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Jaiswal LK, Singh RK, Nayak T, Kakkar A, Kandwal G, Singh VS, Gupta A. A comparative analysis of mycobacterial ribonucleases: Toward a therapeutic novel drug target. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2024:105645. [PMID: 39067582 DOI: 10.1016/j.meegid.2024.105645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 06/18/2024] [Accepted: 07/21/2024] [Indexed: 07/30/2024]
Abstract
Bacterial responses to continuously changing environments are addressed through modulation of gene expression at the level of transcription initiation, RNA processing and/or decay. Ribonucleases (RNases) are hydrolytic or phosphorolytic enzymes involved in a majority of RNA metabolism reactions. RNases play a crucial role in RNA degradation, either independently or in collaboration with various trans-acting regulatory factors. The genus Mycobacterium consists of five subgenera: Mycobacteroides, Mycolicibacterium, Mycobacterium, Mycolicibacter and Mycolicibacillus, which include 63 fully sequenced species (pathogenic/non-pathogenic) to date. These include 13 different RNases, among which 5 are exonucleases (RNase PH, PNPase, RNase D, nano-RNases and RNase AS) and 8 are endonucleases (RNase J, RNase H, RNase P, RNase III, RNase BN, RNase Z, RNase G and RNase E), although RNase J and RNase BN were later identified to have exoribonuclease functions also. Here, we provide a detailed comparative insight into the Escherichia coli and mycobacterial RNases with respect to their types, phylogeny, structure, function, regulation and mechanism of action, with the main emphasis on RNase E. Among these 13 different mycobacterial RNases, 10 are essential for cell survival and have diverse structures hence, they are promising drug targets. RNase E is also an essential endonuclease that is abundant in many bacteria, forms an RNA degradosome complex that controls central RNA processing/degradation and has a conserved 5' sensor domain/DNase-I like region in its RNase domain. The essential mycobacterial RNases especially RNase E provide a potential repertoire of drug targets that can be exploited for inhibitor/modulator screening against many deadly mycobacterial diseases.
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Affiliation(s)
- Lav Kumar Jaiswal
- Molecular Microbiology Laboratory, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi U.P.-221005, India
| | - Rakesh Kumar Singh
- Molecular Microbiology Laboratory, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi U.P.-221005, India
| | - Tanmayee Nayak
- Molecular Microbiology Laboratory, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi U.P.-221005, India
| | - Anuja Kakkar
- Molecular Microbiology Laboratory, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi U.P.-221005, India
| | - Garima Kandwal
- Molecular Microbiology Laboratory, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi U.P.-221005, India
| | - Vijay Shankar Singh
- Department of Microbiology, School of life Sciences, Sikkim University, Gangtok 737102, Sikkim, India
| | - Ankush Gupta
- Molecular Microbiology Laboratory, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi U.P.-221005, India.
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Jia H, Dantuluri S, Margulies S, Smith V, Lever R, Allers T, Koh J, Chen S, Maupin-Furlow JA. RecJ3/4-aRNase J form a Ubl-associated nuclease complex functioning in survival against DNA damage in Haloferax volcanii. mBio 2023; 14:e0085223. [PMID: 37458473 PMCID: PMC10470531 DOI: 10.1128/mbio.00852-23] [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: 04/05/2023] [Accepted: 06/02/2023] [Indexed: 09/02/2023] Open
Abstract
Nucleases are strictly regulated and often localized in the cell to avoid the uncontrolled degradation of DNA and RNA. Here, a new type of nuclease complex, composed of RecJ3, RecJ4, and aRNase J, was identified through its ATP-dependent association with the ubiquitin-like SAMP1 and AAA-ATPase Cdc48a. The complex was discovered in Haloferax volcanii, an archaeon lacking an RNA exosome. Genetic analysis revealed aRNase J to be essential and RecJ3, RecJ4, and Cdc48a to function in the recovery from DNA damage including genotoxic agents that generate double-strand breaks. The RecJ3:RecJ4:aRNase J complex (isolated in 2:2:1 stoichiometry) functioned primarily as a 3'-5' exonuclease in hydrolyzing RNA and ssDNA, with the mechanism non-processive for ssDNA. aRNase J could also be purified as a homodimer that catalyzed endoribonuclease activity and, thus, was not restricted to the 5'-3' exonuclease activity typical of aRNase J homologs. Moreover, RecJ3 and RecJ4 could be purified as a 560-kDa subcomplex in equimolar subunit ratio with nuclease activities mirroring the full RecJ3/4-aRNase J complex. These findings prompted reconstitution assays that suggested RecJ3/4 could suppress, alter, and/or outcompete the nuclease activities of aRNase J. Based on the phenotypic results, this control mechanism of aRNase J by RecJ3/4 is not necessary for cell growth but instead appears important for DNA repair. IMPORTANCE Nucleases are critical for various cellular processes including DNA replication and repair. Here, a dynamic type of nuclease complex is newly identified in the archaeon Haloferax volcanii, which is missing the canonical RNA exosome. The complex, composed of RecJ3, RecJ4, and aRNase J, functions primarily as a 3'-5' exonuclease and was discovered through its ATP-dependent association with the ubiquitin-like SAMP1 and Cdc48a. aRNase J alone forms a homodimer that has endonuclease function and, thus, is not restricted to 5'-3' exonuclease activity typical of other aRNase J enzymes. RecJ3/4 appears to suppress, alter, and/or outcompete the nuclease activities of aRNase J. While aRNase J is essential for growth, RecJ3/4, Cdc48a, and SAMPs are important for recovery against DNA damage. These biological distinctions may correlate with the regulated nuclease activity of aRNase J in the RecJ3/4-aRNaseJ complex.
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Affiliation(s)
- Huiyong Jia
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Science, University of Florida, Gainesville, Florida, USA
| | - Swathi Dantuluri
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Science, University of Florida, Gainesville, Florida, USA
| | - Shae Margulies
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Science, University of Florida, Gainesville, Florida, USA
| | - Victoria Smith
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Rebecca Lever
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Thorsten Allers
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Jin Koh
- Proteomics and Mass Spectrometry, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida, USA
| | - Sixue Chen
- Proteomics and Mass Spectrometry, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida, USA
- Genetics Institute, University of Florida, Gainesville, Florida, USA
- Department of Biology, College of Liberal Arts and Sciences, University of Florida, Gainesville, Florida, USA
| | - Julie A. Maupin-Furlow
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Science, University of Florida, Gainesville, Florida, USA
- Genetics Institute, University of Florida, Gainesville, Florida, USA
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RNase Z Oxidative Degradation Impedes tRNA Maturation and is Involved in Streptococcal Translation Regulation in Response to Oxidative Stress. Microbiol Spectr 2021; 9:e0116721. [PMID: 34704809 PMCID: PMC8549757 DOI: 10.1128/spectrum.01167-21] [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] [Indexed: 11/24/2022] Open
Abstract
When encountering oxidative stress, organisms selectively upregulate antioxidant genes and simultaneously suppress the translation of most other proteins. Eukaryotes employ multiple strategies to adjust translation at both the initiation and elongation stages; however, how prokaryotes modulate translation under oxidative stress remains unclear. Here, we report that upon hydrogen peroxide (H2O2) challenge, Streptococcus oligofermentans reduced translation via RNase Z (So-RNaseZ) oxidative degradation, thus hindering tRNA maturation. S. oligofermentans encodes all CCA-less tRNAs that require So-RNaseZ for 3′ end maturation. A combination of nonreducing SDS-PAGE and liquid chromatography/tandem mass spectrometry (LC/MS-MS) assays demonstrated that H2O2 oxidation induced Cys38-Cys149 disulfide linkages in recombinant So-RNaseZ protein, and serine substitution of Cys38 or Cys149 abolished these disulfide linkages. Consistently, redox Western blotting also determined intramolecular disulfide-linked So-RNaseZ in H2O2-treated S. oligofermentans cells. The disulfide-linked So-RNaseZ and monomer were both subject to proteolysis, whereas C149S mutation alleviated oxidative degradation of So-RNaseZ, suggesting that H2O2-mediated disulfide linkages substantially contributed to So-RNaseZ degradation. Accordingly, Northern blotting determined that tRNA precursor accumulation and mature tRNA species decrease in H2O2-treated S. oligofermentans. Moreover, reduced overall protein synthesis, as indicated by puromycin incorporation, and retarded growth of S. oligofermentans occurred in an H2O2 concentration-dependent manner. Overexpression of So-RNaseZ not only elevated tRNA precursor processing and protein synthesis but also partly rescued H2O2-suppressed S. oligofermentans growth. Moreover, So-RNaseZ oxidative degradation-mediated translation repression elevated S. oligofermentans survival under high H2O2 stress. Therefore, this work found that So-RNaseZ oxidative degradation-impeded tRNA maturation contributes to streptococcal translation repression and provides the oxidative stress adaptability for S. oligofermentans. IMPORTANCE Translation regulation is a common strategy used by organisms to reduce oxidative damage. Catalase-negative streptococci produce as well as tolerate high levels of H2O2. This work reports a novel translation regulation mechanism employed by Streptococcus oligofermentans in response to H2O2 challenge, in which the key tRNA endonuclease So-RNaseZ is oxidized to form Cys38-Cys149 disulfide linkages and both the disulfide-linked So-RNaseZ and monomers are subject to proteolysis; thus, tRNA maturation, protein translation, and growth are all suppressed. Notably, So-RNaseZ oxidative degradation-mediated translation repression offers oxidative adaptability to S. oligofermentans and enhances its survival against high H2O2 challenge. So-RNaseZ orthologs and H2O2-sensitive cysteines (Cys38 and Cys149) are widely distributed in Streptococcus and Lactococcus species genomes, which also encode all CCA-less tRNAs and lack catalase. Therefore, RNase Z oxidative degradation-based translation regulation could be widely employed by these lactic acid bacteria, including pathogenic streptococci, to cope with H2O2.
