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Han W, Wei D, Sun Z, Qu D. Investigating the mechanism of rough phenotype in a naturally attenuated Brucella strain: insights from whole genome sequencing. Front Med (Lausanne) 2024; 11:1363785. [PMID: 38711779 PMCID: PMC11073494 DOI: 10.3389/fmed.2024.1363785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Accepted: 02/23/2024] [Indexed: 05/08/2024] Open
Abstract
Objective Brucellosis, a significant zoonotic disease, not only impacts animal health but also profoundly influences the host immune responses through gut microbiome. Our research focuses on whole genome sequencing and comparative genomic analysis of these Brucella strains to understand the mechanisms of their virulence changes that may deepen our comprehension of the host immune dysregulation. Methods The Brucella melitensis strain CMCC55210 and its naturally attenuated variant CMCC55210a were used as models. Biochemical identification tests and in vivo experiments in mice verified the characteristics of the strain. To understand the mechanism of attenuation, we then performed de novo sequencing of these two strains. Results We discovered notable genomic differences between the two strains, with a key single nucleotide polymorphism (SNP) mutation in the manB gene potentially altering lipopolysaccharide (LPS) structure and influencing host immunity to the pathogen. This mutation might contribute to the attenuated strain's altered impact on the host's macrophage immune response, overing insights into the mechanisms of immune dysregulation linked to intracellular survival. Furthermore, we explore that manipulating the Type I restriction-modification system in Brucella can significantly impact its genome stability with the DNA damage response, consequently affecting the host's immune system. Conclusion This study not only contributes to understanding the complex relationship between pathogens, and the immune system but also opens avenues for innovative therapeutic interventions in inflammatory diseases driven by microbial and immune dysregulation.
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Affiliation(s)
- Wendong Han
- BSL-3 Laboratory of Fudan University, Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Dong Wei
- Division of Tuberculosis Vaccines and Allergen, National Institute for Food and Drug Control, Beijing, China
| | - Zhiping Sun
- BSL-3 Laboratory of Fudan University, Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Di Qu
- BSL-3 Laboratory of Fudan University, Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
- Shanghai Institute of Infectious Diseases and Biosecurity, Shanghai Medical College, Fudan University, Shanghai, China
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2
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Bommisetti P, Young A, Bandarian V. Elucidation of the substrate of tRNA-modifying enzymes MnmEG leads to in vitro reconstitution of an evolutionarily conserved uridine hypermodification. J Biol Chem 2022; 298:102548. [PMID: 36181794 PMCID: PMC9626948 DOI: 10.1016/j.jbc.2022.102548] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 12/02/2022] Open
Abstract
The evolutionarily conserved bacterial proteins MnmE and MnmG collectively install a carboxymethylaminomethyl (cmnm) group at the fifth position of wobble uridines of several tRNA species. While the reaction catalyzed by MnmEG is one of the central steps in the biosynthesis of the methylaminomethyl (mnm) posttranscriptional tRNA modification, details of the reaction remain elusive. Glycine is known to be the source of the carboxy methylamino moiety of cmnm, and a tetrahydrofolate (THF) analog is thought to supply the one carbon that is appended to the fifth position of U. However, the nature of the folate analog remains unknown. This article reports the in vitro biochemical reconstitution of the MnmEG reaction. Using isotopically labeled methyl and methylene THF analogs, we demonstrate that methylene THF is the true substrate. We also show that reduced FAD is required for the reaction and that DTT can replace the NADH in its role as a reductant. We discuss the implications of these methylene-THF and reductant requirements on the mechanism of this key tRNA modification catalyzed by MnmEG.
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Affiliation(s)
- Praneeth Bommisetti
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - Anthony Young
- Soliome Inc, 479 Jessie Street, San Francisco, CA 94103, United States
| | - Vahe Bandarian
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States.
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3
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Post-Transcriptional Modifications of Conserved Nucleotides in the T-Loop of tRNA: A Tale of Functional Convergent Evolution. Genes (Basel) 2021; 12:genes12020140. [PMID: 33499018 PMCID: PMC7912444 DOI: 10.3390/genes12020140] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/18/2021] [Accepted: 01/20/2021] [Indexed: 12/30/2022] Open
Abstract
The high conservation of nucleotides of the T-loop, including their chemical identity, are hallmarks of tRNAs from organisms belonging to the three Domains of Life. These structural characteristics allow the T-loop to adopt a peculiar intraloop conformation able to interact specifically with other conserved residues of the D-loop, which ultimately folds the mature tRNA in a unique functional canonical L-shaped architecture. Paradoxically, despite the high conservation of modified nucleotides in the T-loop, enzymes catalyzing their formation depend mostly on the considered organism, attesting for an independent but convergent evolution of the post-transcriptional modification processes. The driving force behind this is the preservation of a native conformation of the tRNA elbow that underlies the various interactions of tRNA molecules with different cellular components.
