1
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Lachowicz JC, Lennox-Hvenekilde D, Myling-Petersen N, Salomonsen B, Verkleij G, Acevedo-Rocha CG, Caddell B, Gronenberg LS, Almo SC, Sommer MOA, Genee HJ, Grove TL. Discovery of a Biotin Synthase That Utilizes an Auxiliary 4Fe-5S Cluster for Sulfur Insertion. J Am Chem Soc 2024; 146:1860-1873. [PMID: 38215281 PMCID: PMC10813225 DOI: 10.1021/jacs.3c05481] [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: 06/03/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 01/14/2024]
Abstract
Biotin synthase (BioB) is a member of the Radical SAM superfamily of enzymes that catalyzes the terminal step of biotin (vitamin B7) biosynthesis, in which it inserts a sulfur atom in desthiobiotin to form a thiolane ring. How BioB accomplishes this difficult reaction has been the subject of much controversy, mainly around the source of the sulfur atom. However, it is now widely accepted that the sulfur atom inserted to form biotin stems from the sacrifice of the auxiliary 2Fe-2S cluster of BioB. Here, we bioinformatically explore the diversity of BioBs available in sequence databases and find an unexpected variation in the coordination of the auxiliary iron-sulfur cluster. After in vitro characterization, including the determination of biotin formation and representative crystal structures, we report a new type of BioB utilized by virtually all obligate anaerobic organisms. Instead of a 2Fe-2S cluster, this novel type of BioB utilizes an auxiliary 4Fe-5S cluster. Interestingly, this auxiliary 4Fe-5S cluster contains a ligated sulfide that we propose is used for biotin formation. We have termed this novel type of BioB, Type II BioB, with the E. coli 2Fe-2S cluster sacrificial BioB representing Type I. This surprisingly ubiquitous Type II BioB has implications for our understanding of the function and evolution of Fe-S clusters in enzyme catalysis, highlighting the difference in strategies between the anaerobic and aerobic world.
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Affiliation(s)
- Jake C. Lachowicz
- Department
of Biochemistry, Albert Einstein College
of Medicine, Bronx, New York 10461, United States
| | - David Lennox-Hvenekilde
- The
Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
- Biosyntia
ApS, Copenhagen, 2100, Denmark
| | | | | | | | - Carlos G. Acevedo-Rocha
- The
Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
- Biosyntia
ApS, Copenhagen, 2100, Denmark
| | | | | | - Steven C. Almo
- Department
of Biochemistry, Albert Einstein College
of Medicine, Bronx, New York 10461, United States
| | - Morten O. A. Sommer
- The
Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
| | | | - Tyler L. Grove
- Department
of Biochemistry, Albert Einstein College
of Medicine, Bronx, New York 10461, United States
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2
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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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3
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Thakur P, Alaba MO, Rauniyar S, Singh RN, Saxena P, Bomgni A, Gnimpieba EZ, Lushbough C, Goh KM, Sani RK. Text-Mining to Identify Gene Sets Involved in Biocorrosion by Sulfate-Reducing Bacteria: A Semi-Automated Workflow. Microorganisms 2023; 11:119. [PMID: 36677411 PMCID: PMC9867429 DOI: 10.3390/microorganisms11010119] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 01/05/2023] Open
Abstract
A significant amount of literature is available on biocorrosion, which makes manual extraction of crucial information such as genes and proteins a laborious task. Despite the fast growth of biology related corrosion studies, there is a limited number of gene collections relating to the corrosion process (biocorrosion). Text mining offers a potential solution by automatically extracting the essential information from unstructured text. We present a text mining workflow that extracts biocorrosion associated genes/proteins in sulfate-reducing bacteria (SRB) from literature databases (e.g., PubMed and PMC). This semi-automatic workflow is built with the Named Entity Recognition (NER) method and Convolutional Neural Network (CNN) model. With PubMed and PMCID as inputs, the workflow identified 227 genes belonging to several Desulfovibrio species. To validate their functions, Gene Ontology (GO) enrichment and biological network analysis was performed using UniprotKB and STRING-DB, respectively. The GO analysis showed that metal ion binding, sulfur binding, and electron transport were among the principal molecular functions. Furthermore, the biological network analysis generated three interlinked clusters containing genes involved in metal ion binding, cellular respiration, and electron transfer, which suggests the involvement of the extracted gene set in biocorrosion. Finally, the dataset was validated through manual curation, yielding a similar set of genes as our workflow; among these, hysB and hydA, and sat and dsrB were identified as the metal ion binding and sulfur metabolism genes, respectively. The identified genes were mapped with the pangenome of 63 SRB genomes that yielded the distribution of these genes across 63 SRB based on the amino acid sequence similarity and were further categorized as core and accessory gene families. SRB's role in biocorrosion involves the transfer of electrons from the metal surface via a hydrogen medium to the sulfate reduction pathway. Therefore, genes encoding hydrogenases and cytochromes might be participating in removing hydrogen from the metals through electron transfer. Moreover, the production of corrosive sulfide from the sulfur metabolism indirectly contributes to the localized pitting of the metals. After the corroboration of text mining results with SRB biocorrosion mechanisms, we suggest that the text mining framework could be utilized for genes/proteins extraction and significantly reduce the manual curation time.
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Affiliation(s)
- Payal Thakur
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
- Data Driven Material Discovery Center for Bioengineering Innovation, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
| | - Mathew O. Alaba
- Department of Biomedical Engineering, University of South Dakota, Sioux Falls, SD 57069, USA
| | - Shailabh Rauniyar
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
- 2-Dimensional Materials for Biofilm Engineering, Science and Technology, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
| | - Ram Nageena Singh
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
- 2-Dimensional Materials for Biofilm Engineering, Science and Technology, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
| | - Priya Saxena
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
- Data Driven Material Discovery Center for Bioengineering Innovation, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
| | - Alain Bomgni
- Department of Biomedical Engineering, University of South Dakota, Sioux Falls, SD 57069, USA
| | - Etienne Z. Gnimpieba
- Data Driven Material Discovery Center for Bioengineering Innovation, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
- Department of Biomedical Engineering, University of South Dakota, Sioux Falls, SD 57069, USA
- 2-Dimensional Materials for Biofilm Engineering, Science and Technology, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
| | - Carol Lushbough
- Department of Biomedical Engineering, University of South Dakota, Sioux Falls, SD 57069, USA
| | - Kian Mau Goh
- Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor, Malaysia
| | - Rajesh Kumar Sani
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
- Data Driven Material Discovery Center for Bioengineering Innovation, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
- 2-Dimensional Materials for Biofilm Engineering, Science and Technology, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
- BuG ReMeDEE Consortium, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
- Composite and Nanocomposite Advanced Manufacturing Centre—Biomaterials, Rapid City, SD 57701, USA
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Neti SS, Sil D, Warui DM, Esakova OA, Solinski AE, Serrano DA, Krebs C, Booker SJ. Characterization of LipS1 and LipS2 from Thermococcus kodakarensis: Proteins Annotated as Biotin Synthases, which Together Catalyze Formation of the Lipoyl Cofactor. ACS BIO & MED CHEM AU 2022; 2:509-520. [PMID: 36281299 PMCID: PMC9585515 DOI: 10.1021/acsbiomedchemau.2c00018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 06/28/2022] [Accepted: 06/29/2022] [Indexed: 11/28/2022]
Abstract
Lipoic acid is an eight-carbon sulfur-containing biomolecule that functions primarily as a cofactor in several multienzyme complexes. It is biosynthesized as an attachment to a specific lysyl residue on one of the subunits of these multienzyme complexes. In Escherichia coli and many other organisms, this biosynthetic pathway involves two dedicated proteins: octanoyltransferase (LipB) and lipoyl synthase (LipA). LipB transfers an n-octanoyl chain from the octanoyl-acyl carrier protein to the target lysyl residue, and then, LipA attaches two sulfur atoms (one at C6 and one at C8) to give the final lipoyl cofactor. All classical lipoyl synthases (LSs) are radical S-adenosylmethionine (SAM) enzymes, which use an [Fe4S4] cluster to reductively cleave SAM to generate a 5'-deoxyadenosyl 5'-radical. Classical LSs also contain a second [Fe4S4] cluster that serves as the source of both appended sulfur atoms. Recently, a novel pathway for generating the lipoyl cofactor was reported. This pathway replaces the canonical LS with two proteins, LipS1 and LipS2, which act together to catalyze formation of the lipoyl cofactor. In this work, we further characterize LipS1 and LipS2 biochemically and spectroscopically. Although LipS1 and LipS2 were previously annotated as biotin synthases, we show that both proteins, unlike E. coli biotin synthase, contain two [Fe4S4] clusters. We identify the cluster ligands to both iron-sulfur clusters in both proteins and show that LipS2 acts only on an octanoyl-containing substrate, while LipS1 acts only on an 8-mercaptooctanoyl-containing substrate. Therefore, similarly to E. coli biotin synthase and in contrast to E. coli LipA, sulfur attachment takes place initially at the terminal carbon (C8) and then at the C6 methylene carbon.
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Affiliation(s)
- Syam Sundar Neti
- Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Debangsu Sil
- Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Douglas M. Warui
- Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Olga A. Esakova
- Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Amy E. Solinski
- Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Dante A. Serrano
- Department
of Biochemistry and Molecular Biology, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Carsten Krebs
- Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department
of Biochemistry and Molecular Biology, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Squire J. Booker
- Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department
of Biochemistry and Molecular Biology, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Howard
Hughes
Medical Institute, The Pennsylvania State
University, University
Park, Pennsylvania 16802, United States
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5
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Bigness A, Vaddypally S, Zdilla MJ, Mendoza-Cortes JL. Ubiquity of cubanes in bioinorganic relevant compounds. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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6
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McLean JT, Benny A, Nolan MD, Swinand G, Scanlan EM. Cysteinyl radicals in chemical synthesis and in nature. Chem Soc Rev 2021; 50:10857-10894. [PMID: 34397045 DOI: 10.1039/d1cs00254f] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nature harnesses the unique properties of cysteinyl radical intermediates for a diverse range of essential biological transformations including DNA biosynthesis and repair, metabolism, and biological photochemistry. In parallel, the synthetic accessibility and redox chemistry of cysteinyl radicals renders them versatile reactive intermediates for use in a vast array of synthetic applications such as lipidation, glycosylation and fluorescent labelling of proteins, peptide macrocyclization and stapling, desulfurisation of peptides and proteins, and development of novel therapeutics. This review provides the reader with an overview of the role of cysteinyl radical intermediates in both chemical synthesis and biological systems, with a critical focus on mechanistic details. Direct insights from biological systems, where applied to chemical synthesis, are highlighted and potential avenues from nature which are yet to be explored synthetically are presented.