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Colson P, Pinault L, Azza S, Armstrong N, Chabriere E, La Scola B, Pontarotti P, Raoult D. A protein of the metallo-hydrolase/oxidoreductase superfamily with both beta-lactamase and ribonuclease activity is linked with translation in giant viruses. Sci Rep 2020; 10:21685. [PMID: 33303919 PMCID: PMC7729979 DOI: 10.1038/s41598-020-78658-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 11/23/2020] [Indexed: 12/21/2022] Open
Abstract
Proteins with a metallo-beta-lactamase (MBL) fold have been largely studied in bacteria in the framework of resistance to beta-lactams, but their spectrum of activities is broader. We show here that the giant Tupanvirus also encodes a MBL fold-protein that has orthologs in other giant viruses, a deep phylogenetic root and is clustered with tRNases. This protein is significantly associated with translation components in giant viruses. After expression in Escherichia coli, it was found to hydrolyse nitrocefin, a beta-lactam, and penicillin G. This was inhibited by sulbactam, a beta-lactamase inhibitor. In addition, the tupanvirus MBL fold-protein was not active on single- or double-stranded DNA, but degraded RNAs from bacteria and Acanthamoeba castellanii, the tupanvirus amoebal host. This activity was not neutralized by sulbactam. Overall, our results still broaden the host range of MBL fold-proteins, showing dual beta-lactamase/nuclease activities in giant viruses.
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Affiliation(s)
- Philippe Colson
- Aix-Marseille Univ., Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), 27 boulevard Jean Moulin, 13005, Marseille, France.,IHU Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005, Marseille, France
| | - Lucile Pinault
- IHU Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005, Marseille, France
| | - Said Azza
- IHU Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005, Marseille, France
| | - Nicholas Armstrong
- IHU Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005, Marseille, France
| | - Eric Chabriere
- Aix-Marseille Univ., Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), 27 boulevard Jean Moulin, 13005, Marseille, France.,IHU Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005, Marseille, France
| | - Bernard La Scola
- Aix-Marseille Univ., Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), 27 boulevard Jean Moulin, 13005, Marseille, France.,IHU Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005, Marseille, France
| | - Pierre Pontarotti
- Aix-Marseille Univ., Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), 27 boulevard Jean Moulin, 13005, Marseille, France.,CNRS, Marseille, France
| | - Didier Raoult
- Aix-Marseille Univ., Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), 27 boulevard Jean Moulin, 13005, Marseille, France. .,IHU Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005, Marseille, France.
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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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Mohanty BK, Kushner SR. New Insights into the Relationship between tRNA Processing and Polyadenylation in Escherichia coli. Trends Genet 2019; 35:434-445. [PMID: 31036345 PMCID: PMC7368558 DOI: 10.1016/j.tig.2019.03.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/28/2019] [Accepted: 03/12/2019] [Indexed: 11/30/2022]
Abstract
Recent studies suggest that poly(A) polymerase I (PAP I)-mediated polyadenylation in Escherichia coli is highly prevalent among mRNAs as well as tRNA precursors. Primary tRNA transcripts are initially processed endonucleolytically to generate pre-tRNA species, which undergo 5'-end maturation by the ribozyme RNase P. Subsequently, a group of 3' → 5' exonucleases mature the 3' ends of the majority of tRNAs with few exceptions. PAP I competes with the 3' → 5' exonucleases for pre-tRNA substrates adding short poly(A) tails, which not only modulate the stability of the pre-tRNAs, but also regulate the availability of functional tRNAs. In this review, we discuss the recent discoveries of new tRNA processing pathways and the implications of polyadenylation in tRNA metabolism in E. coli.
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Affiliation(s)
- Bijoy K Mohanty
- Department of Genetics, University of Georgia, Athens, GA 30605, USA
| | - Sidney R Kushner
- Department of Genetics, University of Georgia, Athens, GA 30605, USA; Department of Microbiology, University of Georgia, Athens, GA 30605, USA.
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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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9
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Hameş EE, Demir T. Microbial ribonucleases (RNases): production and application potential. World J Microbiol Biotechnol 2015; 31:1853-62. [PMID: 26433394 DOI: 10.1007/s11274-015-1945-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/07/2015] [Indexed: 01/15/2023]
Abstract
Ribonuclease (RNase) is hydrolytic enzyme that catalyzes the cleavage of phosphodiester bonds in RNA. RNases play an important role in the metabolism of cellular RNAs, such as mRNA and rRNA or tRNA maturation. Besides their cellular roles, RNases possess biological activity, cell stimulating properties, cytotoxicity and genotoxicity. Cytotoxic effect of particular microbial RNases was comparable to that of animal derived counterparts. In this respect, microbial RNases have a therapeutic potential as anti-tumor drugs. The significant development of DNA vaccines and the progress of gene therapy trials increased the need for RNases in downstream processes. In addition, RNases are used in different fields, such as food industry for single cell protein preparations, and in some molecular biological studies for the synthesis of specific nucleotides, identifying RNA metabolism and the relationship between protein structure and function. In some cases, the use of bovine or other animal-derived RNases have increased the difficulties due to the safety and regulatory issues. Microbial RNases have promising potential mainly for pharmaceutical purposes as well as downstream processing. Therefore, an effort has been given to determination of optimum fermentation conditions to maximize RNase production from different bacterial and fungal producers. Also immobilization or strain development experiments have been carried out.
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Affiliation(s)
- E Esin Hameş
- Department of Bioengineering, Faculty of Engineering, Ege University, 35100, Bornova, Izmir, Turkey.
| | - Tuğçe Demir
- Department of Chemical Engineering, Kocaeli University, Umut Tepe Yerleşkesi, 41380, Kocaeli, Turkey
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10
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Maier LK, Stachler AE, Saunders SJ, Backofen R, Marchfelder A. An active immune defense with a minimal CRISPR (clustered regularly interspaced short palindromic repeats) RNA and without the Cas6 protein. J Biol Chem 2014; 290:4192-201. [PMID: 25512373 PMCID: PMC4326828 DOI: 10.1074/jbc.m114.617506] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The prokaryotic immune system CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated) is a defense system that protects prokaryotes against foreign DNA. The short CRISPR RNAs (crRNAs) are central components of this immune system. In CRISPR-Cas systems type I and III, crRNAs are generated by the endonuclease Cas6. We developed a Cas6b-independent crRNA maturation pathway for the Haloferax type I-B system in vivo that expresses a functional crRNA, which we termed independently generated crRNA (icrRNA). The icrRNA is effective in triggering degradation of an invader plasmid carrying the matching protospacer sequence. The Cas6b-independent maturation of the icrRNA allowed mutation of the repeat sequence without interfering with signals important for Cas6b processing. We generated 23 variants of the icrRNA and analyzed them for activity in the interference reaction. icrRNAs with deletions or mutations of the 3′ handle are still active in triggering an interference reaction. The complete 3′ handle could be removed without loss of activity. However, manipulations of the 5′ handle mostly led to loss of interference activity. Furthermore, we could show that in the presence of an icrRNA a strain without Cas6b (Δcas6b) is still active in interference.
