1
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Wang Y, Hao W, Guo Z, Sun Y, Wu Y, Sun Y, Gao T, Luo Y, Jin L, Yang J, Cheng K. Structural and functional investigation of the DHH/DHHA1 family proteins in Deinococcus radiodurans. Nucleic Acids Res 2024; 52:7142-7157. [PMID: 38804263 PMCID: PMC11229311 DOI: 10.1093/nar/gkae451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 04/24/2024] [Accepted: 05/14/2024] [Indexed: 05/29/2024] Open
Abstract
DHH/DHHA1 family proteins have been proposed to play critical roles in bacterial resistance to environmental stresses. Members of the most radioresistant bacteria genus, Deinococcus, possess two DHH/DHHA1 family proteins, RecJ and RecJ-like. While the functions of Deinococcus radiodurans RecJ (DrRecJ) in DNA damage resistance have been well characterized, the role and biochemical activities of D. radiodurans RecJ-like (DrRecJ-like) remain unclear. Phenotypic and transcriptomic analyses suggest that, beyond DNA repair, DrRecJ is implicated in cell growth and division. Additionally, DrRecJ-like not only affects stress response, cell growth, and division but also correlates with the folding/stability of intracellular proteins, as well as the formation and stability of cell membranes/walls. DrRecJ-like exhibits a preferred catalytic activity towards short single-stranded RNA/DNA oligos and c-di-AMP. In contrast, DrRecJ shows no activity against RNA and c-di-AMP. Moreover, a crystal structure of DrRecJ-like, with Mg2+ bound in an open conformation at a resolution of 1.97 Å, has been resolved. Subsequent mutational analysis was conducted to pinpoint the crucial residues essential for metal cation and substrate binding, along with the dimerization state, necessary for DrRecJ-like's function. This finding could potentially extend to all NrnA-like proteins, considering their conserved amino acid sequence and comparable dimerization forms.
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Affiliation(s)
- Ying Wang
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou 311121, China
| | - Wanshan Hao
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou 311121, China
| | - Ziming Guo
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou 311121, China
| | - Yiyang Sun
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou 311121, China
| | - Yu Wu
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou 311121, China
| | - Yukang Sun
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou 311121, China
| | - Tianwen Gao
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou 311121, China
| | - Yun Luo
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou 311121, China
| | - Lizan Jin
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou 311121, China
| | - Jieyu Yang
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou 311121, China
| | - Kaiying Cheng
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou 311121, China
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China
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2
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Skeparnias I, Bou-Nader C, Anastasakis DG, Fan L, Wang YX, Hafner M, Zhang J. Structural basis of MALAT1 RNA maturation and mascRNA biogenesis. Nat Struct Mol Biol 2024:10.1038/s41594-024-01340-4. [PMID: 38956168 DOI: 10.1038/s41594-024-01340-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Accepted: 05/29/2024] [Indexed: 07/04/2024]
Abstract
The metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) long noncoding RNA (lncRNA) has key roles in regulating transcription, splicing, tumorigenesis, etc. Its maturation and stabilization require precise processing by RNase P, which simultaneously initiates the biogenesis of a 3' cytoplasmic MALAT1-associated small cytoplasmic RNA (mascRNA). mascRNA was proposed to fold into a transfer RNA (tRNA)-like secondary structure but lacks eight conserved linking residues required by the canonical tRNA fold. Here we report crystal structures of human mascRNA before and after processing, which reveal an ultracompact, quasi-tRNA-like structure. Despite lacking all linker residues, mascRNA faithfully recreates the characteristic 'elbow' feature of tRNAs to recruit RNase P and ElaC homolog protein 2 (ELAC2) for processing, which exhibit distinct substrate specificities. Rotation and repositioning of the D-stem and anticodon regions preclude mascRNA from aminoacylation, avoiding interference with translation. Therefore, a class of metazoan lncRNA loci uses a previously unrecognized, unusually streamlined quasi-tRNA architecture to recruit select tRNA-processing enzymes while excluding others to drive bespoke RNA biogenesis, processing and maturation.
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Affiliation(s)
- Ilias Skeparnias
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA
| | - Charles Bou-Nader
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA
| | - Dimitrios G Anastasakis
- RNA Molecular Biology Laboratory, National Institute for Arthritis and Musculoskeletal and Skin Disease, Bethesda, MD, USA
| | - Lixin Fan
- Basic Science Program, Frederick National Laboratory for Cancer Research, Small-Angle X-Ray Scattering Core Facility of National Cancer Institute, Frederick, MD, USA
| | - Yun-Xing Wang
- Basic Science Program, Frederick National Laboratory for Cancer Research, Small-Angle X-Ray Scattering Core Facility of National Cancer Institute, Frederick, MD, USA
- Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
| | - Markus Hafner
- RNA Molecular Biology Laboratory, National Institute for Arthritis and Musculoskeletal and Skin Disease, Bethesda, MD, USA
| | - Jinwei Zhang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA.
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3
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Meynier V, Hardwick SW, Catala M, Roske JJ, Oerum S, Chirgadze DY, Barraud P, Yue WW, Luisi BF, Tisné C. Structural basis for human mitochondrial tRNA maturation. Nat Commun 2024; 15:4683. [PMID: 38824131 PMCID: PMC11144196 DOI: 10.1038/s41467-024-49132-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 05/21/2024] [Indexed: 06/03/2024] Open
Abstract
The human mitochondrial genome is transcribed into two RNAs, containing mRNAs, rRNAs and tRNAs, all dedicated to produce essential proteins of the respiratory chain. The precise excision of tRNAs by the mitochondrial endoribonucleases (mt-RNase), P and Z, releases all RNA species from the two RNA transcripts. The tRNAs then undergo 3'-CCA addition. In metazoan mitochondria, RNase P is a multi-enzyme assembly that comprises the endoribonuclease PRORP and a tRNA methyltransferase subcomplex. The requirement for this tRNA methyltransferase subcomplex for mt-RNase P cleavage activity, as well as the mechanisms of pre-tRNA 3'-cleavage and 3'-CCA addition, are still poorly understood. Here, we report cryo-EM structures that visualise four steps of mitochondrial tRNA maturation: 5' and 3' tRNA-end processing, methylation and 3'-CCA addition, and explain the defined sequential order of the tRNA processing steps. The methyltransferase subcomplex recognises the pre-tRNA in a distinct mode that can support tRNA-end processing and 3'-CCA addition, likely resulting from an evolutionary adaptation of mitochondrial tRNA maturation complexes to the structurally-fragile mitochondrial tRNAs. This subcomplex can also ensure a tRNA-folding quality-control checkpoint before the sequential docking of the maturation enzymes. Altogether, our study provides detailed molecular insight into RNA-transcript processing and tRNA maturation in human mitochondria.
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Affiliation(s)
- Vincent Meynier
- Expression Génétique Microbienne, Université Paris Cité, CNRS, Institut de Biologie Physico-Chimique (IBPC), 75005, Paris, France
| | - Steven W Hardwick
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Marjorie Catala
- Expression Génétique Microbienne, Université Paris Cité, CNRS, Institut de Biologie Physico-Chimique (IBPC), 75005, Paris, France
| | - Johann J Roske
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Stephanie Oerum
- Expression Génétique Microbienne, Université Paris Cité, CNRS, Institut de Biologie Physico-Chimique (IBPC), 75005, Paris, France
| | - Dimitri Y Chirgadze
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Pierre Barraud
- Expression Génétique Microbienne, Université Paris Cité, CNRS, Institut de Biologie Physico-Chimique (IBPC), 75005, Paris, France
| | - Wyatt W Yue
- Centre for Medicines Discovery, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7DQ, UK
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Ben F Luisi
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Carine Tisné
- Expression Génétique Microbienne, Université Paris Cité, CNRS, Institut de Biologie Physico-Chimique (IBPC), 75005, Paris, France.
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4
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Ma CR, Liu N, Li H, Xu H, Zhou XL. Activity reconstitution of Kre33 and Tan1 reveals a molecular ruler mechanism in eukaryotic tRNA acetylation. Nucleic Acids Res 2024; 52:5226-5240. [PMID: 38613394 PMCID: PMC11109946 DOI: 10.1093/nar/gkae262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/05/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
RNA acetylation is a universal post-transcriptional modification that occurs in various RNAs. Transfer RNA (tRNA) acetylation is found at position 34 (ac4C34) in bacterial tRNAMet and position 12 (ac4C12) in eukaryotic tRNASer and tRNALeu. The biochemical mechanism, structural basis and functional significance of ac4C34 are well understood; however, despite being discovered in the 1960s and identification of Kre33/NAT10 and Tan1/THUMPD1 as modifying apparatuses, ac4C12 modification activity has never been reconstituted for nearly six decades. Here, we successfully reconstituted the ac4C12 modification activity of yeast Kre33 and Tan1. Biogenesis of ac4C12 is primarily dependent on a minimal set of elements, including a canonical acceptor stem, the presence of the 11CCG13 motif and correct D-arm orientation, indicating a molecular ruler mechanism. A single A13G mutation conferred ac4C12 modification to multiple non-substrate tRNAs. Moreover, we were able to introduce ac4C modifications into small RNAs. ac4C12 modification contributed little to tRNA melting temperature and aminoacylation in vitro and in vivo. Collectively, our results realize in vitro activity reconstitution, delineate tRNA substrate selection mechanism for ac4C12 biogenesis and develop a valuable system for preparing acetylated tRNAs as well as non-tRNA RNA species, which will advance the functional interpretation of the acetylation in RNA structures and functions.