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Affiliation(s)
- Joshua T McLean
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
| | - Alby Benny
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
| | - Mark D Nolan
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
| | - Glenna Swinand
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
| | - Eoin M Scanlan
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
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7
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Esakova OA, Grove TL, Yennawar NH, Arcinas AJ, Wang B, Krebs C, Almo SC, Booker SJ. Structural basis for tRNA methylthiolation by the radical SAM enzyme MiaB. Nature 2021; 597:566-570. [PMID: 34526715 PMCID: PMC9107155 DOI: 10.1038/s41586-021-03904-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 08/12/2021] [Indexed: 02/08/2023]
Abstract
Numerous post-transcriptional modifications of transfer RNAs have vital roles in translation. The 2-methylthio-N6-isopentenyladenosine (ms2i6A) modification occurs at position 37 (A37) in transfer RNAs that contain adenine in position 36 of the anticodon, and serves to promote efficient A:U codon-anticodon base-pairing and to prevent unintended base pairing by near cognates, thus enhancing translational fidelity1-4. The ms2i6A modification is installed onto isopentenyladenosine (i6A) by MiaB, a radical S-adenosylmethionine (SAM) methylthiotransferase. As a radical SAM protein, MiaB contains one [Fe4S4]RS cluster used in the reductive cleavage of SAM to form a 5'-deoxyadenosyl 5'-radical, which is responsible for removing the C2 hydrogen of the substrate5. MiaB also contains an auxiliary [Fe4S4]aux cluster, which has been implicated6-9 in sulfur transfer to C2 of i6A37. How this transfer takes place is largely unknown. Here we present several structures of MiaB from Bacteroides uniformis. These structures are consistent with a two-step mechanism, in which one molecule of SAM is first used to methylate a bridging µ-sulfido ion of the auxiliary cluster. In the second step, a second SAM molecule is cleaved to a 5'-deoxyadenosyl 5'-radical, which abstracts the C2 hydrogen of the substrate but only after C2 has undergone rehybridization from sp2 to sp3. This work advances our understanding of how enzymes functionalize inert C-H bonds with sulfur.
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Affiliation(s)
- Olga A. Esakova
- The Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Tyler L. Grove
- The Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York
| | - Neela H. Yennawar
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Arthur J. Arcinas
- The Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA,Present address: AGC Biologics, Seattle, WA
| | - Bo Wang
- The Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Carsten Krebs
- The Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA,The Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Steven C. Almo
- The Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York
| | - Squire J. Booker
- The Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA,The Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA,Howard Hughes Medical Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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8
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Biochemical Approaches to Probe the Role of the Auxiliary Iron-Sulfur Cluster of Lipoyl Synthase from Mycobacterium Tuberculosis. Methods Mol Biol 2021. [PMID: 34292556 DOI: 10.1007/978-1-0716-1605-5_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Lipoic acid is an essential sulfur-containing cofactor used by several multienzyme complexes involved in energy metabolism and the breakdown of certain amino acids. It is composed of n-octanoic acid with sulfur atoms appended at C6 and C8. Lipoic acid is biosynthesized de novo in its cofactor form, in which it is covalently bound in an amide linkage to a target lysyl residue on a lipoyl carrier protein (LCP). The n-octanoyl moiety of the cofactor is derived from type 2 fatty acid biosynthesis and is transferred to an LCP to afford an octanoyllysyl amino acid. Next, lipoyl synthase (LipA in bacteria) catalyzes the attachment of the two sulfur atoms to afford the intact cofactor. LipA is a radical S-adenosylmethionine (SAM) enzyme that contains two [4Fe-4S] clusters. One [4Fe-4S] cluster is used to facilitate a reductive cleavage of SAM to render the highly oxidizing 5'-deoxyadenosyl 5'-radical needed to abstract C6 and C8 hydrogen atoms to allow for sulfur attachment. By contrast, the second cluster is the sulfur source, necessitating its destruction during turnover. In Escherichia coli, this auxiliary cluster can be restored after each turnover by NfuA or IscU, which are two iron-sulfur cluster carrier proteins that are implicated in iron-sulfur cluster biogenesis. In this chapter, we describe methods for purifying and characterizing LipA and NfuA from Mycobacterium tuberculosis, a human pathogen for which endogenously synthesized lipoic acid is essential. These studies provide the foundation for assessing lipoic acid biosynthesis as a potential target for the design of novel antituberculosis agents.
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Benjdia A, Berteau O. Radical SAM Enzymes and Ribosomally-Synthesized and Post-translationally Modified Peptides: A Growing Importance in the Microbiomes. Front Chem 2021; 9:678068. [PMID: 34350157 PMCID: PMC8326336 DOI: 10.3389/fchem.2021.678068] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/07/2021] [Indexed: 11/13/2022] Open
Abstract
To face the current antibiotic resistance crisis, novel strategies are urgently required. Indeed, in the last 30 years, despite considerable efforts involving notably high-throughput screening and combinatorial libraries, only few antibiotics have been launched to the market. Natural products have markedly contributed to the discovery of novel antibiotics, chemistry and drug leads, with more than half anti-infective and anticancer drugs approved by the FDA being of natural origin or inspired by natural products. Among them, thanks to their modular structure and simple biosynthetic logic, ribosomally synthesized and posttranslationally modified peptides (RiPPs) are promising scaffolds. In addition, recent studies have highlighted the pivotal role of RiPPs in the human microbiota which remains an untapped source of natural products. In this review, we report on recent developments in radical SAM enzymology and how these unique biocatalysts have been shown to install complex and sometimes unprecedented posttranslational modifications in RiPPs with a special focus on microbiome derived enzymes.
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Affiliation(s)
- Alhosna Benjdia
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | - Olivier Berteau
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
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10
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Shetty S, Varshney U. Regulation of translation by one-carbon metabolism in bacteria and eukaryotic organelles. J Biol Chem 2021; 296:100088. [PMID: 33199376 PMCID: PMC7949028 DOI: 10.1074/jbc.rev120.011985] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 11/15/2020] [Accepted: 11/16/2020] [Indexed: 12/20/2022] Open
Abstract
Protein synthesis is an energetically costly cellular activity. It is therefore important that the process of mRNA translation remains in excellent synchrony with cellular metabolism and its energy reserves. Unregulated translation could lead to the production of incomplete, mistranslated, or misfolded proteins, squandering the energy needed for cellular sustenance and causing cytotoxicity. One-carbon metabolism (OCM), an integral part of cellular intermediary metabolism, produces a number of one-carbon unit intermediates (formyl, methylene, methenyl, methyl). These OCM intermediates are required for the production of amino acids such as methionine and other biomolecules such as purines, thymidylate, and redox regulators. In this review, we discuss how OCM impacts the translation apparatus (composed of ribosome, tRNA, mRNA, and translation factors) and regulates crucial steps in protein synthesis. More specifically, we address how the OCM metabolites regulate the fidelity and rate of translation initiation in bacteria and eukaryotic organelles such as mitochondria. Modulation of the fidelity of translation initiation by OCM opens new avenues to understand alternative translation mechanisms involved in stress tolerance and drug resistance.
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Affiliation(s)
- Sunil Shetty
- Biozentrum, University of Basel, Basel, Switzerland
| | - Umesh Varshney
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India; Jawaharlal Nehru Centre for Advanced Scientific Studies, Jakkur, Bangalore, India.
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11
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Sivakumar R, Gunasekaran P, Rajendhran J. Functional characterization of asnC family transcriptional regulator in Pseudomonas aeruginosa PGPR2 during root colonization. Mol Biol Rep 2020; 47:7941-7957. [PMID: 33011891 DOI: 10.1007/s11033-020-05872-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 09/28/2020] [Indexed: 12/18/2022]
Abstract
Transcriptional regulators in bacteria are the crucial players in mediating communication between environmental cues and DNA transcription through a complex network process. Pseudomonas aeruginosa PGPR2 is an efficient root colonizer and a biocontrol strain. Previously, we identified that the transcriptional regulator, asnC, negatively regulates the corn root colonization of P. aeruginosa PGPR2. In a transposon insertion sequencing (INSeq) screen, the asnC insertion mutant was positively selected during root colonization, meaning the disruption of asnC improves the fitness of the P. aeruginosa PGPR2 strain for the root colonization. In this study, we constructed isogenic mutant of asnC family transcriptional regulator encoded by PGPR2_17510 by allele exchange mutagenesis. The ΔasnC mutant was able to efficiently colonize corn roots with a twofold increase in population when compared to the wild-type strain. Similarly, the mutant strain outcompeted the wild-type strain in a competition assay, where the mutant strain represented 90% of the total population recovered from the root. We compared the whole transcriptome of the wild-type and the ΔasnC mutant of P. aeruginosa PGPR2 when exposed to the corn root exudates. The RNA-Seq revealed that a total of 360 genes were differentially expressed in the ΔasnC strain of P. aeruginosa PGPR2. Inactivation of asnC transcriptional regulator resulted in the up-regulation of several genetic factors implicated in metabolism, uptake of nutrients, motility, stress response, and signal transduction, which could play crucial roles in root colonization. This notion was further validated by phenotypic characterization and quantification of transcription pattern of selected genes associated with metabolism, motility, and carbon catabolite repression between wild type and mutant strain, which was in agreement with transcriptome data. Similarly, ΔasnC strain formed increased biofilm on abiotic surface validating our RNA-seq analysis, where transcript levels of several genes associated with biofilm formation were up-regulated in the mutant strain. We report that the inactivation of an asnC family transcriptional regulator encoded by PGPR2_17510 enhances the root colonization and biofilm-forming ability of P. aeruginosa PGPR2. Together, our results provide evidence for the molecular adaptations that enable ΔasnC mutant strain to colonize on the corn roots and to form a biofilm.
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Affiliation(s)
- Ramamoorthy Sivakumar
- Department of Genetics, School of Biological Sciences, Madurai Kamaraj University, Madurai, 625 021, India
| | | | - Jeyaprakash Rajendhran
- Department of Genetics, School of Biological Sciences, Madurai Kamaraj University, Madurai, 625 021, India.
