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Potužník JF, Cahova H. If the 5' cap fits (wear it) - Non-canonical RNA capping. RNA Biol 2024; 21:1-13. [PMID: 39007883 PMCID: PMC11253889 DOI: 10.1080/15476286.2024.2372138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 06/18/2024] [Indexed: 07/16/2024] Open
Abstract
RNA capping is a prominent RNA modification that influences RNA stability, metabolism, and function. While it was long limited to the study of the most abundant eukaryotic canonical m7G cap, the field recently went through a large paradigm shift with the discovery of non-canonical RNA capping in bacteria and ultimately all domains of life. The repertoire of non-canonical caps has expanded to encompass metabolite caps, including NAD, FAD, CoA, UDP-Glucose, and ADP-ribose, alongside alarmone dinucleoside polyphosphate caps, and methylated phosphate cap-like structures. This review offers an introduction into the field, presenting a summary of the current knowledge about non-canonical RNA caps. We highlight the often still enigmatic biological roles of the caps together with their processing enzymes, focusing on the most recent discoveries. Furthermore, we present the methods used for the detection and analysis of these non-canonical RNA caps and thus provide an introduction into this dynamic new field.
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Affiliation(s)
- Jiří František Potužník
- Institute of Organic Chemistry and Biochemistry of the CAS, Prague 6, Czechia
- Department of Cell Biology, Charles University, Faculty of Science, Prague 2, Czechia
| | - Hana Cahova
- Institute of Organic Chemistry and Biochemistry of the CAS, Prague 6, Czechia
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2
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Apprehending the NAD+–ADPr-Dependent Systems in the Virus World. Viruses 2022; 14:v14091977. [PMID: 36146784 PMCID: PMC9503650 DOI: 10.3390/v14091977] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/01/2022] [Accepted: 09/05/2022] [Indexed: 11/19/2022] Open
Abstract
NAD+ and ADP-ribose (ADPr)-containing molecules are at the interface of virus–host conflicts across life encompassing RNA processing, restriction, lysogeny/dormancy and functional hijacking. We objectively defined the central components of the NAD+–ADPr networks involved in these conflicts and systematically surveyed 21,191 completely sequenced viral proteomes representative of all publicly available branches of the viral world to reconstruct a comprehensive picture of the viral NAD+–ADPr systems. These systems have been widely and repeatedly exploited by positive-strand RNA and DNA viruses, especially those with larger genomes and more intricate life-history strategies. We present evidence that ADP-ribosyltransferases (ARTs), ADPr-targeting Macro, NADAR and Nudix proteins are frequently packaged into virions, particularly in phages with contractile tails (Myoviruses), and deployed during infection to modify host macromolecules and counter NAD+-derived signals involved in viral restriction. Genes encoding NAD+–ADPr-utilizing domains were repeatedly exchanged between distantly related viruses, hosts and endo-parasites/symbionts, suggesting selection for them across the virus world. Contextual analysis indicates that the bacteriophage versions of ADPr-targeting domains are more likely to counter soluble ADPr derivatives, while the eukaryotic RNA viral versions might prefer macromolecular ADPr adducts. Finally, we also use comparative genomics to predict host systems involved in countering viral ADP ribosylation of host molecules.
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3
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Yang Z, Zhang C, Lian G, Dong S, Song M, Shao H, Wang J, Zhong T, Luo Z, Jin S, Ding C. Direct adenylation from 5'-OH-terminated oligonucleotides by a fusion enzyme containing Pfu RNA ligase and T4 polynucleotide kinase. Nucleic Acids Res 2022; 50:7560-7569. [PMID: 35819229 PMCID: PMC9303275 DOI: 10.1093/nar/gkac604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 06/23/2022] [Accepted: 06/30/2022] [Indexed: 11/14/2022] Open
Abstract
5′-Adenylated oligonucleotides (AppOligos) are widely used for single-stranded DNA/RNA ligation in next-generation sequencing (NGS) applications such as microRNA (miRNA) profiling. The ligation between an AppOligo adapter and target molecules (such as miRNA) no longer requires ATP, thereby minimizing potential self-ligations and simplifying library preparation procedures. AppOligos can be produced by chemical synthesis or enzymatic modification. However, adenylation via chemical synthesis is inefficient and expensive, while enzymatic modification requires pre-phosphorylated substrate and additional purification. Here we cloned and characterized the Pfu RNA ligase encoded by the PF0353 gene in the hyperthermophilic archaea Pyrococcus furiosus. We further engineered fusion enzymes containing both Pfu RNA ligase and T4 polynucleotide kinase. One fusion enzyme, 8H-AP, was thermostable and can directly catalyze 5′-OH-terminated DNA substrates to adenylated products. The newly discovered Pfu RNA ligase and the engineered fusion enzyme may be useful tools for applications using AppOligos.
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Affiliation(s)
- Zhengquan Yang
- Key Laboratory of Laboratory Medicine, Ministry of Education of China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Chengliang Zhang
- Key Laboratory of Laboratory Medicine, Ministry of Education of China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China.,Department of Clinical Laboratory, Kunming Third People's Hospital, Kunming, Yunnan, 650041, China
| | - Guojun Lian
- Key Laboratory of Laboratory Medicine, Ministry of Education of China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Shijie Dong
- Key Laboratory of Laboratory Medicine, Ministry of Education of China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Menghui Song
- Key Laboratory of Laboratory Medicine, Ministry of Education of China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Hengrong Shao
- Key Laboratory of Laboratory Medicine, Ministry of Education of China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Jingmei Wang
- Key Laboratory of Laboratory Medicine, Ministry of Education of China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Tao Zhong
- Key Laboratory of Laboratory Medicine, Ministry of Education of China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Zhenni Luo
- Key Laboratory of Laboratory Medicine, Ministry of Education of China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Shengnan Jin
- Key Laboratory of Laboratory Medicine, Ministry of Education of China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Chunming Ding
- Key Laboratory of Laboratory Medicine, Ministry of Education of China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
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4
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Olzog VJ, Freist LI, Goldmann R, Fallmann J, Weinberg CE. Application of RtcB ligase to monitor self-cleaving ribozyme activity by RNA-seq. Biol Chem 2022; 403:705-715. [PMID: 35025187 DOI: 10.1515/hsz-2021-0408] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/24/2021] [Indexed: 11/15/2022]
Abstract
Self-cleaving ribozymes are catalytic RNAs and can be found in all domains of life. They catalyze a site-specific cleavage that results in a 5' fragment with a 2',3' cyclic phosphate (2',3' cP) and a 3' fragment with a 5' hydroxyl (5' OH) end. Recently, several strategies to enrich self-cleaving ribozymes by targeted biochemical methods have been introduced by us and others. Here, we develop an alternative strategy in which 5' OH RNAs are specifically ligated by RtcB ligase, which first guanylates the 3' phosphate of the adapter and then ligates it directly to RNAs with 5' OH ends. Our results demonstrate that adapter ligation to highly structured ribozyme fragments is much more efficient using the thermostable RtcB ligase from Pyrococcus horikoshii than the broadly applied Escherichia coli enzyme. Moreover, we investigated DNA, RNA and modified RNA adapters for their suitability in RtcB ligation reactions. We used the optimized RtcB-mediated ligation to produce RNA-seq libraries and captured a spiked 3' twister ribozyme fragment from E. coli total RNA. This RNA-seq-based method is applicable to detect ribozyme fragments as well as other cellular RNAs with 5' OH termini from total RNA.
