anaerobic methanogenic archaea, which are known to employ more Fe-S proteins than other prokaryotes. Here, we utilized a deep proteomics analysis of Methanococcus voltae A3 cultured in the presence of either synthetic pyrite (FeS2) or aqueous forms of ferrous iron and sulfide to elucidate physiological responses to growth on mineral or nonmineral sources of Fe and S. The liquid chromatography-mass spectrometry (LCMS) shotgun proteomics analysis included 77% of the predicted proteome. Through a comparative analysis of intra- and extracellular proteomes, candidate proteins associated with FeS2 reductive dissolution, Fe and S acquisition, and the subsequent transport, trafficking, and storage of Fe and S were identified. The proteomic response shows a large and balanced change, suggesting that M. voltae makes physiological adjustments involving a range of biochemical processes based on the available nutrient source. Among the proteins differentially regulated were members of core methanogenesis, oxidoreductases, membrane proteins putatively involved in transport, Fe-S binding ferredoxin and radical S-adenosylmethionine proteins, ribosomal proteins, and intracellular proteins involved in Fe-S cluster assembly and storage. This work improves our understanding of ancient biogeochemical processes and can support efforts in biomining of minerals. IMPORTANCE Clusters of iron and sulfur are key components of the active sites of enzymes that facilitate microbial conversion of light or electrical energy into chemical bonds. The proteins responsible for transporting iron and sulfur into cells and assembling these elements into metal clusters are not well understood. Using a microorganism that has an unusually high demand for iron and sulfur, we conducted a global investigation of cellular proteins and how they change based on the mineral forms of iron and sulfur. Understanding this process will answer questions about life on early earth and has application in biomining and sustainable sources of energy.
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Affiliation(s)
- Katherine F. Steward
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Devon Payne
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana, USA
| | - Will Kincannon
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Christina Johnson
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Malachi Lensing
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Hunter Fausset
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Brigitta Németh
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Eric M. Shepard
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - William E. Broderick
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Joan B. Broderick
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Jen Dubois
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
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34
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de Kok NAW, Driessen AJM. The catalytic and structural basis of archaeal glycerophospholipid biosynthesis. Extremophiles 2022; 26:29. [PMID: 35976526 PMCID: PMC9385802 DOI: 10.1007/s00792-022-01277-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 08/02/2022] [Indexed: 12/03/2022]
Abstract
Archaeal glycerophospholipids are the main constituents of the cytoplasmic membrane in the archaeal domain of life and fundamentally differ in chemical composition compared to bacterial phospholipids. They consist of isoprenyl chains ether-bonded to glycerol-1-phosphate. In contrast, bacterial glycerophospholipids are composed of fatty acyl chains ester-bonded to glycerol-3-phosphate. This largely domain-distinguishing feature has been termed the “lipid-divide”. The chemical composition of archaeal membranes contributes to the ability of archaea to survive and thrive in extreme environments. However, ether-bonded glycerophospholipids are not only limited to extremophiles and found also in mesophilic archaea. Resolving the structural basis of glycerophospholipid biosynthesis is a key objective to provide insights in the early evolution of membrane formation and to deepen our understanding of the molecular basis of extremophilicity. Many of the glycerophospholipid enzymes are either integral membrane proteins or membrane-associated, and hence are intrinsically difficult to study structurally. However, in recent years, the crystal structures of several key enzymes have been solved, while unresolved enzymatic steps in the archaeal glycerophospholipid biosynthetic pathway have been clarified providing further insights in the lipid-divide and the evolution of early life.
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Affiliation(s)
- Niels A W de Kok
- Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747AG, Groningen, The Netherlands
| | - Arnold J M Driessen
- Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747AG, Groningen, The Netherlands.