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Affiliation(s)
| | | | - Sita J Saunders
- the Bioinformatics Group, Department of Computer Science, Albert-Ludwigs-University Freiburg, Georges-Köhler-Allee 106, 79110 Freiburg, and
| | - Rolf Backofen
- the Bioinformatics Group, Department of Computer Science, Albert-Ludwigs-University Freiburg, Georges-Köhler-Allee 106, 79110 Freiburg, and the BIOSS Centre for Biological Signalling Studies, Cluster of Excellence, Albert-Ludwigs-University Freiburg, Schänzlestrasse 18, 79104 Freiburg, Germany
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Chavarria NE, Hwang S, Cao S, Fu X, Holman M, Elbanna D, Rodriguez S, Arrington D, Englert M, Uthandi S, Söll D, Maupin-Furlow JA. Archaeal Tuc1/Ncs6 homolog required for wobble uridine tRNA thiolation is associated with ubiquitin-proteasome, translation, and RNA processing system homologs. PLoS One 2014; 9:e99104. [PMID: 24906001 PMCID: PMC4048286 DOI: 10.1371/journal.pone.0099104] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 05/11/2014] [Indexed: 11/29/2022] Open
Abstract
While cytoplasmic tRNA 2-thiolation protein 1 (Tuc1/Ncs6) and ubiquitin-related modifier-1 (Urm1) are important in the 2-thiolation of 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) at wobble uridines of tRNAs in eukaryotes, the biocatalytic roles and properties of Ncs6/Tuc1 and its homologs are poorly understood. Here we present the first report of an Ncs6 homolog of archaea (NcsA of Haloferax volcanii) that is essential for maintaining cellular pools of thiolated tRNALysUUU and for growth at high temperature. When purified from Hfx. volcanii, NcsA was found to be modified at Lys204 by isopeptide linkage to polymeric chains of the ubiquitin-fold protein SAMP2. The ubiquitin-activating E1 enzyme homolog of archaea (UbaA) was required for this covalent modification. Non-covalent protein partners that specifically associated with NcsA were also identified including UbaA, SAMP2, proteasome activating nucleotidase (PAN)-A/1, translation elongation factor aEF-1α and a β-CASP ribonuclease homolog of the archaeal cleavage and polyadenylation specificity factor 1 family (aCPSF1). Together, our study reveals that NcsA is essential for growth at high temperature, required for formation of thiolated tRNALysUUU and intimately linked to homologs of ubiquitin-proteasome, translation and RNA processing systems.
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Affiliation(s)
- Nikita E. Chavarria
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Sungmin Hwang
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Shiyun Cao
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Xian Fu
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Mary Holman
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Dina Elbanna
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Suzanne Rodriguez
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Deanna Arrington
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Markus Englert
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
| | - Sivakumar Uthandi
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Department of Chemistry, Yale University, New Haven, Connecticut, United States of America
| | - Julie A. Maupin-Furlow
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
- Genetics Institute, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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12
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13
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Skowronek E, Grzechnik P, Späth B, Marchfelder A, Kufel J. tRNA 3' processing in yeast involves tRNase Z, Rex1, and Rrp6. RNA (NEW YORK, N.Y.) 2014; 20:115-30. [PMID: 24249226 PMCID: PMC3866640 DOI: 10.1261/rna.041467.113] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 10/24/2013] [Indexed: 05/20/2023]
Abstract
Mature tRNA 3' ends in the yeast Saccharomyces cerevisiae are generated by two pathways: endonucleolytic and exonucleolytic. Although two exonucleases, Rex1 and Rrp6, have been shown to be responsible for the exonucleolytic trimming, the identity of the endonuclease has been inferred from other systems but not confirmed in vivo. Here, we show that the yeast tRNA 3' endonuclease tRNase Z, Trz1, is catalyzing endonucleolytic tRNA 3' processing. The majority of analyzed tRNAs utilize both pathways, with a preference for the endonucleolytic one. However, 3'-end processing of precursors with long 3' trailers depends to a greater extent on Trz1. In addition to its function in the nucleus, Trz1 processes the 3' ends of mitochondrial tRNAs, contributing to the general RNA metabolism in this organelle.
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Affiliation(s)
- Ewa Skowronek
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Pawel Grzechnik
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Bettina Späth
- Molekulare Botanik, Universität Ulm, 89069 Ulm, Germany
| | | | - Joanna Kufel
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
- Corresponding authorE-mail
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14
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Matos RG, López-Viñas E, Goméz-Puertas P, Arraiano CM. The only exoribonuclease present in Haloferax volcanii has an unique response to temperature changes. Biochim Biophys Acta Gen Subj 2012; 1820:1543-52. [DOI: 10.1016/j.bbagen.2012.06.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 06/01/2012] [Accepted: 06/07/2012] [Indexed: 10/28/2022]
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15
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Assigning a function to a conserved archaeal metallo-β-lactamase from Haloferax volcanii. Extremophiles 2012; 16:333-43. [PMID: 22350204 PMCID: PMC3296008 DOI: 10.1007/s00792-012-0433-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 01/18/2012] [Indexed: 11/04/2022]
Abstract
The metallo-β-lactamase family of enzymes comprises a large group of proteins with diverse functions in the metabolism of the cell. Among others, this superfamily contains proteins which are involved in DNA and RNA metabolism, acting as nucleases in e.g. repair and maturation. Many proteins have been annotated in prokaryotic genomes as being potential metallo-β-lactamases, but very often the function has not been proven. The protein HVO_2763 from Haloferax volcanii is such a potential metallo-β-lactamase. HVO_2763 has sequence similarity to the metallo-β-lactamase tRNase Z, a tRNA 3′ processing endonuclease. Here, we report the characterisation of this metallo-β-lactamase HVO_2763 in the halophilic archaeon Haloferax volcanii. Using different in vitro assays with the recombinant HVO_2763, we could show that the protein does not have tRNA 3′ processing or exonuclease activity. According to transcriptome analyses of the HVO_2763 deletion strain, expression of proteins involved in membrane transport is downregulated in the mutant. Therefore, HVO_2763 might be involved directly or indirectly in membrane transport.
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16
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Hölzle A, Stoll B, Schnattinger T, Schöning U, Tjaden B, Marchfelder A. tRNA-like elements in Haloferax volcanii. Biochimie 2011; 94:940-6. [PMID: 22178322 DOI: 10.1016/j.biochi.2011.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 12/01/2011] [Indexed: 11/25/2022]
Abstract
All functional RNAs are generated from precursor molecules by a plethora of processing steps. The generation of mature RNA molecules by processing is an important layer of gene expression regulation catalysed by ribonucleases. Here, we analysed 5S rRNA processing in the halophilic Archaeon Haloferax volcanii. Earlier experiments showed that the 5S rRNA is cleaved at its 5' end by the endonuclease tRNase Z. Interestingly, a tRNA-like structure was identified upstream of the 5S rRNA that might be used as a processing signal. Here, we show that this tRNA-like element is indeed recognised as a processing signal by tRNase Z. Substrates containing mutations in the tRNA-like sequence are no longer processed, whereas a substrate containing a deletion in the 5S rRNA sequence is still cleaved. Therefore, an intact 5S rRNA structure is not required for processing. Further, we used bioinformatics analyses to identify additional sequences in Haloferax containing tRNA-like structures. This search resulted in the identification of all tRNAs, the tRNA-like structure upstream of the 5S RNA and 47 new tRNA-like structural elements. However, the in vitro processing of selected examples showed no cleavage of these newly identified elements. Thus, tRNA-like elements are not a general processing signal in Haloferax.
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Affiliation(s)
- Annette Hölzle
- Biology II, Ulm University, Albert-Einstein-Allee 11, 89069 Ulm, Germany
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17
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Abstract
Although the origin of mitochondria from the endosymbiosis of an α-proteobacterium is well established, the nature of the host cell, the metabolic complexity of the endosymbiont and the subsequent evolution of the proto-mitochondrion into all its current appearances are still the subject of discovery and sometimes debate. Here we review what has been inferred about the original composition and subsequent evolution of the mitochondrial proteome and essential mitochondrial systems. The evolutionary mosaic that currently constitutes mitochondrial proteomes contains (i) endosymbiotic proteins (15-45%), (ii) proteins without detectable orthologs outside the eukaryotic lineage (40%), and (iii) proteins that are derived from non-proteobacterial Bacteria, Bacteriophages and Archaea (15%, specifically multiple tRNA-modification proteins). Protein complexes are of endosymbiotic origin, but have greatly expanded with novel eukaryotic proteins; in contrast to mitochondrial enzymes that are both of proteobacterial and non-proteobacterial origin. This disparity is consistent with the complexity hypothesis, which argues that proteins that are a part of large, multi-subunit complexes are unlikely to undergo horizontal gene transfer. We observe that they neither change their subcellular compartments in the course of evolution, even when their genes do.