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4
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Nie S, Wang A, Yuan Y. Comparison of clinicopathological parameters, prognosis, micro-ecological environment and metabolic function of Gastric Cancer with or without Fusobacterium sp. Infection. J Cancer 2021; 12:1023-1032. [PMID: 33442401 PMCID: PMC7797643 DOI: 10.7150/jca.50918] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 11/16/2020] [Indexed: 12/11/2022] Open
Abstract
Background: Fusobacterium sp. plays a crucial role in the tumorigenesis and development of gastrointestinal tumors. Our research group previously disclosed that Fusobacterium sp. was more abundant in gastric cancer (GC) tissues than adjacent non-cancerous (NC) tissues. However, Fusobacterium sp. did not exist in all GC tissues and the differentiated features of GC with or without Fusobacterium sp. infection is not clear. Methods: The expression data of 61 GC tissues came from 16S rRNA gene sequencing. Comparison groups were defined based on sOTU at the genus level of Fusobacterium sp., which was performed by the Qiime2 microbiome bioinformatics platform. We used Chi-square and Fisher's exact test to compare clinicopathological parameters, and used Kaplan-Meier analysis, Cox univariate and multivariate analysis to compare prognosis. Micro-ecological environment comparison was characterized by 16S rRNA gene sequencing, and the metabolic function prediction was applied by PICRUSt2. Results of microbial diversity, differential enrichment genus and metabolic function in GC with or without Fusobacterium sp. infection was validated with 229 GC tissues downloaded from an independent cohort in ENA database (PRJNA428883). Results: The infection rate of Fusobacterium sp. in 61 GC tissues was 52.46% and elderly GC patients were more prone to Fusobacterium sp. infection. GC patients infected with Fusobacterium sp. were more likely to have tumor-infiltrating lymphocytes and p53 expression. The microbial diversity and microbial structure showed significant differences between two GC tissue groups with 42 differential enrichment genera. The metabolic function of Fusobacterium sp.-positive GC tissues was related to the biosynthesis of lysine, peptidoglycan, and tRNA. The differences in microbial structure, the existence of some differential enrichment genera and the metabolic function of Fusobacterium sp.-positive GC tissues, were then validated by 229 GC tissues of an independent cohort. Conclusions: Fusobacterium sp. infection can affect the phenotypic characteristics, micro-ecological environment, and metabolic functions of GC, which may provide a basis for further exploring the relationship between Fusobacterium sp. infection and carcinogenesis of GC.
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Affiliation(s)
- Siru Nie
- Tumor Etiology and Screening Department of Cancer Institute and General Surgery, The First Hospital of China Medical University, Shenyang 110001, China.,Key Laboratory of Cancer Etiology and Prevention in Liaoning Education Department, The First Hospital of China Medical University, Shenyang 110001, China.,Key Laboratory of GI Cancer Etiology and Prevention in Liaoning Province, The First Hospital of China Medical University, Shenyang 110001, China
| | - Ang Wang
- Tumor Etiology and Screening Department of Cancer Institute and General Surgery, The First Hospital of China Medical University, Shenyang 110001, China.,Key Laboratory of Cancer Etiology and Prevention in Liaoning Education Department, The First Hospital of China Medical University, Shenyang 110001, China.,Key Laboratory of GI Cancer Etiology and Prevention in Liaoning Province, The First Hospital of China Medical University, Shenyang 110001, China
| | - Yuan Yuan
- Tumor Etiology and Screening Department of Cancer Institute and General Surgery, The First Hospital of China Medical University, Shenyang 110001, China.,Key Laboratory of Cancer Etiology and Prevention in Liaoning Education Department, The First Hospital of China Medical University, Shenyang 110001, China.,Key Laboratory of GI Cancer Etiology and Prevention in Liaoning Province, The First Hospital of China Medical University, Shenyang 110001, China
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5
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Rose S, Auxilien S, Havelund JF, Kirpekar F, Huber H, Grosjean H, Douthwaite S. The hyperthermophilic partners Nanoarchaeum and Ignicoccus stabilize their tRNA T-loops via different but structurally equivalent modifications. Nucleic Acids Res 2020; 48:6906-6918. [PMID: 32459340 PMCID: PMC7337903 DOI: 10.1093/nar/gkaa411] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 04/19/2020] [Accepted: 05/06/2020] [Indexed: 01/31/2023] Open
Abstract
The universal L-shaped tertiary structure of tRNAs is maintained with the help of nucleotide modifications within the D- and T-loops, and these modifications are most extensive within hyperthermophilic species. The obligate-commensal Nanoarchaeum equitans and its phylogenetically-distinct host Ignicoccus hospitalis grow physically coupled under identical hyperthermic conditions. We report here two fundamentally different routes by which these archaea modify the key conserved nucleotide U54 within their tRNA T-loops. In N. equitans, this nucleotide is methylated by the S-adenosylmethionine-dependent enzyme NEQ053 to form m5U54, and a recombinant version of this enzyme maintains specificity for U54 in Escherichia coli. In N. equitans, m5U54 is subsequently thiolated to form m5s2U54. In contrast, I. hospitalis isomerizes U54 to pseudouridine prior to methylating its N1-position and thiolating the O4-position of the nucleobase to form the previously uncharacterized nucleotide m1s4Ψ. The methyl and thiol groups in m1s4Ψ and m5s2U are presented within the T-loop in a spatially identical manner that stabilizes the 3′-endo-anti conformation of nucleotide-54, facilitating stacking onto adjacent nucleotides and reverse-Hoogsteen pairing with nucleotide m1A58. Thus, two distinct structurally-equivalent solutions have evolved independently and convergently to maintain the tertiary fold of tRNAs under extreme hyperthermic conditions.