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35
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Highlighting the Unique Roles of Radical S-Adenosylmethionine Enzymes in Methanogenic Archaea. J Bacteriol 2022; 204:e0019722. [PMID: 35880875 PMCID: PMC9380564 DOI: 10.1128/jb.00197-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Radical S-adenosylmethionine (SAM) enzymes catalyze an impressive variety of difficult biochemical reactions in various pathways across all domains of life. These metalloenzymes employ a reduced [4Fe-4S] cluster and SAM to generate a highly reactive 5'-deoxyadenosyl radical that is capable of initiating catalysis on otherwise unreactive substrates. Interestingly, the genomes of methanogenic archaea encode many unique radical SAM enzymes with underexplored or completely unknown functions. These organisms are responsible for the yearly production of nearly 1 billion tons of methane, a potent greenhouse gas as well as a valuable energy source. Thus, understanding the details of methanogenic metabolism and elucidating the functions of essential enzymes in these organisms can provide insights into strategies to decrease greenhouse gas emissions as well as inform advances in bioenergy production processes. This minireview provides an overview of the current state of the field regarding the functions of radical SAM enzymes in methanogens and discusses gaps in knowledge that should be addressed.
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36
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Bicyclostreptins are radical SAM enzyme-modified peptides with unique cyclization motifs. Nat Chem Biol 2022; 18:1135-1143. [PMID: 35953547 DOI: 10.1038/s41589-022-01090-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 06/21/2022] [Indexed: 12/22/2022]
Abstract
Microbial natural products comprise diverse architectures that are generated by equally diverse biosynthetic strategies. In peptide natural products, amino acid sidechains are frequently used as sites of modification to generate macrocyclic motifs. Backbone amide groups, among the most stable of biological moieties, are rarely used for this purpose. Here we report the discovery and biosynthesis of bicyclostreptins-peptide natural products from Streptococcus spp. with an unprecedented structural motif consisting of a macrocyclic β-ether and a heterocyclic sp3-sp3 linkage between a backbone amide nitrogen and an adjacent α-carbon. Both reactions are installed, in that order, by two radical S-adenosylmethionine (RaS) metalloenzymes. Bicyclostreptins are produced at nM concentrations and are potent growth regulation agents in Streptococcus thermophilus. Our results add a distinct and unusual chemotype to the growing family of ribosomal peptide natural products, expand the already impressive catalytic scope of RaS enzymes, and provide avenues for further biological studies in human-associated streptococci.
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37
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Knox HL, Booker SJ. Structural characterization of cobalamin-dependent radical S-adenosylmethionine methylases. Methods Enzymol 2022; 669:3-27. [PMID: 35644177 DOI: 10.1016/bs.mie.2021.12.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cobalamin-dependent radical S-adenosylmethionine (SAM) methylases catalyze key steps in the biosynthesis of numerous biomolecules, including protein cofactors, antibiotics, herbicides, and other natural products, but have remained a relatively understudied subclass of radical SAM enzymes due to their inherent insolubility upon overproduction in Escherichia coli. These enzymes contain two cofactors: a [4Fe-4S] cluster that is ligated by three cysteine residues, and a cobalamin cofactor typically bound by residues in the N-terminal portion of the enzyme. Recent advances in the expression and purification of these enzymes in their active states and with both cofactors present has allowed for more detailed biochemical studies as well as structure determination by X-ray crystallography. Herein, we use KsTsrM and TokK to highlight methods for the structural characterization of cobalamin-dependent radical SAM (RS) enzymes and describe recent advances in in the overproduction and purification of these enzymes.
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Affiliation(s)
- Hayley L Knox
- The Department of Chemistry, The Pennsylvania State University, University Park, PA, United States
| | - Squire J Booker
- The Department of Chemistry, The Pennsylvania State University, University Park, PA, United States; The Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States; The Howard Hughes Medical Institute, The Pennsylvania State University, University Park, PA, United States.
