1
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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.
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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
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2
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Byju S, Hassan A, Whitford PC. The energy landscape of the ribosome. Biopolymers 2024; 115:e23570. [PMID: 38051695 DOI: 10.1002/bip.23570] [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: 08/27/2023] [Revised: 10/17/2023] [Accepted: 11/08/2023] [Indexed: 12/07/2023]
Abstract
The ribosome is a prototypical assembly that can be used to establish general principles and techniques for the study of biological molecular machines. Motivated by the fact that the dynamics of every biomolecule is governed by an underlying energy landscape, there has been great interest to understand and quantify ribosome energetics. In the present review, we will focus on theoretical and computational strategies for probing the interactions that shape the energy landscape of the ribosome, with an emphasis on more recent studies of the elongation cycle. These efforts include the application of quantum mechanical methods for describing chemical kinetics, as well as classical descriptions to characterize slower (microsecond to millisecond) large-scale (10-100 Å) rearrangements, where motion is described in terms of diffusion across an energy landscape. Together, these studies provide broad insights into the factors that control a diverse range of dynamical processes in this assembly.
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Affiliation(s)
- Sandra Byju
- Center for Theoretical Biological Physics, Northeastern University, Boston, Massachusetts, USA
- Department of Physics, Northeastern University, Boston, Massachusetts, USA
| | - Asem Hassan
- Department of Chemistry, The University of Texas at Austin, Austin, Texas, United States
| | - Paul C Whitford
- Center for Theoretical Biological Physics, Northeastern University, Boston, Massachusetts, USA
- Department of Physics, Northeastern University, Boston, Massachusetts, USA
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3
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Okuda T, Lenz AK, Seitz F, Vogel J, Höbartner C. A SAM analogue-utilizing ribozyme for site-specific RNA alkylation in living cells. Nat Chem 2023; 15:1523-1531. [PMID: 37667013 PMCID: PMC10624628 DOI: 10.1038/s41557-023-01320-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 08/08/2023] [Indexed: 09/06/2023]
Abstract
Post-transcriptional RNA modification methods are in high demand for site-specific RNA labelling and analysis of RNA functions. In vitro-selected ribozymes are attractive tools for RNA research and have the potential to overcome some of the limitations of chemoenzymatic approaches with repurposed methyltransferases. Here we report an alkyltransferase ribozyme that uses a synthetic, stabilized S-adenosylmethionine (SAM) analogue and catalyses the transfer of a propargyl group to a specific adenosine in the target RNA. Almost quantitative conversion was achieved within 1 h under a wide range of reaction conditions in vitro, including physiological magnesium ion concentrations. A genetically encoded version of the SAM analogue-utilizing ribozyme (SAMURI) was expressed in HEK293T cells, and intracellular propargylation of the target adenosine was confirmed by specific fluorescent labelling. SAMURI is a general tool for the site-specific installation of the smallest tag for azide-alkyne click chemistry, which can be further functionalized with fluorophores, affinity tags or other functional probes.
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Affiliation(s)
- Takumi Okuda
- Institute of Organic Chemistry, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Ann-Kathrin Lenz
- Institute of Organic Chemistry, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Florian Seitz
- Institute of Organic Chemistry, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Jörg Vogel
- Institute of Molecular Infection Biology (IMIB), Julius-Maximilians-Universität Würzburg, Würzburg, Germany
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Claudia Höbartner
- Institute of Organic Chemistry, Julius-Maximilians-Universität Würzburg, Würzburg, Germany.
- Center for Nanosystems Chemistry (CNC), Julius-Maximilians-Universität Würzburg, Würzburg, Germany.
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4
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Radford F, Rinehart J, Isaacs FJ. Mapping the in vivo fitness landscape of a tethered ribosome. SCIENCE ADVANCES 2023; 9:eade8934. [PMID: 37115918 PMCID: PMC10146877 DOI: 10.1126/sciadv.ade8934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Fitness landscapes are models of the sequence space of a genetic element that map how each sequence corresponds to its activity and can be used to guide laboratory evolution. The ribosome is a macromolecular machine that is essential for protein synthesis in all organisms. Because of the prevalence of dominant lethal mutations, a comprehensive fitness landscape of the ribosomal peptidyl transfer center (PTC) has not yet been attained. Here, we develop a method to functionally map an orthogonal tethered ribosome (oRiboT), which permits complete mutagenesis of nucleotides located in the PTC and the resulting epistatic interactions. We found that most nucleotides studied showed flexibility to mutation, and identified epistatic interactions between them, which compensate for deleterious mutations. This work provides a basis for a deeper understanding of ribosome function and malleability and could be used to inform design of engineered ribosomes with applications to synthesize next-generation biomaterials and therapeutics.
