1
|
McKinley LN, Meyer MO, Sebastian A, Chang BK, Messina KJ, Albert I, Bevilacqua PC. Direct testing of natural twister ribozymes from over a thousand organisms reveals a broad tolerance for structural imperfections. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.11.603121. [PMID: 39026743 PMCID: PMC11257566 DOI: 10.1101/2024.07.11.603121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Twister ribozymes are an extensively studied class of nucleolytic RNAs. Thousands of natural twisters have been proposed using sequence homology and structural descriptors. Yet, most of these candidates have not been validated experimentally. To address this gap, we developed CHiTA (Cleavage High-Throughput Assay), a high-throughput pipeline utilizing massively parallel oligonucleotide synthesis and next-generation sequencing to test putative ribozymes en masse in a scarless fashion. As proof of principle, we applied CHiTA to a small set of known active and mutant ribozymes. We then used CHiTA to test two large sets of naturally occurring twister ribozymes: over 1, 600 previously reported putative twisters and ∼1, 000 new candidate twisters. The new candidates were identified computationally in ∼1, 000 organisms, representing a massive increase in the number of ribozyme-harboring organisms. Approximately 94% of the twisters we tested were active and cleaved site-specifically. Analysis of their structural features revealed that many substitutions and helical imperfections can be tolerated. We repeated our computational search with structural descriptors updated from this analysis, whereupon we identified and confirmed the first intrinsically active twister ribozyme in mammals. CHiTA broadly expands the number of active twister ribozymes found in nature and provides a powerful method for functional analyses of other RNAs. GRAPHICAL ABSTRACT
Collapse
|
2
|
Flemmich L, Bereiter R, Micura R. Chemical Synthesis of Modified RNA. Angew Chem Int Ed Engl 2024; 63:e202403063. [PMID: 38529723 DOI: 10.1002/anie.202403063] [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: 02/12/2024] [Revised: 03/16/2024] [Accepted: 03/26/2024] [Indexed: 03/27/2024]
Abstract
Ribonucleic acids (RNAs) play a vital role in living organisms. Many of their cellular functions depend critically on chemical modification. Methods to modify RNA in a controlled manner-both in vitro and in vivo-are thus essential to evaluate and understand RNA biology at the molecular and mechanistic levels. The diversity of modifications, combined with the size and uniformity of RNA (made up of only 4 nucleotides) makes its site-specific modification a challenging task that needs to be addressed by complementary approaches. One such approach is solid-phase RNA synthesis. We discuss recent developments in this field, starting with new protection concepts in the ongoing effort to overcome current size limitations. We continue with selected modifications that have posed significant challenges for their incorporation into RNA. These include deazapurine bases required for atomic mutagenesis to elucidate mechanistic aspects of catalytic RNAs, and RNA containing xanthosine, N4-acetylcytidine, 5-hydroxymethylcytidine, 3-methylcytidine, 2'-OCF3, and 2'-N3 ribose modifications. We also discuss the all-chemical synthesis of 5'-capped mRNAs and the enzymatic ligation of chemically synthesized oligoribonucleotides to obtain long RNA with multiple distinct modifications, such as those needed for single-molecule FRET studies. Finally, we highlight promising developments in RNA-catalyzed RNA modification using cofactors that transfer bioorthogonal functionalities.
Collapse
Affiliation(s)
- Laurin Flemmich
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Raphael Bereiter
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| |
Collapse
|
3
|
Seitz F, Jungnickel T, Kleiber N, Kretschmer J, Dietzsch J, Adelmann J, Bohnsack KE, Bohnsack MT, Höbartner C. Atomic Mutagenesis of N6-Methyladenosine Reveals Distinct Recognition Modes by Human m 6A Reader and Eraser Proteins. J Am Chem Soc 2024; 146:7803-7810. [PMID: 38445613 DOI: 10.1021/jacs.4c00626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
N6-methyladenosine (m6A) is an important modified nucleoside in cellular RNA associated with multiple cellular processes and is implicated in diseases. The enzymes associated with the dynamic installation and removal of m6A are heavily investigated targets for drug research, which requires detailed knowledge of the recognition modes of m6A by proteins. Here, we use atomic mutagenesis of m6A to systematically investigate the mechanisms of the two human m6A demethylase enzymes FTO and ALKBH5 and the binding modes of YTH reader proteins YTHDF2/DC1/DC2. Atomic mutagenesis refers to atom-specific changes that are introduced by chemical synthesis, such as the replacement of nitrogen by carbon atoms. Synthetic RNA oligonucleotides containing site-specifically incorporated 1-deaza-, 3-deaza-, and 7-deaza-m6A nucleosides were prepared by solid-phase synthesis and their RNA binding and demethylation by recombinant proteins were evaluated. We found distinct differences in substrate recognition and transformation and revealed structural preferences for the enzymatic activity. The deaza m6A analogues introduced in this work will be useful probes for other proteins in m6A research.
Collapse
Affiliation(s)
- Florian Seitz
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Tina Jungnickel
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Nicole Kleiber
- Department of Molecular Biology, University Medical Centre Göttingen, Humboldtallee 23, Göttingen 37073, Germany
| | - Jens Kretschmer
- Department of Molecular Biology, University Medical Centre Göttingen, Humboldtallee 23, Göttingen 37073, Germany
| | - Julia Dietzsch
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Juliane Adelmann
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Centre Göttingen, Humboldtallee 23, Göttingen 37073, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Centre Göttingen, Humboldtallee 23, Göttingen 37073, Germany
- Göttingen Center for Molecular Biosciences, Georg-August University Göttingen, Justus-von-Liebig-Weg 11, Göttingen 37077, Germany
| | - Claudia Höbartner
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, Würzburg 97074, Germany
- Center for Nanosystems Chemistry, University of Würzburg, Theodor-Boveri-Weg, Würzburg 97074, Germany
| |
Collapse
|
4
|
Egger M, Bereiter R, Mair S, Micura R. Scaling Catalytic Contributions of Small Self-Cleaving Ribozymes. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 134:e202207590. [PMID: 38505292 PMCID: PMC10946891 DOI: 10.1002/ange.202207590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Indexed: 11/08/2022]
Abstract
Nucleolytic ribozymes utilize general acid-base catalysis to perform phosphodiester cleavage. In most ribozyme classes, a conserved active site guanosine is positioned to act as general base, thereby activating the 2'-OH group to attack the scissile phosphate (γ-catalysis). Here, we present an atomic mutagenesis study for the pistol ribozyme class. Strikingly, "general base knockout" by replacement of the guanine N1 atom by carbon results in only 2.7-fold decreased rate. Therefore, the common view that γ-catalysis critically depends on the N1 moiety becomes challenged. For pistol ribozymes we found that γ-catalysis is subordinate in overall catalysis, made up by two other catalytic factors (α and δ). Our approach allows scaling of the different catalytic contributions (α, β, γ, δ) with unprecedented precision and paves the way for a thorough mechanistic understanding of nucleolytic ribozymes with active site guanines.
Collapse
Affiliation(s)
- Michaela Egger
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
| | - Raphael Bereiter
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
| | - Stefan Mair
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
| |
Collapse
|
5
|
Egger M, Bereiter R, Mair S, Micura R. Scaling Catalytic Contributions of Small Self-Cleaving Ribozymes. Angew Chem Int Ed Engl 2022; 61:e202207590. [PMID: 35982640 PMCID: PMC9826390 DOI: 10.1002/anie.202207590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Indexed: 01/11/2023]
Abstract
Nucleolytic ribozymes utilize general acid-base catalysis to perform phosphodiester cleavage. In most ribozyme classes, a conserved active site guanosine is positioned to act as general base, thereby activating the 2'-OH group to attack the scissile phosphate (γ-catalysis). Here, we present an atomic mutagenesis study for the pistol ribozyme class. Strikingly, "general base knockout" by replacement of the guanine N1 atom by carbon results in only 2.7-fold decreased rate. Therefore, the common view that γ-catalysis critically depends on the N1 moiety becomes challenged. For pistol ribozymes we found that γ-catalysis is subordinate in overall catalysis, made up by two other catalytic factors (α and δ). Our approach allows scaling of the different catalytic contributions (α, β, γ, δ) with unprecedented precision and paves the way for a thorough mechanistic understanding of nucleolytic ribozymes with active site guanines.
Collapse
Affiliation(s)
- Michaela Egger
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
| | - Raphael Bereiter
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
| | - Stefan Mair
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
| |
Collapse
|
6
|
Bereiter R, Renard E, Breuker K, Kreutz C, Ennifar E, Micura R. 1-Deazaguanosine-Modified RNA: The Missing Piece for Functional RNA Atomic Mutagenesis. J Am Chem Soc 2022; 144:10344-10352. [PMID: 35666572 PMCID: PMC9204769 DOI: 10.1021/jacs.2c01877] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
![]()
Atomic mutagenesis
is the key to advance our understanding of RNA
recognition and RNA catalysis. To this end, deazanucleosides are utilized
to evaluate the participation of specific atoms in these processes.
One of the remaining challenges is access to RNA-containing 1-deazaguanosine
(c1G). Here, we present the synthesis of this nucleoside
and its phosphoramidite, allowing first time access to c1G-modified RNA. Thermodynamic analyses revealed the base pairing
parameters for c1G-modified RNA. Furthermore, by NMR spectroscopy,
a c1G-triggered switch of Watson-Crick into Hoogsteen pairing
in HIV-2 TAR RNA was identified. Additionally, using X-ray structure
analysis, a guanine–phosphate backbone interaction affecting
RNA fold stability was characterized, and finally, the critical impact
of an active-site guanine in twister ribozyme on the phosphodiester
cleavage was revealed. Taken together, our study lays the synthetic
basis for c1G-modified RNA and demonstrates the power of
the completed deazanucleoside toolbox for RNA atomic mutagenesis needed
to achieve in-depth understanding of RNA recognition and catalysis.