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38
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Resolution and characterization of contributions of select protein and coupled solvent configurational fluctuations to radical rearrangement catalysis in coenzyme B 12-dependent ethanolamine ammonia-lyase. Methods Enzymol 2022; 669:229-259. [PMID: 35644173 DOI: 10.1016/bs.mie.2021.12.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Coenzyme B12 (adenosylcobalamin) -dependent ethanolamine ammonia-lyase (EAL) is the signature enzyme in ethanolamine utilization metabolism associated with microbiome homeostasis and disease conditions in the human gut. The enzyme conducts a complex choreography of bond-making/bond-breaking steps that rearrange substrate to products through a radical mechanism, with themes common to other coenzyme B12-dependent and radical enzymes. The methods presented are targeted to test the hypothesis that particular, select protein and coupled solvent configurational fluctuations contribute to enzyme function. The general approach is to correlate enzyme function with an introduced perturbation that alters the properties (for example, degree of concertedness, or collectiveness) of protein and coupled solvent dynamics. Methods for sample preparation and low-temperature kinetic measurements by using temperature-step reaction initiation and time-resolved, full-spectrum electron paramagnetic resonance spectroscopy are detailed. A framework for interpretation of results obtained in ensemble systems under conditions of statistical equilibrium within the reacting, globally unstable state is presented. The temperature-dependence of the first-order rate constants for decay of the cryotrapped paramagnetic substrate radical state in EAL, through the chemical step of radical rearrangement, displays a piecewise-continuous Arrhenius dependence from 203 to 295K, punctuated by a kinetic bifurcation over 219-220K. The results reveal the obligatory contribution of a class of select collective protein and coupled solvent fluctuations to the interconversion of two resolved, sequential configurational substates, on the decay time scale. The select class of collective fluctuations also contributes to the chemical step. The methods and analysis are generally applicable to other coenzyme B12-dependent and related radical enzymes.
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39
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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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40
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Tunçkanat T, Gendron A, Sadler Z, Neitz A, Byquist S, Lie TJ, Allen KD. Lysine 2,3-Aminomutase and a Newly Discovered Glutamate 2,3-Aminomutase Produce β-Amino Acids Involved in Salt Tolerance in Methanogenic Archaea. Biochemistry 2022; 61:1077-1090. [PMID: 35544775 DOI: 10.1021/acs.biochem.2c00014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Many methanogenic archaea synthesize β-amino acids as osmolytes that allow survival in high salinity environments. Here, we investigated the radical S-adenosylmethionine (SAM) aminomutases involved in the biosynthesis of Nε-acetyl-β-lysine and β-glutamate in Methanococcus maripaludis C7. Lysine 2,3-aminomutase (KAM), encoded by MmarC7_0106, was overexpressed and purified from Escherichia coli, followed by biochemical characterization. In the presence of l-lysine, SAM, and dithionite, this archaeal KAM had a kcat = 14.3 s-1 and a Km = 19.2 mM. The product was shown to be 3(S)-β-lysine, which is like the well-characterized Clostridium KAM as opposed to the E. coli KAM that produces 3(R)-β-lysine. We further describe the function of MmarC7_1783, a putative radical SAM aminomutase with a ∼160 amino acid extension at its N-terminus. Bioinformatic analysis of the possible substrate-binding residues suggested a function as glutamate 2,3-aminomutase, which was confirmed here through heterologous expression in a methanogen followed by detection of β-glutamate in cell extracts. β-Glutamate has been known to serve as an osmolyte in select methanogens for a long time, but its biosynthetic origin remained unknown until now. Thus, this study defines the biosynthetic routes for β-lysine and β-glutamate in M. maripaludis and expands the importance and diversity of radical SAM enzymes in all domains of life.