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Affiliation(s)
- V Janett Olzog
- Faculty of Life Sciences, Institute for Biochemistry, Leipzig University, Brüderstraße 34, D-04103 Leipzig, Germany
| | - Lena I Freist
- Faculty of Life Sciences, Institute for Biochemistry, Leipzig University, Brüderstraße 34, D-04103 Leipzig, Germany
| | - Robin Goldmann
- Department of Computer Science, Bioinformatics Group, and Interdisciplinary Center for Bioinformatics, Leipzig University, Härtelstraße 16-18, D-04107 Leipzig, Germany
| | - Jörg Fallmann
- Department of Computer Science, Bioinformatics Group, and Interdisciplinary Center for Bioinformatics, Leipzig University, Härtelstraße 16-18, D-04107 Leipzig, Germany
| | - Christina E Weinberg
- Faculty of Life Sciences, Institute for Biochemistry, Leipzig University, Brüderstraße 34, D-04103 Leipzig, Germany
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5
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Wiedermannová J, Julius C, Yuzenkova Y. The expanding field of non-canonical RNA capping: new enzymes and mechanisms. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201979. [PMID: 34017598 PMCID: PMC8131947 DOI: 10.1098/rsos.201979] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Recent years witnessed the discovery of ubiquitous and diverse 5'-end RNA cap-like modifications in prokaryotes as well as in eukaryotes. These non-canonical caps include metabolic cofactors, such as NAD+/NADH, FAD, cell wall precursors UDP-GlcNAc, alarmones, e.g. dinucleotides polyphosphates, ADP-ribose and potentially other nucleoside derivatives. They are installed at the 5' position of RNA via template-dependent incorporation of nucleotide analogues as an initiation substrate by RNA polymerases. However, the discovery of NAD-capped processed RNAs in human cells suggests the existence of alternative post-transcriptional NC capping pathways. In this review, we compiled growing evidence for a number of these other mechanisms which produce various non-canonically capped RNAs and a growing repertoire of capping small molecules. Enzymes shown to be involved are ADP-ribose polymerases, glycohydrolases and tRNA synthetases, and may potentially include RNA 3'-phosphate cyclases, tRNA guanylyl transferases, RNA ligases and ribozymes. An emerging rich variety of capping molecules and enzymes suggests an unrecognized level of complexity of RNA metabolism.
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Affiliation(s)
| | | | - Yulia Yuzenkova
- Medical School, NUBI, Newcastle University, Newcastle upon Tyne, UK
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M. Iyer L, Anantharaman V, Krishnan A, Burroughs AM, Aravind L. Jumbo Phages: A Comparative Genomic Overview of Core Functions and Adaptions for Biological Conflicts. Viruses 2021; 13:v13010063. [PMID: 33466489 PMCID: PMC7824862 DOI: 10.3390/v13010063] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/31/2020] [Accepted: 12/31/2020] [Indexed: 02/07/2023] Open
Abstract
Jumbo phages have attracted much attention by virtue of their extraordinary genome size and unusual aspects of biology. By performing a comparative genomics analysis of 224 jumbo phages, we suggest an objective inclusion criterion based on genome size distributions and present a synthetic overview of their manifold adaptations across major biological systems. By means of clustering and principal component analysis of the phyletic patterns of conserved genes, all known jumbo phages can be classified into three higher-order groups, which include both myoviral and siphoviral morphologies indicating multiple independent origins from smaller predecessors. Our study uncovers several under-appreciated or unreported aspects of the DNA replication, recombination, transcription and virion maturation systems. Leveraging sensitive sequence analysis methods, we identify novel protein-modifying enzymes that might help hijack the host-machinery. Focusing on host–virus conflicts, we detect strategies used to counter different wings of the bacterial immune system, such as cyclic nucleotide- and NAD+-dependent effector-activation, and prevention of superinfection during pseudolysogeny. We reconstruct the RNA-repair systems of jumbo phages that counter the consequences of RNA-targeting host effectors. These findings also suggest that several jumbo phage proteins provide a snapshot of the systems found in ancient replicons preceding the last universal ancestor of cellular life.
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Affiliation(s)
- Lakshminarayan M. Iyer
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA; (L.M.I.); (V.A.); (A.M.B.)
| | - Vivek Anantharaman
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA; (L.M.I.); (V.A.); (A.M.B.)
| | - Arunkumar Krishnan
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Berhampur, Odisha 760010, India;
| | - A. Maxwell Burroughs
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA; (L.M.I.); (V.A.); (A.M.B.)
| | - L. Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA; (L.M.I.); (V.A.); (A.M.B.)
- Correspondence:
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7
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Unciuleac MC, Goldgur Y, Shuman S. Caveat mutator: alanine substitutions for conserved amino acids in RNA ligase elicit unexpected rearrangements of the active site for lysine adenylylation. Nucleic Acids Res 2020; 48:5603-5615. [PMID: 32315072 PMCID: PMC7261155 DOI: 10.1093/nar/gkaa238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/28/2020] [Accepted: 04/01/2020] [Indexed: 11/25/2022] Open
Abstract
Naegleria gruberi RNA ligase (NgrRnl) exemplifies the Rnl5 family of adenosine triphosphate (ATP)-dependent polynucleotide ligases that seal 3′-OH RNA strands in the context of 3′-OH/5′-PO4 nicked duplexes. Like all classic ligases, NgrRnl forms a covalent lysyl–AMP intermediate. A two-metal mechanism of lysine adenylylation was established via a crystal structure of the NgrRnl•ATP•(Mn2+)2 Michaelis complex. Here we conducted an alanine scan of active site constituents that engage the ATP phosphates and the metal cofactors. We then determined crystal structures of ligase-defective NgrRnl-Ala mutants in complexes with ATP/Mn2+. The unexpected findings were that mutations K170A, E227A, K326A and R149A (none of which impacted overall enzyme structure) triggered adverse secondary changes in the active site entailing dislocations of the ATP phosphates, altered contacts to ATP, and variations in the numbers and positions of the metal ions that perverted the active sites into off-pathway states incompatible with lysine adenylylation. Each alanine mutation elicited a distinctive off-pathway distortion of the ligase active site. Our results illuminate a surprising plasticity of the ligase active site in its interactions with ATP and metals. More broadly, they underscore a valuable caveat when interpreting mutational data in the course of enzyme structure-function studies.