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Affiliation(s)
- Chun-Rui Ma
- Key Laboratory of RNA Innovation, Science and Engineering, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Na Liu
- Key Laboratory of RNA Innovation, Science and Engineering, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
- International Peace Maternity & Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, 910 Heng Shan Road, Shanghai 200030, China
| | - Hong Li
- Core Facility of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Hong Xu
- International Peace Maternity & Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, 910 Heng Shan Road, Shanghai 200030, China
| | - Xiao-Long Zhou
- Key Laboratory of RNA Innovation, Science and Engineering, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
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5
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Arrivé M, Bruggeman M, Skaltsogiannis V, Coudray L, Quan YF, Schelcher C, Cognat V, Hammann P, Chicher J, Wolff P, Gobert A, Giegé P. A tRNA-modifying enzyme facilitates RNase P activity in Arabidopsis nuclei. NATURE PLANTS 2023; 9:2031-2041. [PMID: 37945696 DOI: 10.1038/s41477-023-01564-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 10/09/2023] [Indexed: 11/12/2023]
Abstract
RNase P is the essential activity that performs the 5' maturation of transfer RNA (tRNA) precursors. Beyond the ancestral form of RNase P containing a ribozyme, protein-only RNase P enzymes termed PRORP were identified in eukaryotes. In human mitochondria, PRORP forms a complex with two protein partners to become functional. In plants, although PRORP enzymes are active alone, we investigate their interaction network to identify potential tRNA maturation complexes. Here we investigate functional interactions involving the Arabidopsis nuclear RNase P PRORP2. We show, using an immuno-affinity strategy, that PRORP2 occurs in a complex with the tRNA methyl transferases TRM1A and TRM1B in vivo. Beyond RNase P, these enzymes can also interact with RNase Z. We show that TRM1A/TRM1B localize in the nucleus and find that their double knockout mutation results in a severe macroscopic phenotype. Using a combination of immuno-detections, mass spectrometry and a transcriptome-wide tRNA sequencing approach, we observe that TRM1A/TRM1B are responsible for the m22G26 modification of 70% of cytosolic tRNAs in vivo. We use the transcriptome wide tRNAseq approach as well as RNA blot hybridizations to show that RNase P activity is impaired in TRM1A/TRM1B mutants for specific tRNAs, in particular, tRNAs containing a m22G modification at position 26 that are strongly downregulated in TRM1A/TRM1B mutants. Altogether, results indicate that the m22G-adding enzymes TRM1A/TRM1B functionally cooperate with nuclear RNase P in vivo for the early steps of cytosolic tRNA biogenesis.
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Affiliation(s)
- Mathilde Arrivé
- Institut de biologie moléculaire des plantes, UPR2357 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Mathieu Bruggeman
- Institut de biologie moléculaire des plantes, UPR2357 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Vasileios Skaltsogiannis
- Institut de biologie moléculaire des plantes, UPR2357 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Léna Coudray
- Institut de biologie moléculaire des plantes, UPR2357 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Yi-Fat Quan
- Institut de biologie moléculaire des plantes, UPR2357 du CNRS, Université de Strasbourg, Strasbourg, France
- Department of Plant Molecular Biology, University of Lausanne, Lausanne, Switzerland
| | - Cédric Schelcher
- Institut de biologie moléculaire des plantes, UPR2357 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Valérie Cognat
- Institut de biologie moléculaire des plantes, UPR2357 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Philippe Hammann
- Plateforme protéomique Strasbourg Esplanade, FR1589 du CNRS, Strasbourg, France
| | - Johana Chicher
- Plateforme protéomique Strasbourg Esplanade, FR1589 du CNRS, Strasbourg, France
| | - Philippe Wolff
- Plateforme protéomique Strasbourg Esplanade, FR1589 du CNRS, Strasbourg, France
- Architecture et Réactivité de l'ARN, Institut de Biologie Moléculaire et Cellulaire du CNRS, Université de Strasbourg, Strasbourg, France
| | - Anthony Gobert
- Institut de biologie moléculaire des plantes, UPR2357 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Philippe Giegé
- Institut de biologie moléculaire des plantes, UPR2357 du CNRS, Université de Strasbourg, Strasbourg, France.
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6
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Sekulovski S, Trowitzsch S. Transfer RNA processing - from a structural and disease perspective. Biol Chem 2022; 403:749-763. [PMID: 35728022 DOI: 10.1515/hsz-2021-0406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 05/24/2022] [Indexed: 01/05/2023]
Abstract
Transfer RNAs (tRNAs) are highly structured non-coding RNAs which play key roles in translation and cellular homeostasis. tRNAs are initially transcribed as precursor molecules and mature by tightly controlled, multistep processes that involve the removal of flanking and intervening sequences, over 100 base modifications, addition of non-templated nucleotides and aminoacylation. These molecular events are intertwined with the nucleocytoplasmic shuttling of tRNAs to make them available at translating ribosomes. Defects in tRNA processing are linked to the development of neurodegenerative disorders. Here, we summarize structural aspects of tRNA processing steps with a special emphasis on intron-containing tRNA splicing involving tRNA splicing endonuclease and ligase. Their role in neurological pathologies will be discussed. Identification of novel RNA substrates of the tRNA splicing machinery has uncovered functions unrelated to tRNA processing. Future structural and biochemical studies will unravel their mechanistic underpinnings and deepen our understanding of neurological diseases.
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Affiliation(s)
- Samoil Sekulovski
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt/Main, Germany
| | - Simon Trowitzsch
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt/Main, Germany
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7
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Jones SP, Goossen C, Lewis SD, Delaney AM, Gleghorn ML. Not making the cut: Techniques to prevent RNA cleavage in structural studies of RNase-RNA complexes. J Struct Biol X 2022; 6:100066. [PMID: 35340590 PMCID: PMC8943300 DOI: 10.1016/j.yjsbx.2022.100066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/04/2022] [Indexed: 11/16/2022] Open
Abstract
RNases are varied in the RNA structures and sequences they target for cleavage and are an important type of enzyme in cells. Despite the numerous examples of RNases known, and of those with determined three-dimensional structures, relatively few examples exist with the RNase bound to intact cognate RNA substrate prior to cleavage. To better understand RNase structure and sequence specificity for RNA targets, in vitro methods used to assemble these enzyme complexes trapped in a pre-cleaved state have been developed for a number of different RNases. We have surveyed the Protein Data Bank for such structures and in this review detail methodologies that have successfully been used and relate them to the corresponding structures. We also offer ideas and suggestions for future method development. Many strategies within this review can be used in combination with X-ray crystallography, as well as cryo-EM, and other structure-solving techniques. Our hope is that this review will be used as a guide to resolve future yet-to-be-determined RNase-substrate complex structures.
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Affiliation(s)
- Seth P. Jones
- School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, United States
| | - Christian Goossen
- School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, United States
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Lothrop St, Pittsburgh, PA 15261, United States
| | - Sean D. Lewis
- School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, United States
- Mayo Clinic, 200 1st St SW, Rochester, MN 5590, United States
| | - Annie M. Delaney
- School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, United States
| | - Michael L. Gleghorn
- School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, United States
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8
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Yip MCJ, Savickas S, Gygi SP, Shao S. ELAC1 Repairs tRNAs Cleaved during Ribosome-Associated Quality Control. Cell Rep 2021; 30:2106-2114.e5. [PMID: 32075755 DOI: 10.1016/j.celrep.2020.01.082] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 12/30/2019] [Accepted: 01/22/2020] [Indexed: 12/31/2022] Open
Abstract
Ribosome-associated quality control (RQC) disassembles aberrantly stalled translation complexes to recycle or degrade the constituent parts. A key step of RQC is the cleavage of P-site tRNA by the endonuclease ANKZF1 (Vms1 in yeast) to release incompletely synthesized polypeptides from ribosomes for degradation. Re-use of the cleaved tRNA for translation requires re-addition of the universal 3'CCA nucleotides removed by ANKZF1. Here, we show that ELAC1 is both necessary and sufficient to remove the 2',3'-cyclic phosphate on ANKZF1-cleaved tRNAs to permit CCA re-addition by TRNT1. ELAC1 activity is optimized for tRNA recycling, whereas ELAC2, the essential RNase Z isoform in eukaryotes, is required to remove 3' trailers during tRNA biogenesis. Cells lacking ELAC1 specifically accumulate unrepaired tRNA intermediates upon the induction of ribosome stalling. Thus, optimal recycling of ANKZF1-cleaved tRNAs in vertebrates is achieved through the duplication and specialization of a conserved tRNA biosynthesis enzyme.
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Affiliation(s)
- Matthew C J Yip
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Simonas Savickas
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Steven P Gygi
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Sichen Shao
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
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9
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Wang X, Gu X, Li J, Yue L, Li D, Dong X. Characterization of the Methanomicrobial Archaeal RNase Zs for Processing the CCA-Containing tRNA Precursors. Front Microbiol 2020; 11:1851. [PMID: 32982996 PMCID: PMC7479834 DOI: 10.3389/fmicb.2020.01851] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 07/15/2020] [Indexed: 01/19/2023] Open
Abstract
RNase Z is a widely distributed and usually essential endoribonuclease involved in the 3′-end maturation of transfer RNAs (tRNAs). A CCA triplet that is needed for tRNA aminoacylation in protein translation is added by a nucleotidyl-transferase after the 3′-end processing by RNase Z. However, a considerable proportion of the archaeal pre-tRNAs genetically encode a CCA motif, while the enzymatic characteristics of the archaeal RNase (aRNase) Zs in processing CCA-containing pre-tRNAs remain unclear. This study intensively characterized two methanomicrobial aRNase Zs, the Methanolobus psychrophilus mpy-RNase Z and the Methanococcus maripaludis mmp-RNase Z, particularly focusing on the properties of processing the CCA-containing pre-tRNAs, and in parallel comparison with a bacterial bsu-RNase Z from Bacillus subtilis. Kinetic analysis found that Co2+ supplementation enhanced the cleavage efficiency of mpy-RNase Z, mmp-RNase Z, and bsu-RNase Z for 1400-, 2990-, and 34-fold, respectively, and Co2+ is even more indispensable to the aRNase Zs than to bsu-RNase Z. Mg2+ also elevated the initial cleavage velocity (V0) of bsu-RNase Z for 60.5-fold. The two aRNase Zs exhibited indiscriminate efficiencies in processing CCA-containing vs. CCA-less pre-tRNAs. However, V0 of bsu-RNase Z was markedly reduced for 1520-fold by the CCA motif present in pre-tRNAs under Mg2+ supplementation, but only 5.8-fold reduced under Co2+ supplementation, suggesting Co2+ could ameliorate the CCA motif inhibition on bsu-RNase Z. By 3′-RACE, we determined that the aRNase Zs cleaved just downstream the discriminator nucleotide and the CCA triplet in CCA-less and CCA-containing pre-tRNAs, thus exposing the 3′-end for linking CCA and the genetically encoded CCA triplet, respectively. The aRNase Zs, but not bsu-RNase Z, were also able to process the intron-embedded archaeal pre-tRNAs, and even process pre-tRNAs that lack the D, T, or anticodon arm, but strictly required the acceptor stem. In summary, the two methanomicrobial aRNase Zs use cobalt as a metal ligand and process a broad spectrum of pre-tRNAs, and the characteristics would extend our understandings on aRNase Zs.