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Affiliation(s)
- Taylan Tunçkanat
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, United States
| | - Aleksei Gendron
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, United States
| | - Zoie Sadler
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, United States
| | - Alex Neitz
- Department of Chemistry and Biochemistry, Gonzaga University, Spokane, Washington 99258, United States
| | - Sarah Byquist
- Department of Chemistry and Biochemistry, Gonzaga University, Spokane, Washington 99258, United States
| | - Thomas J Lie
- Department of Microbiology, University of Washington, Seattle, Washington 98195, United States
| | - Kylie D Allen
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, United States
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41
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Wu R, Ding W, Zhang Q. Consecutive Methylation catalyzed by
TsrM
, an atypical Class B radical
SAM
methylase. CHINESE J CHEM 2022. [DOI: 10.1002/cjoc.202200174] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Runze Wu
- Department of Chemistry Fudan University Shanghai 200433 China
| | - Wei Ding
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University Shanghai 200240 China
| | - Qi Zhang
- Department of Chemistry Fudan University Shanghai 200433 China
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42
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Liu YA, Quechol R, Solomon JB, Lee CC, Ribbe MW, Hu Y, Hedman B, Hodgson KO. Radical SAM-dependent formation of a nitrogenase cofactor core on NifB. J Inorg Biochem 2022; 233:111837. [PMID: 35550498 PMCID: PMC9526504 DOI: 10.1016/j.jinorgbio.2022.111837] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 04/10/2022] [Accepted: 04/14/2022] [Indexed: 11/15/2022]
Abstract
Nitrogenase is a versatile metalloenzyme that reduces N2, CO and CO2 at its cofactor site. Designated the M-cluster, this complex cofactor has a composition of [(R-homocitrate)MoFe7S9C], and it is assembled through the generation of a unique [Fe8S9C] core prior to the insertion of Mo and homocitrate. NifB is a radical S-adenosyl-L-methionine (SAM) enzyme that is essential for nitrogenase cofactor assembly. This review focuses on the recent work that sheds light on the role of NifB in the formation of the [Fe8S9C] core of the nitrogenase cofactor, highlighting the structure, function and mechanism of this unique radical SAM methyltransferase.
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Affiliation(s)
- Yiling A Liu
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, United States of America
| | - Robert Quechol
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, United States of America
| | - Joseph B Solomon
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, United States of America; Department of Chemistry, University of California, Irvine, CA 92697-2025, United States of America
| | - Chi Chung Lee
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, United States of America
| | - Markus W Ribbe
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, United States of America; Department of Chemistry, University of California, Irvine, CA 92697-2025, United States of America.
| | - Yilin Hu
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, United States of America.
| | - Britt Hedman
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, United States of America.
| | - Keith O Hodgson
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, United States of America; Department of Chemistry, Stanford University, Stanford, CA 94305, United States of America.
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43
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Lundahl MN, Sarksian R, Yang H, Jodts RJ, Pagnier A, Smith DF, Mosquera MA, van der Donk WA, Hoffman BM, Broderick WE, Broderick JB. Mechanism of Radical S-Adenosyl-l-methionine Adenosylation: Radical Intermediates and the Catalytic Competence of the 5'-Deoxyadenosyl Radical. J Am Chem Soc 2022; 144:5087-5098. [PMID: 35258967 PMCID: PMC9524473 DOI: 10.1021/jacs.1c13706] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Radical S-adenosyl-l-methionine (SAM) enzymes employ a [4Fe-4S] cluster and SAM to initiate diverse radical reactions via either H-atom abstraction or substrate adenosylation. Here we use freeze-quench techniques together with electron paramagnetic resonance (EPR) spectroscopy to provide snapshots of the reaction pathway in an adenosylation reaction catalyzed by the radical SAM enzyme pyruvate formate-lyase activating enzyme on a peptide substrate containing a dehydroalanine residue in place of the target glycine. The reaction proceeds via the initial formation of the organometallic intermediate Ω, as evidenced by the characteristic EPR signal with g∥ = 2.035 and g⊥ = 2.004 observed when the reaction is freeze-quenched at 500 ms. Thermal annealing of frozen Ω converts it into a second paramagnetic species centered at giso = 2.004; this second species was generated directly using freeze-quench at intermediate times (∼8 s) and unequivocally identified via isotopic labeling and EPR spectroscopy as the tertiary peptide radical resulting from adenosylation of the peptide substrate. An additional paramagnetic species observed in samples quenched at intermediate times was revealed through thermal annealing while frozen and spectral subtraction as the SAM-derived 5'-deoxyadenosyl radical (5'-dAdo•). The time course of the 5'-dAdo• and tertiary peptide radical EPR signals reveals that the former generates the latter. These results thus support a mechanism in which Ω liberates 5'-dAdo• by Fe-C5' bond homolysis, and the 5'-dAdo• attacks the dehydroalanine residue of the peptide substrate to form the adenosylated peptide radical species. The results thus provide a picture of a catalytically competent 5'-dAdo• intermediate trapped just prior to reaction with the substrate.
