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Añazco-Guenkova AM, Miguel-López B, Monteagudo-García Ó, García-Vílchez R, Blanco S. The impact of tRNA modifications on translation in cancer: identifying novel therapeutic avenues. NAR Cancer 2024; 6:zcae012. [PMID: 38476632 PMCID: PMC10928989 DOI: 10.1093/narcan/zcae012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/16/2024] [Accepted: 02/29/2024] [Indexed: 03/14/2024] Open
Abstract
Recent advancements have illuminated the critical role of RNA modifications in post-transcriptional regulation, shaping the landscape of gene expression. This review explores how tRNA modifications emerge as critical players, fine-tuning functionalities that not only maintain the fidelity of protein synthesis but also dictate gene expression and translation profiles. Highlighting their dysregulation as a common denominator in various cancers, we systematically investigate the intersection of both cytosolic and mitochondrial tRNA modifications with cancer biology. These modifications impact key processes such as cell proliferation, tumorigenesis, migration, metastasis, bioenergetics and the modulation of the tumor immune microenvironment. The recurrence of altered tRNA modification patterns across different cancer types underscores their significance in cancer development, proposing them as potential biomarkers and as actionable targets to disrupt tumorigenic processes, offering new avenues for precision medicine in the battle against cancer.
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Affiliation(s)
- Ana M Añazco-Guenkova
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - University of Salamanca, 37007 Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, 37007 Salamanca, Spain
| | - Borja Miguel-López
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - University of Salamanca, 37007 Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, 37007 Salamanca, Spain
| | - Óscar Monteagudo-García
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - University of Salamanca, 37007 Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, 37007 Salamanca, Spain
| | - Raquel García-Vílchez
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - University of Salamanca, 37007 Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, 37007 Salamanca, Spain
| | - Sandra Blanco
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - University of Salamanca, 37007 Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, 37007 Salamanca, Spain
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Müller M, Legrand C, Tuorto F, Kelly VP, Atlasi Y, Lyko F, Ehrenhofer-Murray AE. Queuine links translational control in eukaryotes to a micronutrient from bacteria. Nucleic Acids Res 2019; 47:3711-3727. [PMID: 30715423 PMCID: PMC6468285 DOI: 10.1093/nar/gkz063] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/11/2019] [Accepted: 01/24/2019] [Indexed: 12/25/2022] Open
Abstract
In eukaryotes, the wobble position of tRNA with a GUN anticodon is modified to the 7-deaza-guanosine derivative queuosine (Q34), but the original source of Q is bacterial, since Q is synthesized by eubacteria and salvaged by eukaryotes for incorporation into tRNA. Q34 modification stimulates Dnmt2/Pmt1-dependent C38 methylation (m5C38) in the tRNAAsp anticodon loop in Schizosaccharomyces pombe. Here, we show by ribosome profiling in S. pombe that Q modification enhances the translational speed of the C-ending codons for aspartate (GAC) and histidine (CAC) and reduces that of U-ending codons for asparagine (AAU) and tyrosine (UAU), thus equilibrating the genome-wide translation of synonymous Q codons. Furthermore, Q prevents translation errors by suppressing second-position misreading of the glycine codon GGC, but not of wobble misreading. The absence of Q causes reduced translation of mRNAs involved in mitochondrial functions, and accordingly, lack of Q modification causes a mitochondrial defect in S. pombe. We also show that Q-dependent stimulation of Dnmt2 is conserved in mice. Our findings reveal a direct mechanism for the regulation of translational speed and fidelity in eukaryotes by a nutrient originating from bacteria.
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Affiliation(s)
- Martin Müller
- Institut für Biologie, Molekulare Zellbiologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Carine Legrand
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Francesca Tuorto
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Vincent P Kelly
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Trinity College Dublin, Dublin, Ireland
| | - Yaser Atlasi
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, Netherlands
| | - Frank Lyko
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Ann E Ehrenhofer-Murray
- Institut für Biologie, Molekulare Zellbiologie, Humboldt-Universität zu Berlin, Berlin, Germany
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3
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Hori H, Kawamura T, Awai T, Ochi A, Yamagami R, Tomikawa C, Hirata A. Transfer RNA Modification Enzymes from Thermophiles and Their Modified Nucleosides in tRNA. Microorganisms 2018; 6:E110. [PMID: 30347855 PMCID: PMC6313347 DOI: 10.3390/microorganisms6040110] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/17/2018] [Accepted: 10/17/2018] [Indexed: 12/11/2022] Open
Abstract
To date, numerous modified nucleosides in tRNA as well as tRNA modification enzymes have been identified not only in thermophiles but also in mesophiles. Because most modified nucleosides in tRNA from thermophiles are common to those in tRNA from mesophiles, they are considered to work essentially in steps of protein synthesis at high temperatures. At high temperatures, the structure of unmodified tRNA will be disrupted. Therefore, thermophiles must possess strategies to stabilize tRNA structures. To this end, several thermophile-specific modified nucleosides in tRNA have been identified. Other factors such as RNA-binding proteins and polyamines contribute to the stability of tRNA at high temperatures. Thermus thermophilus, which is an extreme-thermophilic eubacterium, can adapt its protein synthesis system in response to temperature changes via the network of modified nucleosides in tRNA and tRNA modification enzymes. Notably, tRNA modification enzymes from thermophiles are very stable. Therefore, they have been utilized for biochemical and structural studies. In the future, thermostable tRNA modification enzymes may be useful as biotechnology tools and may be utilized for medical science.
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Affiliation(s)
- Hiroyuki Hori
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Takuya Kawamura
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Takako Awai
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Anna Ochi
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Ryota Yamagami
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Chie Tomikawa
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Akira Hirata
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
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4
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Cross-Talk between Dnmt2-Dependent tRNA Methylation and Queuosine Modification. Biomolecules 2017; 7:biom7010014. [PMID: 28208632 PMCID: PMC5372726 DOI: 10.3390/biom7010014] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 02/02/2017] [Accepted: 02/02/2017] [Indexed: 12/22/2022] Open
Abstract
Enzymes of the Dnmt2 family of methyltransferases have yielded a number of unexpected discoveries. The first surprise came more than ten years ago when it was realized that, rather than being DNA methyltransferases, Dnmt2 enzymes actually are transfer RNA (tRNA) methyltransferases for cytosine-5 methylation, foremost C38 (m5C38) of tRNAAsp. The second unanticipated finding was our recent discovery of a nutritional regulation of Dnmt2 in the fission yeast Schizosaccharomyces pombe. Significantly, the presence of the nucleotide queuosine in tRNAAsp strongly stimulates Dnmt2 activity both in vivo and in vitro in S. pombe. Queuine, the respective base, is a hypermodified guanine analog that is synthesized from guanosine-5’-triphosphate (GTP) by bacteria. Interestingly, most eukaryotes have queuosine in their tRNA. However, they cannot synthesize it themselves, but rather salvage it from food or from gut microbes. The queuine obtained from these sources comes from the breakdown of tRNAs, where the queuine ultimately was synthesized by bacteria. Queuine thus has been termed a micronutrient. This review summarizes the current knowledge of Dnmt2 methylation and queuosine modification with respect to translation as well as the organismal consequences of the absence of these modifications. Models for the functional cooperation between these modifications and its wider implications are discussed.