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Affiliation(s)
| | - Yehuda Goldgur
- Structural Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
| | - Stewart Shuman
- Molecular Biology, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
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8
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Zhang J, Liu S, Li L, Wang G, Liu F, Zhao Y, Jing Y, Li Z. Effect of polysaccharide extract SPSS1 from Apostichopus japonicas spermary on HepG2 cells via iTRAQ-based proteome analysis. J Food Biochem 2020; 44:e13168. [PMID: 32160323 DOI: 10.1111/jfbc.13168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/16/2020] [Accepted: 01/20/2020] [Indexed: 11/30/2022]
Abstract
In this study, polysaccharide extract was prepared from Apostichopus japonicus spermary and purified by ion-exchange chromatography and gel filtration chromatography. Two main fractions named SPSS1 and SPSS2 were obtained and analyzed by ultraviolet spectroscopy and mixed with KBr, respectively. Chemical components analysis proved that SPSS1 and SPSS2 were rich in sulfate. Monosaccharide analysis indicated that in addition to the high content of lactose in both kinds of polysaccharides, the highest content of monosaccharide in SPSS1 was galactose, while in SPSS2 it was fucose. Further, the antitumor study of SPSS1 was carried and the results showed that SPSS1 treatment inhibited the proliferation of HepG2 cells. Through the iTRAQ-based proteome analysis, there were 208 differential proteins between control tumor cells and SPSS1 treatment of tumor cells. Compared to control tumor cells, 135 proteins were upregulated and 73 proteins were downregulated in treatment tumor cells. PRACTICAL APPLICATIONS: Our study suggested that polysaccharide from sea cucumbers had the potential to be further developed as antitumor drugs.
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Affiliation(s)
- Jian Zhang
- Shandong Marine Resource and Environment Research Institute, Yantai, China.,College of Biotechnology, The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Shaowei Liu
- College of Biotechnology, The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Laihao Li
- Key Laboratory of Aquatic Product Processing, Ministry of Agriculture and Rural Affairs, Guangzhou, China.,South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Gongming Wang
- Shandong Marine Resource and Environment Research Institute, Yantai, China
| | - Fang Liu
- Shandong Marine Resource and Environment Research Institute, Yantai, China
| | - Yunping Zhao
- Shandong Marine Resource and Environment Research Institute, Yantai, China
| | - Yuexin Jing
- Shandong Marine Resource and Environment Research Institute, Yantai, China
| | - Zhenduo Li
- Shandong Marine Resource and Environment Research Institute, Yantai, China
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9
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Munir A, Banerjee A, Shuman S. NAD+-dependent synthesis of a 5'-phospho-ADP-ribosylated RNA/DNA cap by RNA 2'-phosphotransferase Tpt1. Nucleic Acids Res 2019; 46:9617-9624. [PMID: 30202863 PMCID: PMC6182162 DOI: 10.1093/nar/gky792] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 08/24/2018] [Indexed: 11/13/2022] Open
Abstract
RNA 2′-phosphotransferase Tpt1 converts an internal RNA 2′-monophosphate to a 2′-OH via a two-step NAD+-dependent mechanism in which: (i) the 2′-phosphate attacks the C1″ of NAD+ to expel nicotinamide and form a 2′-phospho-ADP-ribosylated RNA intermediate; and (ii) the ADP-ribose O2″ attacks the phosphate of the RNA 2′-phospho-ADPR intermediate to expel the RNA 2′-OH and generate ADP-ribose 1″–2″ cyclic phosphate. Tpt1 is an essential component of the fungal tRNA splicing pathway that generates a unique 2′-PO4, 3′-5′ phosphodiester splice junction during tRNA ligation. The wide distribution of Tpt1 enzymes in taxa that have no fungal-type RNA ligase raises the prospect that Tpt1 might catalyze reactions other than RNA 2′-phosphate removal. A survey of Tpt1 enzymes from diverse sources reveals that whereas all of the Tpt1 enzymes are capable of NAD+-dependent conversion of an internal RNA 2′-PO4 to a 2′-OH (the canonical Tpt1 reaction), a subset of Tpt1 enzymes also catalyzed NAD+-dependent ADP-ribosylation of an RNA or DNA 5′-monophosphate terminus. Aeropyrum pernix Tpt1 (ApeTpt1) is particularly adept in this respect. One-step synthesis of a 5′-phospho-ADP-ribosylated cap structure by ApeTpt1 (with no subsequent 5′-phosphotransferase step) extends the repertoire of the Tpt1 enzyme family and the catalogue of ADP-ribosylation reactions involving nucleic acid acceptors.
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Affiliation(s)
- Annum Munir
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Ankan Banerjee
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
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10
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Unciuleac MC, Goldgur Y, Shuman S. Structures of ATP-bound DNA ligase D in a closed domain conformation reveal a network of amino acid and metal contacts to the ATP phosphates. J Biol Chem 2019; 294:5094-5104. [PMID: 30718283 PMCID: PMC6442053 DOI: 10.1074/jbc.ra119.007445] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 02/01/2019] [Indexed: 01/07/2023] Open
Abstract
DNA ligases are the sine qua non of genome integrity and essential for DNA replication and repair in all organisms. DNA ligases join 3'-OH and 5'-PO4 ends via a series of three nucleotidyl transfer steps. In step 1, ligase reacts with ATP or NAD+ to form a covalent ligase-(lysyl-Nζ)-AMP intermediate and release pyrophosphate (PPi) or nicotinamide mononucleotide. In step 2, AMP is transferred from ligase-adenylate to the 5'-PO4 DNA end to form a DNA-adenylate intermediate (AppDNA). In step 3, ligase catalyzes attack by a DNA 3'-OH on the DNA-adenylate to seal the two ends via a phosphodiester bond and release AMP. Eukaryal, archaeal, and many bacterial and viral DNA ligases are ATP-dependent. The catalytic core of ATP-dependent DNA ligases consists of an N-terminal nucleotidyltransferase domain fused to a C-terminal OB domain. Here we report crystal structures at 1.4-1.8 Å resolution of Mycobacterium tuberculosis LigD, an ATP-dependent DNA ligase dedicated to nonhomologous end joining, in complexes with ATP that highlight large movements of the OB domain (∼50 Å), from a closed conformation in the ATP complex to an open conformation in the covalent ligase-AMP intermediate. The LigD·ATP structures revealed a network of amino acid contacts to the ATP phosphates that stabilize the transition state and orient the PPi leaving group. A complex with ATP and magnesium suggested a two-metal mechanism of lysine adenylylation driven by a catalytic Mg2+ that engages the ATP α phosphate and a second metal that bridges the ATP β and γ phosphates.