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Affiliation(s)
- Maike N. Lundahl
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Raymond Sarksian
- Department of Chemistry and Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Hao Yang
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Richard J. Jodts
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Adrien Pagnier
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Donald F. Smith
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Martín A. Mosquera
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Wilfred A. van der Donk
- Department of Chemistry and Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Brian M. Hoffman
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - William E. Broderick
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Joan B. Broderick
- Corresponding Author: Joan B. Broderick – Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States;
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44
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Lechner H, Oberdorfer G. Derivatives of natural organocatalytic cofactors and artificial organocatalytic cofactors as catalysts in enzymes. Chembiochem 2022; 23:e202100599. [PMID: 35302276 PMCID: PMC9401024 DOI: 10.1002/cbic.202100599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 03/14/2022] [Indexed: 11/11/2022]
Abstract
Catalytically active non-metal cofactors in enzymes carry out a variety of different reactions. The efforts to develop derivatives of natural occurring cofactors such as flavins or pyridoxal phosphate and the advances to design new, non-natural cofactors are reviewed here. We report the status quo for enzymes harboring organocatalysts as derivatives of natural cofactors or as artificial ones and their application in the asymmetric synthesis of various compounds.
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Affiliation(s)
- Horst Lechner
- Graz University of Technology: Technische Universitat Graz, Institute of Biochemistry, Petersgasse 12/2, 8010, Graz, AUSTRIA
| | - Gustav Oberdorfer
- Graz University of Technology: Technische Universitat Graz, Institute of Biochemistry, Petersgasse 12/2, 8010, Graz, AUSTRIA
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45
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Li H, Zhao J, Ding W, Zhang Q. Glucuronyl C4 dehydrogenation by the radical SAM enzyme BlsE involved in blasticidin S biosynthesis. Chem Commun (Camb) 2022; 58:3561-3564. [PMID: 35199117 DOI: 10.1039/d1cc07132g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Here we report functional investigation of the radical S-adenosylmethionine enzyme BlsE by using cytosylglucuronamide (CGM), which is the amide analog of cytosylglucuronic acid (CGA), an intermediate involved in blasticidin S biosynthesis. We showed that, instead of decarboxylation of CGA reported previously, BlsE catalyzes C4'-dehydrogenation of CGM, and the resulting ketone is acted on by an aminotransferase BlsH to install the C4'-amino group, which uses L-Asp as the amino donor.
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Affiliation(s)
- He Li
- Department of Chemistry, Fudan University, Shanghai, 200433, China.
| | - Junfeng Zhao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Wei Ding
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Qi Zhang
- Department of Chemistry, Fudan University, Shanghai, 200433, China.
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46
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Frenkel-Pinter M, Petrov AS, Matange K, Travisano M, Glass JB, Williams LD. Adaptation and Exaptation: From Small Molecules to Feathers. J Mol Evol 2022; 90:166-175. [PMID: 35246710 PMCID: PMC8975760 DOI: 10.1007/s00239-022-10049-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 01/26/2022] [Indexed: 11/27/2022]
Abstract
Evolution works by adaptation and exaptation. At an organismal level, exaptation and adaptation are seen in the formation of organelles and the advent of multicellularity. At the sub-organismal level, molecular systems such as proteins and RNAs readily undergo adaptation and exaptation. Here we suggest that the concepts of adaptation and exaptation are universal, synergistic, and recursive and apply to small molecules such as metabolites, cofactors, and the building blocks of extant polymers. For example, adenosine has been extensively adapted and exapted throughout biological evolution. Chemical variants of adenosine that are products of adaptation include 2' deoxyadenosine in DNA and a wide array of modified forms in mRNAs, tRNAs, rRNAs, and viral RNAs. Adenosine and its variants have been extensively exapted for various functions, including informational polymers (RNA, DNA), energy storage (ATP), metabolism (e.g., coenzyme A), and signaling (cyclic AMP). According to Gould, Vrba, and Darwin, exaptation imposes a general constraint on interpretation of history and origins; because of exaptation, extant function should not be used to explain evolutionary history. While this notion is accepted in evolutionary biology, it can also guide the study of the chemical origins of life. We propose that (i) evolutionary theory is broadly applicable from the dawn of life to the present time from molecules to organisms, (ii) exaptation and adaptation were important and simultaneous processes, and (iii) robust origin of life models can be constructed without conflating extant utility with historical basis of origins.