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Kawamura T, Hirata A, Ohno S, Nomura Y, Nagano T, Nameki N, Yokogawa T, Hori H. Multisite-specific archaeosine tRNA-guanine transglycosylase (ArcTGT) from Thermoplasma acidophilum, a thermo-acidophilic archaeon. Nucleic Acids Res 2015; 44:1894-908. [PMID: 26721388 PMCID: PMC4770233 DOI: 10.1093/nar/gkv1522] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/20/2015] [Indexed: 12/17/2022] Open
Abstract
Archaeosine (G+), which is found only at position 15 in many archaeal tRNA, is formed by two steps, the replacement of the guanine base with preQ0 by archaeosine tRNA-guanine transglycosylase (ArcTGT) and the subsequent modification of preQ0 to G+ by archaeosine synthase. However, tRNALeu from Thermoplasma acidophilum, a thermo-acidophilic archaeon, exceptionally has two G+13 and G+15 modifications. In this study, we focused on the biosynthesis mechanism of G+13 and G+15 modifications in this tRNALeu. Purified ArcTGT from Pyrococcus horikoshii, for which the tRNA recognition mechanism and structure were previously characterized, exchanged only the G15 base in a tRNALeu transcript with 14C-guanine. In contrast, T. acidophilum cell extract exchanged both G13 and G15 bases. Because T. acidophilum ArcTGT could not be expressed as a soluble protein in Escherichia coli, we employed an expression system using another thermophilic archaeon, Thermococcus kodakarensis. The arcTGT gene in T. kodakarensis was disrupted, complemented with the T. acidophilum arcTGT gene, and tRNALeu variants were expressed. Mass spectrometry analysis of purified tRNALeu variants revealed the modifications of G+13 and G+15 in the wild-type tRNALeu. Thus, T. acidophilum ArcTGT has a multisite specificity and is responsible for the formation of both G+13 and G+15 modifications.
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Affiliation(s)
- Takuya Kawamura
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan
| | - Akira Hirata
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan
| | - Satoshi Ohno
- Department of Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu, Gifu 501-1193, Japan
| | - Yuichiro Nomura
- Department of Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu, Gifu 501-1193, Japan
| | - Tomoko Nagano
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan
| | - Nobukazu Nameki
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, Tenjin 1-5-1, Kiryu, Gunma 376-8515, Japan
| | - Takashi Yokogawa
- Department of Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu, Gifu 501-1193, Japan
| | - Hiroyuki Hori
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan
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Irla M, Neshat A, Brautaset T, Rückert C, Kalinowski J, Wendisch VF. Transcriptome analysis of thermophilic methylotrophic Bacillus methanolicus MGA3 using RNA-sequencing provides detailed insights into its previously uncharted transcriptional landscape. BMC Genomics 2015; 16:73. [PMID: 25758049 PMCID: PMC4342826 DOI: 10.1186/s12864-015-1239-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 01/12/2015] [Indexed: 01/27/2023] Open
Abstract
Background Bacillus methanolicus MGA3 is a thermophilic, facultative ribulose monophosphate (RuMP) cycle methylotroph. Together with its ability to produce high yields of amino acids, the relevance of this microorganism as a promising candidate for biotechnological applications is evident. The B. methanolicus MGA3 genome consists of a 3,337,035 nucleotides (nt) circular chromosome, the 19,174 nt plasmid pBM19 and the 68,999 nt plasmid pBM69. 3,218 protein-coding regions were annotated on the chromosome, 22 on pBM19 and 82 on pBM69. In the present study, the RNA-seq approach was used to comprehensively investigate the transcriptome of B. methanolicus MGA3 in order to improve the genome annotation, identify novel transcripts, analyze conserved sequence motifs involved in gene expression and reveal operon structures. For this aim, two different cDNA library preparation methods were applied: one which allows characterization of the whole transcriptome and another which includes enrichment of primary transcript 5′-ends. Results Analysis of the primary transcriptome data enabled the detection of 2,167 putative transcription start sites (TSSs) which were categorized into 1,642 TSSs located in the upstream region (5′-UTR) of known protein-coding genes and 525 TSSs of novel antisense, intragenic, or intergenic transcripts. Firstly, 14 wrongly annotated translation start sites (TLSs) were corrected based on primary transcriptome data. Further investigation of the identified 5′-UTRs resulted in the detailed characterization of their length distribution and the detection of 75 hitherto unknown cis-regulatory RNA elements. Moreover, the exact TSSs positions were utilized to define conserved sequence motifs for translation start sites, ribosome binding sites and promoters in B. methanolicus MGA3. Based on the whole transcriptome data set, novel transcripts, operon structures and mRNA abundances were determined. The analysis of the operon structures revealed that almost half of the genes are transcribed monocistronically (940), whereas 1,164 genes are organized in 381 operons. Several of the genes related to methylotrophy had highly abundant transcripts. Conclusion The extensive insights into the transcriptional landscape of B. methanolicus MGA3, gained in this study, represent a valuable foundation for further comparative quantitative transcriptome analyses and possibly also for the development of molecular biology tools which at present are very limited for this organism. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1239-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marta Irla
- Genetics of Prokaryotes, Faculty of Biology & Center for Biotechnology, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany.
| | - Armin Neshat
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätstr. 27, 33615, Bielefeld, Germany.
| | - Trygve Brautaset
- Department of Molecular Biology, SINTEF Materials and Chemistry, Sem Selands vei 2, 7465, Trondheim, Norway. .,Department of Biotechnology, Norwegian University of Science and Technology, Sem Sælands vei 6/8, 7491, Trondheim, Norway.
| | - Christian Rückert
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätstr. 27, 33615, Bielefeld, Germany. .,Technology Platform Genomics, Center for Biotechnology, Bielefeld University, Universitätsstr. 27, 33615, Bielefeld, Germany.
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätstr. 27, 33615, Bielefeld, Germany. .,Technology Platform Genomics, Center for Biotechnology, Bielefeld University, Universitätsstr. 27, 33615, Bielefeld, Germany.
| | - Volker F Wendisch
- Genetics of Prokaryotes, Faculty of Biology & Center for Biotechnology, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany.