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Affiliation(s)
| | - Yehuda Goldgur
- Structural Biology Programs, Sloan Kettering Institute, New York, New York 10065
| | - Stewart Shuman
- From the Molecular Biology and , To whom correspondence should be addressed:
Molecular Biology Program, Sloan Kettering Institute, 1275 York Ave., New York, NY 10065. E-mail:
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11
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Genotoxic, Metabolic, and Oxidative Stresses Regulate the RNA Repair Operon of Salmonella enterica Serovar Typhimurium. J Bacteriol 2018; 200:JB.00476-18. [PMID: 30201777 DOI: 10.1128/jb.00476-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 09/04/2018] [Indexed: 12/12/2022] Open
Abstract
The σ54 regulon in Salmonella enterica serovar Typhimurium includes a predicted RNA repair operon encoding homologs of the metazoan Ro60 protein (Rsr), Y RNAs (YrlBA), RNA ligase (RtcB), and RNA 3'-phosphate cyclase (RtcA). Transcription from σ54-dependent promoters requires that a cognate bacterial enhancer binding protein (bEBP) be activated by a specific environmental or cellular signal; the cognate bEBP for the σ54-dependent promoter of the rsr-yrlBA-rtcBA operon is RtcR. To identify conditions that generate the signal for RtcR activation in S Typhimurium, transcription of the RNA repair operon was assayed under multiple stress conditions that result in nucleic acid damage. RtcR-dependent transcription was highly induced by the nucleic acid cross-linking agents mitomycin C (MMC) and cisplatin, and this activation was dependent on RecA. Deletion of rtcR or rtcB resulted in decreased cell viability relative to that of the wild type following treatment with MMC. Oxidative stress from peroxide exposure also induced RtcR-dependent transcription of the operon. Nitrogen limitation resulted in RtcR-independent increased expression of the operon; the effect of nitrogen limitation required NtrC. The adjacent toxin-antitoxin module, dinJ-yafQ, was cotranscribed with the RNA repair operon but was not required for RtcR activation, although YafQ endoribonuclease activated RtcR-dependent transcription. Stress conditions shown to induce expression the RNA repair operon of Escherichia coli (rtcBA) did not stimulate expression of the S Typhimurium RNA repair operon. Similarly, MMC did not induce expression of the E. coli rtcBA operon, although when expressed in S Typhimurium, E. coli RtcR responds effectively to the unknown signal(s) generated there by MMC exposure.IMPORTANCE Homologs of the metazoan RNA repair enzymes RtcB and RtcA occur widely in eubacteria, suggesting a selective advantage. Although the enzymatic activities of the eubacterial RtcB and RtcA have been well characterized, the physiological roles remain largely unresolved. Here we report stress responses that activate expression of the σ54-dependent RNA repair operon (rsr-yrlBA-rtcBA) of S Typhimurium and demonstrate that expression of the operon impacts cell survival under MMC-induced stress. Characterization of the requirements for activation of this tightly regulated operon provides clues to the possible functions of operon components in vivo, enhancing our understanding of how this human pathogen copes with environmental stressors.
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12
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Temmel H, Müller C, Sauert M, Vesper O, Reiss A, Popow J, Martinez J, Moll I. The RNA ligase RtcB reverses MazF-induced ribosome heterogeneity in Escherichia coli. Nucleic Acids Res 2017; 45:4708-4721. [PMID: 27789694 PMCID: PMC5416887 DOI: 10.1093/nar/gkw1018] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 10/18/2016] [Indexed: 12/22/2022] Open
Abstract
When Escherichia coli encounters stress, the endoribonuclease MazF initiates a post-transcriptional response that results in the reprogramming of protein synthesis. By removing the 3΄-terminus of the 16S rRNA, MazF generates specialized ribosomes that selectively translate mRNAs likewise processed by MazF. Given the energy required for de novo ribosome biosynthesis, we considered the existence of a repair mechanism operating upon stress relief to recycle the modified ribosomes. Here, we show that the stress-ribosomes and the 3΄-terminal 16S rRNA fragment are stable during adverse conditions. Moreover, employing in vitro and in vivo approaches we demonstrate that the RNA ligase RtcB catalyzes the re-ligation of the truncated 16S rRNA present in specialized ribosomes Thereby their ability to translate canonical mRNAs is fully restored. Together, our findings not only provide a physiological function for the RNA ligase RtcB in bacteria but highlight the reversibility of ribosome heterogeneity, a crucial but hitherto undescribed concept for translational regulation.
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Affiliation(s)
- Hannes Temmel
- Max F. Perutz Laboratories, Center for Molecular Biology, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna Biocenter (VBC), Dr Bohr-Gasse 9/4, A-1030 Vienna, Austria
| | - Christian Müller
- Max F. Perutz Laboratories, Center for Molecular Biology, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna Biocenter (VBC), Dr Bohr-Gasse 9/4, A-1030 Vienna, Austria
| | - Martina Sauert
- Max F. Perutz Laboratories, Center for Molecular Biology, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna Biocenter (VBC), Dr Bohr-Gasse 9/4, A-1030 Vienna, Austria
| | - Oliver Vesper
- Max F. Perutz Laboratories, Center for Molecular Biology, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna Biocenter (VBC), Dr Bohr-Gasse 9/4, A-1030 Vienna, Austria
| | - Ariela Reiss
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), A-1030 Vienna, Austria and Max F. Perutz Laboratories, Department of Medical Biochemistry, Medical University of Vienna, Vienna Biocenter (VBC), Dr Bohr-Gasse 9/4, A-1030 Vienna, Austria
| | - Johannes Popow
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), A-1030 Vienna, Austria and Max F. Perutz Laboratories, Department of Medical Biochemistry, Medical University of Vienna, Vienna Biocenter (VBC), Dr Bohr-Gasse 9/4, A-1030 Vienna, Austria
| | - Javier Martinez
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), A-1030 Vienna, Austria and Max F. Perutz Laboratories, Department of Medical Biochemistry, Medical University of Vienna, Vienna Biocenter (VBC), Dr Bohr-Gasse 9/4, A-1030 Vienna, Austria
| | - Isabella Moll
- Max F. Perutz Laboratories, Center for Molecular Biology, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna Biocenter (VBC), Dr Bohr-Gasse 9/4, A-1030 Vienna, Austria
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13
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The DNA Repair Repertoire of Mycobacterium smegmatis FenA Includes the Incision of DNA 5' Flaps and the Removal of 5' Adenylylated Products of Aborted Nick Ligation. J Bacteriol 2017. [PMID: 28630124 DOI: 10.1128/jb.00304-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We characterize Mycobacterium smegmatis FenA as a manganese-dependent 5'-flap endonuclease homologous to the 5'-exonuclease of DNA polymerase I. FenA incises a nicked 5' flap between the first and second nucleotides of the duplex segment to yield a 1-nucleotide gapped DNA, which is then further resected in dinucleotide steps. Initial FenA cleavage at a Y-flap or nick occurs between the first and second nucleotides of the duplex. However, when the template 3' single strand is eliminated to create a 5'-tailed duplex, FenA incision shifts to between the second and third nucleotides. A double-flap substrate with a mobile junction (mimicking limited strand displacement synthesis during gap repair) is preferentially incised as the 1-nucleotide 3'-flap isomer, with the scissile phosphodiester shifted by one nucleotide versus a static double flap. FenA efficiently removes the 5' App(dN) terminus of an aborted nick ligation reaction intermediate, thereby highlighting FenA as an agent of repair of such lesions, which are formed under a variety of circumstances by bacterial NAD+-dependent DNA ligases and especially by mycobacterial DNA ligases D and C.IMPORTANCE Structure-specific DNA endonucleases are implicated in bacterial DNA replication, repair, and recombination, yet there is scant knowledge of the roster and catalytic repertoire of such nucleases in Mycobacteria This study identifies M. smegmatis FenA as a stand-alone endonuclease homologous to the 5'-exonuclease domain of mycobacterial DNA polymerase 1. FenA incises 5' flaps, 5' nicks, and 5' App(dN) intermediates of aborted nick ligation. The isolated N-terminal domain of M. smegmatis Pol1 is also shown to be a flap endonuclease.