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Affiliation(s)
- Xiaoyan Wang
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Shiyan, China.,Hubei Key Laboratory of Embryonic Stem Cell Research, Hubei University of Medicine, Shiyan, China
| | - Xien Gu
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Shiyan, China
| | - Jie Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Lei Yue
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Microbial Resources, University of Chinese Academy of Sciences, Beijing, China
| | - Defeng Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiuzhu Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Microbial Resources, University of Chinese Academy of Sciences, Beijing, China
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10
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Na HW, Namgung B, Song WS, Yoon SI. Structural and biochemical analyses of the metallo-β-lactamase fold protein YhfI from Bacillus subtilis. Biochem Biophys Res Commun 2019; 519:35-40. [PMID: 31481231 DOI: 10.1016/j.bbrc.2019.08.106] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 08/19/2019] [Indexed: 12/12/2022]
Abstract
Metallo-β-lactamase (MBL) fold proteins play critical roles in diverse biological processes, such as DNA repair, RNA processing, detoxification, and metabolism. Although MBL fold proteins share a metal-bound αββα structure, they are highly heterogeneous in metal type, metal coordination, and oligomerization and exhibit different catalytic functions. Bacillus subtilis contains the yhfI gene, which is predicted to encode an MBL fold protein. To reveal the structural and functional features of YhfI, we determined two crystal structures of YhfI and biochemically characterized the catalytic activity of YhfI. YhfI forms an α-helix-decorated β-sandwich structure and assembles into a dimer using highly conserved residues. Each YhfI chain simultaneously interacts with two metal ions, which are coordinated by histidine and aspartate residues that are strictly conserved in YhfI orthologs. A comparative analysis of YhfI and its homologous structures suggests that YhfI would function as a phosphodiesterase. Indeed, YhfI drove the phosphodiesterase reaction and showed high catalytic activity at pH 8.0-9.5 in the presence of manganese. Moreover, we propose that the active site of YhfI is located at a metal-containing pocket generated between the two subunits of a YhfI dimer.
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Affiliation(s)
- Hye-Won Na
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Byeol Namgung
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Wan Seok Song
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Sung-Il Yoon
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
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11
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Bechhofer DH, Deutscher MP. Bacterial ribonucleases and their roles in RNA metabolism. Crit Rev Biochem Mol Biol 2019; 54:242-300. [PMID: 31464530 PMCID: PMC6776250 DOI: 10.1080/10409238.2019.1651816] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/22/2019] [Accepted: 07/31/2019] [Indexed: 12/16/2022]
Abstract
Ribonucleases (RNases) are mediators in most reactions of RNA metabolism. In recent years, there has been a surge of new information about RNases and the roles they play in cell physiology. In this review, a detailed description of bacterial RNases is presented, focusing primarily on those from Escherichia coli and Bacillus subtilis, the model Gram-negative and Gram-positive organisms, from which most of our current knowledge has been derived. Information from other organisms is also included, where relevant. In an extensive catalog of the known bacterial RNases, their structure, mechanism of action, physiological roles, genetics, and possible regulation are described. The RNase complement of E. coli and B. subtilis is compared, emphasizing the similarities, but especially the differences, between the two. Included are figures showing the three major RNA metabolic pathways in E. coli and B. subtilis and highlighting specific steps in each of the pathways catalyzed by the different RNases. This compilation of the currently available knowledge about bacterial RNases will be a useful tool for workers in the RNA field and for others interested in learning about this area.
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Affiliation(s)
- David H. Bechhofer
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Murray P. Deutscher
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA
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12
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Clouet-d'Orval B, Batista M, Bouvier M, Quentin Y, Fichant G, Marchfelder A, Maier LK. Insights into RNA-processing pathways and associated RNA-degrading enzymes in Archaea. FEMS Microbiol Rev 2018; 42:579-613. [PMID: 29684129 DOI: 10.1093/femsre/fuy016] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 04/17/2018] [Indexed: 12/20/2022] Open
Abstract
RNA-processing pathways are at the centre of regulation of gene expression. All RNA transcripts undergo multiple maturation steps in addition to covalent chemical modifications to become functional in the cell. This includes destroying unnecessary or defective cellular RNAs. In Archaea, information on mechanisms by which RNA species reach their mature forms and associated RNA-modifying enzymes are still fragmentary. To date, most archaeal actors and pathways have been proposed in light of information gathered from Bacteria and Eukarya. In this context, this review provides a state of the art overview of archaeal endoribonucleases and exoribonucleases that cleave and trim RNA species and also of the key small archaeal proteins that bind RNAs. Furthermore, synthetic up-to-date views of processing and biogenesis pathways of archaeal transfer and ribosomal RNAs as well as of maturation of stable small non-coding RNAs such as CRISPR RNAs, small C/D and H/ACA box guide RNAs, and other emerging classes of small RNAs are described. Finally, prospective post-transcriptional mechanisms to control archaeal messenger RNA quality and quantity are discussed.
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Affiliation(s)
- Béatrice Clouet-d'Orval
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Manon Batista
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Marie Bouvier
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Yves Quentin
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Gwennaele Fichant
- Laboratoire de Microbiologie et de Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, 31062 Toulouse, France
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Shang J, Yang Y, Wu L, Zou M, Huang Y. The S. pombe mitochondrial transcriptome. RNA (NEW YORK, N.Y.) 2018; 24:1241-1254. [PMID: 29954949 PMCID: PMC6097661 DOI: 10.1261/rna.064477.117] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 06/26/2018] [Indexed: 05/22/2023]
Abstract
Mitochondrial gene expression is largely controlled through post-transcriptional processes including mitochondrial RNA (mt-RNA) processing, modification, decay, and quality control. Defective mitochondrial gene expression results in mitochondrial oxidative phosphorylation (OXPHOS) deficiency and has been implicated in human disease. To fully understand mitochondrial transcription and RNA processing, we performed RNA-seq analyses of mt-RNAs from the fission yeast Schizosaccharomyces pombe RNA-seq analyses show that the abundance of mt-RNAs vary greatly. Analysis of data also reveals mt-RNA processing sites including an unusual RNA cleavage event by mitochondrial tRNA (mt-tRNA) 5'-end processing enzyme RNase P. Additionally, this analysis reveals previously unknown mitochondrial transcripts including the rnpB-derived fragment, mitochondrial small RNAs (mitosRNAs) such as mt-tRNA-derived fragments (mt-tRFs) and mt-tRNA halves, and mt-tRNAs marked with 3'-CCACCA/CCACC in S. pombe Finally, RNA-seq reveals that inactivation of trz2 encoding S. pombe mitochondrial tRNA 3'-end processing enzyme globally impairs mt-tRNA 3'-end processing, inhibits mt-mRNA 5'-end processing, and causes accumulation of unprocessed transcripts, demonstrating the feasibility of using RNA-seq to examine the protein known or predicted to be involved in mt-RNA processing in S. pombe Our work uncovers the complexity of a fungal mitochondrial transcriptome and provides a framework for future studies of mitochondrial gene expression using S. pombe as a model system.
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Affiliation(s)
- Jinjie Shang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Yanmei Yang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Lin Wu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Mengting Zou
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Ying Huang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
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14
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Trz1, the long form RNase Z from yeast, forms a stable heterohexamer with endonuclease Nuc1 and mutarotase. Biochem J 2017; 474:3599-3613. [PMID: 28899942 DOI: 10.1042/bcj20170435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/31/2017] [Accepted: 09/07/2017] [Indexed: 11/17/2022]
Abstract
Proteomic studies have established that Trz1, Nuc1 and mutarotase form a complex in yeast. Trz1 is a β-lactamase-type RNase composed of two β-lactamase-type domains connected by a long linker that is responsible for the endonucleolytic cleavage at the 3'-end of tRNAs during the maturation process (RNase Z activity); Nuc1 is a dimeric mitochondrial nuclease involved in apoptosis, while mutarotase (encoded by YMR099C) catalyzes the conversion between the α- and β-configuration of glucose-6-phosphate. Using gel filtration, small angle X-ray scattering and electron microscopy, we demonstrated that Trz1, Nuc1 and mutarotase form a very stable heterohexamer, composed of two copies of each of the three subunits. A Nuc1 homodimer is at the center of the complex, creating a two-fold symmetry and interacting with both Trz1 and mutarotase. Enzymatic characterization of the ternary complex revealed that the activities of Trz1 and mutarotase are not affected by complex formation, but that the Nuc1 activity is completely inhibited by mutarotase and partially by Trz1. This suggests that mutarotase and Trz1 might be regulators of the Nuc1 apoptotic nuclease activity.
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15
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Ma M, Li de la Sierra-Gallay I, Lazar N, Pellegrini O, Durand D, Marchfelder A, Condon C, van Tilbeurgh H. The crystal structure of Trz1, the long form RNase Z from yeast. Nucleic Acids Res 2017; 45:6209-6216. [PMID: 28379452 PMCID: PMC5449637 DOI: 10.1093/nar/gkx216] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 04/03/2017] [Indexed: 01/25/2023] Open
Abstract
tRNAs are synthesized as precursor RNAs that have to undergo processing steps to become functional. Yeast Trz1 is a key endoribonuclease involved in the 3΄ maturation of tRNAs in all domains of life. It is a member of the β-lactamase family of RNases, characterized by an HxHxDH sequence motif involved in coordination of catalytic Zn-ions. The RNase Z family consists of two subfamilies: the short (250-400 residues) and the long forms (about double in size). Short form RNase Z enzymes act as homodimers: one subunit embraces tRNA with a protruding arm, while the other provides the catalytic site. The long form is thought to contain two fused β-lactamase domains within a single polypeptide. Only structures of short form RNase Z enzymes are known. Here we present the 3.1 Å crystal structure of the long-form Trz1 from Saccharomyces cerevisiae. Trz1 is organized into two β-lactamase domains connected by a long linker. The N-terminal domain has lost its catalytic residues, but retains the long flexible arm that is important for tRNA binding, while it is the other way around in the C-terminal domain. Trz1 likely evolved from a duplication and fusion of the gene encoding the monomeric short form RNase Z.