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Zallot R, Brochier-Armanet C, Gaston KW, Forouhar F, Limbach PA, Hunt JF, de Crécy-Lagard V. Plant, animal, and fungal micronutrient queuosine is salvaged by members of the DUF2419 protein family. ACS Chem Biol 2014; 9:1812-25. [PMID: 24911101 PMCID: PMC4136680 DOI: 10.1021/cb500278k] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
![]()
Queuosine (Q) is a modification found
at the wobble position of
tRNAs with GUN anticodons. Although Q is present in most eukaryotes
and bacteria, only bacteria can synthesize Q de novo. Eukaryotes acquire queuine (q), the free base of Q, from diet and/or
microflora, making q an important but under-recognized micronutrient
for plants, animals, and fungi. Eukaryotic type tRNA-guanine transglycosylases
(eTGTs) are composed of a catalytic subunit (QTRT1) and a homologous
accessory subunit (QTRTD1) forming a complex that catalyzes q insertion
into target tRNAs. Phylogenetic analysis of eTGT subunits revealed
a patchy distribution pattern in which gene losses occurred independently
in different clades. Searches for genes co-distributing with eTGT
family members identified DUF2419 as a potential Q salvage protein
family. This prediction was experimentally validated in Schizosaccharomyces
pombe by confirming that Q was present by analyzing tRNAAsp with anticodon GUC purified from wild-type cells and by
showing that Q was absent from strains carrying deletions in the QTRT1
or DUF2419 encoding genes. DUF2419 proteins occur in most Eukarya
with a few possible cases of horizontal gene transfer to bacteria.
The universality of the DUF2419 function was confirmed by complementing
the S. pombe mutant with the Zea mays (maize), human, and Sphaerobacter thermophilus homologues.
The enzymatic function of this family is yet to be determined, but
structural similarity with DNA glycosidases suggests a ribonucleoside
hydrolase activity.
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Affiliation(s)
- Rémi Zallot
- Department
of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611, United States
| | - Céline Brochier-Armanet
- Université
Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie
Evolutive, Université de Lyon, 69622 Villeurbanne, France
| | - Kirk W. Gaston
- Rieveschl
Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Farhad Forouhar
- Department
of Biological Sciences and Northeast Structural Genomics Consortium, Columbia University, New York, New York 10027, United States
| | - Patrick A. Limbach
- Rieveschl
Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - John F. Hunt
- Department
of Biological Sciences and Northeast Structural Genomics Consortium, Columbia University, New York, New York 10027, United States
| | - Valérie de Crécy-Lagard
- Department
of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611, United States
- University of Florida Genetics Institute, Gainesville, Florida 32611, United States
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Suddala KC, Rinaldi AJ, Feng J, Mustoe AM, Eichhorn CD, Liberman JA, Wedekind JE, Al-Hashimi HM, Brooks CL, Walter NG. Single transcriptional and translational preQ1 riboswitches adopt similar pre-folded ensembles that follow distinct folding pathways into the same ligand-bound structure. Nucleic Acids Res 2013; 41:10462-75. [PMID: 24003028 PMCID: PMC3905878 DOI: 10.1093/nar/gkt798] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Riboswitches are structural elements in the 5′ untranslated regions of many bacterial messenger RNAs that regulate gene expression in response to changing metabolite concentrations by inhibition of either transcription or translation initiation. The preQ1 (7-aminomethyl-7-deazaguanine) riboswitch family comprises some of the smallest metabolite sensing RNAs found in nature. Once ligand-bound, the transcriptional Bacillus subtilis and translational Thermoanaerobacter tengcongensis preQ1 riboswitch aptamers are structurally similar RNA pseudoknots; yet, prior structural studies have characterized their ligand-free conformations as largely unfolded and folded, respectively. In contrast, through single molecule observation, we now show that, at near-physiological Mg2+ concentration and pH, both ligand-free aptamers adopt similar pre-folded state ensembles that differ in their ligand-mediated folding. Structure-based Gō-model simulations of the two aptamers suggest that the ligand binds late (Bacillus subtilis) and early (Thermoanaerobacter tengcongensis) relative to pseudoknot folding, leading to the proposal that the principal distinction between the two riboswitches lies in their relative tendencies to fold via mechanisms of conformational selection and induced fit, respectively. These mechanistic insights are put to the test by rationally designing a single nucleotide swap distal from the ligand binding pocket that we find to predictably control the aptamers′ pre-folded states and their ligand binding affinities.
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Affiliation(s)
- Krishna C Suddala
- Biophysics, University of Michigan, Ann Arbor, MI 48109, USA, Single Molecule Analysis Group, University of Michigan, Ann Arbor, MI 48109, USA, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA, Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, USA, Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA and Center for Theoretical Biological Physics, University of California San Diego, San Diego, CA 92037, USA
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9
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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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10
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Carell T, Brandmayr C, Hienzsch A, Müller M, Pearson D, Reiter V, Thoma I, Thumbs P, Wagner M. Struktur und Funktion nicht-kanonischer Nukleobasen. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201201193] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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11
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Carell T, Brandmayr C, Hienzsch A, Müller M, Pearson D, Reiter V, Thoma I, Thumbs P, Wagner M. Structure and function of noncanonical nucleobases. Angew Chem Int Ed Engl 2012; 51:7110-31. [PMID: 22744788 DOI: 10.1002/anie.201201193] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 05/07/2012] [Indexed: 12/19/2022]
Abstract
DNA and RNA contain, next to the four canonical nucleobases, a number of modified nucleosides that extend their chemical information content. RNA is particularly rich in modifications, which is obviously an adaptation to their highly complex and variable functions. In fact, the modified nucleosides and their chemical structures establish a second layer of information which is of central importance to the function of the RNA molecules. Also the chemical diversity of DNA is greater than originally thought. Next to the four canonical bases, the DNA of higher organisms contains a total of four epigenetic bases: m(5) dC, hm(5) dC, f(5) dC und ca(5) dC. While all cells of an organism contain the same genetic material, their vastly different function and properties inside complex higher organisms require the controlled silencing and activation of cell-type specific genes. The regulation of the underlying silencing and activation process requires an additional layer of epigenetic information, which is clearly linked to increased chemical diversity. This diversity is provided by the modified non-canonical nucleosides in both DNA and RNA.
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Affiliation(s)
- Thomas Carell
- Center for Integrated Protein Science at the Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, 81377 München, Germany.
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12
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McCarty RM, Bandarian V. Biosynthesis of pyrrolopyrimidines. Bioorg Chem 2012; 43:15-25. [PMID: 22382038 DOI: 10.1016/j.bioorg.2012.01.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 01/05/2012] [Accepted: 01/06/2012] [Indexed: 12/17/2022]
Abstract
Pyrrolopyrimidine containing compounds, also known as 7-deazapurines, are a collection of purine-based metabolites that have been isolated from a variety of biological sources and have diverse functions which range from secondary metabolism to RNA modification. To date, nearly 35 compounds with the common 7-deazapurine core structure have been described. This article will illustrate the structural diversity of these compounds and review the current state of knowledge on the biosynthetic pathways that give rise to them.