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12
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Kuang G, Tao W, Zheng S, Wang X, Wang D. Genome-Wide Identification, Evolution and Expression of the Complete Set of Cytoplasmic Ribosomal Protein Genes in Nile Tilapia. Int J Mol Sci 2020; 21:ijms21041230. [PMID: 32059409 PMCID: PMC7072992 DOI: 10.3390/ijms21041230] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 02/06/2020] [Accepted: 02/07/2020] [Indexed: 12/03/2022] Open
Abstract
Ribosomal proteins (RPs) are indispensable in ribosome biogenesis and protein synthesis, and play a crucial role in diverse developmental processes. In the present study, we carried out a comprehensive analysis of RPs in chordates and examined the expression profiles of the complete set of 92 cytoplasmic RP genes in Nile tilapia. The RP genes were randomly distributed throughout the tilapia genome. Phylogenetic and syntenic analyses revealed the existence of duplicated RP genes from 2R (RPL3, RPL7, RPL22 and RPS27) and 3R (RPL5, RPL19, RPL22, RPL41, RPLP2, RPS17, RPS19 and RPS27) in tilapia and even more from 4R in common carp and Atlantic salmon. The RP genes were found to be expressed in all tissues examined, but their expression levels differed among different tissues. Gonadal transcriptome analysis revealed that almost all RP genes were highly expressed, and their expression levels were highly variable between ovaries and testes at different developmental stages in tilapia. No sex- and stage-specific RP genes were found. Eleven RP genes displayed sexually dimorphic expression with nine higher in XY gonad and two higher in XX gonad at all stages examined, which were proved to be phenotypic sex dependent. Quantitative real-time PCR and immunohistochemistry ofRPL5b and RPL24 were performed to validate the transcriptome data. The genomic resources and expression data obtained in this study will contribute to a better understanding of RPs evolution and functions in chordates.
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13
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Chen F, Xue Y, Pan N, Bhatti MZ, Niu T, Chen J. New contribution to the morphology and molecular mechanism of Euplotes encysticus encystment. Sci Rep 2018; 8:12795. [PMID: 30143743 PMCID: PMC6109176 DOI: 10.1038/s41598-018-31160-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 08/13/2018] [Indexed: 11/30/2022] Open
Abstract
Ciliated protists are a large group of single-cell eukaryotes, leading to the resting cysts in unfavorable environmental condition. However, the underlying molecular mechanism of encystment in the free-living ciliates is poorly understood. Here we show that the resting cysts are better than the vegetative cells of Euplotes encysticus in adverse survivor with respect to energy metabolism. Therefore scale identification of encystment-related proteins in Euplotes encysticus was investigated by iTRAQ analysis. We analyzed a total of 130 proteins, in which 19 proteins involving 12 upregulated and 7 downregulated proteins were associated with encystment in the resting cysts in comparison with the vegetative cells. Moreover, direct fluorescent labeling analysis showed that the vegetative cells treated with shRNA-β-tubulin recombinant E. coli accumulated a large number of granular materials, and dramatic cell morphology changes. Importantly, the cell membrane rupture phenomenon was observed after three weeks of shRNA-β-tubulin interference as compared to the control group. These results revealed that different proteins might play an important role in the process of the vegetative cells into the resting cysts. These results will help to reveal the morphological changes and molecular mechanism of resting cyst formation of ciliates.
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Affiliation(s)
- Fenfen Chen
- School of Life Sciences, East China Normal University, Shanghai, 200241, P. R. China
| | - Yanyan Xue
- School of Life Sciences, East China Normal University, Shanghai, 200241, P. R. China
| | - Nan Pan
- School of Life Sciences, East China Normal University, Shanghai, 200241, P. R. China
| | - Muhammad Zeeshan Bhatti
- Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai, 200241, P. R. China
- Department of Molecular Medicine, National University of Medical Sciences, Rawalpindi, Pakistan
| | - Tao Niu
- School of Life Sciences, East China Normal University, Shanghai, 200241, P. R. China
| | - Jiwu Chen
- School of Life Sciences, East China Normal University, Shanghai, 200241, P. R. China.
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14
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Mao Z, Liou SH, Khadka N, Jenney FE, Goodin DB, Seefeldt LC, Adams MWW, Cramer SP, Larsen DS. Cluster-Dependent Charge-Transfer Dynamics in Iron-Sulfur Proteins. Biochemistry 2018; 57:978-990. [PMID: 29303562 DOI: 10.1021/acs.biochem.7b01159] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Photoinduced charge-transfer dynamics and the influence of cluster size on the dynamics were investigated using five iron-sulfur clusters: the 1Fe-4S cluster in Pyrococcus furiosus rubredoxin, the 2Fe-2S cluster in Pseudomonas putida putidaredoxin, the 4Fe-4S cluster in nitrogenase iron protein, and the 8Fe-7S P-cluster and the 7Fe-9S-1Mo FeMo cofactor in nitrogenase MoFe protein. Laser excitation promotes the iron-sulfur clusters to excited electronic states that relax to lower states. The electronic relaxation lifetimes of the 1Fe-4S, 8Fe-7S, and 7Fe-9S-1Mo clusters are on the picosecond time scale, although the dynamics of the MoFe protein is a mixture of the dynamics of the latter two clusters. The lifetimes of the 2Fe-2S and 4Fe-4S clusters, however, extend to several nanoseconds. A competition between reorganization energies and the density of electronic states (thus electronic coupling between states) mediates the charge-transfer lifetimes, with the 2Fe-2S cluster of Pdx and the 4Fe-4S cluster of Fe protein lying at the optimum leading to them having significantly longer lifetimes. Their long lifetimes make them the optimal candidates for long-range electron transfer and as external photosensitizers for other photoactivated chemical reactions like solar hydrogen production. Potential electron-transfer and hole-transfer pathways that possibly facilitate these charge transfers are proposed.
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Affiliation(s)
- Ziliang Mao
- Department of Chemistry, University of California at Davis , One Shields Avenue, Davis, California 95616, United States
| | - Shu-Hao Liou
- Department of Chemistry, University of California at Davis , One Shields Avenue, Davis, California 95616, United States
| | - Nimesh Khadka
- Department of Chemistry and Biochemistry, Utah State University , 0300 Old Main Hill, Logan, Utah 84322, United States
| | - Francis E Jenney
- Georgia Campus, Philadelphia College of Osteopathic Medicine , Suwanee, Georgia 30024, United States
| | - David B Goodin
- Department of Chemistry, University of California at Davis , One Shields Avenue, Davis, California 95616, United States
| | - Lance C Seefeldt
- Department of Chemistry and Biochemistry, Utah State University , 0300 Old Main Hill, Logan, Utah 84322, United States
| | - Michael W W Adams
- Department of Biochemistry, The University of Georgia , Athens, Georgia 30602, United States
| | - Stephen P Cramer
- Department of Chemistry, University of California at Davis , One Shields Avenue, Davis, California 95616, United States
| | - Delmar S Larsen
- Department of Chemistry, University of California at Davis , One Shields Avenue, Davis, California 95616, United States
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15
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Liu WQ, Amara P, Mouesca JM, Ji X, Renoux O, Martin L, Zhang C, Zhang Q, Nicolet Y. 1,2-Diol Dehydration by the Radical SAM Enzyme AprD4: A Matter of Proton Circulation and Substrate Flexibility. J Am Chem Soc 2018; 140:1365-1371. [DOI: 10.1021/jacs.7b10501] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Wan-Qiu Liu
- Department
of Chemistry, Fudan University, Shanghai 200433, China
| | | | | | - Xinjian Ji
- Department
of Chemistry, Fudan University, Shanghai 200433, China
| | | | | | - Chen Zhang
- Department
of Chemistry, Fudan University, Shanghai 200433, China
| | - Qi Zhang
- Department
of Chemistry, Fudan University, Shanghai 200433, China
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16
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Saha A, Das S, Moin M, Dutta M, Bakshi A, Madhav MS, Kirti PB. Genome-Wide Identification and Comprehensive Expression Profiling of Ribosomal Protein Small Subunit (RPS) Genes and their Comparative Analysis with the Large Subunit (RPL) Genes in Rice. FRONTIERS IN PLANT SCIENCE 2017; 8:1553. [PMID: 28966624 PMCID: PMC5605565 DOI: 10.3389/fpls.2017.01553] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 08/25/2017] [Indexed: 05/07/2023]
Abstract
Ribosomal proteins (RPs) are indispensable in ribosome biogenesis and protein synthesis, and play a crucial role in diverse developmental processes. Our previous studies on Ribosomal Protein Large subunit (RPL) genes provided insights into their stress responsive roles in rice. In the present study, we have explored the developmental and stress regulated expression patterns of Ribosomal Protein Small (RPS) subunit genes for their differential expression in a spatiotemporal and stress dependent manner. We have also performed an in silico analysis of gene structure, cis-elements in upstream regulatory regions, protein properties and phylogeny. Expression studies of the 34 RPS genes in 13 different tissues of rice covering major growth and developmental stages revealed that their expression was substantially elevated, mostly in shoots and leaves indicating their possible involvement in the development of vegetative organs. The majority of the RPS genes have manifested significant expression under all abiotic stress treatments with ABA, PEG, NaCl, and H2O2. Infection with important rice pathogens, Xanthomonas oryzae pv. oryzae (Xoo) and Rhizoctonia solani also induced the up-regulation of several of the RPS genes. RPS4, 13a, 18a, and 4a have shown higher transcript levels under all the abiotic stresses, whereas, RPS4 is up-regulated in both the biotic stress treatments. The information obtained from the present investigation would be useful in appreciating the possible stress-regulatory attributes of the genes coding for rice ribosomal small subunit proteins apart from their functions as house-keeping proteins. A detailed functional analysis of independent genes is required to study their roles in stress tolerance and generating stress- tolerant crops.