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Affiliation(s)
- Moran Frenkel-Pinter
- NASA Center for the Origins of Life, Atlanta, GA, 30332-0400, USA.,NSF-NASA Center of Chemical Evolution, Atlanta, GA, 30332-0400, USA.,Institute of Chemistry, The Hebrew University of Jerusalem, 91904, Jerusalem, Israel
| | - Anton S Petrov
- NASA Center for the Origins of Life, Atlanta, GA, 30332-0400, USA.,NSF-NASA Center of Chemical Evolution, Atlanta, GA, 30332-0400, USA.,School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
| | - Kavita Matange
- NASA Center for the Origins of Life, Atlanta, GA, 30332-0400, USA.,School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
| | - Michael Travisano
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Jennifer B Glass
- NASA Center for the Origins of Life, Atlanta, GA, 30332-0400, USA.,School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
| | - Loren Dean Williams
- NASA Center for the Origins of Life, Atlanta, GA, 30332-0400, USA. .,NSF-NASA Center of Chemical Evolution, Atlanta, GA, 30332-0400, USA. .,School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA.
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47
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Oberg N, Precord TW, Mitchell DA, Gerlt JA. RadicalSAM.org: A Resource to Interpret Sequence-Function Space and Discover New Radical SAM Enzyme Chemistry. ACS BIO & MED CHEM AU 2022; 2:22-35. [PMID: 36119373 PMCID: PMC9477430 DOI: 10.1021/acsbiomedchemau.1c00048] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The radical SAM superfamily (RSS), arguably the most functionally diverse enzyme superfamily, is also one of the largest with ~700K members currently in the UniProt database. The vast majority of the members have uncharacterized enzymatic activities and metabolic functions. In this Perspective, we describe RadicalSAM.org, a new web-based resource that enables a user-friendly genomic enzymology strategy to explore sequence-function space in the RSS. The resource attempts to enable identification of isofunctional groups of radical SAM enzymes using sequence similarity networks (SSNs) and the genome context of the bacterial, archaeal, and fungal members provided by genome neighborhood diagrams (GNDs). Enzymatic activities and in vivo functions frequently can be inferred from genome context given the tendency for genes of related function to be clustered. We invite the scientific community to use RadicalSAM.org to (i) guide their experimental studies to discover new enzymatic activities and metabolic functions, (ii) contribute experimentally verified annotations to RadicalSAM.org to enhance the ability to predict novel activities and functions, and (iii) provide suggestions for improving this resource.
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Affiliation(s)
- Nils Oberg
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States
| | - Timothy W. Precord
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States,Department of Chemistry, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States
| | - Douglas A. Mitchell
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States,Department of Chemistry, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States,Department of Microbiology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States
| | - John A. Gerlt
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States,Department of Chemistry, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States,Department of Biochemistry, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States
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48
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Sinner E, Marous DR, Townsend CA. Evolution of Methods for the Study of Cobalamin-Dependent Radical SAM Enzymes. ACS BIO & MED CHEM AU 2022; 2:4-10. [PMID: 35341020 PMCID: PMC8950095 DOI: 10.1021/acsbiomedchemau.1c00032] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
While bioinformatic evidence of cobalamin-dependent radical S-adenosylmethionine (SAM) enzymes has existed since the naming of the radical SAM superfamily in 2001, none were biochemically characterized until 2011. In the past decade, the field has flourished as methodological advances have facilitated study of the subfamily. Because of the ingenuity and perseverance of researchers in this field, we now have functional, mechanistic, and structural insight into how this class of enzymes harnesses the power of both the cobalamin and radical SAM cofactors to achieve catalysis. All of the early characterized enzymes in this subfamily were methylases, but the activity of these enzymes has recently been expanded beyond methylation. We anticipate that the characterized functions of these enzymes will become both better understood and increasingly diverse with continued study.