Collapse
Affiliation(s)
- Raphael Bereiter
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, Innsbruck 6020, Austria
| | - Eva Renard
- Architecture et Réactivité de l'ARN - CNRS UPR 9002, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, 2 Allée Conrad Roentgen, Strasbourg 67084, France
| | - Kathrin Breuker
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, Innsbruck 6020, Austria
| | - Christoph Kreutz
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, Innsbruck 6020, Austria
| | - Eric Ennifar
- Architecture et Réactivité de l'ARN - CNRS UPR 9002, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, 2 Allée Conrad Roentgen, Strasbourg 67084, France
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, Innsbruck 6020, Austria
| |
Collapse
|
7
|
Liu G, Jiang H, Sun W, Zhang J, Chen D, Murchie AIH. The function of twister ribozyme variants in non-LTR retrotransposition in Schistosoma mansoni. Nucleic Acids Res 2021; 49:10573-10588. [PMID: 34551436 PMCID: PMC8501958 DOI: 10.1093/nar/gkab818] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 08/23/2021] [Accepted: 09/08/2021] [Indexed: 12/13/2022] Open
Abstract
The twister ribozyme is widely distributed over numerous organisms and is especially abundant in Schistosoma mansoni, but has no confirmed biological function. Of the 17 non-LTR retrotransposons known in S. mansoni, none have thus far been associated with ribozymes. Here we report the identification of novel twister variant (T-variant) ribozymes and their function in S. mansoni non-LTR retrotransposition. We show that T-variant ribozymes are located at the 5′ end of Perere-3 non-LTR retrotransposons in the S. mansoni genome. T-variant ribozymes were demonstrated to be catalytically active in vitro. In reporter constructs, T-variants were shown to cleave in vivo, and cleavage of T-variants was sufficient for the translation of downstream reporter genes. Our analysis shows that the T-variants and Perere-3 are transcribed together. Target site duplications (TSDs); markers of target-primed reverse transcription (TPRT) and footmarks of retrotransposition, are located adjacent to the T-variant cleavage site and suggest that T-variant cleavage has taken place inS. mansoni. Sequence heterogeneity in the TSDs indicates that Perere-3 retrotransposition is not site-specific. The TSD sequences contribute to the 5′ end of the terminal ribozyme helix (P1 stem). Based on these results we conclude that T-variants have a functional role in Perere-3 retrotransposition.
Collapse
Affiliation(s)
- Getong Liu
- Fudan University Pudong Medical Center, and Institutes of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai 200032, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Hengyi Jiang
- Fudan University Pudong Medical Center, and Institutes of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai 200032, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Wenxia Sun
- Fudan University Pudong Medical Center, and Institutes of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai 200032, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Jun Zhang
- Fudan University Pudong Medical Center, and Institutes of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai 200032, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Dongrong Chen
- Fudan University Pudong Medical Center, and Institutes of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai 200032, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Alastair I H Murchie
- Fudan University Pudong Medical Center, and Institutes of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai 200032, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| |
Collapse
|
8
|
Peng H, Latifi B, Müller S, Lupták A, Chen IA. Self-cleaving ribozymes: substrate specificity and synthetic biology applications. RSC Chem Biol 2021; 2:1370-1383. [PMID: 34704043 PMCID: PMC8495972 DOI: 10.1039/d0cb00207k] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 06/14/2021] [Indexed: 12/22/2022] Open
Abstract
Various self-cleaving ribozymes appearing in nature catalyze the sequence-specific intramolecular cleavage of RNA and can be engineered to catalyze cleavage of appropriate substrates in an intermolecular fashion, thus acting as true catalysts. The mechanisms of the small, self-cleaving ribozymes have been extensively studied and reviewed previously. Self-cleaving ribozymes can possess high catalytic activity and high substrate specificity; however, substrate specificity is also engineerable within the constraints of the ribozyme structure. While these ribozymes share a common fundamental catalytic mechanism, each ribozyme family has a unique overall architecture and active site organization, indicating that several distinct structures yield this chemical activity. The multitude of catalytic structures, combined with some flexibility in substrate specificity within each family, suggests that such catalytic RNAs, taken together, could access a wide variety of substrates. Here, we give an overview of 10 classes of self-cleaving ribozymes and capture what is understood about their substrate specificity and synthetic applications. Evolution of these ribozymes in an RNA world might be characterized by the emergence of a new ribozyme family followed by rapid adaptation or diversification for specific substrates. Self-cleaving ribozymes have become important tools of synthetic biology. Here we summarize the substrate specificity and applications of the main classes of these ribozymes.![]()
Collapse
Affiliation(s)
- Huan Peng
- Department of Chemical and Biomolecular Engineering, University of California Los Angeles CA 90095 USA
| | - Brandon Latifi
- Department of Pharmaceutical Sciences, University of California Irvine CA 92697 USA
| | - Sabine Müller
- Institute for Biochemistry, University Greifswald 17487 Greifswald Germany
| | - Andrej Lupták
- Department of Pharmaceutical Sciences, University of California Irvine CA 92697 USA
| | - Irene A Chen
- Department of Chemical and Biomolecular Engineering, University of California Los Angeles CA 90095 USA
| |
Collapse
|
9
|
Bereiter R, Himmelstoß M, Renard E, Mairhofer E, Egger M, Breuker K, Kreutz C, Ennifar E, Micura R. Impact of 3-deazapurine nucleobases on RNA properties. Nucleic Acids Res 2021; 49:4281-4293. [PMID: 33856457 PMCID: PMC8096147 DOI: 10.1093/nar/gkab256] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/29/2021] [Indexed: 11/13/2022] Open
Abstract
Deazapurine nucleosides such as 3-deazaadenosine (c3A) are crucial for atomic mutagenesis studies of functional RNAs. They were the key for our current mechanistic understanding of ribosomal peptide bond formation and of phosphodiester cleavage in recently discovered small ribozymes, such as twister and pistol RNAs. Here, we present a comprehensive study on the impact of c3A and the thus far underinvestigated 3-deazaguanosine (c3G) on RNA properties. We found that these nucleosides can decrease thermodynamic stability of base pairing to a significant extent. The effects are much more pronounced for 3-deazapurine nucleosides compared to their constitutional isomers of 7-deazapurine nucleosides (c7G, c7A). We furthermore investigated base pair opening dynamics by solution NMR spectroscopy and revealed significantly enhanced imino proton exchange rates. Additionally, we solved the X-ray structure of a c3A-modified RNA and visualized the hydration pattern of the minor groove. Importantly, the characteristic water molecule that is hydrogen-bonded to the purine N3 atom and always observed in a natural double helix is lacking in the 3-deazapurine-modified counterpart. Both, the findings by NMR and X-ray crystallographic methods hence provide a rationale for the reduced pairing strength. Taken together, our comparative study is a first major step towards a comprehensive understanding of this important class of nucleoside modifications.
Collapse
Affiliation(s)
- Raphael Bereiter
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Maximilian Himmelstoß
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Eva Renard
- Architecture et Réactivité de l'ARN - CNRS UPR 9002, Université de Strasbourg, Strasbourg, France
| | - Elisabeth Mairhofer
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Michaela Egger
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Kathrin Breuker
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Christoph Kreutz
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Eric Ennifar
- Architecture et Réactivité de l'ARN - CNRS UPR 9002, Université de Strasbourg, Strasbourg, France
| | - Ronald Micura
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
10
|
Scheitl CPM, Ghaem Maghami M, Lenz AK, Höbartner C. Site-specific RNA methylation by a methyltransferase ribozyme. Nature 2020; 587:663-667. [PMID: 33116304 PMCID: PMC7116789 DOI: 10.1038/s41586-020-2854-z] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 07/27/2020] [Indexed: 12/21/2022]
Abstract
Nearly all classes of coding and non-coding RNA undergo post-transcriptional modification, including RNA methylation. Methylated nucleotides are among the evolutionarily most-conserved features of transfer (t)RNA and ribosomal (r)RNA1,2. Many contemporary methyltransferases use the universal cofactor S-adenosylmethionine (SAM) as a methyl-group donor. SAM and other nucleotide-derived cofactors are considered to be evolutionary leftovers from an RNA world, in which ribozymes may have catalysed essential metabolic reactions beyond self-replication3. Chemically diverse ribozymes seem to have been lost in nature, but may be reconstructed in the laboratory by in vitro selection. Here we report a methyltransferase ribozyme that catalyses the site-specific installation of 1-methyladenosine in a substrate RNA, using O6-methylguanine as a small-molecule cofactor. The ribozyme shows a broad RNA-sequence scope, as exemplified by site-specific adenosine methylation in various RNAs. This finding provides fundamental insights into the catalytic abilities of RNA, serves a synthetic tool to install 1-methyladenosine in RNA and may pave the way to in vitro evolution of other methyltransferase and demethylase ribozymes.
Collapse
Affiliation(s)
- Carolin P M Scheitl
- Institut für Organische Chemie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Mohammad Ghaem Maghami
- Institut für Organische Chemie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Ann-Kathrin Lenz
- Institut für Organische Chemie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Claudia Höbartner
- Institut für Organische Chemie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany.
| |
Collapse
|
11
|
Micura R, Höbartner C. Fundamental studies of functional nucleic acids: aptamers, riboswitches, ribozymes and DNAzymes. Chem Soc Rev 2020; 49:7331-7353. [PMID: 32944725 DOI: 10.1039/d0cs00617c] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This review aims at juxtaposing common versus distinct structural and functional strategies that are applied by aptamers, riboswitches, and ribozymes/DNAzymes. Focusing on recently discovered systems, we begin our analysis with small-molecule binding aptamers, with emphasis on in vitro-selected fluorogenic RNA aptamers and their different modes of ligand binding and fluorescence activation. Fundamental insights are much needed to advance RNA imaging probes for detection of exo- and endogenous RNA and for RNA process tracking. Secondly, we discuss the latest gene expression-regulating mRNA riboswitches that respond to the alarmone ppGpp, to PRPP, to NAD+, to adenosine and cytidine diphosphates, and to precursors of thiamine biosynthesis (HMP-PP), and we outline new subclasses of SAM and tetrahydrofolate-binding RNA regulators. Many riboswitches bind protein enzyme cofactors that, in principle, can catalyse a chemical reaction. For RNA, however, only one system (glmS ribozyme) has been identified in Nature thus far that utilizes a small molecule - glucosamine-6-phosphate - to participate directly in reaction catalysis (phosphodiester cleavage). We wonder why that is the case and what is to be done to reveal such likely existing cellular activities that could be more diverse than currently imagined. Thirdly, this brings us to the four latest small nucleolytic ribozymes termed twister, twister-sister, pistol, and hatchet as well as to in vitro selected DNA and RNA enzymes that promote new chemistry, mainly by exploiting their ability for RNA labelling and nucleoside modification recognition. Enormous progress in understanding the strategies of nucleic acids catalysts has been made by providing thorough structural fundaments (e.g. first structure of a DNAzyme, structures of ribozyme transition state mimics) in combination with functional assays and atomic mutagenesis.