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14
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Hartman CE, Samuels DJ, Karls AC. Modulating Salmonella Typhimurium's Response to a Changing Environment through Bacterial Enhancer-Binding Proteins and the RpoN Regulon. Front Mol Biosci 2016; 3:41. [PMID: 27583250 PMCID: PMC4987338 DOI: 10.3389/fmolb.2016.00041] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 07/28/2016] [Indexed: 12/25/2022] Open
Abstract
Transcription sigma factors direct the selective binding of RNA polymerase holoenzyme (Eσ) to specific promoters. Two families of sigma factors determine promoter specificity, the σ(70) (RpoD) family and the σ(54) (RpoN) family. In transcription controlled by σ(54), the Eσ(54)-promoter closed complex requires ATP hydrolysis by an associated bacterial enhancer-binding protein (bEBP) for the transition to open complex and transcription initiation. Given the wide host range of Salmonella enterica serovar Typhimurium, it is an excellent model system for investigating the roles of RpoN and its bEBPs in modulating the lifestyle of bacteria. The genome of S. Typhimurium encodes 13 known or predicted bEBPs, each responding to a unique intracellular or extracellular signal. While the regulons of most alternative sigma factors respond to a specific environmental or developmental signal, the RpoN regulon is very diverse, controlling genes for response to nitrogen limitation, nitric oxide stress, availability of alternative carbon sources, phage shock/envelope stress, toxic levels of zinc, nucleic acid damage, and other stressors. This review explores how bEBPs respond to environmental changes encountered by S. Typhimurium during transmission/infection and influence adaptation through control of transcription of different components of the S. Typhimurium RpoN regulon.
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Affiliation(s)
| | - David J Samuels
- Department of Microbiology, University of Georgia Athens, GA, USA
| | - Anna C Karls
- Department of Microbiology, University of Georgia Athens, GA, USA
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15
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Burroughs AM, Aravind L. RNA damage in biological conflicts and the diversity of responding RNA repair systems. Nucleic Acids Res 2016; 44:8525-8555. [PMID: 27536007 PMCID: PMC5062991 DOI: 10.1093/nar/gkw722] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/08/2016] [Indexed: 12/16/2022] Open
Abstract
RNA is targeted in biological conflicts by enzymatic toxins or effectors. A vast diversity of systems which repair or ‘heal’ this damage has only recently become apparent. Here, we summarize the known effectors, their modes of action, and RNA targets before surveying the diverse systems which counter this damage from a comparative genomics viewpoint. RNA-repair systems show a modular organization with extensive shuffling and displacement of the constituent domains; however, a general ‘syntax’ is strongly maintained whereby systems typically contain: a RNA ligase (either ATP-grasp or RtcB superfamilies), nucleotidyltransferases, enzymes modifying RNA-termini for ligation (phosphatases and kinases) or protection (methylases), and scaffold or cofactor proteins. We highlight poorly-understood or previously-uncharacterized repair systems and components, e.g. potential scaffolding cofactors (Rot/TROVE and SPFH/Band-7 modules) with their respective cognate non-coding RNAs (YRNAs and a novel tRNA-like molecule) and a novel nucleotidyltransferase associating with diverse ligases. These systems have been extensively disseminated by lateral transfer between distant prokaryotic and microbial eukaryotic lineages consistent with intense inter-organismal conflict. Components have also often been ‘institutionalized’ for non-conflict roles, e.g. in RNA-splicing and in RNAi systems (e.g. in kinetoplastids) which combine a distinct family of RNA-acting prim-pol domains with DICER-like proteins.
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Affiliation(s)
- A Maxwell Burroughs
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - L Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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16
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Chevallereau A, Blasdel BG, De Smet J, Monot M, Zimmermann M, Kogadeeva M, Sauer U, Jorth P, Whiteley M, Debarbieux L, Lavigne R. Next-Generation "-omics" Approaches Reveal a Massive Alteration of Host RNA Metabolism during Bacteriophage Infection of Pseudomonas aeruginosa. PLoS Genet 2016; 12:e1006134. [PMID: 27380413 PMCID: PMC4933390 DOI: 10.1371/journal.pgen.1006134] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 05/31/2016] [Indexed: 01/08/2023] Open
Abstract
As interest in the therapeutic and biotechnological potentials of bacteriophages has grown, so has value in understanding their basic biology. However, detailed knowledge of infection cycles has been limited to a small number of model bacteriophages, mostly infecting Escherichia coli. We present here the first analysis coupling data obtained from global next-generation approaches, RNA-Sequencing and metabolomics, to characterize interactions between the virulent bacteriophage PAK_P3 and its host Pseudomonas aeruginosa. We detected a dramatic global depletion of bacterial transcripts coupled with their replacement by viral RNAs over the course of infection, eventually leading to drastic changes in pyrimidine metabolism. This process relies on host machinery hijacking as suggested by the strong up-regulation of one bacterial operon involved in RNA processing. Moreover, we found that RNA-based regulation plays a central role in PAK_P3 lifecycle as antisense transcripts are produced mainly during the early stage of infection and viral small non coding RNAs are massively expressed at the end of infection. This work highlights the prominent role of RNA metabolism in the infection strategy of a bacteriophage belonging to a new characterized sub-family of viruses with promising therapeutic potential.
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Affiliation(s)
- Anne Chevallereau
- Institut Pasteur, Molecular Biology of the Gene in Extremophiles Unit, Department of Microbiology, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Paris, France
| | - Bob G. Blasdel
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Jeroen De Smet
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Marc Monot
- Institut Pasteur, Laboratoire Pathogenèse des bactéries anaérobies, Département de Microbiologie, Paris, France
| | - Michael Zimmermann
- Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Maria Kogadeeva
- Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Uwe Sauer
- Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Peter Jorth
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, Center for Infectious Disease, University of Texas, Austin, Texas, United States of America
| | - Marvin Whiteley
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, Center for Infectious Disease, University of Texas, Austin, Texas, United States of America
| | - Laurent Debarbieux
- Institut Pasteur, Molecular Biology of the Gene in Extremophiles Unit, Department of Microbiology, Paris, France
| | - Rob Lavigne
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Leuven, Belgium
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17
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Lama L, Ryan K. Adenylylation of small RNA sequencing adapters using the TS2126 RNA ligase I. RNA (NEW YORK, N.Y.) 2016; 22:155-61. [PMID: 26567315 PMCID: PMC4691829 DOI: 10.1261/rna.054999.115] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 06/25/2015] [Indexed: 05/27/2023]
Abstract
Many high-throughput small RNA next-generation sequencing protocols use 5' preadenylylated DNA oligonucleotide adapters during cDNA library preparation. Preadenylylation of the DNA adapter's 5' end frees from ATP-dependence the ligation of the adapter to RNA collections, thereby avoiding ATP-dependent side reactions. However, preadenylylation of the DNA adapters can be costly and difficult. The currently available method for chemical adenylylation of DNA adapters is inefficient and uses techniques not typically practiced in laboratories profiling cellular RNA expression. An alternative enzymatic method using a commercial RNA ligase was recently introduced, but this enzyme works best as a stoichiometric adenylylating reagent rather than a catalyst and can therefore prove costly when several variant adapters are needed or during scale-up or high-throughput adenylylation procedures. Here, we describe a simple, scalable, and highly efficient method for the 5' adenylylation of DNA oligonucleotides using the thermostable RNA ligase 1 from bacteriophage TS2126. Adapters with 3' blocking groups are adenylylated at >95% yield at catalytic enzyme-to-adapter ratios and need not be gel purified before ligation to RNA acceptors. Experimental conditions are also reported that enable DNA adapters with free 3' ends to be 5' adenylylated at >90% efficiency.