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Affiliation(s)
- Reid M McCarty
- Department of Chemistry and Biochemistry, University of Arizona, 1041 E. Lowell St., Tucson, AZ 85721, USA
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13
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Miles ZD, McCarty RM, Molnar G, Bandarian V. Discovery of epoxyqueuosine (oQ) reductase reveals parallels between halorespiration and tRNA modification. Proc Natl Acad Sci U S A 2011; 108:7368-72. [PMID: 21502530 PMCID: PMC3088584 DOI: 10.1073/pnas.1018636108] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Transfer RNA is one of the most richly modified biological molecules. Biosynthetic pathways that introduce these modifications are underexplored, largely because their absence does not lead to obvious phenotypes under normal growth conditions. Queuosine (Q) is a hypermodified base found in the wobble positions of tRNA Asp, Asn, His, and Tyr from bacteria to mankind. Using liquid chromatography MS methods, we have screened 1,755 single gene knockouts of Escherichia coli and have identified the key final step in the biosynthesis of Q. The protein is homologous to B(12)-dependent iron-sulfur proteins involved in halorespiration. The recombinant Bacillus subtilis epoxyqueuosine (oQ) reductase catalyzes the conversion of oQ to Q in a synthetic substrate, as well as undermodified RNA isolated from an oQ reductase knockout strain. The activity requires inclusion of a reductant and a redox mediator. Finally, exogenously supplied cobalamin stimulates the activity. This work provides the framework for studies of the biosynthesis of other modified RNA components, where lack of accessible phenotype or obvious gene clustering has impeded discovery. Moreover, discovery of the elusive oQ reductase protein completes the biosynthetic pathway of Q.
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Affiliation(s)
- Zachary D. Miles
- Department of Chemistry and Biochemistry, University of Arizona, 1041 East Lowell Street, Tucson, AZ 85721-0088
| | - Reid M. McCarty
- Department of Chemistry and Biochemistry, University of Arizona, 1041 East Lowell Street, Tucson, AZ 85721-0088
| | - Gabriella Molnar
- Department of Chemistry and Biochemistry, University of Arizona, 1041 East Lowell Street, Tucson, AZ 85721-0088
| | - Vahe Bandarian
- Department of Chemistry and Biochemistry, University of Arizona, 1041 East Lowell Street, Tucson, AZ 85721-0088
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14
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Ming X, Seela F. Efficient synthesis of the tRNA nucleoside preQ0, 7-cyano-7-deazaguanosine, via microwave-assisted iodo→carbonitrile exchange. Chem Biodivers 2011; 7:2616-21. [PMID: 20963777 DOI: 10.1002/cbdv.201000239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The naturally occurring tRNA nucleoside preQ(0), 7-cyano-7-deazaguanosine, which is a central intermediate for other natural occurring 7-deazapurine nucleosides was synthesized via a copper(I)-ion-mediated iodo→carbonitrile exchange. The reaction was performed on the easily accessible 7-iodo-7-deazaguanosine under microwave conditions. The overall reaction yield was 30% starting with the glycosylation reaction of the nucleobase. Corresponding 2'-deoxyribonucleosides were prepared following the same route.
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Affiliation(s)
- Xin Ming
- Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, D-48149 Münster, Germany
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15
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Chen YC, Brooks AF, Goodenough-Lashua DM, Kittendorf JD, Showalter HD, Garcia GA. Evolution of eukaryal tRNA-guanine transglycosylase: insight gained from the heterocyclic substrate recognition by the wild-type and mutant human and Escherichia coli tRNA-guanine transglycosylases. Nucleic Acids Res 2010; 39:2834-44. [PMID: 21131277 PMCID: PMC3074131 DOI: 10.1093/nar/gkq1188] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The enzyme tRNA-guanine transglycosylase (TGT) is involved in the queuosine modification of tRNAs in eukarya and eubacteria and in the archaeosine modification of tRNAs in archaea. However, the different classes of TGTs utilize different heterocyclic substrates (and tRNA in the case of archaea). Based on the X-ray structural analyses, an earlier study [Stengl et al. (2005) Mechanism and substrate specificity of tRNA-guanine transglycosylases (TGTs): tRNA-modifying enzymes from the three different kingdoms of life share a common catalytic mechanism. Chembiochem, 6, 1926–1939] has made a compelling case for the divergent evolution of the eubacterial and archaeal TGTs. The X-ray structure of the eukaryal class of TGTs is not known. We performed sequence homology and phylogenetic analyses, and carried out enzyme kinetics studies with the wild-type and mutant TGTs from Escherichia coli and human using various heterocyclic substrates that we synthesized. Observations with the Cys145Val (E. coli) and the corresponding Val161Cys (human) TGTs are consistent with the idea that the Cys145 evolved in eubacterial TGTs to recognize preQ1 but not queuine, whereas the eukaryal equivalent, Val161, evolved for increased recognition of queuine and a concomitantly decreased recognition of preQ1. Both the phylogenetic and kinetic analyses support the conclusion that all TGTs have divergently evolved to specifically recognize their cognate heterocyclic substrates.
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Affiliation(s)
- Yi-Chen Chen
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109-1065, USA
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16
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Abstract
tRNAs possess a high content of modified nucleosides, which display an incredible structural variety. These modified nucleosides are conserved in their sequence and have important roles in tRNA functions. Most often, hypermodified nucleosides are found in the wobble position of tRNAs, which play a direct role in maintaining translational efficiency and fidelity, codon recognition, etc. One of such hypermodified base is queuine, which is a base analogue of guanine, found in the first anticodon position of specific tRNAs (tyrosine, histidine, aspartate and asparagine tRNAs). These tRNAs of the ‘Q-family’ originally contain guanine in the first position of anticodon, which is post-transcriptionally modified with queuine by an irreversible insertion during maturation. Queuine is ubiquitously present throughout the living system from prokaryotes to eukaryotes, including plants. Prokaryotes can synthesize queuine de novo by a complex biosynthetic pathway, whereas eukaryotes are unable to synthesize either the precursor or queuine. They utilize salvage system and acquire queuine as a nutrient factor from their diet or from intestinal microflora. The tRNAs of the Q-family are completely modified in terminally differentiated somatic cells. However, hypomodification of Q-tRNA (queuosine-modified tRNA) is closely associated with cell proliferation and malignancy. The precise mechanisms of queuine- and Q-tRNA-mediated action are still a mystery. Direct or indirect evidence suggests that queuine or Q-tRNA participates in many cellular functions, such as inhibition of cell proliferation, control of aerobic and anaerobic metabolism, bacterial virulence, etc. The role of Q-tRNA modification in cellular machinery and the signalling pathways involved therein is the focus of this review.