Collapse
Affiliation(s)
- Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck CMBI, Leopold-Franzens University Innsbruck, Innsbruck, Austria.
| | | |
Collapse
|
12
|
Zhang J, Liu G, Sun W, Chen D, Murchie AIH. Aminoglycoside antibiotics can inhibit or activate twister ribozyme cleavage. FEBS J 2020; 288:1586-1598. [PMID: 32790122 DOI: 10.1111/febs.15517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/19/2020] [Accepted: 08/10/2020] [Indexed: 12/11/2022]
Abstract
Interactions between aminoglycoside antibiotics and the twister ribozyme were investigated in this study. An initial screen of 17 RNA-binding antibiotics showed that a number of aminoglycosides inhibit the ribozyme, while a subset of aminoglycosides enhances twister cleavage. Initial kinetic analysis of the twister ribozyme showed a sevenfold inhibition of ribozyme cleavage by paromomycin and a fivefold enhancement of cleavage by sisomicin. Direct binding between the twister ribozyme RNA and paromomycin or sisomicin was measured by microscale thermophoresis. Selective 2'-hydroxyl acylation analysed by primer extension shows that both paromomycin and sisomicin induce distinctive tertiary structure changes to the twister ribozyme. Published crystal structures and mechanistic analysis of the twister ribozyme have deduced a nucleobase-mediated general acid-base catalytic mechanism, in which a conserved guanine plays a key role. Here, we show that paromomycin binding induces a structural transition to the twister ribozyme such that a highly conserved guanine in the active site becomes displaced, leading to inhibition of cleavage. In contrast, sisomicin binding appears to change interactions between P3 and L2, inducing allosteric changes to the active site that enhance twister RNA cleavage. Therefore, we show that small-molecule binding can modulate twister ribozyme activity. These results suggest that aminoglycosides may be used as molecular tools to study this widely distributed ribozyme.
Collapse
Affiliation(s)
- Jun Zhang
- Fudan University Pudong Medical Center, and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Getong Liu
- Fudan University Pudong Medical Center, and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Wenxia Sun
- Fudan University Pudong Medical Center, and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Dongrong Chen
- Fudan University Pudong Medical Center, and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Alastair I H Murchie
- Fudan University Pudong Medical Center, and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, China
| |
Collapse
|
13
|
Light-controlled twister ribozyme with single-molecule detection resolves RNA function in time and space. Proc Natl Acad Sci U S A 2020; 117:12080-12086. [PMID: 32430319 DOI: 10.1073/pnas.2003425117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Small ribozymes such as Oryza sativa twister spontaneously cleave their own RNA when the ribozyme folds into its active conformation. The coupling between twister folding and self-cleavage has been difficult to study, however, because the active ribozyme rapidly converts to product. Here, we describe the synthesis of a photocaged nucleotide that releases guanosine within microseconds upon photosolvolysis with blue light. Application of this tool to O. sativa twister achieved the spatial (75 µm) and temporal (≤30 ms) control required to resolve folding and self-cleavage events when combined with single-molecule fluorescence detection of the ribozyme folding pathway. Real-time observation of single ribozymes after photo-deprotection showed that the precleaved folded state is unstable and quickly unfolds if the RNA does not react. Kinetic analysis showed that Mg2+ and Mn2+ ions increase ribozyme efficiency by making transitions to the high energy active conformation more probable, rather than by stabilizing the folded ground state or the cleaved product. This tool for light-controlled single RNA folding should offer precise and rapid control of other nucleic acid systems.
Collapse
|
14
|
Kognole AA, MacKerell AD. Mg 2+ Impacts the Twister Ribozyme through Push-Pull Stabilization of Nonsequential Phosphate Pairs. Biophys J 2020; 118:1424-1437. [PMID: 32053774 PMCID: PMC7091459 DOI: 10.1016/j.bpj.2020.01.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 12/23/2019] [Accepted: 01/21/2020] [Indexed: 11/15/2022] Open
Abstract
RNA molecules perform a variety of biological functions for which the correct three-dimensional structure is essential, including as ribozymes where they catalyze chemical reactions. Metal ions, especially Mg2+, neutralize these negatively charged nucleic acids and specifically stabilize RNA tertiary structures as well as impact the folding landscape of RNAs as they assume their tertiary structures. Specific binding sites of Mg2+ in folded conformations of RNA have been studied extensively; however, the full range of interactions of the ion with compact intermediates and unfolded states of RNA is challenging to investigate, and the atomic details of the mechanism by which the ion facilitates tertiary structure formation is not fully known. Here, umbrella sampling combined with oscillating chemical potential Grand Canonical Monte Carlo/molecular dynamics simulations are used to capture the energetics and atomic-level details of Mg2+-RNA interactions that occur along an unfolding pathway of the Twister ribozyme. The free energy profiles reveal stabilization of partially unfolded states by Mg2+, as observed in unfolding experiments, with this stabilization being due to increased sampling of simultaneous interactions of Mg2+ with two or more nonsequential phosphate groups. Notably, these results indicate a push-pull mechanism in which the Mg2+-RNA interactions actually lead to destabilization of specific nonsequential phosphate-phosphate interactions (i.e., pushed apart), whereas other interactions are stabilized (i.e., pulled together), a balance that stabilizes unfolded states and facilitates the folding of Twister, including the formation of hydrogen bonds associated with the tertiary structure. This study establishes a better understanding of how Mg2+-ion interactions contribute to RNA structural properties and stability.
Collapse
Affiliation(s)
- Abhishek A Kognole
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland
| | - Alexander D MacKerell
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland.
| |
Collapse
|
15
|
Gaines CS, Piccirilli JA, York DM. The L-platform/L-scaffold framework: a blueprint for RNA-cleaving nucleic acid enzyme design. RNA (NEW YORK, N.Y.) 2020; 26:111-125. [PMID: 31776179 PMCID: PMC6961537 DOI: 10.1261/rna.071894.119] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 11/14/2019] [Indexed: 05/13/2023]
Abstract
We develop an L-platform/L-scaffold framework we hypothesize may serve as a blueprint to facilitate site-specific RNA-cleaving nucleic acid enzyme design. Building on the L-platform motif originally described by Suslov and coworkers, we identify new critical scaffolding elements required to anchor a conserved general base guanine ("L-anchor") and bind functionally important metal ions at the active site ("L-pocket"). Molecular simulations, together with a broad range of experimental structural and functional data, connect the L-platform/L-scaffold elements to necessary and sufficient conditions for catalytic activity. We demonstrate that the L-platform/L-scaffold framework is common to five of the nine currently known naturally occurring ribozyme classes (Twr, HPr, VSr, HHr, Psr), and intriguingly from a design perspective, the framework also appears in an artificially engineered DNAzyme (8-17dz). The flexibility of the L-platform/L-scaffold framework is illustrated on these systems, highlighting modularity and trends in the variety of known general acid moieties that are supported. These trends give rise to two distinct catalytic paradigms, building on the classifications proposed by Wilson and coworkers and named for the implicated general base and acid. The "G + A" paradigm (Twr, HPr, VSr) exclusively utilizes nucleobase residues for chemistry, and the "G + M + " paradigm (HHr, 8-17dz, Psr) involves structuring of the "L-pocket" metal ion binding site for recruitment of a divalent metal ion that plays an active role in the chemical steps of the reaction. Finally, the modularity of the L-platform/L-scaffold framework is illustrated in the VS ribozyme where the "L-pocket" assumes the functional role of the "L-anchor" element, highlighting a distinct mechanism, but one that is functionally linked with the hammerhead ribozyme.
Collapse
Affiliation(s)
- Colin S Gaines
- Laboratory for Biomolecular Simulation Research, Institute for Quantitative Biomedicine, and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Joseph A Piccirilli
- Department of Biochemistry and Molecular Biology and Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA
| | - Darrin M York
- Laboratory for Biomolecular Simulation Research, Institute for Quantitative Biomedicine, and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| |
Collapse
|
16
|
Teplova M, Falschlunger C, Krasheninina O, Egger M, Ren A, Patel DJ, Micura R. Crucial Roles of Two Hydrated Mg
2+
Ions in Reaction Catalysis of the Pistol Ribozyme. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201912522] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Marianna Teplova
- Structural Biology ProgramMemorial Sloan-Kettering Cancer Center New York New York 10065 USA
| | - Christoph Falschlunger
- Institute of Organic Chemistry and Center for Molecular BiosciencesLeopold-Franzens University Innrain 80–82 6020 Innsbruck Austria
| | - Olga Krasheninina
- Institute of Organic Chemistry and Center for Molecular BiosciencesLeopold-Franzens University Innrain 80–82 6020 Innsbruck Austria
| | - Michaela Egger
- Institute of Organic Chemistry and Center for Molecular BiosciencesLeopold-Franzens University Innrain 80–82 6020 Innsbruck Austria
| | - Aiming Ren
- Life Sciences InstituteZhejiang University Hangzhou Zhejiang 310058 China
| | - Dinshaw J. Patel
- Structural Biology ProgramMemorial Sloan-Kettering Cancer Center New York New York 10065 USA
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular BiosciencesLeopold-Franzens University Innrain 80–82 6020 Innsbruck Austria
| |
Collapse
|
17
|
Teplova M, Falschlunger C, Krasheninina O, Egger M, Ren A, Patel DJ, Micura R. Crucial Roles of Two Hydrated Mg 2+ Ions in Reaction Catalysis of the Pistol Ribozyme. Angew Chem Int Ed Engl 2020; 59:2837-2843. [PMID: 31804735 PMCID: PMC7027511 DOI: 10.1002/anie.201912522] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Indexed: 12/19/2022]
Abstract
Pistol ribozymes constitute a new class of small self‐cleaving RNAs. Crystal structures have been solved, providing three‐dimensional snapshots along the reaction coordinate of pistol phosphodiester cleavage, corresponding to the pre‐catalytic state, a vanadate mimic of the transition state, and the product. The results led to the proposed underlying chemical mechanism. Importantly, a hydrated Mg2+ ion remains innersphere‐coordinated to N7 of G33 in all three states, and is consistent with its likely role as acid in general acid base catalysis (δ and β catalysis). Strikingly, the new structures shed light on a second hydrated Mg2+ ion that approaches the scissile phosphate from its binding site in the pre‐cleavage state to reach out for water‐mediated hydrogen bonding in the cyclophosphate product. The major role of the second Mg2+ ion appears to be the stabilization of product conformation. This study delivers a mechanistic understanding of ribozyme‐catalyzed backbone cleavage.