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Affiliation(s)
- Lodoe Lama
- Department of Chemistry, The City College of New York, The City University of New York, New York, New York 10031, USA Biochemistry Ph.D. Program, The City University of New York Graduate Center, New York, New York 10016, USA
| | - Kevin Ryan
- Department of Chemistry, The City College of New York, The City University of New York, New York, New York 10031, USA Biochemistry Ph.D. Program, The City University of New York Graduate Center, New York, New York 10016, USA
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18
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Characterization of 3'-Phosphate RNA Ligase Paralogs RtcB1, RtcB2, and RtcB3 from Myxococcus xanthus Highlights DNA and RNA 5'-Phosphate Capping Activity of RtcB3. J Bacteriol 2015; 197:3616-24. [PMID: 26350128 DOI: 10.1128/jb.00631-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 08/28/2015] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED Escherichia coli RtcB exemplifies a family of GTP-dependent RNA repair/splicing enzymes that join 3'-PO4 ends to 5'-OH ends via stable RtcB-(histidinyl-N)-GMP and transient RNA3'pp5'G intermediates. E. coli RtcB also transfers GMP to a DNA 3'-PO4 end to form a stable "capped" product, DNA3'pp5'G. RtcB homologs are found in a multitude of bacterial proteomes, and many bacteria have genes encoding two or more RtcB paralogs; an extreme example is Myxococcus xanthus, which has six RtcBs. In this study, we purified, characterized, and compared the biochemical activities of three M. xanthus RtcB paralogs. We found that M. xanthus RtcB1 resembles E. coli RtcB in its ability to perform intra- and intermolecular sealing of a HORNAp substrate and capping of a DNA 3'-PO4 end. M. xanthus RtcB2 can splice HORNAp but has 5-fold-lower RNA ligase specific activity than RtcB1. In contrast, M. xanthus RtcB3 is distinctively feeble at ligating the HORNAp substrate, although it readily caps a DNA 3'-PO4 end. The novelty of M. xanthus RtcB3 is its capacity to cap DNA and RNA 5'-PO4 ends to form GppDNA and GppRNA products, respectively. As such, RtcB3 joins a growing list of enzymes (including RNA 3'-phosphate cyclase RtcA and thermophilic ATP-dependent RNA ligases) that can cap either end of a polynucleotide substrate. GppDNA formed by RtcB3 can be decapped to pDNA by the DNA repair enzyme aprataxin. IMPORTANCE RtcB enzymes comprise a widely distributed family of RNA 3'-PO4 ligases distinguished by their formation of 3'-GMP-capped RNAppG and/or DNAppG polynucleotides. The mechanism and biochemical repertoire of E. coli RtcB are well studied, but it is unclear whether its properties apply to the many bacteria that have genes encoding multiple RtcB paralogs. A comparison of the biochemical activities of three M. xanthus paralogs, RtcB1, RtcB2, and RtcB3, shows that not all RtcBs are created equal. The standout findings concern RtcB3, which is (i) inactive as an RNA 3'-PO4 ligase but adept at capping a DNA 3'-PO4 end and (ii) able to cap DNA and RNA 5'-PO4 ends to form GppDNA and GppRNA, respectively. The GppDNA and GppRNA capping reactions are novel nucleic acid modifications.
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19
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Chauleau M, Jacewicz A, Shuman S. DNA3'pp5'G de-capping activity of aprataxin: effect of cap nucleoside analogs and structural basis for guanosine recognition. Nucleic Acids Res 2015; 43:6075-83. [PMID: 26007660 PMCID: PMC4499129 DOI: 10.1093/nar/gkv501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 05/01/2015] [Indexed: 01/03/2023] Open
Abstract
DNA3′pp5′G caps synthesized by the 3′-PO4/5′-OH ligase RtcB have a strong impact on enzymatic reactions at DNA 3′-OH ends. Aprataxin, an enzyme that repairs A5′pp5′DNA ends formed during abortive ligation by classic 3′-OH/5′-PO4 ligases, is also a DNA 3′ de-capping enzyme, converting DNAppG to DNA3′p and GMP. By taking advantage of RtcB's ability to utilize certain GTP analogs to synthesize DNAppN caps, we show that aprataxin hydrolyzes inosine and 6-O-methylguanosine caps, but is not adept at removing a deoxyguanosine cap. We report a 1.5 Å crystal structure of aprataxin in a complex with GMP, which reveals that: (i) GMP binds at the same position and in the same anti nucleoside conformation as AMP; and (ii) aprataxin makes more extensive nucleobase contacts with guanine than with adenine, via a hydrogen bonding network to the guanine O6, N1, N2 base edge. Alanine mutations of catalytic residues His147 and His149 abolish DNAppG de-capping activity, suggesting that the 3′ de-guanylylation and 5′ de-adenylylation reactions follow the same pathway of nucleotidyl transfer through a covalent aprataxin-(His147)–NMP intermediate. Alanine mutation of Asp63, which coordinates the guanosine ribose hydroxyls, impairs DNAppG de-capping.
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Affiliation(s)
- Mathieu Chauleau
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Agata Jacewicz
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
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20
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Unciuleac MC, Shuman S. Characterization of a novel eukaryal nick-sealing RNA ligase from Naegleria gruberi. RNA (NEW YORK, N.Y.) 2015; 21:824-832. [PMID: 25740837 PMCID: PMC4408790 DOI: 10.1261/rna.049197.114] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/07/2015] [Indexed: 06/04/2023]
Abstract
The proteome of the amoebo-flagellate protozoan Naegleria gruberi is rich in candidate RNA repair enzymes, including 15 putative RNA ligases, one of which, NgrRnl, is a eukaryal homolog of Deinococcus radiodurans RNA ligase, DraRnl. Here we report that purified recombinant NgrRnl seals nicked 3'-OH/5'-PO4 duplexes in which the 3'-OH strand is RNA. It does so via the "classic" ligase pathway, entailing reaction with ATP to form a covalent NgrRnl-AMP intermediate, transfer of AMP to the nick 5'-PO4, and attack of the RNA 3'-OH on the adenylylated nick to form a 3'-5' phosphodiester. Unlike members of the four known families of ATP-dependent RNA ligases, NgrRnl lacks a carboxy-terminal appendage to its nucleotidyltransferase domain. Instead, it contains a defining amino-terminal domain that we show is important for 3'-OH/5'-PO4 nick-sealing and ligase adenylylation, but dispensable for phosphodiester synthesis at a preadenylylated nick. We propose that NgrRnl, DraRnl, and their homologs from diverse bacteria, viruses, and unicellular eukarya comprise a new "Rnl5 family" of nick-sealing ligases with a signature domain organization.