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Affiliation(s)
- Radek Szklarczyk
- Radboud University Nijmegen Medical Centre, CMBI/NCMLS, Nijmegen, The Netherlands
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18
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Hartman AL, Norais C, Badger JH, Delmas S, Haldenby S, Madupu R, Robinson J, Khouri H, Ren Q, Lowe TM, Maupin-Furlow J, Pohlschroder M, Daniels C, Pfeiffer F, Allers T, Eisen JA. The complete genome sequence of Haloferax volcanii DS2, a model archaeon. PLoS One 2010; 5:e9605. [PMID: 20333302 PMCID: PMC2841640 DOI: 10.1371/journal.pone.0009605] [Citation(s) in RCA: 195] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 02/11/2010] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Haloferax volcanii is an easily culturable moderate halophile that grows on simple defined media, is readily transformable, and has a relatively stable genome. This, in combination with its biochemical and genetic tractability, has made Hfx. volcanii a key model organism, not only for the study of halophilicity, but also for archaeal biology in general. METHODOLOGY/PRINCIPAL FINDINGS We report here the sequencing and analysis of the genome of Hfx. volcanii DS2, the type strain of this species. The genome contains a main 2.848 Mb chromosome, three smaller chromosomes pHV1, 3, 4 (85, 438, 636 kb, respectively) and the pHV2 plasmid (6.4 kb). CONCLUSIONS/SIGNIFICANCE The completed genome sequence, presented here, provides an invaluable tool for further in vivo and in vitro studies of Hfx. volcanii.
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Affiliation(s)
- Amber L. Hartman
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
- The Institute for Genomic Research (J. Craig Venter Institute), Rockville, Maryland, United States of America
- UC Davis Genome Center, University of California Davis, Davis, California, United States of America
| | - Cédric Norais
- Institut de Génétique et Microbiologie, Université Paris-Sud, Paris, France
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jonathan H. Badger
- The Institute for Genomic Research (J. Craig Venter Institute), Rockville, Maryland, United States of America
| | - Stéphane Delmas
- Institute of Genetics, University of Nottingham, Nottingham, United Kingdom
| | - Sam Haldenby
- Institute of Genetics, University of Nottingham, Nottingham, United Kingdom
| | - Ramana Madupu
- The Institute for Genomic Research (J. Craig Venter Institute), Rockville, Maryland, United States of America
| | - Jeffrey Robinson
- The Institute for Genomic Research (J. Craig Venter Institute), Rockville, Maryland, United States of America
| | - Hoda Khouri
- The Institute for Genomic Research (J. Craig Venter Institute), Rockville, Maryland, United States of America
| | - Qinghu Ren
- The Institute for Genomic Research (J. Craig Venter Institute), Rockville, Maryland, United States of America
| | - Todd M. Lowe
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Julie Maupin-Furlow
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Mecky Pohlschroder
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Charles Daniels
- Department of Microbiology, Ohio State University, Columbus, Ohio, United States of America
| | - Friedhelm Pfeiffer
- Department of Membrane Biochemistry, Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | - Thorsten Allers
- Institute of Genetics, University of Nottingham, Nottingham, United Kingdom
| | - Jonathan A. Eisen
- The Institute for Genomic Research (J. Craig Venter Institute), Rockville, Maryland, United States of America
- UC Davis Genome Center, University of California Davis, Davis, California, United States of America
- Department of Medical Microbiology and Immunology, University of California Davis, Davis, California, United States of America
- Department of Evolution and Ecology, University of California Davis, Davis, California, United States of America
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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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20
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Abstract
In recent years, sRNAs (small non-coding RNAs) have been found to be abundant in eukaryotes and bacteria and have been recognized as a novel class of gene expression regulators. In contrast, much less is known about sRNAs in archaea, except for snoRNAs (small nucleolar RNAs) that are involved in the modification of bases in stable RNAs. Therefore bioinformatic and experimental RNomics approaches were undertaken to search for the presence of sRNAs in the model archaeon Haloferax volcanii, resulting in more than 150 putative sRNA genes being identified. Northern blot analyses were used to study (differential) expression of sRNA genes. Several chromosomal deletion mutants of sRNA genes were generated and compared with the wild-type. It turned out that two sRNAs are essential for growth at low salt concentrations and high temperatures respectively, and one is involved in the regulation of carbon metabolism. Taken together, it could be shown that sRNAs are as abundant in H. volcanii as they are in well-studied bacterial species and that they fulfil important biological roles under specific conditions.
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21
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Evguenieva‐Hackenberg E, Klug G. Chapter 7 RNA Degradation in Archaea and Gram‐Negative Bacteria Different from Escherichia coli. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 85:275-317. [DOI: 10.1016/s0079-6603(08)00807-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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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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23
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Hölzle A, Fischer S, Heyer R, Schütz S, Zacharias M, Walther P, Allers T, Marchfelder A. Maturation of the 5S rRNA 5' end is catalyzed in vitro by the endonuclease tRNase Z in the archaeon H. volcanii. RNA (NEW YORK, N.Y.) 2008; 14:928-37. [PMID: 18369184 PMCID: PMC2327364 DOI: 10.1261/rna.933208] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Ribosomal RNA molecules are synthesized as precursors that have to undergo several processing steps to generate the functional rRNA. The 5S rRNA in the archaeon Haloferax volcanii is transcribed as part of a multicistronic transcript containing both large rRNAs and one or two tRNAs. Release of the 5S rRNA from the precursor requires two endonucleolytic cleavages by enzymes as yet not identified. Here we report the first identification of an archaeal 5S rRNA processing endonuclease. The enzyme tRNase Z, which was initially identified as tRNA processing enzyme, generates not only tRNA 3' ends but also mature 5S rRNA 5' ends in vitro. Interestingly, the sequence upstream of the 5S rRNA can be folded into a mini-tRNA, which might explain the processing of this RNA by tRNase Z. The endonuclease is active only at low salt concentrations in vitro, which is in contrast to the 2-4 M KCl concentration present inside the cell in vivo. Electron microscopy studies show that there are no compartments inside the Haloferax cell that could provide lower salt environments. Processing of the 5S rRNA 5' end is not restricted to the haloarchaeal tRNase Z since tRNase Z enzymes from a thermophilic archaeon, a lower and a higher eukaryote, are as well able to cleave the tRNA-like structure 5' of the 5S rRNA. Knock out of the tRNase Z gene in Haloferax volcanii is lethal, showing that the protein is essential for the cell.
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MESH Headings
- Base Sequence
- Endoribonucleases/genetics
- Endoribonucleases/metabolism
- Genes, Archaeal
- Haloferax volcanii/genetics
- Haloferax volcanii/metabolism
- Haloferax volcanii/ultrastructure
- Microscopy, Electron, Transmission
- Models, Molecular
- Nucleic Acid Conformation
- RNA Precursors/genetics
- RNA Precursors/metabolism
- RNA Processing, Post-Transcriptional
- RNA, Archaeal/chemistry
- RNA, Archaeal/genetics
- RNA, Archaeal/metabolism
- RNA, Ribosomal, 5S/genetics
- RNA, Ribosomal, 5S/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Substrate Specificity
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24
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Späth B, Schubert S, Lieberoth A, Settele F, Schütz S, Fischer S, Marchfelder A. Two archaeal tRNase Z enzymes: similar but different. Arch Microbiol 2008; 190:301-8. [PMID: 18437358 DOI: 10.1007/s00203-008-0368-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Revised: 03/19/2008] [Accepted: 03/25/2008] [Indexed: 11/29/2022]
Abstract
The endoribonuclease tRNase Z plays an essential role in tRNA metabolism by removal of the 3' trailer element of precursor RNAs. To investigate tRNA processing in archaea, we identified and expressed the tRNase Z from Haloferax volcanii, a halophilic archaeon. The recombinant enzyme is a homodimer and efficiently processes precursor tRNAs. Although the protein is active in vivo at 2-4 M KCl, it is inhibited by high KCl concentrations in vitro, whereas 2-3 M (NH4)(2)SO4 do not inhibit tRNA processing. Analysis of the metal content of the metal depleted tRNase Z revealed that it still contains 0.4 Zn2+ ions per dimer. In addition tRNase Z requires Mn2+ ions for processing activity. We compared the halophilic tRNase Z to the homologous one from Pyrococcus furiosus, a thermophilic archaeon. Although both enzymes have 46% sequence similarity, they differ in their optimal reaction conditions. Both archaeal tRNase Z proteins process mitochondrial pre-tRNAs. Only the thermophilic tRNase Z shows in addition activity toward intron containing pre-tRNAs, 5' extended precursors, the phosphodiester bis(p-nitrophenyl)phosphate (bpNPP) and the glyoxalase II substrate S-D-lactoylglutathion (SLG).