Collapse
Affiliation(s)
- Marianna Teplova
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, 10065, USA
| | - Christoph Falschlunger
- Institute of Organic Chemistry and Center for Molecular Biosciences, Leopold-Franzens University, Innrain 80-82, 6020, Innsbruck, Austria
| | - Olga Krasheninina
- Institute of Organic Chemistry and Center for Molecular Biosciences, Leopold-Franzens University, Innrain 80-82, 6020, Innsbruck, Austria
| | - Michaela Egger
- Institute of Organic Chemistry and Center for Molecular Biosciences, Leopold-Franzens University, Innrain 80-82, 6020, Innsbruck, Austria
| | - Aiming Ren
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, 10065, USA
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences, Leopold-Franzens University, Innrain 80-82, 6020, Innsbruck, Austria
| |
Collapse
|
18
|
Ma L, Kartik S, Liu B, Liu J. From general base to general acid catalysis in a sodium-specific DNAzyme by a guanine-to-adenine mutation. Nucleic Acids Res 2019; 47:8154-8162. [PMID: 31276580 PMCID: PMC6736077 DOI: 10.1093/nar/gkz578] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/20/2019] [Accepted: 06/26/2019] [Indexed: 02/07/2023] Open
Abstract
Recently, a few Na+-specific RNA-cleaving DNAzymes were reported, where nucleobases are likely to play critical roles in catalysis. The NaA43 and NaH1 DNAzymes share the same 16-nt Na+-binding motif, but differ in one or two nucleotides in a small catalytic loop. Nevertheless, they display an opposite pH-dependency, implicating distinct catalytic mechanisms. In this work, rational mutation studies locate a catalytic adenine residue, A22, in NaH1, while previous studies found a guanine (G23) to be important for the catalysis of NaA43. Mutation with pKa-perturbed analogs, such as 2-aminopurine (∼3.8), 2,6-diaminopurine (∼5.6) and hypoxanthine (∼8.7) affected the overall reaction rate. Therefore, we propose that the N1 position of G23 (pKa ∼6.6) in NaA43 functions as a general base, while that of A22 (pKa ∼6.3) in NaH1 as a general acid. Further experiments with base analogs and a phosphorothioate-modified substrate suggest that the exocyclic amine in A22 and both of the non-bridging oxygens at the scissile phosphate are important for catalysis for NaH1. This is an interesting example where single point mutations can change the mechanism of cleavage from general base to general acid, and it can also explain this Na+-dependent DNAzyme scaffold being sensitive to a broad range of metal ions and molecules.
Collapse
Affiliation(s)
- Lingzi Ma
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Sanjana Kartik
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Biwu Liu
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Juewen Liu
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| |
Collapse
|
19
|
Messina KJ, Kierzek R, Tracey MA, Bevilacqua PC. Small Molecule Rescue and Glycosidic Conformational Analysis of the Twister Ribozyme. Biochemistry 2019; 58:4857-4868. [PMID: 31742390 PMCID: PMC6901379 DOI: 10.1021/acs.biochem.9b00742] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The number of self-cleaving ribozymes has increased sharply in recent years, giving rise to elaborations of the four known ribozyme catalytic strategies, α, β, γ, and δ. One such extension is utilized by the twister ribozyme, which is hypothesized to conduct δ, or general acid catalysis, via N3 of the syn adenine +1 nucleobase indirectly via buffer catalysis at biological pH and directly at lower pH. Herein, we test the δ catalysis role of A1 via chemical rescue and the catalytic relevance of the syn orientation of the nucleobase by conformational analysis. Using inhibited twister ribozyme variants with A1(N3) deaza or A1 abasic modifications, we observe >100-fold chemical rescue effects in the presence of protonatable biological small molecules such as imidazole and histidine, similar to observed rescue values previously reported for C75U/C76Δ in the HDV ribozyme. Brønsted plots for the twister variants support a model in which small molecules rescue catalytic activity via a proton transfer mechanism, suggesting that A1 in the wild type is involved in proton transfer, most likely general acid catalysis. Additionally, through glycosidic conformational analysis in an appropriate background that accommodates the bromine atom, we observe that an 8BrA1-modified twister ribozyme is up to 10-fold faster than a nonmodified A1 ribozyme, supporting crystallographic data that show that A1 is syn when conducting proton transfer. Overall, this study provides functional evidence that the nucleotide immediately downstream of the cleavage site participates directly or indirectly in general acid-base catalysis in the twister ribozyme while occupying the syn conformation.
Collapse
Affiliation(s)
- Kyle J. Messina
- Department of Chemistry, Pennsylvania State University, University Park, PA 16802
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA 16802
| | - Ryszard Kierzek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Matthew A. Tracey
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802
- Current Address: Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104
| | - Philip C. Bevilacqua
- Department of Chemistry, Pennsylvania State University, University Park, PA 16802
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA 16802
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802
| |
Collapse
|
20
|
Fuchs E, Falschlunger C, Micura R, Breuker K. The effect of adenine protonation on RNA phosphodiester backbone bond cleavage elucidated by deaza-nucleobase modifications and mass spectrometry. Nucleic Acids Res 2019; 47:7223-7234. [PMID: 31276590 PMCID: PMC6698743 DOI: 10.1093/nar/gkz574] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/15/2019] [Accepted: 06/21/2019] [Indexed: 12/14/2022] Open
Abstract
The catalytic strategies of small self-cleaving ribozymes often involve interactions between nucleobases and the ribonucleic acid (RNA) backbone. Here we show that multiply protonated, gaseous RNA has an intrinsic preference for the formation of ionic hydrogen bonds between adenine protonated at N3 and the phosphodiester backbone moiety on its 5'-side that facilitates preferential phosphodiester backbone bond cleavage upon vibrational excitation by low-energy collisionally activated dissociation. Removal of the basic N3 site by deaza-modification of adenine was found to abrogate preferential phosphodiester backbone bond cleavage. No such effects were observed for N1 or N7 of adenine. Importantly, we found that the pH of the solution used for generation of the multiply protonated, gaseous RNA ions by electrospray ionization affects phosphodiester backbone bond cleavage next to adenine, which implies that the protonation patterns in solution are at least in part preserved during and after transfer into the gas phase. Our study suggests that interactions between protonated adenine and phosphodiester moieties of RNA may play a more important mechanistic role in biological processes than considered until now.
Collapse
Affiliation(s)
- Elisabeth Fuchs
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Christoph Falschlunger
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Kathrin Breuker
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| |
Collapse
|
21
|
Gasser C, Gebetsberger J, Gebetsberger M, Micura R. SHAPE probing pictures Mg2+-dependent folding of small self-cleaving ribozymes. Nucleic Acids Res 2019; 46:6983-6995. [PMID: 29924364 PMCID: PMC6101554 DOI: 10.1093/nar/gky555] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 06/07/2018] [Indexed: 12/28/2022] Open
Abstract
Self-cleaving ribozymes are biologically relevant RNA molecules which catalyze site-specific cleavage of the phosphodiester backbone. Gathering knowledge of their three-dimensional structures is critical toward an in-depth understanding of their function and chemical mechanism. Equally important is collecting information on the folding process and the inherent dynamics of a ribozyme fold. Over the past years, Selective-2′-Hydroxyl Acylation analyzed by Primer Extension (SHAPE) turned out to be a significant tool to probe secondary and tertiary interactions of diverse RNA species at the single nucleotide level under varying environmental conditions. Small self-cleaving ribozymes, however, have not been investigated by this method so far. Here, we describe SHAPE probing of pre-catalytic folds of the recently discovered ribozyme classes twister, twister-sister (TS), pistol and hatchet. The study has implications on Mg2+-dependent folding and reveals potentially dynamic residues of these ribozymes that are otherwise difficult to identify. For twister, TS and pistol ribozymes the new findings are discussed in the light of their crystal structures, and in case of twister also with respect to a smFRET folding analysis. For the hatchet ribozyme where an atomic resolution structure is not yet available, the SHAPE data challenge the proposed secondary structure model and point at selected residues and putative long-distance interactions that appear crucial for structure formation and cleavage activity.
Collapse
Affiliation(s)
- Catherina Gasser
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck CMBI, Leopold-Franzens University, Innrain 80-82, Innsbruck 6020, Austria
| | - Jennifer Gebetsberger
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck CMBI, Leopold-Franzens University, Innrain 80-82, Innsbruck 6020, Austria
| | - Manuel Gebetsberger
- Division for Biomedical Physics, Medical University of Innsbruck, Müllerstraße 44, Innsbruck 6020, Austria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck CMBI, Leopold-Franzens University, Innrain 80-82, Innsbruck 6020, Austria
| |
Collapse
|
22
|
Gaines CS, Giese TJ, York DM. Cleaning Up Mechanistic Debris Generated by Twister Ribozymes Using Computational RNA Enzymology. ACS Catal 2019; 9:5803-5815. [PMID: 31328021 PMCID: PMC6641568 DOI: 10.1021/acscatal.9b01155] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The catalytic properties of RNA have been a subject of fascination and intense research since their discovery over 30 years ago. Very recently, several classes of nucleolytic ribozymes have emerged and been characterized structurally. Among these, the twister ribozyme has been center-stage, and a topic of debate about its architecture and mechanism owing to conflicting interpretations of different crystal structures, and in some cases conflicting interpretations of the same functional data. In the present work, we attempt to clean up the mechanistic "debris" generated by twister ribozymes using a comprehensive computational RNA enzymology approach aimed to provide a unified interpretation of existing structural and functional data. Simulations in the crystalline environment and in solution provide insight into the origins of observed differences in crystal structures, and coalesce on a common active site architecture, and dynamical ensemble in solution. We use GPU-accelerated free energy methods with enhanced sampling to ascertain microscopic nucleobase pK a values of the implicated general acid and base, from which predicted activity-pH profiles can be compared directly with experiments. Next, ab initio quantum mechanical/molecular mechanical (QM/MM) simulations with full dynamic solvation under periodic boundary conditions are used to determine mechanistic pathways through multi-dimensional free energy landscapes for the reaction. We then characterize the rate-controlling transition state, and make predictions about kinetic isotope effects and linear free energy relations. Computational mutagenesis is performed to explain the origin of rate effects caused by chemical modifications and make experimentally testable predictions. Finally, we provide evidence that helps to resolve conflicting issues related to the role of metal ions in catalysis. Throughout each stage, we highlight how a conserved L-platform structural motif, to- gether with a key L-anchor residue, forms the characteristic active site scaffold enabling each of the catalytic strategies to come together not only for the twister ribozyme, but the majority of the known small nucleolytic ribozyme classes.