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Affiliation(s)
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
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21
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Huang SYN, Ghosh S, Pommier Y. Topoisomerase I alone is sufficient to produce short DNA deletions and can also reverse nicks at ribonucleotide sites. J Biol Chem 2015; 290:14068-76. [PMID: 25887397 DOI: 10.1074/jbc.m115.653345] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Indexed: 11/06/2022] Open
Abstract
Ribonucleotide monophosphates (rNMPs) are among the most frequent form of DNA aberration, as high ratios of ribonucleotide triphosphate:deoxyribonucleotide triphosphate pools result in approximately two misincorporated rNMPs/kb of DNA. The main pathway for the removal of rNMPs is by RNase H2. However, in a RNase H2 knock-out yeast strain, a topoisomerase I (Top1)-dependent mutator effect develops with accumulation of short deletions within tandem repeats. Proposed models for these deletions implicated processing of Top1-generated nicks at rNMP sites and/or sequential Top1 binding, but experimental support has been lacking thus far. Here, we investigated the biochemical mechanism of the Top1-induced short deletions at the rNMP sites by generating nicked DNA substrates bearing 2',3'-cyclic phosphates at the nick sites, mimicking the Top1-induced nicks. We demonstrate that a second Top1 cleavage complex adjacent to the nick and subsequent faulty Top1 religation led to the short deletions. Moreover, when acting on the nicked DNA substrates containing 2',3'-cyclic phosphates, Top1 generated not only the short deletion, but also a full-length religated DNA product. A catalytically inactive Top1 mutant (Top1-Y723F) also induced the full-length products, indicating that Top1 binding independent of its enzymatic activity promotes the sealing of DNA backbones via nucleophilic attacks by the 5'-hydroxyl on the 2',3'-cyclic phosphate. The resealed DNA would allow renewed attempt for repair by the error-free RNase H2-dependent pathway in vivo. Our results provide direct evidence for the generation of short deletions by sequential Top1 cleavage events and for the promotion of nick religation at rNMP sites by Top1.
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Affiliation(s)
- Shar-Yin Naomi Huang
- From the Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Sanchari Ghosh
- From the Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Yves Pommier
- From the Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
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22
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Zhelkovsky AM, McReynolds LA. Polynucleotide 3'-terminal phosphate modifications by RNA and DNA ligases. J Biol Chem 2014; 289:33608-16. [PMID: 25324547 DOI: 10.1074/jbc.m114.612929] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
RNA and DNA ligases catalyze the formation of a phosphodiester bond between the 5'-phosphate and 3'-hydroxyl ends of nucleic acids. In this work, we describe the ability of the thermophilic RNA ligase MthRnl from Methanobacterium thermoautotrophicum to recognize and modify the 3'-terminal phosphate of RNA and single-stranded DNA (ssDNA). This ligase can use an RNA 3'p substrate to generate an RNA 2',3'-cyclic phosphate or convert DNA3'p to ssDNA(3')pp(5')A. An RNA ligase from the Thermus scotoductus bacteriophage TS2126 and a predicted T4 Rnl1-like protein from Thermovibrio ammonificans, TVa, were also able to adenylate ssDNA 3'p. These modifications of RNA and DNA 3'-phosphates are similar to the activities of RtcA, an RNA 3'-phosphate cyclase. The initial step involves adenylation of the enzyme by ATP, which is then transferred to either RNA 3'p or DNA 3'p to generate the adenylated intermediate. For RNA (3')pp(5')A, the third step involves attack of the adjacent 2' hydroxyl to generate the RNA 2',3'-cyclic phosphate. These steps are analogous to those in classical 5' phosphate ligation. MthRnl and TS2126 RNA ligases were not able to modify a 3'p in nicked double-stranded DNA. However, T4 DNA ligase and RtcA can use 3'-phosphorylated nicks in double-stranded DNA to produce a 3'-adenylated product. These 3'-terminal phosphate-adenylated intermediates are substrates for deadenylation by yeast 5'Deadenylase. Our findings that classic ligases can duplicate the adenylation and phosphate cyclization activity of RtcA suggests that they have an essential role in metabolism of nucleic acids with 3'-terminal phosphates.
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Affiliation(s)
- Alexander M Zhelkovsky
- From the Division of RNA Biology, New England Biolabs, Inc., Ipswich, Massachusetts 01938
| | - Larry A McReynolds
- From the Division of RNA Biology, New England Biolabs, Inc., Ipswich, Massachusetts 01938
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23
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Das U, Shuman S. 2'-Phosphate cyclase activity of RtcA: a potential rationale for the operon organization of RtcA with an RNA repair ligase RtcB in Escherichia coli and other bacterial taxa. RNA (NEW YORK, N.Y.) 2013; 19:1355-62. [PMID: 23945037 PMCID: PMC3854526 DOI: 10.1261/rna.039917.113] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 06/20/2013] [Indexed: 05/19/2023]
Abstract
RNA terminal phosphate cyclase catalyzes the ATP-dependent conversion of a 3'-phosphate RNA end to a 2',3'-cyclic phosphate via covalent enzyme-(histidinyl-Nε)-AMP and RNA(3')pp(5')A intermediates. Here, we report that Escherichia coli RtcA (and its human homolog Rtc1) are capable of cyclizing a 2'-phosphate RNA end in high yield. The rate of 2'-phosphate cyclization by RtcA is five orders of magnitude slower than 3'-phosphate cyclization, notwithstanding that RtcA binds with similar affinity to RNA3'p and RNA2'p substrates. These findings expand the functional repertoire of RNA cyclase and suggest that phosphate geometry during adenylate transfer to RNA is a major factor in the kinetics of cyclization. RtcA is coregulated in an operon with an RNA ligase, RtcB, that splices RNA 5'-OH ends to either 3'-phosphate or 2',3'-cyclic phosphate ends. Our results suggest that RtcA might serve an end healing function in an RNA repair pathway, by converting RNA 2'-phosphates, which cannot be spliced by RtcB, to 2',3'-cyclic phosphates that can be sealed. The rtcBA operon is controlled by the σ(54) coactivator RtcR encoded by an adjacent gene. This operon arrangement is conserved in diverse bacterial taxa, many of which have also incorporated the RNA-binding protein Ro (which is implicated in RNA quality control under stress conditions) as a coregulated component of the operon.
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Abstract
Yeast L-A double-stranded RNA virus furnishes its transcript with a 5' cap structure by a novel cap-snatching mechanism in which m(7)Gp from a host mRNA cap structure is transferred to the 5'-diphosphate terminus of the viral transcript. His-154 of the coat protein Gag forms an m(7)Gp adduct, and the H154R mutation abolishes both m(7)Gp adduct formation and cap snatching. Here we show that L-BC, another totivirus closely related to L-A, also synthesizes 5'-diphosphorylated transcripts and transfers m(7)Gp from mRNA to the 5' termini of the transcripts. L-BC Gag also covalently binds to the cap structure and the mutation H156R, which corresponds to H154R of L-A Gag, abolishes cap adduct formation. Cap snatching of the L-BC virus is very similar to that of L-A; N7 methylation of the mRNA cap is essential for cap donor activity, and only 5'-diphosphorylated RNA is used as cap acceptor. L-BC cap snatching is also activated by viral transcription. Furthermore, both viruses require Mg(2+) and Mn(2+) for cap snatching. These cations are not only required for transcription activation but also directly involved in the cap transfer process. These findings support our previous proposal that the cap-snatching mechanism of the L-A virus is shared by fungal totiviruses closely related to L-A. Interestingly, L-A and L-BC viruses accept either viral transcript as cap acceptor in vitro. Because L-A and L-BC viruses cohabit in many yeast strains, it raises the possibility that their cohabitation in the same host may be beneficial for their mutual cap acquisition.