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Affiliation(s)
- Simon Rose
- Department of Biochemistry & Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Sylvie Auxilien
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Jesper F Havelund
- Department of Biochemistry & Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Finn Kirpekar
- Department of Biochemistry & Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Harald Huber
- Lehrstuhl für Mikrobiologie und Archaeenzentrum, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Henri Grosjean
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Stephen Douthwaite
- Department of Biochemistry & Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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6
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Sirand-Pugnet P, Brégeon D, Béven L, Goyenvalle C, Blanchard A, Rose S, Grosjean H, Douthwaite S, Hamdane D, de Crécy-Lagard V. Reductive Evolution and Diversification of C5-Uracil Methylation in the Nucleic Acids of Mollicutes. Biomolecules 2020; 10:E587. [PMID: 32290235 PMCID: PMC7226160 DOI: 10.3390/biom10040587] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/02/2020] [Accepted: 04/07/2020] [Indexed: 01/17/2023] Open
Abstract
The C5-methylation of uracil to form 5-methyluracil (m5U) is a ubiquitous base modification of nucleic acids. Four enzyme families have converged to catalyze this methylation using different chemical solutions. Here, we investigate the evolution of 5-methyluracil synthase families in Mollicutes, a class of bacteria that has undergone extensive genome erosion. Many mollicutes have lost some of the m5U methyltransferases present in their common ancestor. Cases of duplication and subsequent shift of function are also described. For example, most members of the Spiroplasma subgroup use the ancestral tetrahydrofolate-dependent TrmFO enzyme to catalyze the formation of m5U54 in tRNA, while a TrmFO paralog (termed RlmFO) is responsible for m5U1939 formation in 23S rRNA. RlmFO has replaced the S-adenosyl-L-methionine (SAM)-enzyme RlmD that adds the same modification in the ancestor and which is still present in mollicutes from the Hominis subgroup. Another paralog of this family, the TrmFO-like protein, has a yet unidentified function that differs from the TrmFO and RlmFO homologs. Despite having evolved towards minimal genomes, the mollicutes possess a repertoire of m5U-modifying enzymes that is highly dynamic and has undergone horizontal transfer.
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Affiliation(s)
- Pascal Sirand-Pugnet
- INRAE, UMR BFP, University Bordeaux, 33882 Bordeaux Villenave D’Ornon, France; (L.B.); (A.B.)
| | - Damien Brégeon
- IBPS, Biology of Aging and Adaptation, Sorbonne University, 7 quai Saint Bernard, CEDEX 05, F-75252 Paris, France; (D.B.); (C.G.)
| | - Laure Béven
- INRAE, UMR BFP, University Bordeaux, 33882 Bordeaux Villenave D’Ornon, France; (L.B.); (A.B.)
| | - Catherine Goyenvalle
- IBPS, Biology of Aging and Adaptation, Sorbonne University, 7 quai Saint Bernard, CEDEX 05, F-75252 Paris, France; (D.B.); (C.G.)
| | - Alain Blanchard
- INRAE, UMR BFP, University Bordeaux, 33882 Bordeaux Villenave D’Ornon, France; (L.B.); (A.B.)
| | - Simon Rose
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark; (S.R.); (S.D.)
| | - Henri Grosjean
- Institute for Integrative Biology of the Cell (I2BC), French Atomic Energy and Energy Commission Alternatives, CNRS, Paris-Sud University, Paris-Saclay University, Gif-sur-Yvette CEDEX, 91198 Paris, France;
| | - Stephen Douthwaite
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark; (S.R.); (S.D.)
| | - Djemel Hamdane
- Laboratory of Biological Process Chemistry, CNRS-UMR 8229, College De France, Sorbonne University, 11 Place Marcelin Berthelot, CEDEX 05, 75231 Paris, France
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
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7
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Myllykallio H, Sournia P, Heliou A, Liebl U. Unique Features and Anti-microbial Targeting of Folate- and Flavin-Dependent Methyltransferases Required for Accurate Maintenance of Genetic Information. Front Microbiol 2018; 9:918. [PMID: 29867829 PMCID: PMC5954106 DOI: 10.3389/fmicb.2018.00918] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/20/2018] [Indexed: 12/14/2022] Open
Abstract
Comparative genome analyses have led to the discovery and characterization of novel flavin- and folate-dependent methyltransferases that mainly function in DNA precursor synthesis and post-transcriptional RNA modification by forming (ribo) thymidylate and its derivatives. Here we discuss the recent literature on the novel mechanistic features of these enzymes sometimes referred to as “uracil methyltransferases,” albeit we prefer to refer to them as (ribo) thymidylate synthases. These enzyme families attest to the convergent evolution of nucleic acid methylation. Special focus is given to describing the unique characteristics of these flavin- and folate-dependent enzymes that have emerged as new models for studying the non-canonical roles of reduced flavin co-factors (FADH2) in relaying carbon atoms between enzyme substrates. This ancient enzymatic methylation mechanism with a very wide phylogenetic distribution may be more commonly used for biological methylation reactions than previously anticipated. This notion is exemplified by the recent discovery of additional substrates for these enzymes. Moreover, similar reaction mechanisms can be reversed by demethylases, which remove methyl groups e.g., from human histones. Future work is now required to address whether the use of different methyl donors facilitates the regulation of distinct methylation reactions in the cell. It will also be of great interest to address whether the low activity flavin-dependent thymidylate synthases ThyX represent ancestral enzymes that were eventually replaced by the more active thymidylate synthases of the ThyA family to facilitate the maintenance of larger genomes in fast-growing microbes. Moreover, we discuss the recent efforts from several laboratories to identify selective anti-microbial compounds that target flavin-dependent thymidylate synthase ThyX. Altogether we underline how the discovery of the alternative flavoproteins required for methylation of DNA and/or RNA nucleotides, in addition to providing novel targets for antibiotics, has provided new insight into microbial physiology and virulence.