Collapse
Affiliation(s)
- Colin S. Gaines
- Laboratory for Biomolecular Simulation Research, Institute for Quantitative Biomedicine and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Timothy J. Giese
- Laboratory for Biomolecular Simulation Research, Institute for Quantitative Biomedicine and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Darrin M. York
- Laboratory for Biomolecular Simulation Research, Institute for Quantitative Biomedicine and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| |
Collapse
|
23
|
Bevilacqua PC, Harris ME, Piccirilli JA, Gaines C, Ganguly A, Kostenbader K, Ekesan Ş, York DM. An Ontology for Facilitating Discussion of Catalytic Strategies of RNA-Cleaving Enzymes. ACS Chem Biol 2019; 14:1068-1076. [PMID: 31095369 PMCID: PMC6661149 DOI: 10.1021/acschembio.9b00202] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A predictive understanding of the mechanisms of RNA cleavage is important for the design of emerging technology built from biological and synthetic molecules that have promise for new biochemical and medicinal applications. Over the past 15 years, RNA cleavage reactions involving 2'-O-transphosphorylation have been discussed using a simplified framework introduced by Breaker that consists of four fundamental catalytic strategies (designated α, β, γ, and δ) that contribute to rate enhancement. As more detailed mechanistic data emerge, there is need for the framework to evolve and keep pace. We develop an ontology for discussion of strategies of enzymes that catalyze RNA cleavage via 2'-O-transphosphorylation that stratifies Breaker's framework into primary (1°), secondary (2°), and tertiary (3°) contributions to enable more precise interpretation of mechanism in the context of structure and bonding. Further, we point out instances where atomic-level changes give rise to changes in more than one catalytic contribution, a phenomenon we refer to as "functional blurring". We hope that this ontology will help clarify our conversations and pave the path forward toward a consensus view of these fundamental and fascinating mechanisms. The insight gained will deepen our understanding of RNA cleavage reactions catalyzed by natural protein and RNA enzymes, as well as aid in the design of new engineered DNA and synthetic enzymes.
Collapse
Affiliation(s)
- Philip C. Bevilacqua
- Department of Chemistry, Center for RNA Molecular Biology, and Department of Biochemistry, Microbiology, and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Michael E. Harris
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
| | - Joseph A. Piccirilli
- Department of Chemistry, and Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Colin Gaines
- Laboratory for Biomolecular Simulation Research, Institute for Quantitative Biomedicine, Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854-8087, USA
| | - Abir Ganguly
- Laboratory for Biomolecular Simulation Research, Institute for Quantitative Biomedicine, Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854-8087, USA
| | - Ken Kostenbader
- Laboratory for Biomolecular Simulation Research, Institute for Quantitative Biomedicine, Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854-8087, USA
| | - Şölen Ekesan
- Laboratory for Biomolecular Simulation Research, Institute for Quantitative Biomedicine, Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854-8087, USA
| | - Darrin M. York
- Laboratory for Biomolecular Simulation Research, Institute for Quantitative Biomedicine, Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854-8087, USA
| |
Collapse
|
24
|
Guo F, Yue Z, Trajkovski M, Zhou X, Cao D, Li Q, Wang B, Wen X, Plavec J, Peng Q, Xi Z, Zhou C. Effect of Ribose Conformation on RNA Cleavage via Internal Transesterification. J Am Chem Soc 2018; 140:11893-11897. [PMID: 30207719 DOI: 10.1021/jacs.8b06313] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
RNA cleavage via internal transesterification is a fundamental reaction involved in RNA processing and metabolism, and the regulation thereof. Herein, the influence of ribose conformation on this reaction was investigated with conformationally constrained ribonucleotides. RNA cleavage rates were found to decrease in the order South-constrained ribonucleotide > native ribonucleotide ≫ North-constrained counterpart, indicating that the ribose conformation plays an important role in modulating RNA cleavage via internal transesterification.
Collapse
Affiliation(s)
- Fengmin Guo
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Zekun Yue
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Marko Trajkovski
- Slovenian NMR Centre, National Institute of Chemistry , University of Ljubljana, Faculty of Chemistry and Chemical Technology, Ljubljana, EN-FIST Centre of Excellence , Hajdrihova 19 , Ljubljana 1000 , Slovenia
| | - Xiaoping Zhou
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Dong Cao
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Qiang Li
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Baifan Wang
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Xin Wen
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Janez Plavec
- Slovenian NMR Centre, National Institute of Chemistry , University of Ljubljana, Faculty of Chemistry and Chemical Technology, Ljubljana, EN-FIST Centre of Excellence , Hajdrihova 19 , Ljubljana 1000 , Slovenia
| | - Qian Peng
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Zhen Xi
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Chuanzheng Zhou
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071 , China
| |
Collapse
|
25
|
Messina KJ, Bevilacqua PC. Cellular Small Molecules Contribute to Twister Ribozyme Catalysis. J Am Chem Soc 2018; 140:10578-10582. [PMID: 30102530 PMCID: PMC6472948 DOI: 10.1021/jacs.8b06065] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The number of self-cleaving small ribozymes has increased sharply in recent years. Advances have been made in describing these ribozymes in terms of four catalytic strategies: α describes in-line attack, β describes neutralization of the nonbridging oxygens, γ describes activation of the nucleophile, and δ describes stabilization of the leaving group. Current literature presents the rapid self-cleavage of the twister ribozyme in terms of all four of these classic catalytic strategies. Herein, we describe the nonspecific contribution of small molecules to ribozyme catalysis. At biological pH, the rate of the wild-type twister ribozyme is enhanced up to 5-fold in the presence of moderate buffer concentrations, similar to the 3-5-fold effects reported previously for buffer catalysis for protein enzymes. We observe this catalytic enhancement not only with standard laboratory buffers, but also with diverse biological small molecules, including imidazole, amino acids, and amino sugars. Brønsted plots suggest that small molecules assist in proton transfer, most likely with δ catalysis. Cellular small molecules provide a simple way to overcome the limited functional diversity of RNA and have the potential to participate in the catalytic mechanisms of many ribozymes in vivo.
Collapse
Affiliation(s)
- Kyle J. Messina
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Philip C. Bevilacqua
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802 United States
| |
Collapse
|
26
|
Abstract
The emergence of functional cooperation between the three main classes of biomolecules - nucleic acids, peptides and lipids - defines life at the molecular level. However, how such mutually interdependent molecular systems emerged from prebiotic chemistry remains a mystery. A key hypothesis, formulated by Crick, Orgel and Woese over 40 year ago, posits that early life must have been simpler. Specifically, it proposed that an early primordial biology lacked proteins and DNA but instead relied on RNA as the key biopolymer responsible not just for genetic information storage and propagation, but also for catalysis, i.e. metabolism. Indeed, there is compelling evidence for such an 'RNA world', notably in the structure of the ribosome as a likely molecular fossil from that time. Nevertheless, one might justifiably ask whether RNA alone would be up to the task. From a purely chemical perspective, RNA is a molecule of rather uniform composition with all four bases comprising organic heterocycles of similar size and comparable polarity and pK a values. Thus, RNA molecules cover a much narrower range of steric, electronic and physicochemical properties than, e.g. the 20 amino acid side-chains of proteins. Herein we will examine the functional potential of RNA (and other nucleic acids) with respect to self-replication, catalysis and assembly into simple protocellular entities.
Collapse
|
27
|
Li Z, Zhu J, He J. Conformational studies of 10-23 DNAzyme in solution through pyrenyl-labeled 2'-deoxyadenosine derivatives. Org Biomol Chem 2018; 14:9846-9858. [PMID: 27714317 DOI: 10.1039/c6ob01702a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
10-23 DNAzyme is a small catalytic DNA molecule. Studies on its conformation in solution are critical for understanding its catalytic mechanism and functional optimization. Based on our previous research, two fluorescent nucleoside analogues 1 and 2 were designed for the introduction of a pyrenyl group at one of the five dA residues in the catalytic core and the unpaired adenosine residue in its full-DNA substrate, respectively. Ten pyrenyl-pyrenyl pairs are formed in the DNAzyme-substrate complexes in solution for sensing the spacial positions of the five dA residues relative to the cleavage site using fluorescence spectra. The position-dependent quenching effect of pyrene emission fluorescence by nucleobases, especially the pyrenyl-pyrenyl interaction, was observed for some positions. The adenine residues in the 3'-part of the catalytic loop seem to be closer to the cleavage site than the adenine residues in the 5'-part, which is consistent with the molecular dynamics simulation result. The catalytic activities and Tm changes also confirmed the effect of the pyrenyl-nucleobase and pyrenyl-pyrenyl pair interactions. Together with functional group mutations, catalytically relevant nucleobases will be identified for understanding the catalytic mechanism of 10-23 DNAzyme.
Collapse
Affiliation(s)
- Zhiwen Li
- College of Life Science, Guizhou University, Guiyang 550025, China
| | - Junfei Zhu
- College of Life Science, Guizhou University, Guiyang 550025, China
| | - Junlin He
- Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| |
Collapse
|
28
|
Seith DD, Bingaman JL, Veenis AJ, Button AC, Bevilacqua PC. Elucidation of Catalytic Strategies of Small Nucleolytic Ribozymes From Comparative Analysis of Active Sites. ACS Catal 2018; 8:314-327. [PMID: 32547833 PMCID: PMC7296830 DOI: 10.1021/acscatal.7b02976] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A number of small, self-cleaving ribozyme classes have been identified including the hammerhead, hairpin, hepatitis delta virus (HDV), Varkud satellite (VS), glmS, twister, hatchet, pistol, and twister sister ribozymes. Within the active sites of these ribozymes, myriad functional groups contribute to catalysis. There has been extensive structure-function analysis of individual ribozymes, but the extent to which catalytic devices are shared across different ribozyme classes is unclear. As such, emergent catalytic principles for ribozymes may await discovery. Identification of conserved catalytic devices can deepen our understanding of RNA catalysis specifically and of enzymic catalysis generally. To probe similarities and differences amongst ribozyme classes, active sites from more than 80 high-resolution crystal structures of self-cleaving ribozymes were compared computationally. We identify commonalities amongst ribozyme classes pertaining to four classic catalytic devices: deprotonation of the 2'OH nucleophile (γ), neutralization of the non-bridging oxygens of the scissile phosphate (β), neutralization of the O5' leaving group (δ), and in-line nucleophilic attack (α). In addition, we uncover conservation of two catalytic devices, each of which centers on the activation of the 2'OH nucleophile by a guanine: one to acidify the 2'OH by hydrogen bond donation to it (γ') and one to acidify the 2'OH by releasing it from non-productive interactions by competitive hydrogen bonding (γ''). Our findings reveal that the amidine functionalities of G, A, and C are especially important for these strategies, and help explain absence of U at ribozyme active sites. The identified γ' and γ'' catalytic strategies help unify the catalytic strategies shared amongst catalytic RNAs and may be important for large ribozymes, as well as protein enzymes that act on nucleic acids.