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Affiliation(s)
- Anusree Saha
- Department of Plant Sciences, University of HyderabadHyderabad, India
| | - Shubhajit Das
- Department of Plant Sciences, University of HyderabadHyderabad, India
| | - Mazahar Moin
- Department of Plant Sciences, University of HyderabadHyderabad, India
| | - Mouboni Dutta
- Department of Plant Sciences, University of HyderabadHyderabad, India
| | - Achala Bakshi
- Department of Plant Sciences, University of HyderabadHyderabad, India
| | - M. S. Madhav
- Department of Biotechnology, Indian Institute of Rice ResearchHyderabad, India
| | - P. B. Kirti
- Department of Plant Sciences, University of HyderabadHyderabad, India
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17
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Mulliez E, Duarte V, Arragain S, Fontecave M, Atta M. On the Role of Additional [4Fe-4S] Clusters with a Free Coordination Site in Radical-SAM Enzymes. Front Chem 2017; 5:17. [PMID: 28361051 PMCID: PMC5352715 DOI: 10.3389/fchem.2017.00017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 03/03/2017] [Indexed: 11/13/2022] Open
Abstract
The canonical CysXXXCysXXCys motif is the hallmark of the Radical-SAM superfamily. This motif is responsible for the ligation of a [4Fe-4S] cluster containing a free coordination site available for SAM binding. The five enzymes MoaA, TYW1, MiaB, RimO and LipA contain in addition a second [4Fe-4S] cluster itself bound to three other cysteines and thus also displaying a potentially free coordination site. This review article summarizes recent important achievements obtained on these five enzymes with the main focus to delineate the role of this additional [4Fe-4S] cluster in catalysis.
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Affiliation(s)
- Etienne Mulliez
- Biosciences and Biotechnology Institute of Grenoble, Laboratoire de Chimie et Biologie des Métaux, UMR 5249 CEA-Centre National de la Recherche Scientifique-UGA Grenoble, France
| | - Victor Duarte
- Biosciences and Biotechnology Institute of Grenoble, Laboratoire de Chimie et Biologie des Métaux, UMR 5249 CEA-Centre National de la Recherche Scientifique-UGA Grenoble, France
| | - Simon Arragain
- Laboratoire de Chimie des Processus Biologiques, UMR 8229, Collége de France-Centre National de la Recherche Scientifique-Université P. et M. Curie Paris, France
| | - Marc Fontecave
- Biosciences and Biotechnology Institute of Grenoble, Laboratoire de Chimie et Biologie des Métaux, UMR 5249 CEA-Centre National de la Recherche Scientifique-UGAGrenoble, France; Laboratoire de Chimie des Processus Biologiques, UMR 8229, Collége de France-Centre National de la Recherche Scientifique-Université P. et M. CurieParis, France
| | - Mohamed Atta
- Biosciences and Biotechnology Institute of Grenoble, Laboratoire de Chimie et Biologie des Métaux, UMR 5249 CEA-Centre National de la Recherche Scientifique-UGA Grenoble, France
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18
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Post-translational modification of ribosomally synthesized peptides by a radical SAM epimerase in Bacillus subtilis. Nat Chem 2017. [PMID: 28644475 DOI: 10.1038/nchem.2714] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ribosomally synthesized peptides are built out of L-amino acids, whereas D-amino acids are generally the hallmark of non-ribosomal synthetic processes. Here we show that the model bacterium Bacillus subtilis is able to produce a novel type of ribosomally synthesized and post-translationally modified peptide that contains D-amino acids, and which we propose to call epipeptides. We demonstrate that a two [4Fe-4S]-cluster radical S-adenosyl-L-methionine (SAM) enzyme converts L-amino acids into their D-counterparts by catalysing Cα-hydrogen-atom abstraction and using a critical cysteine residue as the hydrogen-atom donor. Unexpectedly, these D-amino acid residues proved to be essential for the activity of a peptide that induces the expression of LiaRS, a major component of the bacterial cell envelope stress-response system. Present in B. subtilis and in several members of the human microbiome, these epipeptides and radical SAM epimerases broaden the landscape of peptidyl structures accessible to living organisms.
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19
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Kathirvelu V, Perche-Letuvée P, Latour JM, Atta M, Forouhar F, Gambarelli S, Garcia-Serres R. Spectroscopic evidence for cofactor–substrate interaction in the radical-SAM enzyme TYW1. Dalton Trans 2017. [DOI: 10.1039/c7dt00736a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
EPR and Mössbauer spectroscpies provide evidence for interaction between SAM and pyruvate in the catalytic pocket of the iron-sulfur cluster enzyme TYW1.
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Affiliation(s)
| | | | | | - Mohamed Atta
- Univ. Grenoble Alpes
- BIG-LCBM
- F-38000 Grenoble
- France
- CEA
| | - Farhad Forouhar
- Department of Biological Sciences and Northeast Structural Genomics Consortium
- Columbia University
- New York
- USA
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20
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Molle T, Moreau Y, Clemancey M, Forouhar F, Ravanat JL, Duraffourg N, Fourmond V, Latour JM, Gambarelli S, Mulliez E, Atta M. Redox Behavior of the S-Adenosylmethionine (SAM)-Binding Fe-S Cluster in Methylthiotransferase RimO, toward Understanding Dual SAM Activity. Biochemistry 2016; 55:5798-5808. [PMID: 27677419 DOI: 10.1021/acs.biochem.6b00597] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
RimO, a radical-S-adenosylmethionine (SAM) enzyme, catalyzes the specific C3 methylthiolation of the D89 residue in the ribosomal S12 protein. Two intact iron-sulfur clusters and two SAM cofactors both are required for catalysis. By using electron paramagnetic resonance, Mössbauer spectroscopies, and site-directed mutagenesis, we show how two SAM molecules sequentially bind to the unique iron site of the radical-SAM cluster for two distinct chemical reactions in RimO. Our data establish that the two SAM molecules bind the radical-SAM cluster to the unique iron site, and spectroscopic evidence obtained under strongly reducing conditions supports a mechanism in which the first molecule of SAM causes the reoxidation of the reduced radical-SAM cluster, impeding reductive cleavage of SAM to occur and allowing SAM to methylate a HS- ligand bound to the additional cluster. Furthermore, by using density functional theory-based methods, we provide a description of the reaction mechanism that predicts the attack of the carbon radical substrate on the methylthio group attached to the additional [4Fe-4S] cluster.
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Affiliation(s)
- Thibaut Molle
- Laboratoire de Chimie et Biologie des Métaux, team "Biocatalyse", Biosciences & Biotechnology Institute of Grenoble (BIG), BIG/LCBM/Biocat, UMR 5249 CEA/CNRS/UGA, CEA/Grenoble, 17, rue des Martyrs, Grenoble, France
| | - Yohann Moreau
- Laboratoire de Chimie et Biologie des Métaux, team "MCT" Biosciences & Biotechnology Institute of Grenoble (BIG), BIG/LCBM/MCT, UMR 5249 CEA/CNRS/UGA, CEA/Grenoble, 17, rue des Martyrs, Grenoble, France
| | - Martin Clemancey
- Laboratoire de Chimie et Biologie des Métaux, team "PMB" Biosciences & Biotechnology Institute of Grenoble (BIG), BIG/LCBM/PMB, UMR 5249 CEA/CNRS/UGA, CEA/Grenoble, 17, rue des Martyrs, Grenoble, France
| | - Farhad Forouhar
- Department of Biological Sciences, Northeast Structural Genomics Consortium, Columbia University , New York, New York 10027, United States
| | - Jean-Luc Ravanat
- University Grenoble Alpes , INAC-SCIB, F-38000 Grenoble, France.,CEA , INAC-SyMMES, F-38000 Grenoble, France
| | - Nicolas Duraffourg
- Laboratoire de Chimie et Biologie des Métaux, team "Affond" Biosciences & Biotechnology Institute of Grenoble (BIG), BIG/LCBM/Affond, UMR 5249 CEA/CNRS/UGA, CEA/Grenoble, 17, rue des Martyrs, Grenoble, France
| | - Vincent Fourmond
- Aix-Marseille University , CNRS, BIP UMR 7281, 31 chemin J. Aiguier, 13402 Marseille Cedex 20, France
| | - Jean-Marc Latour
- Laboratoire de Chimie et Biologie des Métaux, team "PMB" Biosciences & Biotechnology Institute of Grenoble (BIG), BIG/LCBM/PMB, UMR 5249 CEA/CNRS/UGA, CEA/Grenoble, 17, rue des Martyrs, Grenoble, France
| | - Serge Gambarelli
- University Grenoble Alpes, INAC, SCIB/LRM , F-38000 Grenoble, France.,CEA, INAC, SCIB/LRM, F-38054 Grenoble, France
| | - Etienne Mulliez
- Laboratoire de Chimie et Biologie des Métaux, team "Biocatalyse", Biosciences & Biotechnology Institute of Grenoble (BIG), BIG/LCBM/Biocat, UMR 5249 CEA/CNRS/UGA, CEA/Grenoble, 17, rue des Martyrs, Grenoble, France
| | - Mohamed Atta
- Laboratoire de Chimie et Biologie des Métaux, team "Biocatalyse", Biosciences & Biotechnology Institute of Grenoble (BIG), BIG/LCBM/Biocat, UMR 5249 CEA/CNRS/UGA, CEA/Grenoble, 17, rue des Martyrs, Grenoble, France
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21
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Maiocco SJ, Arcinas AJ, Landgraf BJ, Lee KH, Booker SJ, Elliott SJ. Transformations of the FeS Clusters of the Methylthiotransferases MiaB and RimO, Detected by Direct Electrochemistry. Biochemistry 2016; 55:5531-5536. [PMID: 27598886 PMCID: PMC5461913 DOI: 10.1021/acs.biochem.6b00670] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The methylthiotransferases (MTTases) represent a subfamily of the S-adenosylmethionine (AdoMet) radical superfamily of enzymes that catalyze the attachment of a methylthioether (-SCH3) moiety on unactivated carbon centers. These enzymes contain two [4Fe-4S] clusters, one of which participates in the reductive fragmentation of AdoMet to generate a 5'-deoxyadenosyl 5'-radical and the other of which, termed the auxiliary cluster, is believed to play a central role in constructing the methylthio group and attaching it to the substrate. Because the redox properties of the bound cofactors within the AdoMet radical superfamily are so poorly understood, we have examined two MTTases in parallel, MiaB and RimO, using protein electrochemistry. We resolve the redox potentials of each [4Fe-4S] cluster, show that the auxiliary cluster has a potential higher than that of the AdoMet-binding cluster, and demonstrate that upon incubation of either enzyme with AdoMet, a unique low-potential state of the enzyme emerges. Our results are consistent with a mechanism whereby the auxiliary cluster is transiently methylated during substrate methylthiolation.