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17
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Biosynthesis of 7-deazaguanosine-modified tRNA nucleosides: a new role for GTP cyclohydrolase I. J Bacteriol 2008; 190:7876-84. [PMID: 18931107 DOI: 10.1128/jb.00874-08] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Queuosine (Q) and archaeosine (G(+)) are hypermodified ribonucleosides found in tRNA. Q is present in the anticodon region of tRNA(GUN) in Eukarya and Bacteria, while G(+) is found at position 15 in the D-loop of archaeal tRNA. Prokaryotes produce these 7-deazaguanosine derivatives de novo from GTP through the 7-cyano-7-deazaguanine (pre-Q(0)) intermediate, but mammals import the free base, queuine, obtained from the diet or the intestinal flora. By combining the results of comparative genomic analysis with those of genetic studies, we show that the first enzyme of the folate pathway, GTP cyclohydrolase I (GCYH-I), encoded in Escherichia coli by folE, is also the first enzyme of pre-Q(0) biosynthesis in both prokaryotic kingdoms. Indeed, tRNA extracted from an E. coli DeltafolE strain is devoid of Q and the deficiency is complemented by expressing GCYH-I-encoding genes from different bacterial or archaeal origins. In a similar fashion, tRNA extracted from a Haloferax volcanii strain carrying a deletion of the GCYH-I-encoding gene contains only traces of G(+). These results link the production of a tRNA-modified base to primary metabolism and further clarify the biosynthetic pathway for these complex modified nucleosides.
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18
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Environmental and growth phase regulation of the Streptococcus gordonii arginine deiminase genes. Appl Environ Microbiol 2008; 74:5023-30. [PMID: 18552185 DOI: 10.1128/aem.00556-08] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A 1,026-bp open reading frame sharing significant similarity with queA, which encodes a predicted S-adenosylmethionine:tRNA ribosyltransferase-isomerase responsible for queosine modification of tRNAs, was found immediately 5' of the gene for the transcriptional activator (ArcR) of the arginine deiminase system (ADS) operon of Streptococcus gordonii. The role of QueA in bacterial physiology is enigmatic, but loss of QueA has been shown to compromise stationary-phase survival or virulence in certain enteric bacteria. Interestingly, S. gordonii appears to be unique among ADS-positive bacteria in the linkage of queA with the ADS genes. A putative sigma(70) promoter (p(queA); TTGCCA-N(21)-TATAAT) was mapped 5' of queA by primer extension, and queA and arcR were shown to be cotranscribed. The expression from p(queA) was found to be constitutive under all conditions tested, but the expression of p(arcA), which drives the expression of the arc structural genes, was enhanced in stationary phase and could be induced by low pH and arginine. QueA and CcpA acted repressively on arc transcription, but neither QueA-deficient strains nor CcpA-deficient strains showed significant differences in arginine deiminase enzyme activities compared with the wild-type strain. The growth rate of a QueA-deficient strain did not differ significantly from that of the parental strain, but the QueA-deficient strain did not compete well with the wild-type during serial passage. In addition to the finding that ADS expression can be regulated separately by growth phase and pH, a significant linkage between the ADS, translational efficiency modulated by QueA, and post-exponential-phase survival of S. gordonii was found.
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19
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Meyer MM, Roth A, Chervin SM, Garcia GA, Breaker RR. Confirmation of a second natural preQ1 aptamer class in Streptococcaceae bacteria. RNA (NEW YORK, N.Y.) 2008; 14:685-95. [PMID: 18305186 PMCID: PMC2271366 DOI: 10.1261/rna.937308] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Bioinformatics searches of eubacterial genomes have yielded many riboswitch candidates where the identity of the ligand is not immediately obvious on examination of associated genes. One of these motifs is found exclusively in the family Streptococcaceae within the 5' untranslated regions (UTRs) of genes encoding the hypothetical membrane protein classified as COG4708 or DUF988. While the function of this protein class is unproven, a riboswitch binding the queuosine biosynthetic intermediate pre-queuosine(1) (preQ(1)) has been identified in the 5' UTR of homologous genes in many Firmicute species of bacteria outside of Streptococcaceae. Here we show that a representative of the COG4708 RNA motif from Streptococcus pneumoniae R6 also binds preQ(1). Furthermore, representatives of this RNA have structural and molecular recognition characteristics that are distinct from those of the previously described preQ(1) riboswitch class. PreQ(1) is the second metabolite for which two or more distinct classes of natural aptamers exist, indicating that natural aptamers utilizing different structures to bind the same metabolite may be more common than is currently known. Additionally, the association of preQ(1) binding RNAs with most genes encoding proteins classified as COG4708 strongly suggests that these proteins function as transporters for preQ(1) or another queuosine biosynthetic intermediate.
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Affiliation(s)
- Michelle M Meyer
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520-8103, USA
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20
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Roth A, Winkler WC, Regulski EE, Lee BWK, Lim J, Jona I, Barrick JE, Ritwik A, Kim JN, Welz R, Iwata-Reuyl D, Breaker RR. A riboswitch selective for the queuosine precursor preQ1 contains an unusually small aptamer domain. Nat Struct Mol Biol 2007; 14:308-17. [PMID: 17384645 DOI: 10.1038/nsmb1224] [Citation(s) in RCA: 185] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Accepted: 03/05/2007] [Indexed: 01/09/2023]
Abstract
A previous bioinformatics-based search for riboswitches yielded several candidate motifs in eubacteria. One of these motifs commonly resides in the 5' untranslated regions of genes involved in the biosynthesis of queuosine (Q), a hypermodified nucleoside occupying the anticodon wobble position of certain transfer RNAs. Here we show that this structured RNA is part of a riboswitch selective for 7-aminomethyl-7-deazaguanine (preQ(1)), an intermediate in queuosine biosynthesis. Compared with other natural metabolite-binding RNAs, the preQ(1) aptamer appears to have a simple structure, consisting of a single stem-loop and a short tail sequence that together are formed from as few as 34 nucleotides. Despite its small size, this aptamer is highly selective for its cognate ligand in vitro and has an affinity for preQ(1) in the low nanomolar range. Relatively compact RNA structures can therefore serve effectively as metabolite receptors to regulate gene expression.
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Affiliation(s)
- Adam Roth
- Howard Hughes Medical Institute, USA
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21
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Abstract
As the molecular adapters between codons and amino acids, transfer-RNAs are pivotal molecules of the genetic code. The coding properties of a tRNA molecule do not reside only in its primary sequence. Posttranscriptional nucleoside modifications, particularly in the anticodon loop, can modify cognate codon recognition, affect aminoacylation properties, or stabilize the codon-anticodon wobble base pairing to prevent ribosomal frameshifting. Despite a wealth of biophysical and structural knowledge of the tRNA modifications themselves, their pathways of biosynthesis had been until recently only partially characterized. This discrepancy was mainly due to the lack of obvious phenotypes for tRNA modification-deficient strains and to the difficulty of the biochemical assays used to detect tRNA modifications. However, the availability of hundreds of whole-genome sequences has allowed the identification of many of these missing tRNA-modification genes. This chapter reviews the methods that were used to identify these genes with a special emphasis on the comparative genomic approaches. Methods that link gene and function but do not rely on sequence homology will be detailed, with examples taken from the tRNA modification field.