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Affiliation(s)
- Erica
K. Sinner
- Department
of Chemistry, Johns Hopkins University, 3400 N Charles St., Baltimore, Maryland 21218, United States
| | - Daniel R. Marous
- Department
of Chemistry, Wittenberg University, 200 W Ward St., Springfield, Ohio 45504, United States
| | - Craig A. Townsend
- Department
of Chemistry, Johns Hopkins University, 3400 N Charles St., Baltimore, Maryland 21218, United States
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49
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Donnan PH, Mansoorabadi SO. Broken-Symmetry Density Functional Theory Analysis of the Ω Intermediate in Radical S-Adenosyl-l-methionine Enzymes: Evidence for a Near-Attack Conformer over an Organometallic Species. J Am Chem Soc 2022; 144:3381-3385. [PMID: 35170316 DOI: 10.1021/jacs.2c00678] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Radical S-adenosyl-l-methionine (SAM) enzymes are found in all domains of life and catalyze a wide range of biochemical reactions. Recently, an organometallic intermediate, Ω, has been experimentally implicated in the 5'-deoxyadenosyl radical generation mechanism of the radical SAM superfamily. In this work, we employ broken-symmetry density functional theory to evaluate several structural models of Ω. The results show that the calculated hyperfine coupling constants (HFCCs) for the proposed organometallic structure of Ω are inconsistent with the experiment. In contrast, a near-attack conformer of SAM bound to the catalytic [4Fe-4S] cluster, in which the distance between the unique iron and SAM sulfur is ∼3 Å, yields HFCCs that are all within 1 MHz of the experimental values. These results clarify the structure of the ubiquitous Ω intermediate and suggest a paradigm shift reversal regarding the mechanism of SAM cleavage by members of the radical SAM superfamily.
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Affiliation(s)
- Patrick H Donnan
- Department of Chemistry and Biochemistry, Auburn University, 179 Chemistry Building, Auburn, Alabama 36849, United States
| | - Steven O Mansoorabadi
- Department of Chemistry and Biochemistry, Auburn University, 179 Chemistry Building, Auburn, Alabama 36849, United States
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Lee YH, Liu HW. Studies of GenK and OxsB, two B 12-dependent radical SAM enzymes involved in natural product biosynthesis. Methods Enzymol 2022; 669:71-90. [PMID: 35644181 PMCID: PMC9178707 DOI: 10.1016/bs.mie.2021.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The B12-dependent radical SAM enzymes are an emerging subgroup of biological catalysts that bind a cobalamin cofactor in addition to the canonical [Fe4S4] cluster characteristic of radical SAM enzymes. Most of the B12-dependent radical SAM enzymes that have been characterized mediated methyltransfer reactions; however, a small number are known to catalyze more diverse reactions such as ring contractions. Thus, Genk is a methyltransferase from the gentamicin C biosynthetic pathway, whereas OxsB catalyzes the oxidative ring contraction of 2'-deoxyadenosine 5'-phosphates to generate an oxetane aldehyde during the biosynthesis of oxetanocin A. The preparation and in vitro characterization of such enzymes is complicated by the presence of two redox sensitive cofactors in addition to challenges in obtaining soluble protein for study. This chapter describes expression, purification and assay methodologies for GenK and OxsB highlighting the use of denaturation/refolding protocols for solubilizing inclusion bodies as well as the use of cluster assembly and cobalamin uptake machinery during in vivo expression.
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Affiliation(s)
- Yu-Hsuan Lee
- Department of Chemistry, University of Texas at Austin, Austin, TX, United States
| | - Hung-Wen Liu
- Department of Chemistry, University of Texas at Austin, Austin, TX, United States; Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX, United States.
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