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Affiliation(s)
- Bettina Späth
- Valckenburg Schule, Valckenburgufer 21, 89073 Ulm, Germany
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25
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Evguenieva-Hackenberg E, Wagner S, Klug G. In vivo and in vitro studies of RNA degrading activities in Archaea. Methods Enzymol 2008; 447:381-416. [PMID: 19161853 DOI: 10.1016/s0076-6879(08)02219-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Controlled degradation of RNA is important for the regulation of gene expression in Bacteria and Eukarya, but information about these processes is limited in the domain of Archaea. To address this, we studied the half-life of different mRNAs in halophilic Archaea after blocking transcription with actinomycin D. We found that the stability of mRNAs of the gvp operons in Haloferax mediterranei varies under different growth conditions. To understand regulated mRNA decay in Archaea, we need to identify stability determinants within mRNAs and proteins, mainly ribonucleases (RNases), which recognize these determinants. First, we wanted to identify archaeal RNases independently of their sequence similarity to known RNases from Bacteria and Eukarya. To this end we performed fractionation of proteins from Halobacterium salinarum and tested the fractions for RNase activity with an internally labeled in vitro-synthesized mRNA. After three purification steps, we isolated an endoribonucleolytically active protein with similarities to the eukaryotic initiation factor 5A. Further characterization was performed with recombinant halobacterial IF-5A, which was purified from H. salinarum or Escherichia coli. Mutational analysis confirmed unambiguously its RNase activity. In another study, we aimed to purify a double-strand-specific endoribonuclease from Sulfolobus solfataricus. Seven purification steps led to the isolation of two different dehydrogenases with RNase properties. Interestingly, their RNase activity resembled that of aIF-5A and of highly diluted RNase A. RNA was cleaved preferentially between C and A nucleotides in single-stranded regions, and the activity was inhibited at MgCl(2) concentrations >5 mM and at KCl concentrations >200 mM. However, it was possible to distinguish the activity of the archaeal proteins from the activity of RNase A. In a different approach, we used a bioinformatics prediction of the archaeal exosome to purify this protein complex from S. solfataricus. Isolation by coimmunoprecipitation revealed the presence of four orthologs of eukaryotic exosomal subunits and at least one archaea-specific subunit. We characterized the S. solfataricus exosome as a major enzyme involved in phosphorolytic RNA degradation and in RNA polyadenylation. Here we describe in detail the techniques used to achieve these results.
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26
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Mohanty BK, Kushner SR. Rho-independent transcription terminators inhibit RNase P processing of the secG leuU and metT tRNA polycistronic transcripts in Escherichia coli. Nucleic Acids Res 2007; 36:364-75. [PMID: 18033800 PMCID: PMC2241853 DOI: 10.1093/nar/gkm991] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The widely accepted model for the processing of tRNAs in Escherichia coli involves essential initial cleavages by RNase E within polycistronic transcripts to generate pre-tRNAs that subsequently become substrates for RNase P. However, recently we identified two polycistronic tRNA transcripts whose endonucleolytic processing was solely dependent on RNase P. Here we show that the processing of the secG leuU and metT leuW glnU glnW metU glnV glnX polycistronic transcripts takes place through a different type of maturation pathway. Specifically, RNase P separates the tRNA units within each operon following the endonucleolytic removal of the distal Rho-independent transcription terminator, primarily by RNase E. Failure to remove the Rho-independent transcription terminator inhibits RNase P processing of both transcripts leading to a decrease in mature tRNA levels and dramatically increased levels of full-length transcripts in an RNase E deletion strain. Furthermore, we show for the first time that RNase G also removes the Rho-independent transcription terminator associated with the secG leuU operon. Our data also demonstrate that the Rne-1 protein retains significant activity on tRNA substrates at the non-permissive temperature. Taken together it is clear that there are multiple pathways involved in the maturation of tRNAs in E. coli.
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Affiliation(s)
- Bijoy K Mohanty
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
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27
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Affiliation(s)
- Claire Torchet
- Institut Jacques-Monod, Biochimie de l'Evolution et Adaptabilité Moléculaire, Université Paris VI, Tour 43, 2 place Jussieu, 75251 Paris Cedex 05, France
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28
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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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29
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Dominski Z. Nucleases of the metallo-beta-lactamase family and their role in DNA and RNA metabolism. Crit Rev Biochem Mol Biol 2007; 42:67-93. [PMID: 17453916 DOI: 10.1080/10409230701279118] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Proteins of the metallo-beta-lactamase family with either demonstrated or predicted nuclease activity have been identified in a number of organisms ranging from bacteria to humans and has been shown to be important constituents of cellular metabolism. Nucleases of this family are believed to utilize a zinc-dependent mechanism in catalysis and function as 5' to 3' exonucleases and or endonucleases in such processes as 3' end processing of RNA precursors, DNA repair, V(D)J recombination, and telomere maintenance. Examples of metallo-beta-lactamase nucleases include CPSF-73, a known component of the cleavage/polyadenylation machinery, which functions as the endonuclease in 3' end formation of both polyadenylated and histone mRNAs, and Artemis that opens DNA hairpins during V(D)J recombination. Mutations in two metallo-beta-lactamase nucleases have been implicated in human diseases: tRNase Z required for 3' processing of tRNA precursors has been linked to the familial form of prostate cancer, whereas inactivation of Artemis causes severe combined immunodeficiency (SCID). There is also a group of as yet uncharacterized proteins of this family in bacteria and archaea that based on sequence similarity to CPSF-73 are predicted to function as nucleases in RNA metabolism. This article reviews the cellular roles of nucleases of the metallo-beta-lactamase family and the recent advances in studying these proteins.
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Affiliation(s)
- Zbigniew Dominski
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
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30
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Wagner S, Klug G. An archaeal protein with homology to the eukaryotic translation initiation factor 5A shows ribonucleolytic activity. J Biol Chem 2007; 282:13966-76. [PMID: 17369252 DOI: 10.1074/jbc.m701166200] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To identify proteins that are involved in RNA degradation and processing in Halobacterium sp. NRC-1, we purified proteins with RNA-degrading activity by classical biochemical techniques. One of these proteins showed strong homology to the eukaryotic initiation factor 5A (eIF-5A) and was accordingly named archaeal initiation factor 5A (aIF-5A). Eukaryotic IF-5A is known to be involved in mRNA turnover and to bind RNA. Hypusination of eIF-5A is required for sequence-specific binding of RNA. This unique post-translational modification is restricted to Eukarya and Archaea. The exact function of eIF-5A in RNA turnover remained obscure. Here we show for the first time that aIF-5A from Halobacterium sp. NRC-1 exhibits RNA cleavage activity, preferentially cleaving adjacent to A nucleotides. Detectable RNA binding could be shown for aIF-5A purified from Halobacterium sp. NRC-1 but not from Escherichia coli, while both proteins possess RNA cleavage activity, indicating that hypusination of aIF-5A is required for RNA binding but not for its RNA cleavage activity. Furthermore, we show that the hypusinated form of eIF-5A also shows RNase activity while the unmodified protein does not. Charged amino acids in the N-terminal domain of aIF-5A as well as in the C-terminal domain, which is highly similar to the cold shock protein A (CspA), an RNA chaperone of E. coli, are important for RNA cleavage activity. Moreover our results reveal that activity of aIF-5A depends on its oligomeric state.
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Affiliation(s)
- Steffen Wagner
- Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
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31
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Redko Y, Li de la Sierra-Gallay I, Condon C. When all's zed and done: the structure and function of RNase Z in prokaryotes. Nat Rev Microbiol 2007; 5:278-86. [PMID: 17363966 DOI: 10.1038/nrmicro1622] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
RNase Z is a widely distributed and often essential endoribonuclease that is responsible for the maturation of the 3'-end of a large family of transfer RNAs (tRNAs). Although it has been the subject of study for more than 25 years, interest in this enzyme intensified dramatically with the identification of the encoding gene in 2002. This led to the discovery of RNase Z in bacteria, in which the final step in the generation of the mature 3'-end of tRNAs had previously been assumed to be catalysed by exoribonucleases. It also led inevitably to structural studies, and the recent resolution of the structure of RNase Z in complex with tRNA has provided a detailed understanding of the molecular mechanisms of RNase Z substrate recognition and cleavage. The identification of the RNase Z gene also allowed the search for alternative substrates for this enzyme to begin in earnest. In this Review, we outline the important recent developments that have contributed to our understanding of this enzyme, particularly in prokaryotes.
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Affiliation(s)
- Yulia Redko
- Centre National de Recherche Scientifique (CNRS) UPR9073 (affiliated with Université Paris VII-Denis Diderot), Institut de Biologie, Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
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32
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Abstract
This chapter discusses several topics relating to the mechanisms of mRNA decay. These topics include the following: important physical properties of mRNA molecules that can alter their stability; methods for determining mRNA half-lives; the genetics and biochemistry of proteins and enzymes involved in mRNA decay; posttranscriptional modification of mRNAs; the cellular location of the mRNA decay apparatus; regulation of mRNA decay; the relationships among mRNA decay, tRNA maturation, and ribosomal RNA processing; and biochemical models for mRNA decay. Escherichia coli has multiple pathways for ensuring the effective decay of mRNAs and mRNA decay is closely linked to the cell's overall RNA metabolism. Finally, the chapter highlights important unanswered questions regarding both the mechanism and importance of mRNA decay.