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Affiliation(s)
- Stephanie J Maiocco
- Department of Chemistry, Boston University , 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | | | | | | | | | - Sean J Elliott
- Department of Chemistry, Boston University , 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
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22
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Unanticipated coordination of tris buffer to the Radical SAM cluster of the RimO methylthiotransferase. J Biol Inorg Chem 2016; 21:549-57. [PMID: 27259294 DOI: 10.1007/s00775-016-1365-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 05/27/2016] [Indexed: 10/21/2022]
Abstract
Radical SAM enzymes generally contain a [4Fe-4S](2+/1+) (RS cluster) cluster bound to the protein via the three cysteines of a canonical motif CxxxCxxC. The non-cysteinyl iron is used to coordinate SAM via its amino-carboxylate moiety. The coordination-induced proximity between the cluster acting as an electron donor and the adenosyl-sulfonium bond of SAM allows for the homolytic cleavage of the latter leading to the formation of the reactive 5'-deoxyadenosyl radical used for substrate activation. Most of the structures of Radical SAM enzymes have been obtained in the presence of SAM, and therefore, little is known about the situation when SAM is not present. In this report, we show that RimO, a methylthiotransferase belonging to the radical SAM superfamily, binds a Tris molecule in the absence of SAM leading to specific spectroscopic signatures both in Mössbauer and pulsed EPR spectroscopies. These data provide a cautionary note for researchers who work with coordinative unsaturated iron sulfur clusters.
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23
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Abstract
Radical S-adenosylmethionine (SAM) enzymes catalyze an astonishing array of complex and chemically challenging reactions across all domains of life. Of approximately 114,000 of these enzymes, 8 are known to be present in humans: MOCS1, molybdenum cofactor biosynthesis; LIAS, lipoic acid biosynthesis; CDK5RAP1, 2-methylthio-N(6)-isopentenyladenosine biosynthesis; CDKAL1, methylthio-N(6)-threonylcarbamoyladenosine biosynthesis; TYW1, wybutosine biosynthesis; ELP3, 5-methoxycarbonylmethyl uridine; and RSAD1 and viperin, both of unknown function. Aberrations in the genes encoding these proteins result in a variety of diseases. In this review, we summarize the biochemical characterization of these 8 radical S-adenosylmethionine enzymes and, in the context of human health, describe the deleterious effects that result from such genetic mutations.
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Affiliation(s)
- Bradley J Landgraf
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Erin L McCarthy
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Squire J Booker
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802.,Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802.,The Howard Hughes Medical Institute, The Pennsylvania State University, University Park, Pennsylvania 16802;
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24
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Sirota FL, Maurer-Stroh S, Eisenhaber B, Eisenhaber F. Single-residue posttranslational modification sites at the N-terminus, C-terminus or in-between: To be or not to be exposed for enzyme access. Proteomics 2016; 15:2525-46. [PMID: 26038108 PMCID: PMC4745020 DOI: 10.1002/pmic.201400633] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 04/17/2015] [Accepted: 05/29/2015] [Indexed: 11/30/2022]
Abstract
Many protein posttranslational modifications (PTMs) are the result of an enzymatic reaction. The modifying enzyme has to recognize the substrate protein's sequence motif containing the residue(s) to be modified; thus, the enzyme's catalytic cleft engulfs these residue(s) and the respective sequence environment. This residue accessibility condition principally limits the range where enzymatic PTMs can occur in the protein sequence. Non‐globular, flexible, intrinsically disordered segments or large loops/accessible long side chains should be preferred whereas residues buried in the core of structures should be void of what we call canonical, enzyme‐generated PTMs. We investigate whether PTM sites annotated in UniProtKB (with MOD_RES/LIPID keys) are situated within sequence ranges that can be mapped to known 3D structures. We find that N‐ or C‐termini harbor essentially exclusively canonical PTMs. We also find that the overwhelming majority of all other PTMs are also canonical though, later in the protein's life cycle, the PTM sites can become buried due to complex formation. Among the remaining cases, some can be explained (i) with autocatalysis, (ii) with modification before folding or after temporary unfolding, or (iii) as products of interaction with small, diffusible reactants. Others require further research how these PTMs are mechanistically generated in vivo.
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Affiliation(s)
- Fernanda L Sirota
- Bioinformatics Institute (BII), Agency for Science and Technology (A*STAR), Matrix, Singapore
| | - Sebastian Maurer-Stroh
- Bioinformatics Institute (BII), Agency for Science and Technology (A*STAR), Matrix, Singapore.,School of Biological Sciences (SBS), Nanyang Technological University (NTU), Singapore
| | - Birgit Eisenhaber
- Bioinformatics Institute (BII), Agency for Science and Technology (A*STAR), Matrix, Singapore
| | - Frank Eisenhaber
- Bioinformatics Institute (BII), Agency for Science and Technology (A*STAR), Matrix, Singapore.,Department of Biological Sciences (DBS), National University of Singapore (NUS), Singapore.,School of Computer Engineering (SCE), Nanyang Technological University (NTU), Singapore
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25
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Landgraf BJ, Booker SJ. Stereochemical Course of the Reaction Catalyzed by RimO, a Radical SAM Methylthiotransferase. J Am Chem Soc 2016; 138:2889-92. [PMID: 26871608 DOI: 10.1021/jacs.5b11035] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
RimO is a member of the growing radical S-adenosylmethionine (SAM) superfamily of enzymes, which use a reduced [4Fe-4S] cluster to effect reductive cleavage of the 5' C-S bond of SAM to form a 5'-deoxyadenosyl 5'-radical (5'-dA(•)) intermediate. RimO uses this potent oxidant to catalyze the attachment of a methylthio group (-SCH3) to C3 of aspartate 89 of protein S12, one of 21 proteins that compose the 30S subunit of the bacterial ribosome. However, the exact mechanism by which this transformation takes place has remained elusive. Herein, we describe the stereochemical course of the RimO reaction. Using peptide mimics of the S12 protein bearing deuterium at the 3 pro-R or 3 pro-S positions of the target aspartyl residue, we show that RimO from Bacteroides thetaiotaomicron (Bt) catalyzes abstraction of the pro-S hydrogen atom, as evidenced by the transfer of deuterium into 5'-deoxyadenosine (5'-dAH). The observed kinetic isotope effect on H atom versus D atom abstraction is ∼1.9, suggesting that this step is at least partially rate determining. We also demonstrate that Bt RimO can utilize the flavodoxin/flavodoxin oxidoreductase/NADPH reducing system from Escherichia coli as a source of requisite electrons. Use of this in vivo reducing system decreases, but does not eliminate, formation of 5'-dAH in excess of methylthiolated product.
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Affiliation(s)
- Bradley J Landgraf
- Department of Chemistry, ‡Department of 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, ‡Department of Biochemistry and Molecular Biology, and §The Howard Hughes Medical Institute, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
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26
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Shibata N, Toraya T. Molecular architectures and functions of radical enzymes and their (re)activating proteins. J Biochem 2015; 158:271-92. [PMID: 26261050 DOI: 10.1093/jb/mvv078] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 07/22/2015] [Indexed: 02/07/2023] Open
Abstract
Certain proteins utilize the high reactivity of radicals for catalysing chemically challenging reactions. These proteins contain or form a radical and therefore named 'radical enzymes'. Radicals are introduced by enzymes themselves or by (re)activating proteins called (re)activases. The X-ray structures of radical enzymes and their (re)activases revealed some structural features of these molecular apparatuses which solved common enigmas of radical enzymes—i.e. how the enzymes form or introduce radicals at the active sites, how they use the high reactivity of radicals for catalysis, how they suppress undesired side reactions of highly reactive radicals and how they are (re)activated when inactivated by extinction of radicals. This review highlights molecular architectures of radical B12 enzymes, radical SAM enzymes, tyrosyl radical enzymes, glycyl radical enzymes and their (re)activating proteins that support their functions. For generalization, comparisons of the recently reported structures of radical enzymes with those of canonical radical enzymes are summarized here.
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Affiliation(s)
- Naoki Shibata
- Department of Life Science, Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan and
| | - Tetsuo Toraya
- Department of Bioscience and Biotechnology, Graduate School of Natural Science and Technology, Okayama University, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
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27
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Zhu W, Liu Y. Ring Contraction Catalyzed by the Metal-Dependent Radical SAM Enzyme: 7-Carboxy-7-deazaguanine Synthase from B. multivorans. Theoretical Insights into the Reaction Mechanism and the Influence of Metal Ions. ACS Catal 2015. [DOI: 10.1021/acscatal.5b00156] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Wenyou Zhu
- Key
Laboratory of Colloid and Interface Chemistry, Ministry of Education,
School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Yongjun Liu
- Key
Laboratory of Colloid and Interface Chemistry, Ministry of Education,
School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
- Key
Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau
Biology, Chinese Academy of Sciences, Xining, Qinghai 810001, China
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28
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Structures of lipoyl synthase reveal a compact active site for controlling sequential sulfur insertion reactions. Biochem J 2015; 464:123-33. [PMID: 25100160 DOI: 10.1042/bj20140895] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Lipoyl cofactors are essential for living organisms and are produced by the insertion of two sulfur atoms into the relatively unreactive C-H bonds of an octanoyl substrate. This reaction requires lipoyl synthase, a member of the radical S-adenosylmethionine (SAM) enzyme superfamily. In the present study, we solved crystal structures of lipoyl synthase with two [4Fe-4S] clusters bound at opposite ends of the TIM barrel, the usual fold of the radical SAM superfamily. The cluster required for reductive SAM cleavage conserves the features of the radical SAM superfamily, but the auxiliary cluster is bound by a CX4CX5C motif unique to lipoyl synthase. The fourth ligand to the auxiliary cluster is an extremely unusual serine residue. Site-directed mutants show this conserved serine ligand is essential for the sulfur insertion steps. One crystallized lipoyl synthase (LipA) complex contains 5'-methylthioadenosine (MTA), a breakdown product of SAM, bound in the likely SAM-binding site. Modelling has identified an 18 Å (1 Å=0.1 nm) deep channel, well-proportioned to accommodate an octanoyl substrate. These results suggest that the auxiliary cluster is the likely sulfur donor, but access to a sulfide ion for the second sulfur insertion reaction requires the loss of an iron atom from the auxiliary cluster, which the serine ligand may enable.