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Affiliation(s)
- Hannu Myllykallio
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Palaiseau, France
| | - Pierre Sournia
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Palaiseau, France
| | - Alice Heliou
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Palaiseau, France.,Laboratoire d'Informatique de l'École Polytechnique, Ecole Polytechnique, Centre National de la Recherche Scientifique, Université Paris-Saclay, Palaiseau, France
| | - Ursula Liebl
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Palaiseau, France
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8
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Flavin-Dependent Methylation of RNAs: Complex Chemistry for a Simple Modification. J Mol Biol 2016; 428:4867-4881. [PMID: 27825927 DOI: 10.1016/j.jmb.2016.10.031] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 10/19/2016] [Accepted: 10/31/2016] [Indexed: 12/28/2022]
Abstract
RNA methylation is the most abundant and evolutionarily conserved chemical modification of bases or ribose in noncoding and coding RNAs. This rather simple modification has nevertheless major consequences on the function of maturated RNA molecules and ultimately on their cellular fates. The methyl group employed in the methylation is almost universally derived from S-adenosyl-L-methionine via a simple SN2 displacement reaction. However, in some rare cases, the carbon originates from N5,N10-methylenetetrahydrofolate (CH2=THF). Here, a methylene group is transferred first and requires a subsequent reduction step (2e-+H+) via the flavin adenine dinucleotide hydroquinone (FADH-) to form the final methylated derivative. This FAD/folate-dependent mode of chemical reaction, called reductive methylation, is thus far more complex than the usual simple S-adenosyl-L-methionine-dependent one. This reaction is catalyzed by flavoenzymes, now named TrmFO and RlmFO, which respectively modify transfer and ribosomal RNAs. In this review, we briefly recount how these new RNA methyltransferases were discovered and describe a novel aspect of the chemistry of flavins, wherein this versatile biological cofactor is not just a simple redox catalyst but is also a new methyl transfer agent acting via a critical CH2=(N5)FAD iminium intermediate. The enigmatic structural reorganization of these enzymes that needs to take place during catalysis in order to build their active center is also discussed. Finally, recent findings demonstrated that this flavin-dependent mechanism is also employed by enzymatic systems involved in DNA synthesis, suggesting that the use of this cofactor as a methylating agent of biomolecules could be far more usual than initially anticipated.
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9
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Abstract
tRNA molecules undergo extensive post-transcriptional processing to generate the mature functional tRNA species that are essential for translation in all organisms. These processing steps include the introduction of numerous specific chemical modifications to nucleotide bases and sugars; among these modifications, methylation reactions are by far the most abundant. The tRNA methyltransferases comprise a diverse enzyme superfamily, including members of multiple structural classes that appear to have arisen independently during evolution. Even among closely related family members, examples of unusual substrate specificity and chemistry have been observed. Here we review recent advances in tRNA methyltransferase mechanism and function with a particular emphasis on discoveries of alternative substrate specificities and chemistry associated with some methyltransferases. Although the molecular function for a specific tRNA methylation may not always be clear, mutations in tRNA methyltransferases have been increasingly associated with human disease. The impact of tRNA methylation on human biology is also discussed.
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Affiliation(s)
- William E Swinehart
- a Center for RNA Biology and Department of Chemistry and Biochemistry ; Ohio State University ; Columbus , OH USA
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10
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Lartigue C, Lebaudy A, Blanchard A, El Yacoubi B, Rose S, Grosjean H, Douthwaite S. The flavoprotein Mcap0476 (RlmFO) catalyzes m5U1939 modification in Mycoplasma capricolum 23S rRNA. Nucleic Acids Res 2014; 42:8073-82. [PMID: 24939895 PMCID: PMC4081110 DOI: 10.1093/nar/gku518] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/23/2014] [Accepted: 05/24/2014] [Indexed: 01/26/2023] Open
Abstract
Efficient protein synthesis in all organisms requires the post-transcriptional methylation of specific ribosomal ribonucleic acid (rRNA) and transfer RNA (tRNA) nucleotides. The methylation reactions are almost invariably catalyzed by enzymes that use S-adenosylmethionine (AdoMet) as the methyl group donor. One noteworthy exception is seen in some bacteria, where the conserved tRNA methylation at m5U54 is added by the enzyme TrmFO using flavin adenine dinucleotide together with N5,N10-methylenetetrahydrofolate as the one-carbon donor. The minimalist bacterium Mycoplasma capricolum possesses two homologs of trmFO, but surprisingly lacks the m5U54 tRNA modification. We created single and dual deletions of the trmFO homologs using a novel synthetic biology approach. Subsequent analysis of the M. capricolum RNAs by mass spectrometry shows that the TrmFO homolog encoded by Mcap0476 specifically modifies m5U1939 in 23S rRNA, a conserved methylation catalyzed by AdoMet-dependent enzymes in all other characterized bacteria. The Mcap0476 methyltransferase (renamed RlmFO) represents the first folate-dependent flavoprotein seen to modify ribosomal RNA.