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Affiliation(s)
- Miao Ma
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, University of Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Ines Li de la Sierra-Gallay
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, University of Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Noureddine Lazar
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, University of Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Olivier Pellegrini
- UMR8261 (CNRS-University of Paris Diderot, Sorbonne Paris Cité), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Dominique Durand
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, University of Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | | | - Ciarán Condon
- UMR8261 (CNRS-University of Paris Diderot, Sorbonne Paris Cité), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Herman van Tilbeurgh
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS UMR 9198, University of Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
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16
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Zhang J, Ferré-DAmaré AR. Trying on tRNA for Size: RNase P and the T-box Riboswitch as Molecular Rulers. Biomolecules 2016; 6:biom6020018. [PMID: 27043647 PMCID: PMC4919913 DOI: 10.3390/biom6020018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 03/23/2016] [Accepted: 03/25/2016] [Indexed: 12/27/2022] Open
Abstract
Length determination is a fundamental problem in biology and chemistry. Numerous proteins measure distances on linear biopolymers to exert effects with remarkable spatial precision. Recently, ruler-like devices made of noncoding RNAs have been structurally and biochemically characterized. Two prominent examples are the RNase P ribozyme and the T-box riboswitch. Both act as molecular calipers. The two RNAs clamp onto the elbow of tRNA (or pre-tRNA) and make distance measurements orthogonal to each other. Here, we compare and contrast the molecular ruler characteristics of these RNAs. RNase P appears pre-configured to measure a fixed distance on pre-tRNA to ensure the fidelity of its maturation. RNase P is a multiple-turnover ribozyme, and its rigid structure efficiently selects pre-tRNAs, cleaves, and releases them. In contrast, the T-box is flexible and segmented, an architecture that adapts to the intrinsically flexible tRNA. The tripartite T-box inspects the overall shape, anticodon sequence, and aminoacylation status of an incoming tRNA while it folds co-transcriptionally, leading to a singular, conditional genetic switching event. The elucidation of the structures and mechanisms of action of these two RNA molecular rulers may augur the discovery of new RNA measuring devices in noncoding and viral transcriptomes, and inform the design of artificial RNA rulers.
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Affiliation(s)
- Jinwei Zhang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, 50 South Drive, Bethesda, MD 20892, USA.
| | - Adrian R Ferré-DAmaré
- Laboratory of RNA Biophysics and Cellular Physiology, National Heart, Lung and Blood Institute, 50 South Drive, Bethesda, MD 20892, USA.
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17
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Soma A. Circularly permuted tRNA genes: their expression and implications for their physiological relevance and development. Front Genet 2014; 5:63. [PMID: 24744771 PMCID: PMC3978253 DOI: 10.3389/fgene.2014.00063] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 03/12/2014] [Indexed: 12/02/2022] Open
Abstract
A number of genome analyses and searches using programs that focus on the RNA-specific bulge-helix-bulge (BHB) motif have uncovered a wide variety of disrupted tRNA genes. The results of these analyses have shown that genetic information encoding functional RNAs is described in the genome cryptically and is retrieved using various strategies. One such strategy is represented by circularly permuted tRNA genes, in which the sequences encoding the 5′-half and 3′-half of the specific tRNA are separated and inverted on the genome. Biochemical analyses have defined a processing pathway in which the termini of tRNA precursors (pre-tRNAs) are ligated to form a characteristic circular RNA intermediate, which is then cleaved at the acceptor-stem to generate the typical cloverleaf structure with functional termini. The sequences adjacent to the processing site located between the 3′-half and the 5′-half of pre-tRNAs potentially form a BHB motif, which is the dominant recognition site for the tRNA-intron splicing endonuclease, suggesting that circularization of pre-tRNAs depends on the splicing machinery. Some permuted tRNAs contain a BHB-mediated intron in their 5′- or 3′-half, meaning that removal of an intron, as well as swapping of the 5′- and 3′-halves, are required during maturation of their pre-tRNAs. To date, 34 permuted tRNA genes have been identified from six species of unicellular algae and one archaeon. Although their physiological significance and mechanism of development remain unclear, the splicing system of BHB motifs seems to have played a key role in the formation of permuted tRNA genes. In this review, current knowledge of circularly permuted tRNA genes is presented and some unanswered questions regarding these species are discussed.
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Affiliation(s)
- Akiko Soma
- Graduate School of Horticulture, Chiba University Matsudo, Japan
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18
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Dutta T, Malhotra A, Deutscher MP. How a CCA sequence protects mature tRNAs and tRNA precursors from action of the processing enzyme RNase BN/RNase Z. J Biol Chem 2013; 288:30636-30644. [PMID: 24022488 DOI: 10.1074/jbc.m113.514570] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In many organisms, 3' maturation of tRNAs is catalyzed by the endoribonuclease, RNase BN/RNase Z, which cleaves after the discriminator nucleotide to generate a substrate for addition of the universal CCA sequence. However, tRNAs or tRNA precursors that already contain a CCA sequence are not cleaved, thereby avoiding a futile cycle of removal and readdition of these essential residues. We show here that the adjacent C residues of the CCA sequence and an Arg residue within a highly conserved sequence motif in the channel leading to the RNase catalytic site are both required for the protective effect of the CCA sequence. When both of these determinants are present, CCA-containing RNAs in the channel are unable to move into the catalytic site; however, substitution of either of the C residues by A or U or mutation of Arg(274) to Ala allows RNA movement and catalysis to proceed. These data define a novel mechanism for how tRNAs are protected against the promiscuous action of a processing enzyme.
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Affiliation(s)
- Tanmay Dutta
- From the Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Arun Malhotra
- From the Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Murray P Deutscher
- From the Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33136.
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19
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Wilson C, Ramai D, Serjanov D, Lama N, Levinger L, Chang EJ. Tethered domains and flexible regions in tRNase Z(L), the long form of tRNase Z. PLoS One 2013; 8:e66942. [PMID: 23874404 PMCID: PMC3714273 DOI: 10.1371/journal.pone.0066942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 05/13/2013] [Indexed: 11/30/2022] Open
Abstract
tRNase Z, a member of the metallo-β-lactamase family, endonucleolytically removes the pre-tRNA 3′ trailer in a step central to tRNA maturation. The short form (tRNase ZS) is the only one found in bacteria and archaebacteria and is also present in some eukaryotes. The homologous long form (tRNase ZL), exclusively found in eukaryotes, consists of related amino- and carboxy-domains, suggesting that tRNase ZL arose from a tandem duplication of tRNase ZS followed by interdependent divergence of the domains. X-ray crystallographic structures of tRNase ZS reveal a flexible arm (FA) extruded from the body of tRNase Z remote from the active site that binds tRNA far from the scissile bond. No tRNase ZL structures have been solved; alternative biophysical studies are therefore needed to illuminate its functional characteristics. Structural analyses of tRNase ZL performed by limited proteolysis, two dimensional gel electrophoresis and mass spectrometry establish stability of the amino and carboxy domains and flexibility of the FA and inter-domain tether, with implications for tRNase ZL function.
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Affiliation(s)
- Christopher Wilson
- Department of Biology, York College of The City University of New York, Jamaica, New York, United States of America
| | - Daryl Ramai
- Department of Chemistry, York College of The City University of New York, Jamaica, New York, United States of America
| | - Dmitri Serjanov
- Department of Biology, York College of The City University of New York, Jamaica, New York, United States of America
| | - Neema Lama
- Department of Chemistry, York College of The City University of New York, Jamaica, New York, United States of America
| | - Louis Levinger
- Department of Biology, York College of The City University of New York, Jamaica, New York, United States of America
| | - Emmanuel J. Chang
- Department of Chemistry, York College of The City University of New York, Jamaica, New York, United States of America
- * E-mail:
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Intracellular ribonucleases involved in transcript processing and decay: precision tools for RNA. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2013; 1829:491-513. [PMID: 23545199 DOI: 10.1016/j.bbagrm.2013.03.009] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 03/19/2013] [Accepted: 03/22/2013] [Indexed: 12/15/2022]
Abstract
In order to adapt to changing environmental conditions and regulate intracellular events such as division, cells are constantly producing new RNAs while discarding old or defective transcripts. These functions require the coordination of numerous ribonucleases that precisely cleave and trim newly made transcripts to produce functional molecules, and rapidly destroy unnecessary cellular RNAs. In recent years our knowledge of the nature, functions and structures of these enzymes in bacteria, archaea and eukaryotes has dramatically expanded. We present here a synthetic overview of the recent development in this dynamic area which has seen the identification of many new endoribonucleases and exoribonucleases. Moreover, the increasing pace at which the structures of these enzymes, or of their catalytic domains, have been solved has provided atomic level detail into their mechanisms of action. Based on sequence conservation and structural data, these proteins have been grouped into families, some of which contain only ribonuclease members, others including a variety of nucleolytic enzymes that act upon DNA and/or RNA. At the other extreme some ribonucleases belong to families of proteins involved in a wide variety of enzymatic reactions. Functional characterization of these fascinating enzymes has provided evidence for the extreme diversity of their biological functions that include, for example, removal of poly(A) tails (deadenylation) or poly(U) tails from eukaryotic RNAs, processing of tRNA and mRNA 3' ends, maturation of rRNAs and destruction of unnecessary mRNAs. This article is part of a Special Issue entitled: RNA Decay mechanisms.
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Pellegrini O, Li de la Sierra-Gallay I, Piton J, Gilet L, Condon C. Activation of tRNA Maturation by Downstream Uracil Residues in B. subtilis. Structure 2012; 20:1769-77. [PMID: 22940585 DOI: 10.1016/j.str.2012.08.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 07/30/2012] [Accepted: 08/05/2012] [Indexed: 11/16/2022]
Affiliation(s)
- Olivier Pellegrini
- CNRS UPR 9073 (affiliated with Université Paris Diderot, Sorbonne Paris Cité), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
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22
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Identification and sequence analysis of metazoan tRNA 3'-end processing enzymes tRNase Zs. PLoS One 2012; 7:e44264. [PMID: 22962606 PMCID: PMC3433465 DOI: 10.1371/journal.pone.0044264] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 07/31/2012] [Indexed: 11/19/2022] Open
Abstract
tRNase Z is the endonuclease responsible for removing the 3'-trailer sequences from precursor tRNAs, a prerequisite for the addition of the CCA sequence. It occurs in the short (tRNase ZS) and long (tRNase ZL) forms. Here we report the identification and sequence analysis of candidate tRNase Zs from 81 metazoan species. We found that the vast majority of deuterostomes, lophotrochozoans and lower metazoans have one tRNase ZS and one tRNase ZL genes, whereas ecdysozoans possess only a single tRNase ZL gene. Sequence analysis revealed that in metazoans, a single nuclear tRNase ZL gene is likely to encode both the nuclear and mitochondrial forms of tRNA 3′-end processing enzyme through mechanisms that include alternative translation initiation from two in-frame start codons and alternative splicing. Sequence conservation analysis revealed a variant PxKxRN motif, PxPxRG, which is located in the N-terminal region of tRNase ZSs. We also identified a previously unappreciated motif, AxDx, present in the C-terminal region of both tRNase ZSs and tRNase ZLs. The AxDx motif consisting mainly of a very short loop is potentially close enough to form hydrogen bonds with the loop containing the PxKxRN or PxPxRG motif. Through complementation analysis, we demonstrated the likely functional importance of the AxDx motif. In conclusion, our analysis supports the notion that in metazoans a single tRNase ZL has evolved to participate in both nuclear and mitochondrial tRNA 3′-end processing, whereas tRNase ZS may have evolved new functions. Our analysis also unveils new evolutionarily conserved motifs in tRNase Zs, including the C-terminal AxDx motif, which may have functional significance.