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29
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Lanz ND, Booker SJ. Auxiliary iron-sulfur cofactors in radical SAM enzymes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1316-34. [PMID: 25597998 DOI: 10.1016/j.bbamcr.2015.01.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 12/15/2014] [Accepted: 01/06/2015] [Indexed: 11/19/2022]
Abstract
A vast number of enzymes are now known to belong to a superfamily known as radical SAM, which all contain a [4Fe-4S] cluster ligated by three cysteine residues. The remaining, unligated, iron ion of the cluster binds in contact with the α-amino and α-carboxylate groups of S-adenosyl-l-methionine (SAM). This binding mode facilitates inner-sphere electron transfer from the reduced form of the cluster into the sulfur atom of SAM, resulting in a reductive cleavage of SAM to methionine and a 5'-deoxyadenosyl radical. The 5'-deoxyadenosyl radical then abstracts a target substrate hydrogen atom, initiating a wide variety of radical-based transformations. A subset of radical SAM enzymes contains one or more additional iron-sulfur clusters that are required for the reactions they catalyze. However, outside of a subset of sulfur insertion reactions, very little is known about the roles of these additional clusters. This review will highlight the most recent advances in the identification and characterization of radical SAM enzymes that harbor auxiliary iron-sulfur clusters. This article is part of a Special Issue entitled: Fe/S proteins: Analysis, structure, function, biogenesis and diseases.
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Affiliation(s)
- Nicholas D Lanz
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States
| | - Squire J Booker
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States; Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States.
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30
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Iron-sulfur proteins responsible for RNA modifications. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:1272-83. [PMID: 25533083 DOI: 10.1016/j.bbamcr.2014.12.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/08/2014] [Accepted: 12/09/2014] [Indexed: 12/22/2022]
Abstract
RNA molecules are decorated with various chemical modifications, which are introduced post-transcriptionally by RNA-modifying enzymes. These modifications are required for proper RNA function. Among more than 100 known species of RNA modifications, several modified bases in tRNAs and rRNAs are introduced by RNA-modifying enzymes containing iron-sulfur (Fe/S) clusters. Most Fe/S-containing RNA-modifying enzymes contain radical SAM domains that catalyze a variety of chemical reactions, including methylation, methylthiolation, carboxymethylation, tricyclic purine formation, and deazaguanine formation. Lack of these modifications can cause pathological consequences. Here, we review recent studies on the biogenesis and function of RNA modifications mediated by Fe/S proteins. This article is part of a Special Issue entitled: Fe/S proteins: Analysis, structure, function, biogenesis and diseases.
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31
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Wang J, Woldring RP, Román-Meléndez GD, McClain AM, Alzua BR, Marsh ENG. Recent advances in radical SAM enzymology: new structures and mechanisms. ACS Chem Biol 2014; 9:1929-38. [PMID: 25009947 PMCID: PMC4168785 DOI: 10.1021/cb5004674] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
![]()
The radical S-adenosylmethionine
(SAM) superfamily of enzymes catalyzes
an amazingly diverse variety of reactions ranging from simple hydrogen
abstraction to complicated multistep rearrangements and insertions.
The reactions they catalyze are important for a broad range of biological
functions, including cofactor and natural product biosynthesis, DNA
repair, and tRNA modification. Generally conserved features of the
radical SAM superfamily include a CX3CX2C motif
that binds an [Fe4S4] cluster essential for
the reductive cleavage of SAM. Here, we review recent advances in
our understanding of the structure and mechanisms of these enzymes
that, in some cases, have overturned widely accepted mechanisms.
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Affiliation(s)
- Jiarui Wang
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Rory P. Woldring
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | | | - Alan M. McClain
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Brian R. Alzua
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - E. Neil G. Marsh
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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32
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Lanz ND, Pandelia ME, Kakar ES, Lee KH, Krebs C, Booker SJ. Evidence for a catalytically and kinetically competent enzyme-substrate cross-linked intermediate in catalysis by lipoyl synthase. Biochemistry 2014; 53:4557-72. [PMID: 24901788 PMCID: PMC4216189 DOI: 10.1021/bi500432r] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lipoyl synthase (LS) catalyzes the final step in lipoyl cofactor biosynthesis: the insertion of two sulfur atoms at C6 and C8 of an (N(6)-octanoyl)-lysyl residue on a lipoyl carrier protein (LCP). LS is a member of the radical SAM superfamily, enzymes that use a [4Fe-4S] cluster to effect the reductive cleavage of S-adenosyl-l-methionine (SAM) to l-methionine and a 5'-deoxyadenosyl 5'-radical (5'-dA(•)). In the LS reaction, two equivalents of 5'-dA(•) are generated sequentially to abstract hydrogen atoms from C6 and C8 of the appended octanoyl group, initiating sulfur insertion at these positions. The second [4Fe-4S] cluster on LS, termed the auxiliary cluster, is proposed to be the source of the inserted sulfur atoms. Herein, we provide evidence for the formation of a covalent cross-link between LS and an LCP or synthetic peptide substrate in reactions in which insertion of the second sulfur atom is slowed significantly by deuterium substitution at C8 or by inclusion of limiting concentrations of SAM. The observation that the proteins elute simultaneously by anion-exchange chromatography but are separated by aerobic SDS-PAGE is consistent with their linkage through the auxiliary cluster that is sacrificed during turnover. Generation of the cross-linked species with a small, unlabeled (N(6)-octanoyl)-lysyl-containing peptide substrate allowed demonstration of both its chemical and kinetic competence, providing strong evidence that it is an intermediate in the LS reaction. Mössbauer spectroscopy of the cross-linked intermediate reveals that one of the [4Fe-4S] clusters, presumably the auxiliary cluster, is partially disassembled to a 3Fe-cluster with spectroscopic properties similar to those of reduced [3Fe-4S](0) clusters.
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Affiliation(s)
- Nicholas D Lanz
- Department of Biochemistry and Molecular Biology and ‡Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
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33
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Broderick JB, Duffus B, Duschene KS, Shepard EM. Radical S-adenosylmethionine enzymes. Chem Rev 2014; 114:4229-317. [PMID: 24476342 PMCID: PMC4002137 DOI: 10.1021/cr4004709] [Citation(s) in RCA: 584] [Impact Index Per Article: 58.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Indexed: 12/22/2022]
Affiliation(s)
- Joan B. Broderick
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Benjamin
R. Duffus
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Kaitlin S. Duschene
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Eric M. Shepard
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
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34
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Shisler KA, Broderick JB. Glycyl radical activating enzymes: structure, mechanism, and substrate interactions. Arch Biochem Biophys 2014; 546:64-71. [PMID: 24486374 PMCID: PMC4083501 DOI: 10.1016/j.abb.2014.01.020] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 01/20/2014] [Accepted: 01/21/2014] [Indexed: 11/20/2022]
Abstract
The glycyl radical enzyme activating enzymes (GRE-AEs) are a group of enzymes that belong to the radical S-adenosylmethionine (SAM) superfamily and utilize a [4Fe-4S] cluster and SAM to catalyze H-atom abstraction from their substrate proteins. GRE-AEs activate homodimeric proteins known as glycyl radical enzymes (GREs) through the production of a glycyl radical. After activation, these GREs catalyze diverse reactions through the production of their own substrate radicals. The GRE-AE pyruvate formate lyase activating enzyme (PFL-AE) is extensively characterized and has provided insights into the active site structure of radical SAM enzymes including GRE-AEs, illustrating the nature of the interactions with their corresponding substrate GREs and external electron donors. This review will highlight research on PFL-AE and will also discuss a few GREs and their respective activating enzymes.
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Affiliation(s)
- Krista A Shisler
- Department of Chemistry & Biochemistry and the Astrobiology Biogeocatalysis Research Center, Montana State University, Bozeman, MT 59717, United States
| | - Joan B Broderick
- Department of Chemistry & Biochemistry and the Astrobiology Biogeocatalysis Research Center, Montana State University, Bozeman, MT 59717, United States.
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35
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Landgraf BJ, Arcinas AJ, Lee KH, Booker SJ. Identification of an intermediate methyl carrier in the radical S-adenosylmethionine methylthiotransferases RimO and MiaB. J Am Chem Soc 2013; 135:15404-15416. [PMID: 23991893 PMCID: PMC4023531 DOI: 10.1021/ja4048448] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
RimO and MiaB are radical S-adenosylmethionine (SAM) enzymes that catalyze the attachment of methylthio (-SCH3) groups to macromolecular substrates. RimO attaches a methylthio group at C3 of aspartate 89 of protein S12, a component of the 30S subunit of the bacterial ribosome. MiaB attaches a methylthio group at C2 of N(6)-(isopentenyl)adenosine, found at nucleotide 37 in several prokaryotic tRNAs. These two enzymes are prototypical members of a subclass of radical SAM enzymes called methylthiotransferases (MTTases). It had been assumed that the sequence of steps in MTTase reactions involves initial sulfur insertion into the organic substrate followed by capping of the inserted sulfur atom with a SAM-derived methyl group. In this work, however, we show that both RimO and MiaB from Thermotoga maritima catalyze methyl transfer from SAM to an acid/base labile acceptor on the protein in the absence of their respective macromolecular substrates. Consistent with the assignment of the acceptor as an iron-sulfur cluster, denaturation of the SAM-treated protein with acid results in production of methanethiol. When RimO or MiaB is first incubated with SAM in the absence of substrate and reductant and then incubated with excess S-adenosyl-l-[methyl-d3]methionine in the presence of substrate and reductant, production of the unlabeled product precedes production of the deuterated product, showing that the methylated species is chemically and kinetically competent to be an intermediate.
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Affiliation(s)
- Bradley J. Landgraf
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, 16802, United States
| | - Arthur J. Arcinas
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, 16802, United States
| | - Kyung-Hoon Lee
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, 16802, United States
| | - Squire J. Booker
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, 16802, United States
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36
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Fujimori DG. Radical SAM-mediated methylation reactions. Curr Opin Chem Biol 2013; 17:597-604. [PMID: 23835516 DOI: 10.1016/j.cbpa.2013.05.032] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 05/28/2013] [Indexed: 10/26/2022]
Abstract
A subset of enzymes that belong to the radical S-adenosylmethionine (SAM) superfamily is able to catalyze methylation reactions. Substrates of these enzymes are distinct from the nucleophilic substrates that undergo methylation by a polar mechanism. Recently, activities of several radical SAM methylating enzymes have been reconstituted in vitro and their mechanisms of catalysis investigated. The RNA modifying enzymes RlmN and Cfr catalyze methylation via a methyl synthase mechanism. These enzymes use SAM in two distinct roles: as a source of a methyl group transferred to a conserved cysteine and as a source of 5'-deoxyadenosyl radical (5'-dA). Hydrogen atom abstraction by this species generates a thiomethylene radical which adds into the RNA substrate, forming an enzyme-substrate covalent adduct. In another recent study, methylation of the indole moiety of tryptophan by the radical SAM and cobalamin-binding domain enzyme TsrM has been reconstituted. Methylcobalamin serves as an intermediate methyl donor in TsrM, and is proposed to transfer the methyl group as a methyl radical. Interestingly, despite the presence of the radical SAM motif, no reductive cleavage of SAM has been observed in this methylation. These important reconstitutions set the stage for further studies on mechanisms of radical methylation.