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33
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Portnoy V, Schuster G. RNA polyadenylation and degradation in different Archaea; roles of the exosome and RNase R. Nucleic Acids Res 2006; 34:5923-31. [PMID: 17065466 PMCID: PMC1635327 DOI: 10.1093/nar/gkl763] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Polyadenylation is a process common to almost all organisms. In eukaryotes, stable poly(A)-tails, important for mRNA stability and translation initiation, are added to the 3′ ends of most mRNAs. Contrarily, polyadenylation can stimulate RNA degradation, a phenomenon witnessed in prokaryotes, organelles and recently, for nucleus-encoded RNA as well. Polyadenylation takes place in hyperthermophilic archaea and is mediated by the archaeal exosome, but no RNA polyadenylation was detected in halophiles. Here, we analyzed polyadenylation in the third archaea group, the methanogens, in which some members contain genes encoding the exosome but others lack these genes. Polyadenylation was found in the methanogen, Methanopyrus kandleri, containing the exosome genes, but not in members which lack these genes. To explore how RNA is degraded in the absence of the exosome and without polyadenylation, we searched for the exoribonuclease that is involved in this process. No homologous proteins for any other known exoribonuclease were detected in this group. However, the halophilic archaea contain a gene homologous to the exoribonuclease RNase R. This ribonuclease is not able to degrade structured RNA better than PNPase. RNase R, which appears to be the only exoribonucleases in Haloferax volcanii, was found to be essential for viability.
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Affiliation(s)
| | - Gadi Schuster
- To whom correspondence should be addressed. Tel: +972 4 8293171; Fax: +972 4 8295587;
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34
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Abstract
Genetic and biochemical analysis of RNase Z in eukaryotes, such as Arabadopsis thaliana, and prokaryotes like Bacillus subtilis have demonstrated that this endoribonuclease is essential for the maturation of tRNA precursors that do not contain a chromosomally encoded CCA determinant. As all Escherichia coli tRNA transcripts have chromosomally encoded CCA determinants, the function of its putative RNase Z homologue, the product of the elaC gene, is not clear. Here we demonstrate that the E. coli ElaC protein (RNase Z) endonucleolytically processes B. subtilis tRNA precursors lacking a CCA determinant both in vivo and in vitro. More importantly, E. coli RNase Z plays a significant role in mRNA decay, a previously unidentified activity for the enzyme. The purified RNase Z protein cleaves the rpsT mRNA at locations distinct from those obtained with RNase E. As expected, under physiological conditions E. coli and B. subtilis tRNA precursors containing a CCA determinant are not substrates. These results suggest a potentially important new role for the RNase Z family of proteins in RNA metabolism, particularly in organisms lacking RNase E.
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Affiliation(s)
- Tariq Perwez
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
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35
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Li de la Sierra-Gallay I, Mathy N, Pellegrini O, Condon C. Structure of the ubiquitous 3' processing enzyme RNase Z bound to transfer RNA. Nat Struct Mol Biol 2006; 13:376-7. [PMID: 16518398 DOI: 10.1038/nsmb1066] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Accepted: 01/17/2006] [Indexed: 11/08/2022]
Abstract
The highly conserved ribonuclease RNase Z catalyzes the endonucleolytic removal of the 3' extension of the majority of tRNA precursors. Here we present the structure of the complex between Bacillus subtilis RNase Z and tRNA(Thr), the first structure of a ribonucleolytic processing enzyme bound to tRNA. Binding of tRNA to RNase Z causes conformational changes in both partners to promote reorganization of the catalytic site and tRNA cleavage.
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36
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Späth B, Kirchner S, Vogel A, Schubert S, Meinlschmidt P, Aymanns S, Nezzar J, Marchfelder A. Analysis of the functional modules of the tRNA 3' endonuclease (tRNase Z). J Biol Chem 2005; 280:35440-7. [PMID: 16118225 DOI: 10.1074/jbc.m506418200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
tRNA 3' processing is one of the essential steps during tRNA maturation. The tRNA 3'-processing endonuclease tRNase Z was only recently isolated, and its functional domains have not been identified so far. We performed an extensive mutational study to identify amino acids and regions involved in dimerization, tRNA binding, and catalytic activity. 29 deletion and point variants of the tRNase Z enzyme were generated. According to the results obtained, variants can be sorted into five different classes. The first class still had wild type activity in all three respects. Members of the second and third class still formed dimers and bound tRNAs but had reduced catalytic activity (class two) or no catalytic activity (class three). The fourth class still formed dimers but did not bind the tRNA and did not process precursors. Since this class still formed dimers, it seems that the amino acids mutated in these variants are important for RNA binding. The fifth class did not have any activity anymore. Several conserved amino acids could be mutated without or with little loss of activity.
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Affiliation(s)
- Bettina Späth
- Molekulare Botanik, Universität Ulm, Albert-Einstein-Allee 11, 89069 Ulm, Germany
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37
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Ceballos-Chávez M, Vioque A. Sequence-dependent cleavage site selection by RNase Z from the cyanobacterium Synechocystis sp. PCC 6803. J Biol Chem 2005; 280:33461-9. [PMID: 16051605 DOI: 10.1074/jbc.m504691200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Biosynthesis of transfer RNA requires processing from longer precursors at the 5'- and 3'-ends. In eukaryotes, in archaea, and in those bacteria where the 3'-terminal CCA sequence is not encoded, 3' processing is carried out by the endonuclease RNase Z, which cleaves after the discriminator nucleotide to generate a mature 3'-end ready for the addition of the CCA sequence. We have identified and cloned the gene coding for RNase Z in the cyanobacterium Synechocystis sp. PCC 6803. The gene has been expressed in Escherichia coli, and the recombinant protein was purified. The enzymatic activity of RNase Z from Synechocystis has been studied in vitro with a variety of substrates. The presence of C or CC after the discriminator nucleotide modifies the cleavage site of RNase Z so that it is displaced by one and two nucleotides to the 3'-side, respectively. The presence of the complete 3'-terminal CCA sequence in the precursor of the tRNA completely inhibits RNase Z activity. The inactive CCA-containing precursor binds to Synechocystis RNase Z with similar affinity than the mature tRNA. The properties of the enzyme described here could be related with the mechanism by which CCA is added in this organism, with the participation of two separate nucleotidyl transferases, one specific for the addition of C and another for the addition of A. This work is the first characterization of RNase Z from a cyanobacterium, and the first from an organism with two separate nucleotidyl transferases.
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Affiliation(s)
- María Ceballos-Chávez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Américo Vespucio 49, E-41092 Sevilla, Spain
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38
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Schilling O, Vogel A, Kostelecky B, Natal da Luz H, Spemann D, Späth B, Marchfelder A, Tröger W, Meyer-Klaucke W. Zinc- and iron-dependent cytosolic metallo-beta-lactamase domain proteins exhibit similar zinc-binding affinities, independent of an atypical glutamate at the metal-binding site. Biochem J 2005; 385:145-53. [PMID: 15324305 PMCID: PMC1134682 DOI: 10.1042/bj20040773] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
ZiPD (zinc phosphodiesterase; synonyms are ElaC, ecoZ, RNaseZ and 3' tRNase) and the iron-dependent redox enzyme FlRd (flavorubredoxin) from Escherichia coli represent prototypical cases of proteins sharing the metallo-beta-lactamase fold that require strict metal selectivity for catalytic activity, yet their metal selectivity has only been partially understood. In contrast with hydrolytic metallo-beta-lactamase proteins, iron-dependent FlRd-like enzymes have an atypical glutamate ligand, which replaces one otherwise conserved histidine ligand. X-ray absorption spectroscopy revealed that the FlRd metallo-beta-lactamase domain is capable of incorporating two zinc ions into the binuclear metal-binding site. Zinc dissociation constants, determined by isothermal titration calorimetry are similar for zinc binding to E. coli ZiPD (K(d1)=2.2+/-0.2 microM and K(d2)=23.0+/-0.6 microM) and to the E. coli FlRd metallo-beta-lactamase domain (K(d1)=0.7+/-0.1 microM and K(d2)=26.0+/-0.1 microM). In good correspondence, apo-ZiPD requires incubation with 10 microM zinc for full reconstitution of the phosphodiesterase activity. Accordingly, metal selectivity of ZiPD and FlRd only partially relies on first shell metal ligands. Back mutation of the atypical glutamate in FlRd to a histidine unexpectedly resulted in an increased first zinc dissociation constant (K(d1)=30+/-4 microM and K(d2)=23+/-2 microM). In combination with a recent mutational study on ZiPD [Vogel, Schilling and Meyer-Klaucke (2004) Biochemistry 43, 10379-10386], we conclude that the atypical glutamate does not guide metal selectivity of the FlRd metallo-beta-lactamase domain but suppresses possible hydrolytic cross-activity.