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23
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Ito K, Murakami R, Mochizuki M, Qi H, Shimizu Y, Miura KI, Ueda T, Uchiumi T. Structural basis for the substrate recognition and catalysis of peptidyl-tRNA hydrolase. Nucleic Acids Res 2012; 40:10521-31. [PMID: 22923517 PMCID: PMC3488237 DOI: 10.1093/nar/gks790] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Peptidyl-tRNA hydrolase (Pth) cleaves the ester bond between the peptide and the tRNA of peptidyl-tRNA molecules, which are produced by aborted translation, to recycle tRNA for further rounds of protein synthesis. Pth is ubiquitous in nature, and its enzymatic activity is essential for bacterial viability. We have determined the crystal structure of Escherichia coli Pth in complex with the tRNA CCA-acceptor-TΨC domain, the enzyme-binding region of the tRNA moiety of the substrate, at 2.4 Å resolution. In combination with site-directed mutagenesis studies, the structure identified the amino acid residues involved in tRNA recognition. The structure also revealed that Pth interacts with the tRNA moiety through the backbone phosphates and riboses, and no base-specific interactions were observed, except for the interaction with the highly conserved base G53. This feature enables Pth to accept the diverse sequences of the elongator-tRNAs as substrate components. Furthermore, we propose an authentic Pth:peptidyl-tRNA complex model and a detailed mechanism for the hydrolysis reaction, based on the present crystal structure and the previous studies’ results.
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Affiliation(s)
- Kosuke Ito
- Department of Biology, Faculty of Science, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181, Japan.
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Dutta T, Malhotra A, Deutscher MP. Exoribonuclease and endoribonuclease activities of RNase BN/RNase Z both function in vivo. J Biol Chem 2012; 287:35747-35755. [PMID: 22893707 DOI: 10.1074/jbc.m112.407403] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Escherichia coli RNase BN, a member of the RNase Z family of endoribonucleases, differs from other family members in that it also can act as an exoribonuclease in vitro. Here, we examine whether this activity of RNase BN also functions in vivo. Comparison of the x-ray structure of RNase BN with that of Bacillus subtilis RNase Z, which lacks exoribonuclease activity, revealed that RNase BN has a narrower and more rigid channel downstream of the catalytic site. We hypothesized that this difference in the putative RNA exit channel might be responsible for the acquisition of exoribonuclease activity by RNase BN. Accordingly, we generated several mutant RNase BN proteins in which residues within a loop in this channel were converted to the corresponding residues present in B. subtilis RNase Z, thus widening the channel and increasing its flexibility. The resulting mutant RNase BN proteins had reduced or were essentially devoid of exoribonuclease activity in vitro. Substitution of one mutant rbn gene (P142G) for wild type rbn in the E. coli chromosome revealed that the exoribonuclease activity of RNase BN is not required for maturation of phage T4 tRNA precursors, a known specific function of this RNase. On the other hand, removal of the exoribonuclease activity of RNase BN in a cell lacking other processing RNases leads to slower growth and affects maturation of multiple tRNA precursors. These findings help explain how RNase BN can act as both an exo- and an endoribonuclease and also demonstrate that its exoribonuclease activity is capable of functioning in vivo, thus widening the potential role of this enzyme in E. coli.
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Affiliation(s)
- Tanmay Dutta
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Arun Malhotra
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Murray P Deutscher
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33136.
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Levinger L, Serjanov D. Pathogenesis-related mutations in the T-loops of human mitochondrial tRNAs affect 3' end processing and tRNA structure. RNA Biol 2012; 9:283-91. [PMID: 22336717 PMCID: PMC3384583 DOI: 10.4161/rna.19025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Numerous mutations in the mitochondrial genome are associated with maternally transmitted diseases and syndromes that affect muscle and other high energy-demand tissues. The mitochondrial genome encodes 13 polypeptides, 2 rRNAs and 22 interspersed tRNAs via long bidirectional polycistronic primary transcripts, requiring precise excision of the tRNAs. Despite making up only ~10% of the mitochondrial genome, tRNA genes harbor most of the pathogenesis-related mutations. tRNase Z endonucleolytically removes the pre-tRNA 3' trailer. The flexible arm of tRNase Z recognizes and binds the elbow (including the T-loop) of pre-tRNA. Pathogenesis-related T-loop mutations in mitochondrial tRNAs could thus affect tRNA structure, reduce tRNase Z binding and 3' processing, and consequently slow mitochondrial protein synthesis. Here we inspect the effects of pathogenesis-related mutations in the T-loops of mitochondrial tRNAs on pre-tRNA structure and tRNase Z processing. Increases in K(M) arising from 59A > G substitutions in mitochondrial tRNA(Gly) and tRNA(Ile) accompany changes in T-loop structure, suggesting impaired substrate binding to enzyme.
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Affiliation(s)
- Louis Levinger
- York College of The City University of New York, Jamaica, NY, USA.
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Rossmanith W. Of P and Z: mitochondrial tRNA processing enzymes. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1819:1017-26. [PMID: 22137969 PMCID: PMC3790967 DOI: 10.1016/j.bbagrm.2011.11.003] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 11/11/2011] [Accepted: 11/15/2011] [Indexed: 12/18/2022]
Abstract
Mitochondrial tRNAs are generally synthesized as part of polycistronic transcripts. Release of tRNAs from these precursors is thus not only required to produce functional adaptors for translation, but also responsible for the maturation of other mitochondrial RNA species. Cleavage of mitochondrial tRNAs appears to be exclusively accomplished by endonucleases. 5'-end maturation in the mitochondria of different Eukarya is achieved by various kinds of RNase P, representing the full range of diversity found in this enzyme family. While ribonucleoprotein enzymes with RNA components of bacterial-like appearance are found in a few unrelated protists, algae, and fungi, highly degenerate RNAs of dramatic size variability are found in the mitochondria of many fungi. The majority of mitochondrial RNase P enzymes, however, appear to be pure protein enzymes. Human mitochondrial RNase P, the first to be identified and possibly the prototype of all animal mitochondrial RNases P, is composed of three proteins. Homologs of its nuclease subunit MRPP3/PRORP, are also found in plants, algae and several protists, where they are apparently responsible for RNase P activity in mitochondria (and beyond) without the help of extra subunits. The diversity of RNase P enzymes is contrasted by the uniformity of mitochondrial RNases Z, which are responsible for 3'-end processing. Only the long form of RNase Z, which is restricted to eukarya, is found in mitochondria, even when an additional short form is present in the same organism. Mitochondrial tRNA processing thus appears dominated by new, eukaryal inventions rather than bacterial heritage. This article is part of a Special Issue entitled: Mitochondrial Gene Expression.
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Affiliation(s)
- Walter Rossmanith
- Center for Anatomy & Cell Biology, Medical University of Vienna, Austria.
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He SM, Wathier M, Podzelinska K, Wong M, McSorley FR, Asfaw A, Hove-Jensen B, Jia Z, Zechel DL. Structure and mechanism of PhnP, a phosphodiesterase of the carbon-phosphorus lyase pathway. Biochemistry 2011; 50:8603-15. [PMID: 21830807 DOI: 10.1021/bi2005398] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PhnP is a phosphodiesterase that plays an important role within the bacterial carbon-phosphorus lyase (CP-lyase) pathway by recycling a "dead-end" intermediate, 5-phospho-α-d-ribosyl 1,2-cyclic phosphate, that is formed during organophosphonate catabolism. As a member of the metallo-β-lactamase superfamily, PhnP is most homologous in sequence and structure to tRNase Z phosphodiesterases. X-ray structural analysis of PhnP complexed with orthovanadate to 1.5 Å resolution revealed this inhibitor bound in a tetrahedral geometry by the two catalytic manganese ions and the putative general acid residue H200. Guided by this structure, we probed the contributions of first- and second-sphere active site residues to catalysis and metal ion binding by site-directed mutagenesis, kinetic analysis, and ICP-MS. Alteration of H200 to alanine resulted in a 6-33-fold decrease in k(cat)/K(M) with substituted methyl phenylphosphate diesters with leaving group pK(a) values ranging from 4 to 8.4. With bis(p-nitrophenyl)phosphate as a substrate, there was a 10-fold decrease in k(cat)/K(M), primarily the result of a large increase in K(M). Moreover, the nickel ion-activated H200A PhnP displayed a bell-shaped pH dependence for k(cat)/K(M) with pK(a) values (pK(a1) = 6.3; pK(a2) = 7.8) that were comparable to those of the wild-type enzyme (pK(a1) = 6.5; pK(a2) = 7.8). Such modest effects are counter to what is expected for a general acid catalyst and suggest an alternate role for H200 in this enzyme. A Brønsted analysis of the PhnP reaction with a series of substituted phenyl methyl phosphate esters yielded a linear correlation, a β(lg) of -1.06 ± 0.1, and a Leffler α value of 0.61, consistent with a synchronous transition state for phosphoryl transfer. On the basis of these data, we propose a mechanism for PhnP.