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Affiliation(s)
- Tsutomu Fujimura
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca 37007, Spain.
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25
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Remus BS, Shuman S. A kinetic framework for tRNA ligase and enforcement of a 2'-phosphate requirement for ligation highlights the design logic of an RNA repair machine. RNA (NEW YORK, N.Y.) 2013; 19:659-69. [PMID: 23515942 PMCID: PMC3677281 DOI: 10.1261/rna.038406.113] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 02/22/2013] [Indexed: 05/23/2023]
Abstract
tRNA ligases are essential components of informational and stress-response pathways entailing repair of RNA breaks with 2',3'-cyclic phosphate and 5'-OH ends. Plant and fungal tRNA ligases comprise three catalytic domains. Phosphodiesterase and kinase modules heal the broken ends to generate the 3'-OH, 2'-PO₄, and 5'-PO₄ required for sealing by the ligase. We exploit RNA substrates with different termini to define rates of individual steps or subsets of steps along the repair pathway of plant ligase AtRNL. The results highlight rate-limiting transactions, how repair is affected by active-site mutations, and how mutations are bypassed by RNA alterations. We gain insights to 2'-PO₄ specificity by showing that AtRNL is deficient in transferring AMP to pRNAOH to form AppRNAOH but proficient at sealing pre-adenylylated AppRNAOH. This strategy for discriminating 2'-PO₄ versus 2'-OH ends provides a quality-control checkpoint to ensure that only purposeful RNA breaks are sealed and to avoid nonspecific "capping" of 5'-PO₄ ends.
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Structural and mechanistic insights into guanylylation of RNA-splicing ligase RtcB joining RNA between 3'-terminal phosphate and 5'-OH. Proc Natl Acad Sci U S A 2012; 109:15235-40. [PMID: 22949672 DOI: 10.1073/pnas.1213795109] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The RtcB protein has recently been identified as a 3'-phosphate RNA ligase that directly joins an RNA strand ending with a 2',3'-cyclic phosphate to the 5'-hydroxyl group of another RNA strand in a GTP/Mn(2+)-dependent reaction. Here, we report two crystal structures of Pyrococcus horikoshii RNA-splicing ligase RtcB in complex with Mn(2+) alone (RtcB/ Mn(2+)) and together with a covalently bound GMP (RtcB-GMP/Mn(2+)). The RtcB/ Mn(2+) structure (at 1.6 Å resolution) shows two Mn(2+) ions at the active site, and an array of sulfate ions nearby that indicate the binding sites of the RNA phosphate backbone. The structure of the RtcB-GMP/Mn(2+) complex (at 2.3 Å resolution) reveals the detailed geometry of guanylylation of histidine 404. The critical roles of the key residues involved in the binding of the two Mn(2+) ions, the four sulfates, and GMP are validated in extensive mutagenesis and biochemical experiments, which also provide a thorough characterization for the three steps of the RtcB ligation pathway: (i) guanylylation of the enzyme, (ii) guanylyl-transfer to the RNA substrate, and (iii) overall ligation. These results demonstrate that the enzyme's substrate-induced GTP binding site and the putative reactive RNA ends are in the vicinity of the binuclear Mn(2+) active center, which provides detailed insight into how the enzyme-bound GMP is tansferred to the 3'-phosphate of the RNA substrate for activation and subsequent nucleophilic attack by the 5'-hydroxyl of the second RNA substrate, resulting in the ligated product and release of GMP.
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RNA ligase RtcB splices 3'-phosphate and 5'-OH ends via covalent RtcB-(histidinyl)-GMP and polynucleotide-(3')pp(5')G intermediates. Proc Natl Acad Sci U S A 2012; 109:6072-7. [PMID: 22474365 DOI: 10.1073/pnas.1201207109] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
A cherished tenet of nucleic acid enzymology holds that synthesis of polynucleotide 3'-5' phosphodiesters proceeds via the attack of a 3'-OH on a high-energy 5' phosphoanhydride: either a nucleoside 5'-triphosphate in the case of RNA/DNA polymerases or an adenylylated intermediate A(5')pp(5')N--in the case of polynucleotide ligases. RtcB exemplifies a family of RNA ligases implicated in tRNA splicing and repair. Unlike classic ligases, RtcB seals broken RNAs with 3'-phosphate and 5'-OH ends. Here we show that RtcB executes a three-step ligation pathway entailing (i) reaction of His337 of the enzyme with GTP to form a covalent RtcB-(histidinyl-N)-GMP intermediate; (ii) transfer of guanylate to a polynucleotide 3'-phosphate to form a polynucleotide-(3')pp(5')G intermediate; and (iii) attack of a 5'-OH on the -N(3')pp(5')G end to form the splice junction. RtcB is structurally sui generis, and its chemical mechanism is unique. The wide distribution of RtcB proteins in bacteria, archaea, and metazoa raises the prospect of an alternative enzymology based on covalently activated 3' ends.
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Tanaka N, Shuman S. RtcB is the RNA ligase component of an Escherichia coli RNA repair operon. J Biol Chem 2011; 286:7727-7731. [PMID: 21224389 DOI: 10.1074/jbc.c111.219022] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
RNA 2',3'-cyclic phosphate ends play important roles in RNA metabolism as substrates for RNA ligases during tRNA restriction-repair and tRNA splicing. Diverse bacteria from multiple phyla encode a two-component RNA repair cassette, comprising Pnkp (polynucleotide kinase-phosphatase-ligase) and Hen1 (RNA 3'-terminal ribose 2'-O-methyltransferase), that heals and then seals broken tRNAs with 2',3'-cyclic phosphate and 5'-OH ends. The Pnkp-Hen1 repair operon is absent in the majority of bacterial species, thereby raising the prospect that other RNA repair systems might be extant. A candidate component is RNA 3'-phosphate cyclase, a widely distributed enzyme that transforms RNA 3'-monophosphate termini into 2',3'-cyclic phosphates but cannot seal the ends it produces. Escherichia coli RNA cyclase (RtcA) is encoded in a σ(54)-regulated operon with RtcB, a protein of unknown function. Taking a cue from Pnkp-Hen1, we purified E. coli RtcB and tested it for RNA ligase activity. We report that RtcB per se seals broken tRNA-like stem-loop structures with 2',3'-cyclic phosphate and 5'-OH ends to form a splice junction with a 2'-OH, 3',5'-phosphodiester. We speculate that: (i) RtcB might afford bacteria a means to recover from stress-induced RNA damage; and (ii) RtcB homologs might catalyze tRNA repair or splicing reactions in archaea and eukarya.
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Affiliation(s)
- Naoko Tanaka
- From the Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065
| | - Stewart Shuman
- From the Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065.
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