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Affiliation(s)
- Danica Galonić Fujimori
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158-2280, USA.
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37
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Forouhar F, Arragain S, Atta M, Gambarelli S, Mouesca JM, Hussain M, Xiao R, Kieffer-Jaquinod S, Seetharaman J, Acton TB, Montelione GT, Mulliez E, Hunt JF, Fontecave M. Two Fe-S clusters catalyze sulfur insertion by radical-SAM methylthiotransferases. Nat Chem Biol 2013; 9:333-8. [PMID: 23542644 DOI: 10.1038/nchembio.1229] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 03/05/2013] [Indexed: 11/09/2022]
Abstract
How living organisms create carbon-sulfur bonds during the biosynthesis of critical sulfur-containing compounds is still poorly understood. The methylthiotransferases MiaB and RimO catalyze sulfur insertion into tRNAs and ribosomal protein S12, respectively. Both belong to a subgroup of radical-S-adenosylmethionine (radical-SAM) enzymes that bear two [4Fe-4S] clusters. One cluster binds S-adenosylmethionine and generates an Ado• radical via a well-established mechanism. However, the precise role of the second cluster is unclear. For some sulfur-inserting radical-SAM enzymes, this cluster has been proposed to act as a sacrificial source of sulfur for the reaction. In this paper, we report parallel enzymological, spectroscopic and crystallographic investigations of RimO and MiaB, which provide what is to our knowledge the first evidence that these enzymes are true catalysts and support a new sulfation mechanism involving activation of an exogenous sulfur cosubstrate at an exchangeable coordination site on the second cluster, which remains intact during the reaction.
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Affiliation(s)
- Farhad Forouhar
- Northeast Structural Genomics Consortium, New York, New York, USA
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38
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Strader MB, Hervey WJ, Costantino N, Fujigaki S, Chen CY, Akal-Strader A, Ihunnah CA, Makusky AJ, Court DL, Markey SP, Kowalak JA. A coordinated proteomic approach for identifying proteins that interact with the E. coli ribosomal protein S12. J Proteome Res 2013; 12:1289-99. [PMID: 23305560 DOI: 10.1021/pr3009435] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The bacterial ribosomal protein S12 contains a universally conserved D88 residue on a loop region thought to be critically involved in translation due to its proximal location to the A site of the 30S subunit. While D88 mutants are lethal this residue has been found to be post-translationally modified to β-methylthioaspartic acid, a post-translational modification (PTM) identified in S12 orthologs from several phylogenetically distinct bacteria. In a previous report focused on characterizing this PTM, our results provided evidence that this conserved loop region might be involved in forming multiple proteins-protein interactions ( Strader , M. B. ; Costantino , N. ; Elkins , C. A. ; Chen , C. Y. ; Patel , I. ; Makusky , A. J. ; Choy , J. S. ; Court , D. L. ; Markey , S. P. ; Kowalak , J. A. A proteomic and transcriptomic approach reveals new insight into betamethylthiolation of Escherichia coli ribosomal protein S12. Mol. Cell. Proteomics 2011 , 10 , M110 005199 ). To follow-up on this study, the D88 containing loop was probed to identify candidate binders employing a two-step complementary affinity purification strategy. The first involved an endogenously expressed S12 protein containing a C-terminal tag for capturing S12 binding partners. The second strategy utilized a synthetic biotinylated peptide representing the D88 conserved loop region for capturing S12 loop interaction partners. Captured proteins from both approaches were detected by utilizing SDS-PAGE and one-dimensional liquid chromatography-tandem mass spectrometry. The results presented in this report revealed proteins that form direct interactions with the 30S subunit and elucidated which are likely to interact with S12. In addition, we provide evidence that two proteins involved in regulating ribosome and/or mRNA transcript levels under stress conditions, RNase R and Hfq, form direct interactions with the S12 conserved loop, suggesting that it is likely part of a protein binding interface.
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Affiliation(s)
- Michael Brad Strader
- Laboratory of Neurotoxicology, National Institute of Mental Health , Bethesda, Maryland 20892, United States
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39
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Shisler KA, Broderick JB. Emerging themes in radical SAM chemistry. Curr Opin Struct Biol 2012; 22:701-10. [PMID: 23141873 DOI: 10.1016/j.sbi.2012.10.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 10/11/2012] [Accepted: 10/11/2012] [Indexed: 12/21/2022]
Abstract
Enzymes in the radical SAM (RS) superfamily catalyze a wide variety of reactions through unique radical chemistry. The characteristic markers of the superfamily include a [4Fe-4S] cluster coordinated to the protein via a cysteine triad motif, typically CX(3)CX(2)C, with the fourth iron coordinated by S-adenosylmethionine (SAM). The SAM serves as a precursor for a 5'-deoxyadenosyl radical, the central intermediate in nearly all RS enzymes studied to date. The SAM-bound [4Fe-4S] cluster is located within a partial or full triosephosphate isomerase (TIM) barrel where the radical chemistry occurs protected from the surroundings. In addition to the TIM barrel and a RS [4Fe-4S] cluster, many members of the superfamily contain additional domains and/or additional Fe-S clusters. Recently characterized superfamily members are providing new examples of the remarkable range of reactions that can be catalyzed, as well as new structural and mechanistic insights into these fascinating reactions.
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Affiliation(s)
- Krista A Shisler
- Department of Chemistry & Biochemistry and the Astrobiology Biogeocatalysis Research Center, Montana State University, Bozeman, MT 59717, United States
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40
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Dowling DP, Vey JL, Croft AK, Drennan CL. Structural diversity in the AdoMet radical enzyme superfamily. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1824:1178-95. [PMID: 22579873 PMCID: PMC3523193 DOI: 10.1016/j.bbapap.2012.04.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 04/04/2012] [Accepted: 04/19/2012] [Indexed: 11/18/2022]
Abstract
AdoMet radical enzymes are involved in processes such as cofactor biosynthesis, anaerobic metabolism, and natural product biosynthesis. These enzymes utilize the reductive cleavage of S-adenosylmethionine (AdoMet) to afford l-methionine and a transient 5'-deoxyadenosyl radical, which subsequently generates a substrate radical species. By harnessing radical reactivity, the AdoMet radical enzyme superfamily is responsible for an incredible diversity of chemical transformations. Structural analysis reveals that family members adopt a full or partial Triose-phosphate Isomerase Mutase (TIM) barrel protein fold, containing core motifs responsible for binding a catalytic [4Fe-4S] cluster and AdoMet. Here we evaluate over twenty structures of AdoMet radical enzymes and classify them into two categories: 'traditional' and 'ThiC-like' (named for the structure of 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate synthase (ThiC)). In light of new structural data, we reexamine the 'traditional' structural motifs responsible for binding the [4Fe-4S] cluster and AdoMet, and compare and contrast these motifs with the ThiC case. We also review how structural data combine with biochemical, spectroscopic, and computational data to help us understand key features of this enzyme superfamily, such as the energetics, the triggering, and the molecular mechanisms of AdoMet reductive cleavage. This article is part of a Special Issue entitled: Radical SAM Enzymes and Radical Enzymology.
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Affiliation(s)
- Daniel P. Dowling
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Jessica L. Vey
- Department of Chemistry and Biochemistry, California State University Northridge, Northridge, CA 91330-8262
| | - Anna K. Croft
- School of Chemistry, University of Wales Bangor, Bangor, Gwynedd LL57 2UW, UK
| | - Catherine L. Drennan
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- Departments of Chemistry and Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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41
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McCusker KP, Medzihradszky KF, Shiver AL, Nichols RJ, Yan F, Maltby DA, Gross CA, Fujimori DG. Covalent intermediate in the catalytic mechanism of the radical S-adenosyl-L-methionine methyl synthase RlmN trapped by mutagenesis. J Am Chem Soc 2012; 134:18074-81. [PMID: 23088750 PMCID: PMC3499099 DOI: 10.1021/ja307855d] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The posttranscriptional modification of ribosomal RNA (rRNA) modulates ribosomal function and confers resistance to antibiotics targeted to the ribosome. The radical S-adenosyl-L-methionine (SAM) methyl synthases, RlmN and Cfr, both methylate A2503 within the peptidyl transferase center of prokaryotic ribosomes, yielding 2-methyl- and 8-methyl-adenosine, respectively. The C2 and C8 positions of adenosine are unusual methylation substrates due to their electrophilicity. To accomplish this reaction, RlmN and Cfr use a shared radical-mediated mechanism. In addition to the radical SAM CX(3)CX(2)C motif, both RlmN and Cfr contain two conserved cysteine residues required for in vivo function, putatively to form (cysteine 355 in RlmN) and resolve (cysteine 118 in RlmN) a covalent intermediate needed to achieve this challenging transformation. Currently, there is no direct evidence for this proposed covalent intermediate. We have further investigated the roles of these conserved cysteines in the mechanism of RlmN. Cysteine 118 mutants of RlmN are unable to resolve the covalent intermediate, either in vivo or in vitro, enabling us to isolate and characterize this intermediate. Additionally, tandem mass spectrometric analyses of mutant RlmN reveal a methylene-linked adenosine modification at cysteine 355. Employing deuterium-labeled SAM and RNA substrates in vitro has allowed us to further clarify the mechanism of formation of this intermediate. Together, these experiments provide compelling evidence for the formation of a covalent intermediate species between RlmN and its rRNA substrate and well as the roles of the conserved cysteine residues in catalysis.
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Affiliation(s)
- Kevin P McCusker
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94158, USA
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Hutcheson RU, Broderick JB. Radical SAM enzymes in methylation and methylthiolation. Metallomics 2012; 4:1149-54. [PMID: 22992596 DOI: 10.1039/c2mt20136d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Radical S-adenosyl-l-methionine (SAM) enzymes are a large and diverse superfamily with functions ranging from enzyme activation through a single H atom abstraction to complex organic and metal cofactor synthesis involving a series of steps. Though these enzymes carry out a variety of functions, they share common structural and mechanistic characteristics. All of them contain a site-differentiated [4Fe-4S] cluster, ligated by a CX(3)CX(2)C or similar motif, which binds SAM at the unique iron. The [4Fe-4S](1+) state of the cluster reductively cleaves SAM to produce a 5'-deoxyadenosyl radical, which serves to initiate the diverse reactions catalyzed by these enzymes. Recent highlights in the understanding of radical SAM enzymes will be presented, with a particular emphasis on enzymes catalyzing methylation and methythiolation reactions.