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Affiliation(s)
- Felix Radford
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA
- Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Jesse Rinehart
- Systems Biology Institute, Yale University, West Haven, CT 06516, USA
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Farren J. Isaacs
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA
- Systems Biology Institute, Yale University, West Haven, CT 06516, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
- Corresponding author.
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5
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Mudryi V, Peske F, Rodnina M. Translation Factor Accelerating Peptide Bond Formation on the Ribosome: EF-P and eIF5A as Entropic Catalysts and a Potential Drug Targets. BBA ADVANCES 2023; 3:100074. [PMID: 37082265 PMCID: PMC10074943 DOI: 10.1016/j.bbadva.2023.100074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 01/11/2023] Open
Abstract
Elongation factor P (EF-P) and its eukaryotic homolog eIF5A are auxiliary translation factors that facilitate peptide bond formation when several sequential proline (Pro) residues are incorporated into the nascent chain. EF-P and eIF5A bind to the exit (E) site of the ribosome and contribute to favorable entropy of the reaction by stabilizing tRNA binding in the peptidyl transferase center of the ribosome. In most organisms, EF-P and eIF5A carry a posttranslational modification that is crucial for catalysis. The chemical nature of the modification varies between different groups of bacteria and between pro- and eukaryotes, making the EF-P-modification enzymes promising targets for antibiotic development. In this review, we summarize our knowledge of the structure and function of EF-P and eIF5A, describe their modification enzymes, and present an approach for potential drug screening aimed at EarP, an enzyme that is essential for EF-P modification in several pathogenic bacteria.
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6
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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.
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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
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7
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Tirumalai MR, Rivas M, Tran Q, Fox GE. The Peptidyl Transferase Center: a Window to the Past. Microbiol Mol Biol Rev 2021; 85:e0010421. [PMID: 34756086 PMCID: PMC8579967 DOI: 10.1128/mmbr.00104-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In his 2001 article, "Translation: in retrospect and prospect," the late Carl Woese made a prescient observation that there was a need for the then-current view of translation to be "reformulated to become an all-embracing perspective about which 21st century Biology can develop" (RNA 7:1055-1067, 2001, https://doi.org/10.1017/s1355838201010615). The quest to decipher the origins of life and the road to the genetic code are both inextricably linked with the history of the ribosome. After over 60 years of research, significant progress in our understanding of how ribosomes work has been made. Particularly attractive is a model in which the ribosome may facilitate an ∼180° rotation of the CCA end of the tRNA from the A-site to the P-site while the acceptor stem of the tRNA would then undergo a translation from the A-site to the P-site. However, the central question of how the ribosome originated remains unresolved. Along the path from a primitive RNA world or an RNA-peptide world to a proto-ribosome world, the advent of the peptidyl transferase activity would have been a seminal event. This functionality is now housed within a local region of the large-subunit (LSU) rRNA, namely, the peptidyl transferase center (PTC). The PTC is responsible for peptide bond formation during protein synthesis and is usually considered to be the oldest part of the modern ribosome. What is frequently overlooked is that by examining the origins of the PTC itself, one is likely going back even further in time. In this regard, it has been proposed that the modern PTC originated from the association of two smaller RNAs that were once independent and now comprise a pseudosymmetric region in the modern PTC. Could such an association have survived? Recent studies have shown that the extant PTC is largely depleted of ribosomal protein interactions. It is other elements like metallic ion coordination and nonstandard base/base interactions that would have had to stabilize the association of RNAs. Here, we present a detailed review of the literature focused on the nature of the extant PTC and its proposed ancestor, the proto-ribosome.
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Affiliation(s)
- Madhan R. Tirumalai
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - Mario Rivas
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - Quyen Tran
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - George E. Fox
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
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8
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Fasnacht M, Gallo S, Sharma P, Himmelstoß M, Limbach PA, Willi J, Polacek N. Dynamic 23S rRNA modification ho5C2501 benefits Escherichia coli under oxidative stress. Nucleic Acids Res 2021; 50:473-489. [PMID: 34904663 PMCID: PMC8754641 DOI: 10.1093/nar/gkab1224] [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: 05/04/2021] [Revised: 11/23/2021] [Accepted: 12/02/2021] [Indexed: 11/30/2022] Open
Abstract
Post-transcriptional modifications are added to ribosomal RNAs (rRNAs) to govern ribosome biogenesis and to fine-tune protein biosynthesis. In Escherichia coli and related bacteria, RlhA uniquely catalyzes formation of a 5-hydroxycytidine (ho5C) at position 2501 of 23S rRNA. However, the molecular and biological functions as well as the regulation of ho5C2501 modification remain unclear. We measured growth curves with the modification-deficient ΔrlhA strain and quantified the extent of the modification during different conditions by mass spectrometry and reverse transcription. The levels of ho5C2501 in E. coli ribosomes turned out to be highly dynamic and growth phase-dependent, with the most effective hydroxylation yields observed in the stationary phase. We demonstrated a direct effect of ho5C2501 on translation efficiencies in vitro and in vivo. High ho5C2501 levels reduced protein biosynthesis which however turned out to be beneficial for E. coli for adapting to oxidative stress. This functional advantage was small under optimal conditions or during heat or cold shock, but becomes pronounced in the presence of hydrogen peroxide. Taken together, these data provided first functional insights into the role of this unique 23S rRNA modification for ribosome functions and bacterial growth under oxidative stress.