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22
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Farkas WR. Queuine, The Q-Containing tRNAs and the Enzymes Responsible for Their Formation. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328318308078845] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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23
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24
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Nishimura S, Watanabe K. The discovery of modified nucleosides from the early days to the present: A personal perspective. J Biosci 2006; 31:465-75. [PMID: 17206067 DOI: 10.1007/bf02705186] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Susumu Nishimura
- Center for TARA, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki, 305-8577, Japan.
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25
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Cheng CS, Hoops GC, Earl RA, Townsend LB. Synthesis of Pyrrolo[2,3-d]pyrimidines that are Structurally Related to Methylated Guanosines from tRNA and the Nucleoside Q Analogs, PreQ0and PreQ1. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328319708001355] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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26
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Chakraborty P, Brückner AM, Diederichsen U. Synthesis of a 7-Deazaguanine-Functionalized β-Amino Acid: Improved Specificity of β-Peptide Helix Organization. European J Org Chem 2006. [DOI: 10.1002/ejoc.200501003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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27
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Gaur R, Varshney U. Genetic analysis identifies a function for the queC (ybaX) gene product at an initial step in the queuosine biosynthetic pathway in Escherichia coli. J Bacteriol 2005; 187:6893-901. [PMID: 16199558 PMCID: PMC1251624 DOI: 10.1128/jb.187.20.6893-6901.2005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Queuosine (Q), one of the most complex modifications occurring at the wobble position of tRNAs with GUN anticodons, is implicated in a number of biological activities, including accuracy of decoding, virulence, and cellular differentiation. Despite these important implications, its biosynthetic pathway has remained unresolved. Earlier, we observed that a naturally occurring strain of Escherichia coli B105 lacked Q modification in the tRNAs. In the present study, we developed a genetic screen to map the defect in E. coli B105 to a single gene, queC (renamed from ybaX), predicted to code for a 231-amino-acid-long protein with a pI of 5.6. As analyzed by mobility of tRNA(Tyr) on acid urea gels and two-dimensional thin-layer chromatography of the modified nucleosides, expression of QueC from a plasmid-borne copy confers a Q+ phenotype to E. coli B105. Further, analyses of tRNA(Tyr) from E. coli JE10651 (queA mutant), its derivative generated by deletion of chromosomal queC (queA deltaqueC), and E. coli JE7325, deficient in converting preQ0 to preQ1, have provided the first genetic evidence for the involvement of QueC at a step leading to production of preQ0, the first known intermediate in the generally accepted pathway that utilizes GTP as the starting molecule. In addition, we discuss the possibilities of collaboration of QueC with other cellular proteins in the production of preQ0.
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Affiliation(s)
- Rahul Gaur
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
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28
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Van Lanen SG, Reader JS, Swairjo MA, de Crécy-Lagard V, Lee B, Iwata-Reuyl D. From cyclohydrolase to oxidoreductase: discovery of nitrile reductase activity in a common fold. Proc Natl Acad Sci U S A 2005; 102:4264-9. [PMID: 15767583 PMCID: PMC555470 DOI: 10.1073/pnas.0408056102] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2004] [Indexed: 11/18/2022] Open
Abstract
The enzyme YkvM from Bacillus subtilis was identified previously along with three other enzymes (YkvJKL) in a bioinformatics search for enzymes involved in the biosynthesis of queuosine, a 7-deazaguanine modified nucleoside found in tRNA(GUN) of Bacteria and Eukarya. Genetic analysis of ykvJKLM mutants in Acinetobacter confirmed that each was essential for queuosine biosynthesis, and the genes were renamed queCDEF. QueF exhibits significant homology to the type I GTP cyclohydrolases characterized by FolE. Given that GTP is the precursor to queuosine and that a cyclohydrolase-like reaction was postulated as the initial step in queuosine biosynthesis, QueF was proposed to be the putative cyclohydrolase-like enzyme responsible for this reaction. We have cloned the queF genes from B. subtilis and Escherichia coli and characterized the recombinant enzymes. Contrary to the predictions based on sequence analysis, we discovered that the enzymes, in fact, catalyze a mechanistically unrelated reaction, the NADPH-dependent reduction of 7-cyano-7-deazaguanineto7-aminomethyl-7-deazaguanine, a late step in the biosynthesis of queuosine. We report here in vitro and in vivo studies that demonstrate this catalytic activity, as well as preliminary biochemical and bioinformatics analysis that provide insight into the structure of this family of enzymes.
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Affiliation(s)
- Steven G Van Lanen
- Department of Chemistry, Portland State University, P.O. Box 751, Portland, OR 97207, USA
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29
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Abstract
Transfer RNA (tRNA) is structurally unique among nucleic acids in harboring an astonishing diversity of post-transcriptionally modified nucleoside. Two of the most radically modified nucleosides known to occur in tRNA are queuosine and archaeosine, both of which are characterized by a 7-deazaguanosine core structure. In spite of the phylogenetic segregation observed for these nucleosides (queuosine is present in Eukarya and Bacteria, while archaeosine is present only in Archaea), their structural similarity suggested a common biosynthetic origin, and recent biochemical and genetic studies have provided compelling evidence that a significant portion of their biosynthesis may in fact be identical. This review covers current understanding of the physiology and biosynthesis of these remarkable nucleosides, with particular emphasis on the only two enzymes that have been discovered in the pathways: tRNA-guanine transglycosylase (TGT), which catalyzes the insertion of a modified base into the polynucleotide with the concomitant elimination of the genetically encoded guanine in the biosynthesis of both nucleosides, and S-adenosylmethionine:tRNA ribosyltransferase-isomerase (QueA), which catalyzes the penultimate step in the biosynthesis of queuosine, the construction of the carbocyclic side chain.
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Affiliation(s)
- Dirk Iwata-Reuyl
- Department of Chemistry, Portland State University, P.O. Box 751, Portland, OR 97201, USA.
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30
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Bai Y, Fox DT, Lacy JA, Van Lanen SG, Iwata-Reuyl D. Hypermodification of tRNA in Thermophilic archaea. Cloning, overexpression, and characterization of tRNA-guanine transglycosylase from Methanococcus jannaschii. J Biol Chem 2000; 275:28731-8. [PMID: 10862614 DOI: 10.1074/jbc.m002174200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
tRNA is structurally unique among nucleic acids in harboring an astonishing diversity of modified nucleosides. Two structural variants of the hypermodified nucleoside 7-deazaguanosine have been identified in tRNA: queuosine, which is found at the wobble position of the anticodon in bacterial and eukaryotic tRNA, and archaeosine, which is found at position 15 of the D-loop in archaeal tRNA. From homology searching of the Methanococcus jannaschii genome, a gene coding for an enzyme in the biosynthesis of archaeosine (tgt) was identified and cloned. The tgt gene was overexpressed in an Escherichia coli expression system, and the recombinant tRNA-guanine transglycosylase enzyme was purified and characterized. The enzyme catalyzes a transglycosylation reaction in which guanine is eliminated from position 15 of the tRNA and an archaeosine precursor (preQ(0)) is inserted. The enzyme is able to utilize both guanine and the 7-deazaguanine base preQ(0) as substrates, but not other 7-deazaguanine bases, and is able to modify tRNA from all three phylogenetic domains. The enzyme shows optimal activity at high temperature and acidic pH, consistent with the optimal growth conditions of M. jannaschii. The nature of the temperature dependence is consistent with a requirement for some degree of tRNA tertiary structure in order for recognition by the enzyme to occur.