Collapse
Affiliation(s)
- Daniel D. Seith
- Department of Chemistry and Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
- These two authors contributed equally to this work
| | - Jamie L. Bingaman
- Department of Chemistry and Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
- These two authors contributed equally to this work
| | - Andrew J. Veenis
- Department of Chemistry and Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Aileen C. Button
- Department of Chemistry and Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
- Department of Biochemistry, The University of Vermont, Burlington, Vermont 05405
| | - Philip C. Bevilacqua
- Department of Chemistry and Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| |
Collapse
|
29
|
Chawla M, Chermak E, Zhang Q, Bujnicki JM, Oliva R, Cavallo L. Occurrence and stability of lone pair-π stacking interactions between ribose and nucleobases in functional RNAs. Nucleic Acids Res 2017; 45:11019-11032. [PMID: 28977572 PMCID: PMC5737201 DOI: 10.1093/nar/gkx757] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Accepted: 08/17/2017] [Indexed: 12/13/2022] Open
Abstract
The specific folding pattern and function of RNA molecules lies in various weak interactions, in addition to the strong base-base pairing and stacking. One of these relatively weak interactions, characterized by the stacking of the O4' atom of a ribose on top of the heterocycle ring of a nucleobase, has been known to occur but has largely been ignored in the description of RNA structures. We identified 2015 ribose-base stacking interactions in a high-resolution set of non-redundant RNA crystal structures. They are widespread in structured RNA molecules and are located in structural motifs other than regular stems. Over 50% of them involve an adenine, as we found ribose-adenine contacts to be recurring elements in A-minor motifs. Fewer than 50% of the interactions involve a ribose and a base of neighboring residues, while approximately 30% of them involve a ribose and a nucleobase at least four residues apart. Some of them establish inter-domain or inter-molecular contacts and often implicate functionally relevant nucleotides. In vacuo ribose-nucleobase stacking interaction energies were calculated by quantum mechanics methods. Finally, we found that lone pair-π stacking interactions also occur between ribose and aromatic amino acids in RNA-protein complexes.
Collapse
Affiliation(s)
- Mohit Chawla
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Thuwal 23955-6900, Saudi Arabia.,Kaust Catalysis Center, Thuwal 23955-6900, Saudi Arabia
| | - Edrisse Chermak
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Thuwal 23955-6900, Saudi Arabia.,Kaust Catalysis Center, Thuwal 23955-6900, Saudi Arabia
| | - Qingyun Zhang
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Thuwal 23955-6900, Saudi Arabia
| | - Janusz M Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, ul. Ks. Trojdena 4, 02-109 Warsaw, Poland.,Laboratory of Bioinformatics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
| | - Romina Oliva
- Department of Sciences and Technologies, University Parthenope of Naples, Centro Direzionale Isola C4, I-80143 Naples, Italy.,King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, Thuwal 23955-6900, Saudi Arabia
| | - Luigi Cavallo
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Thuwal 23955-6900, Saudi Arabia.,Kaust Catalysis Center, Thuwal 23955-6900, Saudi Arabia
| |
Collapse
|
30
|
Ren A, Micura R, Patel DJ. Structure-based mechanistic insights into catalysis by small self-cleaving ribozymes. Curr Opin Chem Biol 2017; 41:71-83. [PMID: 29107885 PMCID: PMC7955703 DOI: 10.1016/j.cbpa.2017.09.017] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 09/22/2017] [Accepted: 09/29/2017] [Indexed: 01/01/2023]
Abstract
Small self-cleaving ribozymes are widely distributed in nature and are essential for rolling-circle-based replication of satellite and pathogenic RNAs. Earlier structure-function studies on the hammerhead, hairpin, glmS, hepatitis delta virus and Varkud satellite ribozymes have provided insights into their overall architecture, their catalytic active site organization, and the role of nearby nucleobases and hydrated divalent cations in facilitating general acid-base and electrostatic-mediated catalysis. This review focuses on recent structure-function research on active site alignments and catalytic mechanisms of the Rzb hammerhead ribozyme, as well as newly-identified pistol, twister and twister-sister ribozymes. In contrast to an agreed upon mechanistic understanding of self-cleavage by Rzb hammerhead and pistol ribozymes, there exists a divergence of views as to the cleavage site alignments and catalytic mechanisms adopted by twister and twister-sister ribozymes. One approach to resolving this conundrum would be to extend the structural studies from currently available pre-catalytic conformations to their transition state mimic vanadate counterparts for both ribozymes.
Collapse
Affiliation(s)
- Aiming Ren
- Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Ronald Micura
- Institute of Organic Chemistry, Leopold Franzens University, Innsbruck A6020, Austria
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
| |
Collapse
|
31
|
Neuner S, Falschlunger C, Fuchs E, Himmelstoss M, Ren A, Patel DJ, Micura R. Atom-Specific Mutagenesis Reveals Structural and Catalytic Roles for an Active-Site Adenosine and Hydrated Mg2+
in Pistol Ribozymes. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201708679] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Sandro Neuner
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI); Leopold-Franzens University; Innrain 80-82 6020 Innsbruck Austria
| | - Christoph Falschlunger
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI); Leopold-Franzens University; Innrain 80-82 6020 Innsbruck Austria
| | - Elisabeth Fuchs
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI); Leopold-Franzens University; Innrain 80-82 6020 Innsbruck Austria
| | - Maximilian Himmelstoss
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI); Leopold-Franzens University; Innrain 80-82 6020 Innsbruck Austria
| | - Aiming Ren
- Life Science Institute; Zhejiang University; Hangzhou 310058 China
| | - Dinshaw J. Patel
- Structural Biology Program; Memorial Sloan-Kettering Cancer Center; New York NY 10065 USA
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI); Leopold-Franzens University; Innrain 80-82 6020 Innsbruck Austria
| |
Collapse
|
32
|
Neuner S, Falschlunger C, Fuchs E, Himmelstoss M, Ren A, Patel DJ, Micura R. Atom-Specific Mutagenesis Reveals Structural and Catalytic Roles for an Active-Site Adenosine and Hydrated Mg 2+ in Pistol Ribozymes. Angew Chem Int Ed Engl 2017; 56:15954-15958. [PMID: 29098759 DOI: 10.1002/anie.201708679] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 10/14/2017] [Indexed: 12/15/2022]
Abstract
The pistol RNA motif represents a new class of self-cleaving ribozymes of yet unknown biological function. Our recent crystal structure of a pre-catalytic state of this RNA shows guanosine G40 and adenosine A32 close to the G53-U54 cleavage site. While the N1 of G40 is within 3.4 Å of the modeled G53 2'-OH group that attacks the scissile phosphate, thus suggesting a direct role in general acid-base catalysis, the function of A32 is less clear. We present evidence from atom-specific mutagenesis that neither the N1 nor N3 base positions of A32 are involved in catalysis. By contrast, the ribose 2'-OH of A32 seems crucial for the proper positioning of G40 through a H-bond network that involves G42 as a bridging unit between A32 and G40. We also found that disruption of the inner-sphere coordination of the active-site Mg2+ cation to N7 of G33 makes the ribozyme drastically slower. A mechanistic proposal is suggested, with A32 playing a structural role and hydrated Mg2+ playing a catalytic role in cleavage.
Collapse
Affiliation(s)
- Sandro Neuner
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI), Leopold-Franzens University, Innrain 80-82, 6020, Innsbruck, Austria
| | - Christoph Falschlunger
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI), Leopold-Franzens University, Innrain 80-82, 6020, Innsbruck, Austria
| | - Elisabeth Fuchs
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI), Leopold-Franzens University, Innrain 80-82, 6020, Innsbruck, Austria
| | - Maximilian Himmelstoss
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI), Leopold-Franzens University, Innrain 80-82, 6020, Innsbruck, Austria
| | - Aiming Ren
- Life Science Institute, Zhejiang University, Hangzhou, 310058, China
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI), Leopold-Franzens University, Innrain 80-82, 6020, Innsbruck, Austria
| |
Collapse
|
33
|
Zheng L, Mairhofer E, Teplova M, Zhang Y, Ma J, Patel DJ, Micura R, Ren A. Structure-based insights into self-cleavage by a four-way junctional twister-sister ribozyme. Nat Commun 2017; 8:1180. [PMID: 29081514 PMCID: PMC5660989 DOI: 10.1038/s41467-017-01276-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 09/01/2017] [Indexed: 11/13/2022] Open
Abstract
Here we report on the crystal structure and cleavage assays of a four-way junctional twister-sister self-cleaving ribozyme. Notably, 11 conserved spatially separated loop nucleotides are brought into close proximity at the ribozyme core through long-range interactions mediated by hydrated Mg2+ cations. The C62–A63 step at the cleavage site adopts a splayed-apart orientation, with flexible C62 directed outwards, whereas A63 is directed inwards and anchored by stacking and hydrogen-bonding interactions. Structure-guided studies of key base, sugar, and phosphate mutations in the twister-sister ribozyme, suggest contributions to the cleavage chemistry from interactions between a guanine at the active site and the non-bridging oxygen of the scissile phosphate, a feature found previously also for the related twister ribozyme. Our four-way junctional pre-catalytic structure differs significantly in the alignment at the cleavage step (splayed-apart vs. base-stacked) and surrounding residues and hydrated Mg2+ ions relative to a reported three-way junctional pre-catalytic structure of the twister-sister ribozyme. Twister-sister is a self-cleaving ribozyme. Here, the authors report the 2.0 Å crystal structure of the four-way junctional twister-sister ribozyme in the pre-catalytic state and discuss mechanistic implications based on their mutagenesis experiments and comparisons with other ribozyme structures.