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Affiliation(s)
- Rachel U Hutcheson
- Department of Chemistry and Biochemistry and the Astrobiology Biogeocatalysis Research Center, Montana State University, Bozeman, MT 59717, USA
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43
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Lanz ND, Booker SJ. Identification and function of auxiliary iron-sulfur clusters in radical SAM enzymes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:1196-212. [PMID: 22846545 DOI: 10.1016/j.bbapap.2012.07.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 07/16/2012] [Accepted: 07/17/2012] [Indexed: 11/27/2022]
Abstract
Radical SAM (RS) enzymes use a 5'-deoxyadenosyl 5'-radical generated from a reductive cleavage of S-adenosyl-l-methionine to catalyze over 40 distinct reaction types. A distinguishing feature of these enzymes is a [4Fe-4S] cluster to which each of three iron ions is ligated by three cysteinyl residues most often located in a Cx(3)Cx(2)C motif. The α-amino and α-carboxylate groups of SAM anchor the molecule to the remaining iron ion, which presumably facilitates its reductive cleavage. A subset of RS enzymes contains additional iron-sulfur clusters, - which we term auxiliary clusters - most of which have unidentified functions. Enzymes in this subset are involved in cofactor biosynthesis and maturation, post-transcriptional and post-translational modification, enzyme activation, and antibiotic biosynthesis. The additional clusters in these enzymes have been proposed to function in sulfur donation, electron transfer, and substrate anchoring. This review will highlight evidence supporting the presence of multiple iron-sulfur clusters in these enzymes as well as their predicted roles in catalysis. This article is part of a special issue entitled: Radical SAM enzymes and radical enzymology.
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Affiliation(s)
- Nicholas D Lanz
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
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44
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Zhang Q, Yu Y. Thioether crosslinkages created by a radical SAM enzyme. Chembiochem 2012; 13:1097-9. [PMID: 22556103 DOI: 10.1002/cbic.201200196] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Indexed: 11/11/2022]
Abstract
Unusually versatile: While the β-carbon thioether linkage in lantibiotics has long been appreciated and is relatively well characterized, a recent publication shows that the unusual sulfur-to-α-carbon thioether crosslinks in subtilosin A are produced by a radical SAM enzyme, AlbA, that contains two [4 Fe-4 S] clusters, thus highlighting the versatility of post-translational modifications in natural product biosynthesis.
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Affiliation(s)
- Qi Zhang
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education) and School of Pharmaceutical Sciences, Wuhan University, 185 East Lake Road, Wuhan 430071, PR China.
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Abstract
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Methylation is an essential and ubiquitous reaction that plays an important role in a wide range of biological processes. Most biological methylations use S-adenosylmethionine (SAM) as the methyl donor and proceed via an SN2 displacement mechanism. However, researchers have discovered an increasing number of methylations that involve radical chemistry. The enzymes known to catalyze these reactions all belong to the radical SAM superfamily. This family of enzymes utilizes a specialized [4Fe-4S] cluster for reductive cleavage of SAM to yield a highly reactive 5'-deoxyadenosyl (dAdo) radical. Radical chemistry is then imposed on a variety of organic substrates, leading to a diverse array of transformations. Until recently, researchers had not fully understood how these enzymes employ radical chemistry to mediate a methyl transfer reaction. Sequence analyses reveal that the currently identified radical SAM methyltransferases (RSMTs) can be grouped into three classes, which appear distinct in protein architecture and mechanism. Class A RSMTs mainly include the rRNA methyltransferases RlmN and Cfr from various origins. As exemplified by Escherichia coli RlmN, these proteins have a single canonical radical SAM core domain that includes an (βα)6 partial barrel most similar to that of pyruvate formate lyase-activase. The exciting recent studies on RlmN and Cfr are beginning to provide insights into the intriguing chemistry of class A RSMTs. These enzymes utilize a methylene radical generated on a unique methylated cysteine residue. However, based on the variety of substrates used by the other classes of RSMTs, alternative mechanisms are likely to be discovered. Class B RSMTs contain a proposed N-terminal cobalamin binding domain in addition to a radical SAM domain at the C-terminus. This class of proteins methylates diverse substrates at inert sp3 carbons, aromatic heterocycles, and phosphinates, possibly involving a cobalamin-mediated methyl transfer process. Class C RSMTs share significant sequence similarity with coproporphyrinogen III oxidase HemN. Despite methylating similar substrates (aromatic heterocycles), class C RSMTs likely employ a mechanism distinct from that of class A because two conserved cysteines that are required for class A are typically not found in class C RSMTs. Class A and class B enzymes probably share the use of two molecules of SAM: one to generate a dAdo radical and one to provide the methyl group to the substrate. In class A, a cysteine would act as a conduit of the methyl group whereas in class B cobalamin may serve this purpose. Currently no clues are available regarding the mechanism of class C RSMTs, but the sequence similarities between its members and HemN and the observation that HemN binds two SAM molecules suggest that class C enzymes could use two SAM molecules for catalysis. The diverse strategies for using two SAM molecules reflect the rich chemistry of radical-mediated methylation reactions and the remarkable versatility of the radical SAM superfamily.
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Affiliation(s)
- Qi Zhang
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | | | - Wen Liu
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
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Fislage M, Roovers M, Tuszynska I, Bujnicki JM, Droogmans L, Versées W. Crystal structures of the tRNA:m2G6 methyltransferase Trm14/TrmN from two domains of life. Nucleic Acids Res 2012; 40:5149-61. [PMID: 22362751 PMCID: PMC3367198 DOI: 10.1093/nar/gks163] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Methyltransferases (MTases) form a major class of tRNA-modifying enzymes needed for the proper functioning of tRNA. Recently, RNA MTases from the TrmN/Trm14 family that are present in Archaea, Bacteria and Eukaryota have been shown to specifically modify tRNAPhe at guanosine 6 in the tRNA acceptor stem. Here, we report the first X-ray crystal structures of the tRNA m2G6 (N2-methylguanosine) MTase TTCTrmN from Thermus thermophilus and its ortholog PfTrm14 from Pyrococcus furiosus. Structures of PfTrm14 were solved in complex with the methyl donor S-adenosyl-l-methionine (SAM or AdoMet), as well as the reaction product S-adenosyl-homocysteine (SAH or AdoHcy) and the inhibitor sinefungin. TTCTrmN and PfTrm14 consist of an N-terminal THUMP domain fused to a catalytic Rossmann-fold MTase (RFM) domain. These results represent the first crystallographic structure analysis of proteins containing both THUMP and RFM domain, and hence provide further insight in the contribution of the THUMP domain in tRNA recognition and catalysis. Electrostatics and conservation calculations suggest a main tRNA binding surface in a groove between the THUMP domain and the MTase domain. This is further supported by a docking model of TrmN in complex with tRNAPhe of T. thermophilus and via site-directed mutagenesis.
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Affiliation(s)
- Marcus Fislage
- VIB Department of Structural Biology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium
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47
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Atta M, Arragain S, Fontecave M, Mulliez E, Hunt JF, Luff JD, Forouhar F. The methylthiolation reaction mediated by the Radical-SAM enzymes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1824:1223-30. [PMID: 22178611 DOI: 10.1016/j.bbapap.2011.11.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 11/28/2011] [Indexed: 01/29/2023]
Abstract
Over the past 10 years, considerable progress has been made in our understanding of the mechanistic enzymology of the Radical-SAM enzymes. It is now clear that these enzymes appear to be involved in a remarkably wide range of chemically challenging reactions. This review article highlights mechanistic and structural aspects of the methylthiotransferases (MTTases) sub-class of the Radical-SAM enzymes. The mechanism of methylthio insertion, now observed to be performed by three different enzymes is an exciting unsolved problem. This article is part of a Special Issue entitled: Radical SAM enzymes and Radical Enzymology.
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Affiliation(s)
- Mohamed Atta
- Institut de Recherches en Technologie et Sciences pour le Vivant IRTSV-LCBM, UMR 5249 CEA/CNRS/UJF, CEA-Grenoble, 17 avenue des Martyrs, 38054, Grenoble Cedex 09, France.
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48
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Challand MR, Driesener RC, Roach PL. Radical S-adenosylmethionine enzymes: mechanism, control and function. Nat Prod Rep 2011; 28:1696-721. [PMID: 21779595 DOI: 10.1039/c1np00036e] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Martin R Challand
- School of Cellular and Molecular Medicine, Medical Sciences Building, University of Bristol, University Walk, Bristol BS81TD, USA
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49
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Vey JL, Drennan CL. Structural insights into radical generation by the radical SAM superfamily. Chem Rev 2011; 111:2487-506. [PMID: 21370834 PMCID: PMC5930932 DOI: 10.1021/cr9002616] [Citation(s) in RCA: 183] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jessica L Vey
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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50
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Nesterchuk M, Sergiev P, Dontsova O. Posttranslational Modifications of Ribosomal Proteins in Escherichia coli. Acta Naturae 2011; 3:22-33. [PMID: 22649682 PMCID: PMC3347575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
А number of ribosomal proteins inEscherichia coliundergo posttranslational modifications. Six ribosomal proteins are methylated (S11, L3, L11, L7/L12, L16, and L33), three proteins are acetylated (S5, S18, and L7), and protein S12 is methylthiolated. Extra amino acid residues are added to protein S6. С-terminal amino acid residues are partially removed from protein L31. The functional significance of these modifications has remained unclear. These modifications are not vital to the cells, and it is likely that they have regulatory functions. This paper reviews all the known posttranslational modifications of ribosomal proteins inEscherichia coli. Certain enzymes responsible for the modifications and mechanisms of enzymatic reactions are also discussed.
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Affiliation(s)
- M.V. Nesterchuk
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University
- Faculty of Chemistry, Lomonosov Moscow State University
| | - P.V. Sergiev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University
- Faculty of Chemistry, Lomonosov Moscow State University
| | - O.A. Dontsova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University
- Faculty of Chemistry, Lomonosov Moscow State University
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