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Affiliation(s)
- Y Bai
- Department of Chemistry, Portland State University, Portland, Oregon 97201, USA
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31
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Watanabe M, Matsuo M, Tanaka S, Akimoto H, Asahi S, Nishimura S, Katze JR, Hashizume T, Crain PF, McCloskey JA, Okada N. Biosynthesis of archaeosine, a novel derivative of 7-deazaguanosine specific to archaeal tRNA, proceeds via a pathway involving base replacement on the tRNA polynucleotide chain. J Biol Chem 1997; 272:20146-51. [PMID: 9242689 DOI: 10.1074/jbc.272.32.20146] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Archaeosine is a novel derivative of 7-deazaguanosine found in transfer RNAs of most organisms exclusively in the archaeal phylogenetic lineage and is present in the D-loop at position 15. We show that this modification is formed by a posttranscriptional base replacement reaction, catalyzed by a new tRNA-guanine transglycosylase (TGT), which has been isolated from Haloferax volcanii and purified nearly to homogeneity. The molecular weight of the enzyme was estimated to be 78 kDa by SDS-gel electrophoresis. The enzyme can insert free 7-cyano-7-deazaguanine (preQ0 base) in vitro at position 15 of an H. volcanii tRNA T7 transcript, replacing the guanine originally located at that position without breakage of the phosphodiester backbone. Since archaeosine base and 7-aminomethyl-7-deazaguanine (preQ1 base) were not incorporated into tRNA by this enzyme, preQ0 base appears to be the actual substrate for the TGT of H. volcanii, a conclusion supported by characterization of preQ0 base in an acid-soluble extract of H. volcanii cells. Thus, this novel TGT in H. volcanii is a key enzyme for the biosynthetic pathway leading to archaeosine in archaeal tRNAs.
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Affiliation(s)
- M Watanabe
- Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226, Japan
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32
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Björk GR. Genetic dissection of synthesis and function of modified nucleosides in bacterial transfer RNA. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1995; 50:263-338. [PMID: 7538683 DOI: 10.1016/s0079-6603(08)60817-x] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- G R Björk
- Department of Microbiology, Umeå University, Sweden
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33
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Abstract
A comprehensive listing is made of posttranscriptionally modified nucleosides from RNA reported in the literature through mid-1994. Included are chemical structures, common names, symbols, Chemical Abstracts registry numbers (for ribonucleoside and corresponding base), Chemical Abstracts Index Name, phylogenetic sources, and initial literature citations for structural characterization or occurrence, and for chemical synthesis. The listing is categorized by type of RNA: tRNA, rRNA, mRNA, snRNA, and other RNAs. A total of 93 different modified nucleosides have been reported in RNA, with the largest number and greatest structural diversity in tRNA, 79; and 28 in rRNA, 12 in mRNA, 11 in snRNA and 3 in other small RNAs.
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Affiliation(s)
- P A Limbach
- Department of Medicinal Chemistry, University of Utah, Salt Lake City 84112
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34
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Abstract
In almost all known tRNAs that are specific for Asp, Asn, His or Tyr the wobble position of the anticodon is occupied by the hypermodified tRNA nucleoside queuosine. This unusual deazaguanine derivative is synthesised only in eubacteria. The biosynthesis, as investigated in Escherichia coli, is accomplished in four steps involving many unprecedented enzymatic reactions.
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Affiliation(s)
- R K Slany
- Institut für Biochemie, Universität Erlangen, Germany
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35
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Slany RK, Bösl M, Kersten H. Transfer and isomerization of the ribose moiety of AdoMet during the biosynthesis of queuosine tRNAs, a new unique reaction catalyzed by the QueA protein from Escherichia coli. Biochimie 1994; 76:389-93. [PMID: 7849103 DOI: 10.1016/0300-9084(94)90113-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The enzyme QueA of E coli is involved in the biosynthesis of the hypermodified tRNA nucleoside queuosine. The enzyme catalyzes the synthesis of an epoxycyclopentane moiety and transfers this compound to specific tRNAs containing the queuosine precursor 7-(aminomethyl)-7-deazaguanine (preQ1). S-adenosylmethionine (AdoMet) is the sole cofactor that is required for this reaction (Slany et al, 1993, Biochemistry 32, 7811-7817). To proof that the ribose moiety of AdoMet is the precursor of the epoxycyclopentane moiety, labeled AdoMet, was generated from different types of 3H ATP and methionine by the AdoMet synthetase enzyme (MetK) from E coli. The resulting 3H labeled AdoMet was directly used as the cofactor for the QueA reaction. Using [2,5', 8-3H]ATP, containing tritium at C5' of the ribose ring, resulted in an incorporation of radioactivity into preQ1 tRNA, whereas this was not the case when [2,8-3H]ATP was applied. A model for the reaction catalyzed by the S-adenosylmethionine:tRNA ribosyltransferase-isomerase QueA is proposed.
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Affiliation(s)
- R K Slany
- Institut für Biochimie, Universität Erlangen, Germany
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Reuter K, Slany R, Ullrich F, Kersten H. Structure and organization of Escherichia coli genes involved in biosynthesis of the deazaguanine derivative queuine, a nutrient factor for eukaryotes. J Bacteriol 1991; 173:2256-64. [PMID: 1706703 PMCID: PMC207776 DOI: 10.1128/jb.173.7.2256-2264.1991] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The plasmid pPR20 contains the gene tgt, which encodes tRNA guanine transglycosylase (Tgt), on a 33-kbp DNA insert from a region around 9 min on the Escherichia coli linkage map. The plasmid was subcloned to determine the sequence and organization of the tgt gene. Tgt is a unique enzyme that exchanges the guanine residue with 7-aminomethyl-7-deazaguanine in tRNAs with GU(N) anticodons. After this exchange, a cyclopentendiol moiety is attached to the 7-aminomethyl group of 7-deazaguanine, resulting in the hypermodified nucleoside queuosine (Q). Here we give the complete sequence of a 3,545-bp StuI-BamHI DNA fragment where we found the tgt gene and three previously unknown genes encoding proteins with calculated molecular masses of 42.5 (Tgt), 14, 39, and 12 kDa. The gene products were characterized on sodium dodecyl sulfate gels after synthesis in a combined transcription-translation system. The mRNA start sites of the open reading frames (ORFs) were determined by primer extension analysis. Plasmids containing the ORF encoding the 39-kDa protein (ORF 39) complemented a mutation in Q biosynthesis after the Tgt step. This gene was designated queA. The genes are arranged in the following order: ORF 14 (transcribed in the counterclockwise direction), queA, tgt, and ORF 12 (all transcribed in the clockwise direction). The organization of the promoter sequences and the termination sites suggests that queA, tgt, and ORF 12 are localized on a putative operon together with the genes secD and secF.