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Affiliation(s)
- Shu-Mei He
- Department of Chemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada
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Fan L, Wang Z, Liu J, Guo W, Yan J, Huang Y. A survey of green plant tRNA 3'-end processing enzyme tRNase Zs, homologs of the candidate prostate cancer susceptibility protein ELAC2. BMC Evol Biol 2011; 11:219. [PMID: 21781332 PMCID: PMC3161902 DOI: 10.1186/1471-2148-11-219] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Accepted: 07/23/2011] [Indexed: 11/10/2022] Open
Abstract
Background tRNase Z removes the 3'-trailer sequences from precursor tRNAs, which is an essential step preceding the addition of the CCA sequence. tRNase Z exists in the short (tRNase ZS) and long (tRNase ZL) forms. Based on the sequence characteristics, they can be divided into two major types: bacterial-type tRNase ZS and eukaryotic-type tRNase ZL, and one minor type, Thermotoga maritima (TM)-type tRNase ZS. The number of tRNase Zs is highly variable, with the largest number being identified experimentally in the flowering plant Arabidopsis thaliana. It is unknown whether multiple tRNase Zs found in A. thaliana is common to the plant kingdom. Also unknown is the extent of sequence and structural conservation among tRNase Zs from the plant kingdom. Results We report the identification and analysis of candidate tRNase Zs in 27 fully sequenced genomes of green plants, the great majority of which are flowering plants. It appears that green plants contain multiple distinct tRNase Zs predicted to reside in different subcellular compartments. Furthermore, while the bacterial-type tRNase ZSs are present only in basal land plants and green algae, the TM-type tRNase ZSs are widespread in green plants. The protein sequences of the TM-type tRNase ZSs identified in green plants are similar to those of the bacterial-type tRNase ZSs but have distinct features, including the TM-type flexible arm, the variant catalytic HEAT and HST motifs, and a lack of the PxKxRN motif involved in CCA anti-determination (inhibition of tRNase Z activity by CCA), which prevents tRNase Z cleavage of mature tRNAs. Examination of flowering plant chloroplast tRNA genes reveals that many of these genes encode partial CCA sequences. Based on our results and previous studies, we predict that the plant TM-type tRNase ZSs may not recognize the CCA sequence as an anti-determinant. Conclusions Our findings substantially expand the current repertoire of the TM-type tRNase ZSs and hint at the possibility that these proteins may have been selected for their ability to process chloroplast pre-tRNAs with whole or partial CCA sequences. Our results also support the coevolution of tRNase Zs and tRNA 3'-trailer sequences in plants.
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Affiliation(s)
- Lijuan Fan
- Laboratory of Yeast Genetics and Molecular Biology, School of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China
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The fission yeast Schizosaccharomyces pombe has two distinct tRNase ZLs encoded by two different genes and differentially targeted to the nucleus and mitochondria. Biochem J 2011; 435:103-11. [DOI: 10.1042/bj20101619] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
tRNase Z is the endonuclease that is involved in tRNA 3′-end maturation by removal of the 3′-trailer sequences from tRNA precursors. Most eukaryotes examined to date, including the budding yeast Saccharomyces cerevisiae and humans, have a single long form of tRNase Z (tRNase ZL). In contrast, the fission yeast Schizosaccharomyces pombe contains two candidate tRNase ZLs encoded by the essential genes sptrz1+ and sptrz2+. In the present study, we have expressed recombinant SpTrz1p and SpTrz2p in S. pombe. Both recombinant proteins possess precursor tRNA 3′-endonucleolytic activity in vitro. SpTrz1p localizes to the nucleus and has a simian virus 40 NLS (nuclear localization signal)-like NLS at its N-terminus, which contains four consecutive arginine and lysine residues between residues 208 and 211 that are critical for the NLS function. In contrast, SpTrz2p is a mitochondrial protein with an N-terminal MTS (mitochondrial-targeting signal). High-level overexpression of sptrz1+ has no detectable phenotypes. In contrast, strong overexpression of sptrz2+ is lethal in wild-type cells and results in morphological abnormalities, including swollen and round cells, demonstrating that the correct expression level of sptrz2+ is critical. The present study provides evidence for partitioning of tRNase Z function between two different proteins in S. pombe, although we cannot rule out specialized functions for each protein.
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31
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Crystal structure of a dimeric archaeal cleavage and polyadenylation specificity factor. J Struct Biol 2010; 173:191-5. [PMID: 20851187 DOI: 10.1016/j.jsb.2010.09.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 09/08/2010] [Accepted: 09/14/2010] [Indexed: 11/24/2022]
Abstract
Proteins of the metallo-β-lactamase (MβL) fold form a large superfamily of metallo-hydrolase/oxidoreductases. Members of this family are found in all three domains of life and are involved in a variety of biological functions related to hydrolysis, redox processes, DNA repair and uptake, and RNA processing. We classified the archaeal homologs of this superfamily based on sequence similarity and characterized a subfamily of the Cleavage and Polyadenylation Specificity Factor (CPSF) with an uncommon domain composition: in addition to an extended MβL domain, which accommodates the active site for RNA cleavage, this group has two N-terminal KH domains. Here, we present the crystal structure of a member of this group from Methanosarcina mazei. It reveals a dimerization mode of the MβL domain that has not been observed before and suggests that RNA is bound across the dimer interface, recognized by the KH domains of one monomer, and cleaved at the active site of the other.
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Abstract
tRNA biology has come of age, revealing an unprecedented level of understanding and many unexpected discoveries along the way. This review highlights new findings on the diverse pathways of tRNA maturation, and on the formation and function of a number of modifications. Topics of special focus include the regulation of tRNA biosynthesis, quality control tRNA turnover mechanisms, widespread tRNA cleavage pathways activated in response to stress and other growth conditions, emerging evidence of signaling pathways involving tRNA and cleavage fragments, and the sophisticated intracellular tRNA trafficking that occurs during and after biosynthesis.
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Affiliation(s)
- Eric M Phizicky
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York 14642, USA.
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Zhao W, Yu H, Li S, Huang Y. Identification and analysis of candidate fungal tRNA 3'-end processing endonucleases tRNase Zs, homologs of the putative prostate cancer susceptibility protein ELAC2. BMC Evol Biol 2010; 10:272. [PMID: 20819227 PMCID: PMC2942849 DOI: 10.1186/1471-2148-10-272] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 09/06/2010] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND tRNase Z is the endonuclease that is responsible for the 3'-end processing of tRNA precursors, a process essential for tRNA 3'-CCA addition and subsequent tRNA aminoacylation. Based on their sizes, tRNase Zs can be divided into the long (tRNase ZL) and short (tRNase ZS) forms. tRNase ZL is thought to have arisen from a tandem gene duplication of tRNase ZS with further sequence divergence. The species distribution of tRNase Z is complex. Fungi represent an evolutionarily diverse group of eukaryotes. The recent proliferation of fungal genome sequences provides an opportunity to explore the structural and functional diversity of eukaryotic tRNase Zs. RESULTS We report a survey and analysis of candidate tRNase Zs in 84 completed fungal genomes, spanning a broad diversity of fungi. We find that tRNase ZL is present in all fungi we have examined, whereas tRNase ZS exists only in the fungal phyla Basidiomycota, Chytridiomycota and Zygomycota. Furthermore, we find that unlike the Pezizomycotina and Saccharomycotina, which contain a single tRNase ZL, Schizosaccharomyces fission yeasts (Taphrinomycotina) contain two tRNase ZLs encoded by two different tRNase ZL genes. These two tRNase ZLs are most likely localized to the nucleus and mitochondria, respectively, suggesting partitioning of tRNase Z function between two different tRNase ZLs in fission yeasts. The fungal tRNase Z phylogeny suggests that tRNase ZSs are ancestral to tRNase ZLs. Additionally, the evolutionary relationship of fungal tRNase ZLs is generally consistent with known phylogenetic relationships among the fungal species and supports tRNase ZL gene duplication in certain fungal taxa, including Schizosaccharomyces fission yeasts. Analysis of tRNase Z protein sequences reveals putative atypical substrate binding domains in most fungal tRNase ZSs and in a subset of fungal tRNase ZLs. Finally, we demonstrate the presence of pseudo-substrate recognition and catalytic motifs at the N-terminal halves of tRNase ZLs. CONCLUSIONS This study describes the first comprehensive identification and sequence analysis of candidate fungal tRNase Zs. Our results support the proposal that tRNase ZL has evolved as a result of duplication and diversification of the tRNase ZS gene.
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Affiliation(s)
- Wei Zhao
- Nanjing Engineering and Technology Research Center for Microbiology, Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Life Sciences, Nanjing Normal University, Nanjing 210046, China
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Cattell E, Sengerová B, McHugh PJ. The SNM1/Pso2 family of ICL repair nucleases: from yeast to man. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2010; 51:635-645. [PMID: 20175117 DOI: 10.1002/em.20556] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Efficient interstrand crosslink (ICL) repair in yeast depends on the Pso2/Snm1 protein. Pso2 is a member of the highly conserved metallo-beta-lactamase structural family of nucleases. Mammalian cells possess three SNM1/Pso2 related proteins, SNM1A, SNM1B/Apollo, and SNM1C/Artemis. Evidence that SNM1A and SNM1B contribute to ICL repair is mounting, whereas Artemis appears to primarily contribute to non-ICL repair pathways, particularly some double-strand break repair events. Yeast Pso2 and all three mammalian SNM1-family proteins have been shown to possess nuclease activity. Here, we review the biochemical, genetic, and cellular evidence for the SNM1 family as DNA repair factors, focusing on ICL repair.
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Affiliation(s)
- Emma Cattell
- Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
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35
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Tertiary structure checkpoint at anticodon loop modification in tRNA functional maturation. Nat Struct Mol Biol 2009; 16:1109-15. [PMID: 19749755 DOI: 10.1038/nsmb.1653] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Accepted: 06/29/2009] [Indexed: 11/08/2022]
Abstract
tRNA precursors undergo a maturation process, involving nucleotide modifications and folding into the L-shaped tertiary structure. The N1-methylguanosine at position 37 (m1G37), 3' adjacent to the anticodon, is essential for translational fidelity and efficiency. In archaea and eukaryotes, Trm5 introduces the m1G37 modification into all tRNAs bearing G37. Here we report the crystal structures of archaeal Trm5 (aTrm5) in complex with tRNA(Leu) or tRNA(Cys). The D2-D3 domains of aTrm5 discover and modify G37, independently of the tRNA sequences. D1 is connected to D2-D3 through a flexible linker and is designed to recognize the shape of the tRNA outer corner, as a hallmark of the completed L shape formation. This interaction by D1 lowers the K(m) value for tRNA, enabling the D2-D3 catalysis. Thus, we propose that aTrm5 provides the tertiary structure checkpoint in tRNA maturation.