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Affiliation(s)
- Oliver Schilling
- *EMBL Outstation Hamburg, Notkestrasse 85, D-22603 Hamburg, Germany
| | - Andreas Vogel
- *EMBL Outstation Hamburg, Notkestrasse 85, D-22603 Hamburg, Germany
| | | | - Hugo Natal da Luz
- †Institute for Experimental Physics II, University of Leipzig, Linnéstr. 5, D-04103 Leipzig, Germany
| | - Daniel Spemann
- †Institute for Experimental Physics II, University of Leipzig, Linnéstr. 5, D-04103 Leipzig, Germany
| | - Bettina Späth
- ‡Molekulare Botanik, Universität Ulm, D-89069 Ulm, Germany
| | | | - Wolfgang Tröger
- †Institute for Experimental Physics II, University of Leipzig, Linnéstr. 5, D-04103 Leipzig, Germany
| | - Wolfram Meyer-Klaucke
- *EMBL Outstation Hamburg, Notkestrasse 85, D-22603 Hamburg, Germany
- To whom correspondence should be addressed (email )
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39
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Schilling O, Späth B, Kostelecky B, Marchfelder A, Meyer-Klaucke W, Vogel A. Exosite Modules Guide Substrate Recognition in the ZiPD/ElaC Protein Family. J Biol Chem 2005; 280:17857-62. [PMID: 15699034 DOI: 10.1074/jbc.m500591200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Escherichia coli ZiPD is the best characterized protein encoded by the elaC gene family and is a model for the 3'-pre-tRNA processing endoribonucleases (tRNase Z). A metal ligand-based sequence alignment of ZiPD with metallo-beta-lactamase domain proteins of known crystallographic structure identifies a ZiPD-specific sequence insertion of approximately 50 residues, which we will refer to as the ZiPD exosite. Functionally characterized ZiPD homologs from Bacillus subtilis, Methanococcus janaschii, and human share the presence of the ZiPD exosite, which is also present in the amino-terminal, but not in the carboxyl-terminal, domain of ElaC2 proteins. Another class of functionally characterized tRNase Z enzymes from Thermotoga maritima and Arabidopsis thaliana lack characteristic motifs in the exosite but possess a sequence segment with clustered basic amino acid residues. As an experimental attempt to investigate the function of the exosite we constructed a ZiPD variant that lacks this module (ZiPDDelta). ZiPDDelta has almost wild-type-like catalytic properties for hydrolysis of the small, chromogenic substrate bis(p-nitrophenyl) phosphate. Removal of the ZiPD exosite only affects k(cat), which is reduced by less than 40%, whereas both K' andthe Hill coefficient (measures of the substrate affinity and cooperativity, respectively) remain unchanged. Hence, the exosite is not required for the intrinsic phosphodiesterase activity of ZiPD. Removal of the exosite also does not affect the dimerization properties of ZiPD. In contrast to the wild-type enzyme, ZiPDDelta does not process pre-tRNA, and gel shift assays demonstrate that only the wild-type enzyme, but not ZiPDDelta, binds mature tRNA. These findings show that the exosite is essential for pre-tRNA recognition. In conclusion, we identify a ZiPD exosite that guides physiological substrate recognition in the ZiPD/ElaC protein family.
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Affiliation(s)
- Oliver Schilling
- European Molecular Biology Laboratory Outstation Hamburg, Notkestrasse 85, 22603 Hamburg and Molekulare Botanik, Universität Ulm, 89069 Ulm, Germany
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40
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Ishii R, Minagawa A, Takaku H, Takagi M, Nashimoto M, Yokoyama S. Crystal structure of the tRNA 3' processing endoribonuclease tRNase Z from Thermotoga maritima. J Biol Chem 2005; 280:14138-44. [PMID: 15701599 DOI: 10.1074/jbc.m500355200] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The maturation of the tRNA 3' end is catalyzed by a tRNA 3' processing endoribonuclease named tRNase Z (RNase Z or 3'-tRNase) in eukaryotes, Archaea, and some bacteria. The tRNase Z generally cuts the 3' extra sequence from the precursor tRNA after the discriminator nucleotide. In contrast, Thermotoga maritima tRNase Z cleaves the precursor tRNA precisely after the CCA sequence. In this study, we determined the crystal structure of T. maritima tRNase Z at 2.6-A resolution. The tRNase Z has a four-layer alphabeta/betaalpha sandwich fold, which is classified as a metallo-beta-lactamase fold, and forms a dimer. The active site is located at one edge of the beta-sandwich and is composed of conserved motifs. Based on the structure, we constructed a docking model with the tRNAs that suggests how tRNase Z may recognize the substrate tRNAs.
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Affiliation(s)
- Ryohei Ishii
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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41
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Li de la Sierra-Gallay I, Pellegrini O, Condon C. Structural basis for substrate binding, cleavage and allostery in the tRNA maturase RNase Z. Nature 2005; 433:657-61. [PMID: 15654328 DOI: 10.1038/nature03284] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2004] [Accepted: 12/16/2004] [Indexed: 11/08/2022]
Abstract
Transfer RNAs (tRNAs) are synthesized as part of longer primary transcripts that require processing of both their 3' and 5' extremities in every living organism known. The 5' side is processed (matured) by the ubiquitously conserved endonucleolytic ribozyme, RNase P, whereas removal of the 3' tails can be either exonucleolytic or endonucleolytic. The endonucleolytic pathway is catalysed by an enzyme known as RNase Z, or 3' tRNase. RNase Z cleaves precursor tRNAs immediately after the discriminator base (the unpaired nucleotide 3' to the last base pair of the acceptor stem, used as an identity determinant by many aminoacyl-tRNA synthetases) in most cases, yielding a tRNA primed for addition of the CCA motif by nucleotidyl transferase. Here we report the crystal structure of Bacillus subtilis RNase Z at 2.1 A resolution, and propose a mechanism for tRNA recognition and cleavage. The structure explains the allosteric properties of the enzyme, and also sheds light on the mechanisms of inhibition by the CCA motif and long 5' extensions. Finally, it highlights the extraordinary adaptability of the metallo-hydrolase domain of the beta-lactamase family for the hydrolysis of covalent bonds.
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42
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Schilling O, Rüggeberg S, Vogel A, Rittner N, Weichert S, Schmidt S, Doig S, Franz T, Benes V, Andrews SC, Baum M, Meyer-Klaucke W. Characterization of an Escherichia coli elaC deletion mutant. Biochem Biophys Res Commun 2004; 320:1365-73. [PMID: 15303284 DOI: 10.1016/j.bbrc.2004.05.227] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The elaC gene of Escherichia coli encodes a binuclear zinc phosphodiesterase (ZiPD). ZiPD homologs from various species act as3' tRNA processing endoribonucleases, and although the homologous gene in Bacillus subtilis is essential for viability [EMBO J. 22(2003) 4534], the physiological function of E. coli ZiPD has remained enigmatic. In order to investigate the function of E. coli ZiPDwe generated and characterized an E. coli elaC deletion mutant. Surprisingly, the E. coli elaC deletion mutant was viable and had wild-type like growth properties. Microarray-based transcriptional analysis indicated expression of the E. coli elaC gene at basal levels during aerobic growth. The elaC gene deletion had no effect on the expression of genes coding for RNases or amino-acyl tRNA synthetases or any other gene among a total of > 1300 genes probed. 2D-PAGE analysis showed that the elaC mutation, like-wise, had no effect on the proteome. These results strengthen doubts about the involvement of E. coli ZiPD in tRNA maturation and suggest functional diversity within the ZiPD/ElaC1 protein family. In addition to these unexpected features of the E. coli elaC deletion mutant, a sequence comparison of ZiPD (ElaC1) proteins revealed specific regions for either enterobacterial or mammalian ZiPD (ElaC1) proteins.
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43
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Dubrovsky EB, Dubrovskaya VA, Levinger L, Schiffer S, Marchfelder A. Drosophila RNase Z processes mitochondrial and nuclear pre-tRNA 3' ends in vivo. Nucleic Acids Res 2004; 32:255-62. [PMID: 14715923 PMCID: PMC373292 DOI: 10.1093/nar/gkh182] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Although correct tRNA 3' ends are crucial for protein biosynthesis, generation of mature tRNA 3' ends in eukaryotes is poorly understood and has so far only been investigated in vitro. We report here for the first time that eukaryotic tRNA 3' end maturation is catalysed by the endonuclease RNase Z in vivo. Silencing of the JhI-1 gene (RNase Z homolog) in vivo with RNAi in Drosophila S2 cultured cells causes accumulation of nuclear and mitochondrial pre-tRNAs, suggesting that JhI-1 encodes both forms of the tRNA 3' endonuclease RNase Z, and establishing its biological role in endonucleolytic tRNA 3' end processing. In addition our data show that in vivo 5' processing of nuclear and mitochondrial pre-tRNAs occurs before 3' processing.