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Affiliation(s)
- K Reuter
- Institut für Biochemie, Universität Erlangen-Nürnberg, Germany
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Chapter 2 Biosynthesis and Function of Queuine and Queuosine tRNAs. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/s0301-4770(08)61488-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Phillipson D, Edmonds C, Crain P, Smith D, Davis D, McCloskey J. Isolation and structure elucidation of an epoxide derivative of the hypermodified nucleoside queuosine from Escherichia coli transfer RNA. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61373-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Kondo T, Okamoto K, Ohgi T, Goto T. Syntheses of hypermodified nucleoside q, and its biosynthetic precursors preq0 and preq1. Tetrahedron 1986. [DOI: 10.1016/s0040-4020(01)87419-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kondo T, Okamoto K, Yamamoto M, Goto T, Tanaka N. A total synthesis of cadeguomycin, a nucleoside antibiotic produced by. Tetrahedron 1986. [DOI: 10.1016/s0040-4020(01)87418-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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41
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Seela F, Driller H. Solid-phase synthesis of the self-complementary hexamer d(c7GpCpc7GpCpc7GpC) via the O-3'-phosphoramidite of 7-deaza-2'-deoxyguanosine. Nucleic Acids Res 1985; 13:911-26. [PMID: 4000931 PMCID: PMC341042 DOI: 10.1093/nar/13.3.911] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The synthesis of the O-3'-phosphoramidite of a suitably protected 7-deaza-2'-deoxyguanosine (c7G) which is an isostere of 2'-deoxyguanosine is described. The phosphoramidite of the modified nucleoside was used in the synthesis of the self-complementary hexamer d(c7GpCpc7GpCpc7GpC) on functionalized silica gel in a mini-reactor. As expected from the parent hexamer d(GpCpGpCpGpC) the isosteric d(c7GpCpc7GpCpc7GpC) exhibits a rigid secondary structure (22% hypochromicity at 280 nm) and forms a duplex in 1 M aqueous sodium chloride solution. Due to the altered pi-electron system of the pyrrolo[2,3-d]pyrimidine nucleobase, which affects base stacking and hydrogen bonding, the Tm of the modified duplex is decreased by 10 degrees C compared to that of the parent purine hexamer. Moreover, it is expected that the incorporation of c7G influences the pitch of the helix.
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Nishimura S. Structure, biosynthesis, and function of queuosine in transfer RNA. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1983; 28:49-73. [PMID: 6410456 DOI: 10.1016/s0079-6603(08)60082-3] [Citation(s) in RCA: 107] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Seela F, Tran-Thi QH, Franzen D. Poly(7-deazaguanylic acid), the homopolynucleotide of the parent nucleoside of queuosine. Biochemistry 1982; 21:4338-43. [PMID: 6289879 DOI: 10.1021/bi00261a024] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Poly(7-deazaguanylic acid) was enzymatically synthesized by the polymerization of 7-deazaguanosine 5'-diphosphate with polynucleotide phosphorylase from Micrococcus luteus in high yield. The homopolymer showed a similar thermal and total hypochromicity to poly(G) at the long wavelength absorption maximum. No sigmoid melting profile was observed for poly(c7G) as is found for poly(G), implying a single-stranded structure in aqueous solution. From the circular dichroism spectra it can be concluded that the 7-deazapurine nucleotide is much more flexible than the purine nucleotide. In analogy to poly(G), the homopolymer poly(c7G) forms a 1:1 complex with poly(C) under neutral conditions, melting at a similar temperature to the poly(G) complex. However, at pH 2.5, where a poly(G) X 2poly(C) complex is observed, poly(c7G) still binds only one poly(C) strand. This is due to the lack of N-7 in poly(c7G), not allowing Hoogsteen base pair formation, which occurs with poly(G). RNase T1 cleaves poly(c7G), indicating that N-7 of guanosine is not a requirement for nucleotide binding to the enzyme, as has been suggested. Because of the single-stranded structure of poly(c7G), the polynucleotide chain is rapidly hydrolyzed by the single-strand-specific nuclease S1, whereas multistranded poly(G) is completely resistant.
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Noguchi S, Nishimura Y, Hirota Y, Nishimura S. Isolation and characterization of an Escherichia coli mutant lacking tRNA-guanine transglycosylase. Function and biosynthesis of queuosine in tRNA. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(20)65176-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Seela F, Hasselmann D. Synthese von 2-Amino-3, 7-(β-D-ribofuranosyl)-4H-pyrrolo[2,3-d] pyrimidin-4-on - 7-Desazaguanosin - der Stammverbindung des Nucleosids Q. ACTA ACUST UNITED AC 1981. [DOI: 10.1002/cber.19811141020] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Crain P, Sethi S, Katze J, McCloskey J. Structure of an amniotic fluid component, 7-(4,5-cis-dihydroxy-1-cyclopenten-3-ylaminomethyl)-7-deazaguanine (queuine), a substrate for tRNA: guanine transglycosylase. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(18)43509-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Kondo T, Nakatsuka SI, Goto T. SYNTHESIS OF 7-CYANO-7-DEAZAGUANINE, ONE OF THE NUCLEOSIDE Q (QUEUOSINE) PRECURSORS FOR THE POST-TRANSCRIPTIONAL MODIFICATION OF tRNA. CHEM LETT 1980. [DOI: 10.1246/cl.1980.559] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Ohgi T, Kondo T, Goto T. SYNTHESIS OF 7-AMINOMETHYL-7-DEAZAGUANINE, ONE OF THE NUCLEOSIDE Q (QUEUOSINE) PRECURSORS FOR THE POST-TRANSCRIPTIONAL MODIFICATION OF tRNA. CHEM LETT 1979. [DOI: 10.1246/cl.1979.1283] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Kasai H, Shindo-Okada N, Noguchi S, Nishimura S. Specific fluorescent labeling of 7-(aminomethyl)-7-deazaguanosine located in the anticodon of tRNATyr isolated from E. coli mutant. Nucleic Acids Res 1979; 7:231-8. [PMID: 386280 PMCID: PMC328008 DOI: 10.1093/nar/7.1.231] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Under-modified E. coli tRNATyr that contains 7-(aminomethyl)-7-deazaguanosine in place of Q nucleoside can be chemically modified by dansyl chloride under neutral conditions. Fluorescent labelling specifically occurred only in the 7-(aminomethyl)-7-deazaguanine moiety. The modified tRNATyr was found to be active both in aminoacylation and in binding to ribosomes.
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