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Functional conservation of tRNase ZL among Saccharomyces cerevisiae, Schizosaccharomyces pombe and humans. Biochem J 2009; 422:483-92. [PMID: 19555350 DOI: 10.1042/bj20090743] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Although tRNase Z from various organisms was shown to process nuclear tRNA 3' ends in vitro, only a very limited number of studies have reported its in vivo biological functions. tRNase Z is present in a short form, tRNase Z(S), and a long form, tRNase Z(L). Unlike Saccharomyces cerevisiae, which contains one tRNase Z(L) gene (scTRZ1) and humans, which contain one tRNase Z(L) encoded by the prostate-cancer susceptibility gene ELAC2 and one tRNase Z(S), Schizosaccharomyces pombe contains two tRNase Z(L) genes, designated sptrz1(+) and sptrz2(+). We report that both sptrz1(+) and sptrz2(+) are essential for growth. Moreover, sptrz1(+) is required for cell viability in the absence of Sla1p, which is thought to be required for endonuclease-mediated maturation of pre-tRNA 3' ends in yeast. Both scTRZ1 and ELAC2 can complement a temperature-sensitive allele of sptrz1(+), sptrz1-1, but not the sptrz1 null mutant, indicating that despite exhibiting species specificity, tRNase Z(L)s are functionally conserved among S. cerevisiae, S. pombe and humans. Overexpression of sptrz1(+), scTRZ1 and ELAC2 can increase suppression of the UGA nonsense mutation ade6-704 through facilitating 3' end processing of the defective suppressor tRNA that mediates suppression. Our findings reveal that 3' end processing is a limiting step for defective tRNA maturation and demonstrate that overexpression of sptrz1(+), scTRZ1 and ELAC2 can promote defective tRNA 3' processing in vivo. Our results also support the notion that yeast tRNase Z(L) is absolutely required for 3' end processing of at least a few pre-tRNAs even in the absence of Sla1p.
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Daou-Chabo R, Condon C. RNase J1 endonuclease activity as a probe of RNA secondary structure. RNA (NEW YORK, N.Y.) 2009; 15:1417-25. [PMID: 19458035 PMCID: PMC2704070 DOI: 10.1261/rna.1574309] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Accepted: 04/16/2009] [Indexed: 05/27/2023]
Abstract
Reliable determination of RNA secondary structure depends on both computer algorithms and experimental probing of nucleotides in single- or double-stranded conformation. Here we describe the exploitation of the endonucleolytic activity of the Bacillus subtilis enzyme RNase J1 as a probe of RNA structure. RNase J1 cleaves in single-stranded regions and, in vitro at least, the enzyme has relatively relaxed nucleotide specificity. We confirmed the feasibility of the approach on an RNA of known structure, B. subtilis tRNA(Thr). We then used RNase J1 to solve the secondary structure of the 5' end of the hbs mRNA. Finally, we showed that RNase J1 can also be used in footprinting experiments by probing the interaction between the 30S ribosomal subunit and the Shine-Dalgarno element of the hbs mRNA.
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Affiliation(s)
- Roula Daou-Chabo
- Institut de Biologie Physico-Chimique, Centre National de la Recherche Scientifique UPR 9073, Université de Paris 7-Denis Diderot, 75005 Paris, France
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Liao RZ, Himo F, Yu JG, Liu RZ. Theoretical Study of the RNA Hydrolysis Mechanism of the Dinuclear Zinc Enzyme RNase Z. Eur J Inorg Chem 2009. [DOI: 10.1002/ejic.200900202] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Dutta T, Deutscher MP. Catalytic properties of RNase BN/RNase Z from Escherichia coli: RNase BN is both an exo- and endoribonuclease. J Biol Chem 2009; 284:15425-31. [PMID: 19366704 PMCID: PMC2708839 DOI: 10.1074/jbc.m109.005462] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Revised: 04/07/2009] [Indexed: 11/06/2022] Open
Abstract
Processing of the 3' terminus of tRNA in many organisms is carried out by an endoribonuclease termed RNase Z or 3'-tRNase, which cleaves after the discriminator nucleotide to allow addition of the universal -CCA sequence. In some eubacteria, such as Escherichia coli, the -CCA sequence is encoded in all known tRNA genes. Nevertheless, an RNase Z homologue (RNase BN) is still present, even though its action is not needed for tRNA maturation. To help identify which RNA molecules might be potential substrates for RNase BN, we carried out a detailed examination of its specificity and catalytic potential using a variety of synthetic substrates. We show here that RNase BN is active on both double- and single-stranded RNA but that duplex RNA is preferred. The enzyme displays a profound base specificity, showing no activity on runs of C residues. RNase BN is strongly inhibited by the presence of a 3'-CCA sequence or a 3'-phosphoryl group. Digestion by RNase BN leads to 3-mers as the limit products, but the rate slows on molecules shorter than 10 nucleotides in length. Most interestingly, RNase BN acts as a distributive exoribonuclease on some substrates, releasing mononucleotides and a ladder of digestion products. However, RNase BN also cleaves endonucleolytically, releasing 3' fragments as short as 4 nucleotides. Although the presence of a 3'-phosphoryl group abolishes exoribonuclease action, it has no effect on the endoribonucleolytic cleavages. These data suggest that RNase BN may differ from other members of the RNase Z family, and they provide important information to be considered in identifying a physiological role for this enzyme.
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Affiliation(s)
- Tanmay Dutta
- From the Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33101
| | - Murray P. Deutscher
- From the Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33101
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Podzelinska K, He SM, Wathier M, Yakunin A, Proudfoot M, Hove-Jensen B, Zechel DL, Jia Z. Structure of PhnP, a phosphodiesterase of the carbon-phosphorus lyase pathway for phosphonate degradation. J Biol Chem 2009; 284:17216-17226. [PMID: 19366688 DOI: 10.1074/jbc.m808392200] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Carbon-phosphorus lyase is a multienzyme system encoded by the phn operon that enables bacteria to metabolize organophosphonates when the preferred nutrient, inorganic phosphate, is scarce. One of the enzymes encoded by this operon, PhnP, is predicted by sequence homology to be a metal-dependent hydrolase of the beta-lactamase superfamily. Screening with a wide array of hydrolytically sensitive substrates indicated that PhnP is an enzyme with phosphodiesterase activity, having the greatest specificity toward bis(p-nitrophenyl)phosphate and 2',3'-cyclic nucleotides. No activity was observed toward RNA. The metal ion dependence of PhnP with bis(p-nitrophenyl)phosphate as substrate revealed a distinct preference for Mn(2+) and Ni(2+) for catalysis, whereas Zn(2+) afforded poor activity. The three-dimensional structure of PhnP was solved by x-ray crystallography to 1.4 resolution. The overall fold of PhnP is very similar to that of the tRNase Z endonucleases but lacks the long exosite module used by these enzymes to bind their tRNA substrates. The active site of PhnP contains what are probably two Mn(2+) ions surrounded by an array of active site residues that are identical to those observed in the tRNase Z enzymes. A second, remote Zn(2+) binding site is also observed, composed of a set of cysteine and histidine residues that are strictly conserved in the PhnP family. This second metal ion site appears to stabilize a structural motif.
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Affiliation(s)
| | - Shu-Mei He
- Chemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Matthew Wathier
- Chemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Alexander Yakunin
- Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario M5G 1L6, Canada
| | - Michael Proudfoot
- Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario M5G 1L6, Canada
| | - Bjarne Hove-Jensen
- Department of Biology, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - David L Zechel
- From the Departments of Biochemistry, Kingston, Ontario K7L 3N6, Canada.
| | - Zongchao Jia
- From the Departments of Biochemistry, Kingston, Ontario K7L 3N6, Canada.
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Levinger L, Hopkinson A, Desetty R, Wilson C. Effect of changes in the flexible arm on tRNase Z processing kinetics. J Biol Chem 2009; 284:15685-91. [PMID: 19351879 DOI: 10.1074/jbc.m900745200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
tRNAs are transcribed as precursors and processed in a series of reactions culminating in aminoacylation and translation. Central to tRNA maturation, the 3' end trailer can be endonucleolytically removed by tRNase Z. A flexible arm (FA) extruded from the body of tRNase Z consists of a structured alphaalphabetabeta hand that binds the elbow of pre-tRNA. Deleting the FA hand causes an almost 100-fold increase in Km with little change in kcat, establishing its contribution to substrate recognition/binding. Remarkably, a 40-residue Ala scan through the FA hand reveals a conserved leucine at the ascending stalk/hand boundary that causes practically the same increase in Km as the hand deletion, thus nearly eliminating its ability to bind substrate. Km also increases with substitutions in the GP (alpha4-alpha5) loop and at other conserved residues in the FA hand predicted to contact substrate based on the co-crystal structure. Substitutions that reduce kcat are clustered in the beta10-beta11 loop.
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Affiliation(s)
- Louis Levinger
- Department of Biology, York College of the City University of New York, Jamaica, New York 11451, USA.
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Hartmann RK, Gössringer M, Späth B, Fischer S, Marchfelder A. The making of tRNAs and more - RNase P and tRNase Z. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 85:319-68. [PMID: 19215776 DOI: 10.1016/s0079-6603(08)00808-8] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Transfer-RNA (tRNA) molecules are essential players in protein biosynthesis. They are transcribed as precursors, which have to be extensively processed at both ends to become functional adaptors in protein synthesis. Two endonucleases that directly interact with the tRNA moiety, RNase P and tRNase Z, remove extraneous nucleotides on the molecule's 5'- and 3'-side, respectively. The ribonucleoprotein enzyme RNase P was identified almost 40 years ago and is considered a vestige from the "RNA world". Here, we present the state of affairs on prokaryotic RNase P, with a focus on recent findings on its role in RNA metabolism. tRNase Z was only identified 6 years ago, and we do not yet have a comprehensive understanding of its function. The current knowledge on prokaryotic tRNase Z in tRNA 3'-processing is reviewed here. A second, tRNase Z-independent pathway of tRNA 3'-end maturation involving 3'-exonucleases will also be discussed.