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Affiliation(s)
- Carole Lartigue
- INRA, UMR 1332 de Biologie du Fruit et Pathologie, F-33140 Villenave d'Ornon, France Université de Bordeaux, UMR 1332 de Biologie du Fruit et Pathologie, F-33140 Villenave d'Ornon, France
| | - Anne Lebaudy
- INRA, UMR 1332 de Biologie du Fruit et Pathologie, F-33140 Villenave d'Ornon, France Université de Bordeaux, UMR 1332 de Biologie du Fruit et Pathologie, F-33140 Villenave d'Ornon, France
| | - Alain Blanchard
- INRA, UMR 1332 de Biologie du Fruit et Pathologie, F-33140 Villenave d'Ornon, France Université de Bordeaux, UMR 1332 de Biologie du Fruit et Pathologie, F-33140 Villenave d'Ornon, France
| | - Basma El Yacoubi
- Department of Microbiology and Cell Science, University of Florida, FL 32611, USA
| | - Simon Rose
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Henri Grosjean
- Centre de Génétique Moléculaire, UPR3404, CNRS, Associée à l'Université Paris Sud 11, FRC 3115, F-91190 Gif-sur-Yvette, France
| | - Stephen Douthwaite
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
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11
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Yokobori SI, Kitamura A, Grosjean H, Bessho Y. Life without tRNAArg-adenosine deaminase TadA: evolutionary consequences of decoding the four CGN codons as arginine in Mycoplasmas and other Mollicutes. Nucleic Acids Res 2013; 41:6531-43. [PMID: 23658230 PMCID: PMC3711424 DOI: 10.1093/nar/gkt356] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
In most bacteria, two tRNAs decode the four arginine CGN codons. One tRNA harboring a wobble inosine (tRNA(Arg)ICG) reads the CGU, CGC and CGA codons, whereas a second tRNA harboring a wobble cytidine (tRNA(Arg)CCG) reads the remaining CGG codon. The reduced genomes of Mycoplasmas and other Mollicutes lack the gene encoding tRNA(Arg)CCG. This raises the question of how these organisms decode CGG codons. Examination of 36 Mollicute genomes for genes encoding tRNA(Arg) and the TadA enzyme, responsible for wobble inosine formation, suggested an evolutionary scenario where tadA gene mutations first occurred. This allowed the temporary accumulation of non-deaminated tRNA(Arg)ACG, capable of reading all CGN codons. This hypothesis was verified in Mycoplasma capricolum, which contains a small fraction of tRNA(Arg)ACG with a non-deaminated wobble adenosine. Subsets of Mollicutes continued to evolve by losing both the mutated tRNA(Arg)CCG and tadA, and then acquired a new tRNA(Arg)UCG. This permitted further tRNA(Arg)ACG mutations with tRNA(Arg)GCG or its disappearance, leaving a single tRNA(Arg)UCG to decode the four CGN codons. The key point of our model is that the A-to-I deamination activity had to be controlled before the loss of the tadA gene, allowing the stepwise evolution of Mollicutes toward an alternative decoding strategy.
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Affiliation(s)
- Shin-ichi Yokobori
- Laboratory of Extremophiles, Department of Applied Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
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El Yacoubi B, Bailly M, de Crécy-Lagard V. Biosynthesis and Function of Posttranscriptional Modifications of Transfer RNAs. Annu Rev Genet 2012; 46:69-95. [DOI: 10.1146/annurev-genet-110711-155641] [Citation(s) in RCA: 380] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Basma El Yacoubi
- Department of Microbiology and Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611-0700;
| | - Marc Bailly
- Department of Microbiology and Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611-0700;
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611-0700;
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Yamagami R, Yamashita K, Nishimasu H, Tomikawa C, Ochi A, Iwashita C, Hirata A, Ishitani R, Nureki O, Hori H. The tRNA recognition mechanism of folate/FAD-dependent tRNA methyltransferase (TrmFO). J Biol Chem 2012; 287:42480-94. [PMID: 23095745 DOI: 10.1074/jbc.m112.390112] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The conserved U54 in tRNA is often modified to 5-methyluridine (m(5)U) and forms a reverse Hoogsteen base pair with A58 that stabilizes the L-shaped tRNA structure. In Gram-positive and some Gram-negative eubacteria, m(5)U54 is produced by folate/FAD-dependent tRNA (m(5)U54) methyltransferase (TrmFO). TrmFO utilizes N(5),N(10)-methylenetetrahydrofolate (CH(2)THF) as a methyl donor. We previously reported an in vitro TrmFO assay system, in which unstable [(14)C]CH(2)THF was supplied from [(14)C]serine and tetrahydrofolate by serine hydroxymethyltransferase. In the current study, we have improved the TrmFO assay system by optimization of enzyme and substrate concentrations and introduction of a filter assay system. Using this assay, we have focused on the tRNA recognition mechanism of TrmFO. 42 tRNA mutant variants were prepared, and experiments with truncated tRNA and microhelix RNAs revealed that the minimum requirement of TrmFO exists in the T-arm structure. The positive determinants for TrmFO were found to be the U54U55C56 sequence and G53-C61 base pair. The gel mobility shift assay and fluorescence quenching showed that the affinity of TrmFO for tRNA in the initial binding process is weak. The inhibition experiments showed that the methylated tRNA is released before the structural change process. Furthermore, we found that A38 prevents incorrect methylation of U32 in the anticodon loop. Moreover, the m(1)A58 modification clearly accelerates the TrmFO reaction, suggesting a synergistic effect of the m(5)U54, m(1)A58, and s(2)U54 modifications on m(5)s(2)U54 formation in Thermus thermophilus cells. The docking model of TrmFO and the T-arm showed that the G53-C61 base pair is not able to directly contact the enzyme.