Collapse
Affiliation(s)
- Luqian Zheng
- Life Sciences Institute, Zhejiang University, 310058, Hangzhou, China
| | - Elisabeth Mairhofer
- Institute of Organic Chemistry, Leopold Franzens University, A6020, Innsbruck, Austria
| | - Marianna Teplova
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Ye Zhang
- Life Sciences Institute, Zhejiang University, 310058, Hangzhou, China
| | - Jinbiao Ma
- Department of Biochemistry, State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, 200438, Shanghai, China.,Collaborative Innovation Centre of Genetics and Development, Fudan University, 200438, Shanghai, China
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Ronald Micura
- Institute of Organic Chemistry, Leopold Franzens University, A6020, Innsbruck, Austria.
| | - Aiming Ren
- Life Sciences Institute, Zhejiang University, 310058, Hangzhou, China. .,Collaborative Innovation Centre of Genetics and Development, Fudan University, 200438, Shanghai, China.
| |
Collapse
|
34
|
Gaines CS, York DM. Model for the Functional Active State of the TS Ribozyme from Molecular Simulation. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201705608] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Colin S. Gaines
- Laboratory for Biomolecular Simulation Research, Center for Integrative Proteomics Research, and Department of Chemistry & Chemical Biology; Rutgers University; 174 Frelinghuysen Road Piscataway NJ 08854-8076 USA
| | - Darrin M. York
- Laboratory for Biomolecular Simulation Research, Center for Integrative Proteomics Research, and Department of Chemistry & Chemical Biology; Rutgers University; 174 Frelinghuysen Road Piscataway NJ 08854-8076 USA
| |
Collapse
|
35
|
Gaines CS, York DM. Model for the Functional Active State of the TS Ribozyme from Molecular Simulation. Angew Chem Int Ed Engl 2017; 56:13392-13395. [PMID: 28763583 DOI: 10.1002/anie.201705608] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Indexed: 12/23/2022]
Abstract
Recently, a crystal structure has been reported of a new catalytic RNA, the TS ribozyme, that has been identified through comparative genomics and is believed to be a metalloribozyme having novel mechanistic features. Although this data provides invaluable structural information, analysis suggests a conformational change is required to arrive at a catalytically relevant state. We report results of molecular simulations that predict a spontaneous local rearrangement of the active site, leading to solution structures consistent with available functional data and providing competing mechanistic hypotheses that can be experimentally tested. The two competing hypotheses differ in the proposed identity of the catalytic general acid: either a water molecule coordinating a Mg2+ ion bound at the Watson-Crick edge of residue C7, or the N3 position of residue C7 itself.
Collapse
Affiliation(s)
- Colin S Gaines
- Laboratory for Biomolecular Simulation Research, Center for Integrative Proteomics Research, and Department of Chemistry & Chemical Biology, Rutgers University, 174 Frelinghuysen Road, Piscataway, NJ, 08854-8076, USA
| | - Darrin M York
- Laboratory for Biomolecular Simulation Research, Center for Integrative Proteomics Research, and Department of Chemistry & Chemical Biology, Rutgers University, 174 Frelinghuysen Road, Piscataway, NJ, 08854-8076, USA
| |
Collapse
|
36
|
Panja S, Hua B, Zegarra D, Ha T, Woodson SA. Metals induce transient folding and activation of the twister ribozyme. Nat Chem Biol 2017; 13:1109-1114. [PMID: 28825710 PMCID: PMC5605428 DOI: 10.1038/nchembio.2459] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 07/18/2017] [Indexed: 11/15/2022]
Abstract
Twister is a small ribozyme present in almost all kingdoms of life that rapidly self-cleaves in variety of divalent metal ions. We used activity assays, bulk FRET and single-molecule FRET (smFRET) to understand how different metal ions promote folding and self-cleavage of the Oryza sativa Twister ribozyme. Although most ribozymes require additional Mg2+ for catalysis, Twister inverts this expectation, requiring 20–30 times less Mg2+ to self-cleave than to fold. Transition metals such as Co2+, Ni2+ and Zn2+ activate Twister more efficiently than Mg2+ ions. Although Twister is fully active in ≤ 0.5 mM MgCl2, smFRET experiments showed that the ribozyme visits the folded state infrequently under these conditions. Comparison of folding and self-cleavage rates indicates that most folding events lead to catalysis, which correlates with metal bond strength. Thus, the robust activity of Twister reports on transient metal ion binding under physiological conditions.
Collapse
Affiliation(s)
- Subrata Panja
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Boyang Hua
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Diego Zegarra
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Taekjip Ha
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.,Howard Hughes Medical Institute, Baltimore, Maryland, USA
| | - Sarah A Woodson
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, USA
| |
Collapse
|
37
|
Vušurović N, Altman RB, Terry DS, Micura R, Blanchard SC. Pseudoknot Formation Seeds the Twister Ribozyme Cleavage Reaction Coordinate. J Am Chem Soc 2017; 139:8186-8193. [PMID: 28598157 PMCID: PMC5697751 DOI: 10.1021/jacs.7b01549] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The twister RNA is a recently discovered nucleolytic ribozyme that is present in both bacteria and eukarya. While its biological role remains unclear, crystal structure analyses and biochemical approaches have revealed critical features of its catalytic mechanism. Here, we set out to explore dynamic aspects of twister RNA folding along the cleavage reaction coordinate. To do so, we have employed both bulk and single-molecule fluorescence resonance energy transfer (FRET) methods to investigate a set of twister RNAs with labels strategically positioned at communicating segments. The data reveal that folding of the central pseudoknot (T1), the most crucial structural determinant to promote cleavage, exhibits reversible opening and closing dynamics at physiological Mg2+ concentration. Uncoupled folding, in which T1 formation precedes structuring for closing of stem P1, was confirmed using pre-steady-state three-color smFRET experiments initiated by Mg2+ injection. This finding suggests that the folding path of twister RNA requires proper orientation of the substrate prior to T1 closure such that the U5-A6 cleavage site becomes embraced to achieve its cleavage competent conformation. We also find that the cleaved 3'-fragment retains its compacted pseudoknot fold, despite the absence of the phylogenetically conserved stem P1, rationalizing the poor turnover efficiency of the twister ribozyme.
Collapse
Affiliation(s)
- Nikola Vušurović
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | - Roger B. Altman
- Weill Cornell Medicine, New York, New York 10065, United States
| | - Daniel S. Terry
- Weill Cornell Medicine, New York, New York 10065, United States
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | | |
Collapse
|
38
|
Lilley DMJ. How RNA acts as a nuclease: some mechanistic comparisons in the nucleolytic ribozymes. Biochem Soc Trans 2017; 45:683-691. [PMID: 28620029 DOI: 10.1042/bst20160158] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 02/28/2017] [Accepted: 03/02/2017] [Indexed: 02/11/2024]
Abstract
Recent structural and mechanistic studies have shed considerable light on the catalytic mechanisms of nucleolytic ribozymes. The discovery of several new ribozymes in this class has now allowed comparisons to be made, and the beginnings of mechanistic groupings to emerge.
Collapse
Affiliation(s)
- David M J Lilley
- Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee DD1 5EH, U.K.
| |
Collapse
|
39
|
Structural and Biochemical Properties of Novel Self-Cleaving Ribozymes. Molecules 2017; 22:molecules22040678. [PMID: 28441772 PMCID: PMC6154101 DOI: 10.3390/molecules22040678] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 04/07/2017] [Accepted: 04/13/2017] [Indexed: 01/20/2023] Open
Abstract
Fourteen well-defined ribozyme classes have been identified to date, among which nine are site-specific self-cleaving ribozymes. Very recently, small self-cleaving ribozymes have attracted renewed interest in their structure, biochemistry, and biological function since the discovery, during the last three years, of four novel ribozymes, termed twister, twister sister, pistol, and hatchet. In this review, we mainly address the structure, biochemistry, and catalytic mechanism of the novel ribozymes. They are characterized by distinct active site architectures and divergent, but similar, biochemical properties. The cleavage activities of the ribozymes are highly dependent upon divalent cations, pH, and base-specific mutations, which can cause changes in the nucleotide arrangement and/or electrostatic potential around the cleavage site. It is most likely that a guanine and adenine in close proximity of the cleavage site are involved in general acid-base catalysis. In addition, metal ions appear to play a structural rather than catalytic role although some of their crystal structures have shown a direct metal ion coordination to a non-bridging phosphate oxygen at the cleavage site. Collectively, the structural and biochemical data of the four newest ribozymes could contribute to advance our mechanistic understanding of how self-cleaving ribozymes accomplish their efficient site-specific RNA cleavages.
Collapse
|
40
|
Abstract
Twister RNAs represent a recently discovered class of natural ribozymes that promote rapid cleaving of RNA backbones. Although an abundance of theoretical, biochemical, and structural data exist for several members of the twister class, disagreements about the architecture and mechanism of its active site have emerged. Historically, such storms regarding mechanistic details typically occur soon after each new self-cleaving ribozyme class is reported, but paths forward exist to quickly reach calmer conditions.
Collapse
Affiliation(s)
- Ronald R. Breaker
- Department
of Molecular, Cellular and Developmental Biology, ‡Department of Molecular
Biophysics and Biochemistry, §Howard Hughes Medical Institute, Yale University, New Haven, Connecticut 06520, United States
| |
Collapse
|
41
|
Molecular mechanism of the site-specific self-cleavage of the RNA phosphodiester backbone by a twister ribozyme. Theor Chem Acc 2017. [DOI: 10.1007/s00214-017-2060-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
42
|
Neuner S, Kreutz C, Micura R. The synthesis of 15N(7)-Hoogsteen face-labeled adenosine phosphoramidite for solid-phase RNA synthesis. MONATSHEFTE FUR CHEMIE 2016; 148:149-155. [PMID: 28127100 PMCID: PMC5225212 DOI: 10.1007/s00706-016-1882-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 11/21/2016] [Indexed: 01/08/2023]
Abstract
ABSTRACT We have developed an efficient route for the synthesis of 15N(7)-labeled adenosine as phosphoramidite building block for site- and atom-specific incorporation into RNA by automated solid-phase synthesis. Such labeled RNA is required for the evaluation of selected non-canonical base pair interactions in folded RNA using NMR spectroscopic methods. GRAPHICAL ABSTRACT
Collapse
Affiliation(s)
- Sandro Neuner
- Institute of Organic Chemistry, Leopold-Franzens University, Innrain 80-82, Innsbruck, Austria
| | - Christoph Kreutz
- Institute of Organic Chemistry, Leopold-Franzens University, Innrain 80-82, Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry, Leopold-Franzens University, Innrain 80-82, Innsbruck, Austria
| |
Collapse
|
43
|
Mairhofer E, Fuchs E, Micura R. Facile synthesis of a 3-deazaadenosine phosphoramidite for RNA solid-phase synthesis. Beilstein J Org Chem 2016; 12:2556-2562. [PMID: 28144324 PMCID: PMC5238537 DOI: 10.3762/bjoc.12.250] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 11/09/2016] [Indexed: 12/14/2022] Open
Abstract
Access to 3-deazaadenosine (c3A) building blocks for RNA solid-phase synthesis represents a severe bottleneck in modern RNA research, in particular for atomic mutagenesis experiments to explore mechanistic aspects of ribozyme catalysis. Here, we report the 5-step synthesis of a c3A phosphoramidite from cost-affordable starting materials. The key reaction is a silyl-Hilbert-Johnson nucleosidation using unprotected 6-amino-3-deazapurine and benzoyl-protected 1-O-acetylribose. The novel path is superior to previously described syntheses in terms of efficacy and ease of laboratory handling.