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Affiliation(s)
- Roland K Hartmann
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, D-35037 Marburg, Germany
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43
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Minagawa A, Ishii R, Takaku H, Yokoyama S, Nashimoto M. The flexible arm of tRNase Z is not essential for pre-tRNA binding but affects cleavage site selection. J Mol Biol 2008; 381:289-99. [PMID: 18602113 DOI: 10.1016/j.jmb.2008.05.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2007] [Revised: 05/02/2008] [Accepted: 05/08/2008] [Indexed: 10/22/2022]
Abstract
tRNase Z is an enzyme responsible for removing a 3' trailer from pre-tRNA. Although most tRNase Zs cleave pre-tRNAs immediately after the discriminator nucleotide with the exception of Thermotoga maritima tRNase Z, which cleaves after the (74)CCA(76) sequence, our knowledge was limited about how the cleavage site in pre-tRNA is selected. Bacterial tRNase Zs contain a unique domain termed flexible arm, which extends from the core domain. Using various tRNase Z variants, here we examined how the flexible arm affects the cleavage site selection. T. maritima tRNase Z variants with modified flexible arms shifted the cleavage site and a Bacillus subtilis tRNase Z variant with no flexible arm showed an anomalous cleavage activity. Some of the T. maritima/B. subtilis chimeric enzymes had both properties: they recognized (74)CCA(76)-containing pre-tRNA and cleaved it after the discriminator. Taken together, the present data indicate that the flexible arm is not essential for pre-tRNA binding but affects the cleavage site selection probably by pushing the distal region of the T arm in such a way that the discriminator nucleotide becomes closer to the catalytic site.
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Affiliation(s)
- Asako Minagawa
- Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata 956-8603, Japan
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44
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Abstract
Most eukaryotic mRNA precursors (premRNAs) must undergo extensive processing, including cleavage and polyadenylation at the 3'-end. Processing at the 3'-end is controlled by sequence elements in the pre-mRNA (cis elements) as well as protein factors. Despite the seeming biochemical simplicity of the processing reactions, more than 14 proteins have been identified for the mammalian complex, and more than 20 proteins have been identified for the yeast complex. The 3'-end processing machinery also has important roles in transcription and splicing. The mammalian machinery contains several sub-complexes, including cleavage and polyadenylation specificity factor, cleavage stimulation factor, cleavage factor I, and cleavage factor II. Additional protein factors include poly(A) polymerase, poly(A)-binding protein, symplekin, and the C-terminal domain of RNA polymerase II largest subunit. The yeast machinery includes cleavage factor IA, cleavage factor IB, and cleavage and polyadenylation factor.
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Affiliation(s)
- C. R. Mandel
- Department of Biological Sciences, Columbia University, New York, NY 10027 USA
| | - Y. Bai
- Department of Biological Sciences, Columbia University, New York, NY 10027 USA
| | - L. Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027 USA
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45
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Structural insights into the dual activity of RNase J. Nat Struct Mol Biol 2008; 15:206-12. [PMID: 18204464 DOI: 10.1038/nsmb.1376] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2007] [Accepted: 12/18/2007] [Indexed: 11/08/2022]
Abstract
The maturation and stability of RNA transcripts is controlled by a combination of endo- and exoRNases. RNase J is unique, as it combines an RNase E-like endoribonucleolytic and a 5'-to-3' exoribonucleolytic activity in a single polypeptide. The structural basis for this dual activity is unknown. Here we report the crystal structures of Thermus thermophilus RNase J and its complex with uridine 5'-monophosphate. A binding pocket coordinating the phosphate and base moieties of the nucleotide in the vicinity of the catalytic center provide a rationale for the 5'-monophosphate-dependent 5'-to-3' exoribonucleolytic activity. We show that this dependence is strict; an initial 5'-PPP transcript cannot be degraded exonucleolytically from the 5'-end. Our results suggest that RNase J might switch promptly from endo- to exonucleolytic mode on the same RNA, a property that has important implications for RNA metabolism in numerous prokaryotic organisms and plant organelles containing RNase J orthologs.
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Karkashon S, Hopkinson A, Levinger L. tRNase Z catalysis and conserved residues on the carboxy side of the His cluster. Biochemistry 2007; 46:9380-7. [PMID: 17655328 PMCID: PMC2526284 DOI: 10.1021/bi700578v] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
tRNAs are transcribed as precursors and processed in a series of required reactions leading to aminoacylation and translation. The 3'-end trailer can be removed by the pre-tRNA processing endonuclease tRNase Z, an ancient, conserved member of the beta-lactamase superfamily of metal-dependent hydrolases. The signature sequence of this family, the His domain (HxHxDH, Motif II), and histidines in Motifs III and V and aspartate in Motif IV contribute seven side chains for the coordination of two divalent metal ions. We previously investigated the effects on catalysis of substitutions in Motif II and in the PxKxRN loop and Motif I on the amino side of Motif II. Herein, we present the effects of substitutions on the carboxy side of Motif II within Motifs III, IV, the HEAT and HST loops, and Motif V. Substitution of the Motif IV aspartate reduces catalytic efficiency more than 10,000-fold. Histidines in Motif III, V, and the HST loop are also functionally important. Strikingly, replacement of Glu in the HEAT loop with Ala reduces efficiency by approximately 1000-fold. Proximity and orientation of this Glu side chain relative to His in the HST loop and the importance of both residues for catalysis suggest that they function as a duo in proton transfer at the final stage of reaction, characteristic of the tRNase Z class of RNA endonucleases.
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Affiliation(s)
| | | | - Louis Levinger
- *to whom correspondence should be addressed: Phone: 718-262-2704 FAX: 718-262-2652
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Ishii R, Minagawa A, Takaku H, Takagi M, Nashimoto M, Yokoyama S. The structure of the flexible arm of Thermotoga maritima tRNase Z differs from those of homologous enzymes. Acta Crystallogr Sect F Struct Biol Cryst Commun 2007; 63:637-41. [PMID: 17671357 PMCID: PMC2335171 DOI: 10.1107/s1744309107033623] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Accepted: 07/10/2007] [Indexed: 11/11/2022]
Abstract
tRNA 3'-processing endoribonuclease (tRNase Z) is one of the enzymes involved in the 3'-end processing of precursor tRNAs and is a member of the metallo-beta-lactamase superfamily. tRNase Z crystal structures have revealed that the enzyme forms a dimer and has a characteristic domain, named a flexible arm or an exosite, which protrudes from the metallo-beta-lactamase core and is involved in tRNA binding. The refined structure of Thermotoga maritima tRNase Z has been determined at 1.97 A resolution, revealing the structure of the flexible arm and the zinc-bound active site. The structure of the flexible arm of T. maritima tRNase Z is distinct from those of the Bacillus subtilis and Escherichia coli tRNase Zs. A comparison of the three tRNase Z structures revealed differences in the dimer orientation, which may be related to the unique cleavage-site specificity of T. maritima tRNase Z.
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Affiliation(s)
- Ryohei Ishii
- RIKEN Genomic Sciences Center, Tsurumi, Yokohama 230-0045, Japan
| | - Asako Minagawa
- Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata 956-8603, Japan
| | - Hiroaki Takaku
- Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata 956-8603, Japan
| | - Masamichi Takagi
- Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata 956-8603, Japan
| | - Masayuki Nashimoto
- Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata 956-8603, Japan
| | - Shigeyuki Yokoyama
- RIKEN Genomic Sciences Center, Tsurumi, Yokohama 230-0045, Japan
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Correspondence e-mail:
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48
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Britton RA, Wen T, Schaefer L, Pellegrini O, Uicker WC, Mathy N, Tobin C, Daou R, Szyk J, Condon C. Maturation of the 5' end of Bacillus subtilis 16S rRNA by the essential ribonuclease YkqC/RNase J1. Mol Microbiol 2007; 63:127-38. [PMID: 17229210 DOI: 10.1111/j.1365-2958.2006.05499.x] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Functional ribosomal RNAs are generated from longer precursor species in every organism known. Maturation of the 5' side of 16S rRNA in Escherichia coli is catalysed in a two-step process by the cooperative action of RNase E and RNase G. However, many bacteria lack RNase E and RNase G orthologues, raising the question as to how 16S rRNA processing occurs in these organisms. Here we show that the maturation of Bacillus subtilis 16S rRNA is also a two-step process and that the enzyme responsible for the generation of the mature 5' end is the widely distributed essential ribonuclease YkqC/RNase J1. Depletion of B. subtilis of RNase J1 results in an accumulation of 16S rRNA precursors in vivo. The precursor species are found in polysomes suggesting that they can function in translation. Mutation of the predicted catalytic site of RNase J1 abolishes both 16S rRNA processing and cell viability. Finally, purified RNase J1 can correctly mature precursor 16S rRNA assembled in 70S ribosomes, showing that its role is direct.
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Affiliation(s)
- Robert A Britton
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
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49
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Li H. Complexes of tRNA and maturation enzymes: shaping up for translation. Curr Opin Struct Biol 2007; 17:293-301. [PMID: 17580114 DOI: 10.1016/j.sbi.2007.05.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2007] [Revised: 03/27/2007] [Accepted: 05/25/2007] [Indexed: 11/29/2022]
Abstract
Several significant structures of transfer ribonucleic acid (tRNA) maturation enzymes complexed with precursor tRNA or fragments thereof have been published recently, providing detailed knowledge of enzyme-tRNA recognition and catalytic strategies. In addition to reinforcing the general principles of RNA-protein interaction, the new structures highlight both the features of composite RNA recognition by multiple enzyme subunits and the pronounced RNA structural flexibility in or near the active site in all cases. These structural principles provide plausible explanations for the exquisite specificity and catalytic power of these enzymes and, in the case of evolutionary adaptation, for the ability of some enzymes to develop novel specificities.
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Affiliation(s)
- Hong Li
- Department of Chemistry and Biochemistry, Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA.
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50
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Condon C. Maturation and degradation of RNA in bacteria. Curr Opin Microbiol 2007; 10:271-8. [PMID: 17560162 DOI: 10.1016/j.mib.2007.05.008] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Accepted: 05/21/2007] [Indexed: 11/20/2022]
Abstract
RNA decay plays an important role, not only in recycling nucleotides but also in determining the rapidity with which cells can react to changing growth conditions. The degradation process can be regulated, thus providing an often-underestimated means of controlling gene expression. Recent developments in the field of RNA maturation and decay in two key model organisms, Escherichia coli and Bacillus subtilis, include the resolution of the structures of many of the participants in these processes in E. coli and the identification of an enzyme in B. subtilis that appears to fit the bill as a major player in RNA decay in this organism.
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Affiliation(s)
- Ciarán Condon
- CNRS UPR 9073 (affiliated with Université de Paris 7 - Denis Diderot), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
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