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Affiliation(s)
- Ryota Yamagami
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, 3 Bunkyo, Matsuyama, Ehime 790-8577, Japan
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14
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Kitamura A, Nishimoto M, Sengoku T, Shibata R, Jäger G, Björk GR, Grosjean H, Yokoyama S, Bessho Y. Characterization and structure of the Aquifex aeolicus protein DUF752: a bacterial tRNA-methyltransferase (MnmC2) functioning without the usually fused oxidase domain (MnmC1). J Biol Chem 2012; 287:43950-60. [PMID: 23091054 PMCID: PMC3527978 DOI: 10.1074/jbc.m112.409300] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Post-transcriptional modifications of the wobble uridine (U34) of tRNAs play a critical role in reading NNA/G codons belonging to split codon boxes. In a subset of Escherichia coli tRNA, this wobble uridine is modified to 5-methylaminomethyluridine (mnm5U34) through sequential enzymatic reactions. Uridine 34 is first converted to 5-carboxymethylaminomethyluridine (cmnm5U34) by the MnmE-MnmG enzyme complex. The cmnm5U34 is further modified to mnm5U by the bifunctional MnmC protein. In the first reaction, the FAD-dependent oxidase domain (MnmC1) converts cmnm5U into 5-aminomethyluridine (nm5U34), and this reaction is immediately followed by the methylation of the free amino group into mnm5U34 by the S-adenosylmethionine-dependent domain (MnmC2). Aquifex aeolicus lacks a bifunctional MnmC protein fusion and instead encodes the Rossmann-fold protein DUF752, which is homologous to the methyltransferase MnmC2 domain of Escherichia coli MnmC (26% identity). Here, we determined the crystal structure of the A. aeolicus DUF752 protein at 2.5 Å resolution, which revealed that it catalyzes the S-adenosylmethionine-dependent methylation of nm5U in vitro, to form mnm5U34 in tRNA. We also showed that naturally occurring tRNA from A. aeolicus contains the 5-mnm group attached to the C5 atom of U34. Taken together, these results support the recent proposal of an alternative MnmC1-independent shortcut pathway for producing mnm5U34 in tRNAs.
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Affiliation(s)
- Aya Kitamura
- RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
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15
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Mishanina TV, Koehn EM, Kohen A. Mechanisms and inhibition of uracil methylating enzymes. Bioorg Chem 2012; 43:37-43. [PMID: 22172597 PMCID: PMC3315608 DOI: 10.1016/j.bioorg.2011.11.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 11/21/2011] [Accepted: 11/21/2011] [Indexed: 10/14/2022]
Abstract
Uracil methylation is essential for survival of organisms and passage of information from generation to generation with high fidelity. Two alternative uridyl methylation enzymes, flavin-dependent thymidylate synthase and folate/FAD-dependent RNA methyltransferase, have joined the long-known classical enzymes, thymidylate synthase and SAM-dependent RNA methyltransferase. These alternative enzymes differ significantly from their classical counterparts in structure, cofactor requirements and chemical mechanism. This review covers the available structural and mechanistic knowledge of the classical and alternative enzymes in biological uracil methylation, and offers a possibility of using inhibitors specifically aiming at microbial thymidylate production as antimicrobial drugs.
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Affiliation(s)
- Tatiana V. Mishanina
- Department of Chemistry, The University of Iowa, E274 Chemistry Building, Iowa City, IA 52245, USA
| | - Eric M. Koehn
- Department of Chemistry, The University of Iowa, E274 Chemistry Building, Iowa City, IA 52245, USA
| | - Amnon Kohen
- Department of Chemistry, The University of Iowa, E274 Chemistry Building, Iowa City, IA 52245, USA
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16
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Distinct co-evolution patterns of genes associated to DNA polymerase III DnaE and PolC. BMC Genomics 2012; 13:69. [PMID: 22333191 PMCID: PMC3814617 DOI: 10.1186/1471-2164-13-69] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 02/14/2012] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Bacterial genomes displaying a strong bias between the leading and the lagging strand of DNA replication encode two DNA polymerases III, DnaE and PolC, rather than a single one. Replication is a highly unsymmetrical process, and the presence of two polymerases is therefore not unexpected. Using comparative genomics, we explored whether other processes have evolved in parallel with each polymerase. RESULTS Extending previous in silico heuristics for the analysis of gene co-evolution, we analyzed the function of genes clustering with dnaE and polC. Clusters were highly informative. DnaE co-evolves with the ribosome, the transcription machinery, the core of intermediary metabolism enzymes. It is also connected to the energy-saving enzyme necessary for RNA degradation, polynucleotide phosphorylase. Most of the proteins of this co-evolving set belong to the persistent set in bacterial proteomes, that is fairly ubiquitously distributed. In contrast, PolC co-evolves with RNA degradation enzymes that are present only in the A+T-rich Firmicutes clade, suggesting at least two origins for the degradosome. CONCLUSION DNA replication involves two machineries, DnaE and PolC. DnaE co-evolves with the core functions of bacterial life. In contrast PolC co-evolves with a set of RNA degradation enzymes that does not derive from the degradosome identified in gamma-Proteobacteria. This suggests that at least two independent RNA degradation pathways existed in the progenote community at the end of the RNA genome world.