Collapse
Affiliation(s)
- Elisabeth Mairhofer
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Austria
| | - Elisabeth Fuchs
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Austria
| |
Collapse
|
44
|
Gebetsberger J, Micura R. Unwinding the twister ribozyme: from structure to mechanism. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27863022 PMCID: PMC5408937 DOI: 10.1002/wrna.1402] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 09/12/2016] [Accepted: 10/10/2016] [Indexed: 11/12/2022]
Abstract
The twister ribozyme motif has been identified by bioinformatic means very recently. Currently, four crystal structures with ordered active sites together with a series of chemical and biochemical data provide insights into how this RNA accomplishes its efficient self‐cleavage. Of particular interest for a mechanistic proposal are structural distinctions observed in the active sites that concern the conformation of the U‐A cleavage site dinucleotide (in‐line alignment of the attacking 2′‐O nucleophile to the to‐be‐cleaved P—O5′ bond versus suboptimal alignments) as well as the presence/absence of Mg2+ ions at the scissile phosphate. All structures support the notion that an active site guanine and the conserved adenine at the cleavage site are important contributors to cleavage chemistry, likely being involved in general acid base catalysis. Evidence for innersphere coordination of a Mg2+ ion to the pro‐S nonbridging oxygen of the scissile phosphate stems from two of the four crystal structures. Together with the finding of thio/rescue effects for phosphorothioate substrates, this suggests the participation of divalent ions in the overall catalytic strategy employed by twister ribozymes. In this context, it is notable that twister retains wild‐type activity when the phylogenetically conserved stem P1 is deleted, able to cleave a single nucleotide only. WIREs RNA 2017, 8:e1402. doi: 10.1002/wrna.1402 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Jennifer Gebetsberger
- Institute of Organic Chemistry, Leopold-Franzens University and Center of Molecular Biosciences Innsbruck CMBI, Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry, Leopold-Franzens University and Center of Molecular Biosciences Innsbruck CMBI, Innsbruck, Austria
| |
Collapse
|
45
|
Zhu J, Li Z, Wang Q, Liu Y, He J. The contribution of adenines in the catalytic core of 10-23 DNAzyme improved by the 6-amino group modifications. Bioorg Med Chem Lett 2016; 26:4462-4465. [DOI: 10.1016/j.bmcl.2016.07.076] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 07/13/2016] [Accepted: 07/29/2016] [Indexed: 10/21/2022]
|
46
|
Ren A, Vušurović N, Gebetsberger J, Gao P, Juen M, Kreutz C, Micura R, Patel DJ. Pistol ribozyme adopts a pseudoknot fold facilitating site-specific in-line cleavage. Nat Chem Biol 2016; 12:702-8. [PMID: 27398999 PMCID: PMC4990474 DOI: 10.1038/nchembio.2125] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/08/2016] [Indexed: 12/20/2022]
Abstract
The field of small self-cleaving nucleolytic ribozymes has been invigorated by the recent discovery of the twister, twister-sister, pistol and hatchet ribozymes. We report the crystal structure of a pistol ribozyme termed env25, which adopts a compact tertiary architecture stabilized by an embedded pseudoknot fold. The G-U cleavage site adopts a splayed-apart conformation with in-line alignment of the modeled 2'-O of G for attack on the adjacent to-be-cleaved P-O5' bond. Highly conserved residues G40 (N1 position) and A32 (N3 and 2'-OH positions) are aligned to act as a general base and a general acid, respectively, to accelerate cleavage chemistry, with their roles confirmed by cleavage assays on variants, and an increased pKa of 4.7 for A32. Our structure of the pistol ribozyme defined how the overall and local topologies dictate the in-line alignment at the G-U cleavage site, with cleavage assays on variants revealing key residues that participate in acid-base-catalyzed cleavage chemistry.
Collapse
Affiliation(s)
- Aiming Ren
- Life Sciences Institute, Zhejiang University, Hangzhou, China
- Structural Biology Program, Memorial Sloan-Kettering Cancer, New York, New York, USA
| | - Nikola Vušurović
- Institute of Organic Chemistry, Leopold Franzens University, Innsbruck, Austria
- Center of Molecular Biosciences (CMBI), Innsbruck, Austria
| | - Jennifer Gebetsberger
- Institute of Organic Chemistry, Leopold Franzens University, Innsbruck, Austria
- Center of Molecular Biosciences (CMBI), Innsbruck, Austria
| | - Pu Gao
- Structural Biology Program, Memorial Sloan-Kettering Cancer, New York, New York, USA
| | - Michael Juen
- Institute of Organic Chemistry, Leopold Franzens University, Innsbruck, Austria
- Center of Molecular Biosciences (CMBI), Innsbruck, Austria
| | - Christoph Kreutz
- Institute of Organic Chemistry, Leopold Franzens University, Innsbruck, Austria
- Center of Molecular Biosciences (CMBI), Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry, Leopold Franzens University, Innsbruck, Austria
- Center of Molecular Biosciences (CMBI), Innsbruck, Austria
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer, New York, New York, USA
| |
Collapse
|
47
|
Kobori S, Yokobayashi Y. High-Throughput Mutational Analysis of a Twister Ribozyme. Angew Chem Int Ed Engl 2016; 55:10354-7. [PMID: 27461281 PMCID: PMC5113685 DOI: 10.1002/anie.201605470] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 07/04/2016] [Indexed: 01/17/2023]
Abstract
Recent discoveries of new classes of self‐cleaving ribozymes in diverse organisms have triggered renewed interest in the chemistry and biology of ribozymes. Functional analysis and engineering of ribozymes often involve performing biochemical assays on multiple ribozyme mutants. However, because each ribozyme mutant must be individually prepared and assayed, the number and variety of mutants that can be studied are severely limited. All of the single and double mutants of a twister ribozyme (a total of 10 296 mutants) were generated and assayed for their self‐cleaving activity by exploiting deep sequencing to count the numbers of cleaved and uncleaved sequences for every mutant. Interestingly, we found that the ribozyme is highly robust against mutations such that 71 % and 30 % of all single and double mutants, respectively, retain detectable activity under the assay conditions. It was also observed that the structural elements that comprise the ribozyme exhibit distinct sensitivity to mutations.
Collapse
Affiliation(s)
- Shungo Kobori
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904 0495, Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904 0495, Japan.
| |
Collapse
|
48
|
Kobori S, Yokobayashi Y. High-Throughput Mutational Analysis of a Twister Ribozyme. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201605470] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Shungo Kobori
- Nucleic Acid Chemistry and Engineering Unit; Okinawa Institute of Science and Technology Graduate University; Onna Okinawa 904 0495 Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit; Okinawa Institute of Science and Technology Graduate University; Onna Okinawa 904 0495 Japan
| |
Collapse
|
49
|
Ucisik MN, Bevilacqua PC, Hammes-Schiffer S. Molecular Dynamics Study of Twister Ribozyme: Role of Mg(2+) Ions and the Hydrogen-Bonding Network in the Active Site. Biochemistry 2016; 55:3834-46. [PMID: 27295275 PMCID: PMC5127262 DOI: 10.1021/acs.biochem.6b00203] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The recently discovered twister ribozyme is thought to utilize general acid-base catalysis in its self-cleavage mechanism, but the roles of nucleobases and metal ions in the mechanism are unclear. Herein, molecular dynamics simulations of the env22 twister ribozyme are performed to elucidate the structural and equilibrium dynamical properties, as well as to examine the role of Mg(2+) ions and possible candidates for the general base and acid in the self-cleavage mechanism. The active site region and the ends of the pseudoknots were found to be less mobile than other regions of the ribozyme, most likely providing structural stability and possibly facilitating catalysis. A purported catalytic Mg(2+) ion and the closest neighboring Mg(2+) ion remained chelated and relatively immobile throughout the microsecond trajectories, although removal of these Mg(2+) ions did not lead to any significant changes in the structure or equilibrium motions of the ribozyme on the microsecond time scale. In addition, a third metal ion, a Na(+) ion remained close to A1(O5'), the leaving group atom, during the majority of the microsecond trajectories, suggesting that it might stabilize the negative charge on A1(O5') during self-cleavage. The locations of these cations and their interactions with key nucleotides in the active site suggest that they may be catalytically relevant. The P1 stem is partially melted at its top and bottom in the crystal structure and further unwinds in the trajectories. The simulations also revealed an interconnected network comprised of hydrogen-bonding and π-stacking interactions that create a relatively rigid network around the self-cleavage site. The nucleotides involved in this network are among the highly conserved nucleotides in twister ribozymes, suggesting that this interaction network may be important to structure and function.
Collapse
Affiliation(s)
- Melek N Ucisik
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801-3364, United States
| | - Philip C Bevilacqua
- Department of Chemistry, Department of Biochemistry & Molecular Biology, and Center for RNA Molecular Biology, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801-3364, United States
| |
Collapse
|
50
|
Wilson TJ, Liu Y, Domnick C, Kath-Schorr S, Lilley DMJ. The Novel Chemical Mechanism of the Twister Ribozyme. J Am Chem Soc 2016; 138:6151-62. [PMID: 27153229 DOI: 10.1021/jacs.5b11791] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We describe the multifactorial origins of catalysis by the twister ribozyme. We provide evidence that the adenine immediately 3' to the scissile phosphate (A1) acts as a general acid. Substitution of ring nitrogen atoms indicates that very unusually the N3 of A1 is the proton donor to the oxyanion leaving group. A1 is accommodated in a specific binding pocket that raises its pKa toward neutrality, juxtaposes its N3 with the O5' to be protonated, and helps create the in-line trajectory required for nucleophilic attack. A1 performs general acid catalysis while G33 acts as a general base. A 100-fold stereospecific phosphorothioate effect at the scissile phosphate is consistent with a significant stabilization of the transition state by the ribozyme, and functional group substitution at G33 indicates that its exocyclic N2 interacts directly with the scissile phosphate. A model of the ribozyme active site is proposed that accommodates these catalytic strategies.
Collapse
Affiliation(s)
- Timothy J Wilson
- Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee , Dow Street, Dundee DD1 5EH, U.K
| | - Yijin Liu
- Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee , Dow Street, Dundee DD1 5EH, U.K
| | - Christof Domnick
- Life and Medical Sciences Institute, University of Bonn , Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - Stephanie Kath-Schorr
- Life and Medical Sciences Institute, University of Bonn , Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - David M J Lilley
- Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee , Dow Street, Dundee DD1 5EH, U.K
| |
Collapse
|