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44
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Pellegrini O, Nezzar J, Marchfelder A, Putzer H, Condon C. Endonucleolytic processing of CCA-less tRNA precursors by RNase Z in Bacillus subtilis. EMBO J 2003; 22:4534-43. [PMID: 12941704 PMCID: PMC202377 DOI: 10.1093/emboj/cdg435] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In contrast to Escherichia coli, where the 3' ends of tRNAs are primarily generated by exoribonucleases, maturation of the 3' end of tRNAs is catalysed by an endoribonuclease, known as RNase Z (or 3' tRNase), in many eukaryotic and archaeal systems. RNase Z cleaves tRNA precursors 3' to the discriminator base. Here we show that this activity, previously unsuspected in bacteria, is encoded by the yqjK gene of Bacillus subtilis. Decreased yqjK expression leads to an accumulation of a population of B.subtilis tRNAs in vivo, none of which have a CCA motif encoded in their genes, and YqjK cleaves tRNA precursors with the same specificity as plant RNase Z in vitro. We have thus renamed the gene rnz. A CCA motif downstream of the discriminator base inhibits RNase Z activity in vitro, with most of the inhibition due to the first C residue. Lastly, tRNAs with long 5' extensions are poor substrates for cleavage, suggesting that for some tRNAs, processing of the 5' end by RNase P may have to precede RNase Z cleavage.
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Affiliation(s)
- Olivier Pellegrini
- CNRS UPR 9073, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
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45
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Ishii R, Nureki O, Yokoyama S. Crystal structure of the tRNA processing enzyme RNase PH from Aquifex aeolicus. J Biol Chem 2003; 278:32397-404. [PMID: 12746447 DOI: 10.1074/jbc.m300639200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
RNase PH is one of the exoribonucleases that catalyze the 3' end processing of tRNA in bacteria. RNase PH removes nucleotides following the CCA sequence of tRNA precursors by phosphorolysis and generates mature tRNAs with amino acid acceptor activity. In this study, we determined the crystal structure of Aquifex aeolicus RNase PH bound with a phosphate, a co-substrate, in the active site at 2.3-A resolution. RNase PH has the typical alpha/beta fold, which forms a hexameric ring structure as a trimer of dimers. This ring structure resembles that of the polynucleotide phosphorylase core domain homotrimer, another phosphorolytic exoribonuclease. Four amino acid residues, Arg-86, Gly-124, Thr-125, and Arg-126, of RNase PH are involved in the phosphate-binding site. Mutational analyses of these residues showed their importance in the phosphorolysis reaction. A docking model with the tRNA acceptor stem suggests how RNase PH accommodates substrate RNAs.
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Affiliation(s)
- Ryohei Ishii
- Department of Biophysics and Biochemistry, Graduate School of Science, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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46
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Abstract
This review focuses on the enzymes and pathways of RNA processing and degradation in Bacillus subtilis, and compares them to those of its gram-negative counterpart, Escherichia coli. A comparison of the genomes from the two organisms reveals that B. subtilis has a very different selection of RNases available for RNA maturation. Of 17 characterized ribonuclease activities thus far identified in E. coli and B. subtilis, only 6 are shared, 3 exoribonucleases and 3 endoribonucleases. Some enzymes essential for cell viability in E. coli, such as RNase E and oligoribonuclease, do not have homologs in B. subtilis, and of those enzymes in common, some combinations are essential in one organism but not in the other. The degradation pathways and transcript half-lives have been examined to various degrees for a dozen or so B. subtilis mRNAs. The determinants of mRNA stability have been characterized for a number of these and point to a fundamentally different process in the initiation of mRNA decay. While RNase E binds to the 5' end and catalyzes the rate-limiting cleavage of the majority of E. coli RNAs by looping to internal sites, the equivalent nuclease in B. subtilis, although not yet identified, is predicted to scan or track from the 5' end. RNase E can also access cleavage sites directly, albeit less efficiently, while the enzyme responsible for initiating the decay of B. subtilis mRNAs appears incapable of direct entry. Thus, unlike E. coli, RNAs possessing stable secondary structures or sites for protein or ribosome binding near the 5' end can have very long half-lives even if the RNA is not protected by translation.
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Affiliation(s)
- Ciarán Condon
- UPR 9073, Institut de Biologie Physico-Chimique, 75005 Paris, France.
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47
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Zaigler A, Schuster SC, Soppa J. Construction and usage of a onefold-coverage shotgun DNA microarray to characterize the metabolism of the archaeon Haloferax volcanii. Mol Microbiol 2003; 48:1089-105. [PMID: 12753198 DOI: 10.1046/j.1365-2958.2003.03497.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Haloferax volcanii is a moderately halophilic archaeon that can grow aerobically and anaerobically with a variety of substrates. We undertook a novel approach for the characterization of metabolic adaptations, i.e. transcriptome analysis with a onefold-coverage shotgun DNA microarray. A genomic library was constructed and converted into a polymerase chain reaction (PCR) product library, which was used to print two DNA microarrays, a 960-spot test array used for optimization of microarray analysis and a 2880-spot onefold-coverage array. H. volcanii cultures were shifted from casamino acid-based metabolism to glucose-based metabolism, and the transcriptome changes were analysed with the onefold-coverage array at five time points covering the transition phase and the onset of exponential growth with the new carbon source. About 10% of all genes were found to be more than 2.5-fold regulated at at least one time point. The genes fall into five clusters of kinetically co-regulated genes. For members of all five clusters, the results were verified by Northern blot analyses. The identity of the regulated genes was determined by sequencing. Many co-regulated genes encode proteins of common functions. Expected as well as a variety of unexpected findings allowed predictions about the central metabolism, the transport capacity and the cellular composition of H. volcanii growing on casamino acids and on glucose. The microarray analyses are in accordance with the growth rates and ribosome contents of H. volcanii growing on the two carbon sources. Analysis of the results revealed that onefold-coverage shotgun DNA microarrays are well suited to characterize the regulation of metabolic pathways as well as protein complexes in response to changes in environmental conditions.
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Affiliation(s)
- Alexander Zaigler
- J. W. Goethe-Universität, Biozentrum Niederursel, Institut für Mikrobiologie, Marie-Curie-Str 9, D-60439 Frankfurt, Germany
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48
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Schiffer S, Rösch S, Marchfelder A. Recombinant RNase Z does not recognize CCA as part of the tRNA and its cleavage efficieny is influenced by acceptor stem length. Biol Chem 2003; 384:333-42. [PMID: 12715884 DOI: 10.1515/bc.2003.039] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
One of the essential maturation steps to yield functional tRNA molecules is the removal of 3'-trailer sequences by RNase Z. After RNase Z cleavage the tRNA nucleotidyl transferase adds the CCA sequence to the tRNA 3'-terminus, thereby generating the mature tRNA. Here we investigated whether a terminal CCA triplet as 3'-trailer or embedded in a longer 3'-trailer influences cleavage site selection by RNase Z using three activities: a recombinant plant RNase Z, a recombinant archaeal RNase Z and an RNase Z active wheat extract. A trailer of only the CCA trinucleotide is left intact by the wheat extract RNase Z but is removed by the recombinant plant and archaeal enzymes. Thus the CCA triplet is not recognized by the RNase Z enzyme itself, but rather requires cofactors still present in the extract. In addition, we investigated the influence of acceptor stem length on cleavage by RNase Z using variants of wild-type tRNATyr. While the wild type and the variant with 8 base pairs in the acceptor stem were processed efficiently by all three activities, variants with shorter and longer acceptor stems were poor substrates or were not cleaved at all.
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Affiliation(s)
- Steffen Schiffer
- Molekulare Botanik, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
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49
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Schiffer S, Rösch S, Marchfelder A. Assigning a function to a conserved group of proteins: the tRNA 3'-processing enzymes. EMBO J 2002; 21:2769-77. [PMID: 12032089 PMCID: PMC126033 DOI: 10.1093/emboj/21.11.2769] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Accurate tRNA 3' end maturation is essential for aminoacylation and thus for protein synthesis in all organisms. Here we report the first identification of protein and DNA sequences for tRNA 3'-processing endonucleases (RNase Z). Purification of RNase Z from wheat identified a 43 kDa protein correlated with the activity. Peptide sequences obtained from the purified protein were used to identify the corresponding gene. In vitro expression of the homologous proteins from Arabidopsis thaliana and Methano coccus janaschii confirmed their tRNA 3'-processing activities. These RNase Z proteins belong to the ELAC1/2 family of proteins and to the cluster of orthologous proteins COG 1234. The RNase Z enzymes from A.thaliana and M.janaschii are the first members of these families to which a function can now be assigned. Proteins with high sequence similarity to the RNase Z enzymes from A.thaliana and M.janaschii are present in all three kingdoms.
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Affiliation(s)
| | | | - Anita Marchfelder
- Molekulare Botanik, Universität Ulm, D-89069 Ulm, Germany
Corresponding author e-mail:
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