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17
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Desmolaize B, Fabret C, Brégeon D, Rose S, Grosjean H, Douthwaite S. A single methyltransferase YefA (RlmCD) catalyses both m5U747 and m5U1939 modifications in Bacillus subtilis 23S rRNA. Nucleic Acids Res 2011; 39:9368-75. [PMID: 21824914 PMCID: PMC3241648 DOI: 10.1093/nar/gkr626] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Methyltransferases that use S-adenosylmethionine (AdoMet) as a cofactor to catalyse 5-methyl uridine (m(5)U) formation in tRNAs and rRNAs are widespread in Bacteria and Eukaryota, and are also found in certain Archaea. These enzymes belong to the COG2265 cluster, and the Gram-negative bacterium Escherichia coli possesses three paralogues. These comprise the methyltransferases TrmA that targets U54 in tRNAs, RlmC that modifies U747 in 23S rRNA and RlmD that is specific for U1939 in 23S rRNA. The tRNAs and rRNAs of the Gram-positive bacterium Bacillus subtilis have the same three m(5)U modifications. However, as previously shown, the m(5)U54 modification in B. subtilis tRNAs is catalysed in a fundamentally different manner by the folate-dependent enzyme TrmFO, which is unrelated to the E. coli TrmA. Here, we show that methylation of U747 and U1939 in B. subtilis rRNA is catalysed by a single enzyme, YefA that is a COG2265 member. A recombinant version of YefA functions in an E. coli m(5)U-null mutant adding the same two rRNA methylations. The findings suggest that during evolution, COG2265 enzymes have undergone a series of changes in target specificity and that YefA is closer to an archetypical m(5)U methyltransferase. To reflect its dual specificity, YefA is renamed RlmCD.
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Affiliation(s)
- Benoit Desmolaize
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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18
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Auxilien S, Rasmussen A, Rose S, Brochier-Armanet C, Husson C, Fourmy D, Grosjean H, Douthwaite S. Specificity shifts in the rRNA and tRNA nucleotide targets of archaeal and bacterial m5U methyltransferases. RNA (NEW YORK, N.Y.) 2011; 17:45-53. [PMID: 21051506 PMCID: PMC3004065 DOI: 10.1261/rna.2323411] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Accepted: 09/29/2010] [Indexed: 05/27/2023]
Abstract
Methyltransferase enzymes that use S-adenosylmethionine as a cofactor to catalyze 5-methyl uridine (m(5)U) formation in tRNAs and rRNAs are widespread in Bacteria and Eukaryota, but are restricted to the Thermococcales and Nanoarchaeota groups amongst the Archaea. The RNA m(5)U methyltransferases appear to have arisen in Bacteria and were then dispersed by horizontal transfer of an rlmD-type gene to the Archaea and Eukaryota. The bacterium Escherichia coli has three gene paralogs and these encode the methyltransferases TrmA that targets m(5)U54 in tRNAs, RlmC (formerly RumB) that modifies m(5)U747 in 23S rRNA, and RlmD (formerly RumA) the archetypical enzyme that is specific for m(5)U1939 in 23S rRNA. The thermococcale archaeon Pyrococcus abyssi possesses two m(5)U methyltransferase paralogs, PAB0719 and PAB0760, with sequences most closely related to the bacterial RlmD. Surprisingly, however, neither of the two P. abyssi enzymes displays RlmD-like activity in vitro. PAB0719 acts in a TrmA-like manner to catalyze m(5)U54 methylation in P. abyssi tRNAs, and here we show that PAB0760 possesses RlmC-like activity and specifically methylates the nucleotide equivalent to U747 in P. abyssi 23S rRNA. The findings indicate that PAB0719 and PAB0760 originated as RlmD-type m(5)U methyltransferases and underwent changes in target specificity after their acquisition by a Thermococcales ancestor from a bacterial source.
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MESH Headings
- Archaea/enzymology
- Archaea/genetics
- Archaea/metabolism
- Methylation
- Methyltransferases/metabolism
- Pyrococcus abyssi/enzymology
- Pyrococcus abyssi/genetics
- Pyrococcus abyssi/metabolism
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Recombinant Proteins/genetics
- Recombinant Proteins/isolation & purification
- Recombinant Proteins/metabolism
- S-Adenosylmethionine/metabolism
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Substrate Specificity
- Uridine/metabolism
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Affiliation(s)
- Sylvie Auxilien
- Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, 91190 Gif-sur-Yvette, France
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19
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Hamdane D, Skouloubris S, Myllykallio H, Golinelli-Pimpaneau B. Expression and purification of untagged and histidine-tagged folate-dependent tRNA:m5U54 methyltransferase from Bacillus subtilis. Protein Expr Purif 2010; 73:83-9. [PMID: 20412857 DOI: 10.1016/j.pep.2010.04.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Revised: 04/15/2010] [Accepted: 04/16/2010] [Indexed: 11/30/2022]
Abstract
Folate-dependent tRNA m(5)U methyltransferase TrmFO is a flavoprotein that catalyzes the C(5)-methylation of uridine at position 54 in the TPsiC loop of tRNA in several bacteria. Here we report the cloning and optimization of expression in Escherichia coli BL21 (DE3) of untagged, N-terminus, C-terminus (His)(6)-tagged TrmFO from Bacillus subtilis. Tagged and untagged TrmFO were purified to homogeneity by metal affinity or ion exchange and heparin affinity, respectively, followed by size-exclusion chromatography. The tag did not significantly alter the expression level, flavin content, activity and secondary structure of the protein.
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Affiliation(s)
- Djemel Hamdane
- Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, 1 Avenue de la Terrasse, 91190 Gif-sur-Yvette, France
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20
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Moukadiri I, Prado S, Piera J, Velázquez-Campoy A, Björk GR, Armengod ME. Evolutionarily conserved proteins MnmE and GidA catalyze the formation of two methyluridine derivatives at tRNA wobble positions. Nucleic Acids Res 2010; 37:7177-93. [PMID: 19767610 PMCID: PMC2790889 DOI: 10.1093/nar/gkp762] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The wobble uridine of certain bacterial and mitochondrial tRNAs is modified, at position 5, through an unknown reaction pathway that utilizes the evolutionarily conserved MnmE and GidA proteins. The resulting modification (a methyluridine derivative) plays a critical role in decoding NNG/A codons and reading frame maintenance during mRNA translation. The lack of this tRNA modification produces a pleiotropic phenotype in bacteria and has been associated with mitochondrial encephalomyopathies in humans. In this work, we use in vitro and in vivo approaches to characterize the enzymatic pathway controlled by the Escherichia coli MnmE•GidA complex. Surprisingly, this complex catalyzes two different GTP- and FAD-dependent reactions, which produce 5-aminomethyluridine and 5-carboxymethylamino-methyluridine using ammonium and glycine, respectively, as substrates. In both reactions, methylene-tetrahydrofolate is the most probable source to form the C5-methylene moiety, whereas NADH is dispensable in vitro unless FAD levels are limiting. Our results allow us to reformulate the bacterial MnmE•GidA dependent pathway and propose a novel mechanism for the modification reactions performed by the MnmE and GidA family proteins.
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Affiliation(s)
- Ismaïl Moukadiri
- Laboratorio de Genética Molecular, Centro de Investigación Príncipe Felipe, 46012-Valencia, Spain
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21
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Atomic structure of a folate/FAD-dependent tRNA T54 methyltransferase. Proc Natl Acad Sci U S A 2009; 106:8180-5. [PMID: 19416846 DOI: 10.1073/pnas.0901330106] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
tRNAs from all 3 phylogenetic domains have a 5-methyluridine at position 54 (T54) in the T-loop. The methyl group is transferred from S-adenosylmethionine by TrmA methyltransferase in most Gram-negative bacteria and some archaea and eukaryotes, whereas it is transferred from 5,10-methylenetetrahydrofolate (MTHF) by TrmFO, a folate/FAD-dependent methyltransferase, in most Gram-positive bacteria and some Gram-negative bacteria. However, the catalytic mechanism remains unclear, because the crystal structure of TrmFO has not been solved. Here, we report the crystal structures of Thermus thermophilus TrmFO in its free form, tetrahydrofolate (THF)-bound form, and glutathione-bound form at 2.1-, 1.6-, and 1.05-A resolutions, respectively. TrmFO consists of an FAD-binding domain and an insertion domain, which both share structural similarity with those of GidA, an enzyme involved in the 5-carboxymethylaminomethylation of U34 of some tRNAs. However, the overall structures of TrmFO and GidA are basically different because of their distinct domain orientations, which are consistent with their respective functional specificities. In the THF complex, the pteridin ring of THF is sandwiched between the flavin ring of FAD and the imidazole ring of a His residue. This structure provides a snapshot of the folate/FAD-dependent methyl transfer, suggesting that the transferring methylene group of MTHF is located close to the redox-active N5 atom of FAD. Furthermore, we established an in vitro system to measure the methylation activity. Our TrmFO-tRNA docking model, in combination with mutational analyses, suggests a catalytic mechanism, in which the methylene of MTHF is directly transferred onto U54, and then the exocyclic methylene of U54 is reduced by FADH(2).
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22
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Chapter 1 A Phylogenetic View of Bacterial Ribonucleases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 85:1-41. [DOI: 10.1016/s0079-6603(08)00801-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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23
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Cicmil N. Crystallization and preliminary X-ray crystallographic characterization of TrmFO, a folate-dependent tRNA methyltransferase from Thermotoga maritima. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:193-5. [PMID: 18323606 DOI: 10.1107/s1744309108003825] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Accepted: 02/05/2008] [Indexed: 11/10/2022]
Abstract
TrmFO, previously classified as GID, is a methyltransferase that catalyzes the formation of 5-methyluridine or ribothymidine (T) at position 54 in tRNA in some Gram-positive bacteria. To date, TrmFO is the only characterized tRNA methyltransferase that does not use S-adenosylmethionine as the methyl-group donor. Instead, the donor of the methyl group is N(5),N(10)-methylenetetrahydrofolate. The crystallization and preliminary X-ray crystallographic studies of TrmFO are reported here. The recombinant protein, cloned from Thermotoga maritima genomic DNA, was overproduced in Esherichia coli and crystallized in 25%(v/v) PEG 4000, 100 mM NaCl and sodium citrate buffer pH 5.0 at 291 K using the hanging-drop vapor-diffusion method. The plate-shaped crystals diffracted to 2.6 A and belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 79.94, b = 92.46, c = 127.20 A.
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Affiliation(s)
- Nenad Cicmil
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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24
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Urbonavičius J, Auxilien S, Walbott H, Trachana K, Golinelli-Pimpaneau B, Brochier-Armanet C, Grosjean H. Acquisition of a bacterial RumA-type tRNA(uracil-54, C5)-methyltransferase by Archaea through an ancient horizontal gene transfer. Mol Microbiol 2007; 67:323-35. [DOI: 10.1111/j.1365-2958.2007.06047.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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