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Affiliation(s)
- Michel Fasnacht
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Stefano Gallo
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Puneet Sharma
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Maximilian Himmelstoß
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, 6020 Innsbruck, Austria
| | - Patrick A Limbach
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, OH, USA
| | - Jessica Willi
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, 3012 Bern, Switzerland.,Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, OH, USA
| | - Norbert Polacek
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland
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9
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Tarashima NS, Kumanomido Y, Nakashima K, Tanaka Y, Minakawa N. Synthesis of a Cyclic Dinucleotide Analogue with Ambiguous Bases, 5-Aminoimidazole-4-carboxamide. J Org Chem 2021; 86:15004-15010. [PMID: 34652132 DOI: 10.1021/acs.joc.1c01706] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyclic dinucleotides (CDNs) are second messengers composed of two purine nucleotides. In recent years, the structural diversity of CDNs and their functionality in biological processes are being intensely studied. Herein we report the chemical synthesis of cyclic di-5-aminoimidazole-4-carboxamide-1-β-d-ribofuranosyl monophosphate (c-di-ZMP) (1), which consists of two 5-amino-4-imidazolecarboxamide ribonucleotides (Z-ribonucleotides) linked via two phosphodiester linkages. Construction of the CDN skeleton with an N1-dinitrophenylhypoxanthine base (HxaDNP-base) by phosphoramidite chemistry and the subsequent ring-opening reaction of HxaDNP-base successfully yielded the desired 1.
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Affiliation(s)
- Noriko S Tarashima
- Graduate School of Pharmaceutical Science, Tokushima University, Shomachi 1-78-1, Tokushima 770-8505, Japan
| | - Yusuke Kumanomido
- Graduate School of Pharmaceutical Science, Tokushima University, Shomachi 1-78-1, Tokushima 770-8505, Japan
| | - Katsuyuki Nakashima
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, 770-8514 Tokushima, Japan
| | - Yoshiyuki Tanaka
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, 770-8514 Tokushima, Japan
| | - Noriaki Minakawa
- Graduate School of Pharmaceutical Science, Tokushima University, Shomachi 1-78-1, Tokushima 770-8505, Japan
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10
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Leškovskis K, Zaķis JM, Novosjolova I, Turks M. Applications of Purine Ring Opening in the Synthesis of Imidazole, Pyrimidine, and New Purine Derivatives. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Kristaps Leškovskis
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry Riga Technical University P. Valdena Str. 3 Riga LV-1048 Latvia
| | - Jānis Miķelis Zaķis
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry Riga Technical University P. Valdena Str. 3 Riga LV-1048 Latvia
| | - Irina Novosjolova
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry Riga Technical University P. Valdena Str. 3 Riga LV-1048 Latvia
| | - Māris Turks
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry Riga Technical University P. Valdena Str. 3 Riga LV-1048 Latvia
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11
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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.
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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
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12
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Tanaka M, Chock PB. Oxidative Modifications of RNA and Its Potential Roles in Biosystem. Front Mol Biosci 2021; 8:685331. [PMID: 34055897 PMCID: PMC8149912 DOI: 10.3389/fmolb.2021.685331] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 04/27/2021] [Indexed: 12/12/2022] Open
Abstract
Elevated level of oxidized RNA was detected in vulnerable neurons in Alzheimer patients. Subsequently, several diseases and pathological conditions were reported to be associated with RNA oxidation. In addition to several oxidized derivatives, cross-linking and unique strand breaks are generated by RNA oxidation. With a premise that dysfunctional RNA mediated by oxidation is the pathogenetic molecular mechanism, intensive investigations have revealed the mechanism for translation errors, including premature termination, which gives rise to aberrant polypeptides. To this end, we and others revealed that mRNA oxidation could compromise its translational activity and fidelity. Under certain conditions, oxidized RNA can also induce several signaling pathways, to mediate inflammatory response and induce apoptosis. In this review, we focus on the oxidative modification of RNA and its resulting effect on protein synthesis as well as cell signaling. In addition, we will also discuss the potential roles of enzymatic oxidative modification of RNA in mediating cellular effects.
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Affiliation(s)
- Mikiei Tanaka
- Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - P Boon Chock
- Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States
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13
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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.
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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
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14
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Willi J, Küpfer P, Evéquoz D, Fernandez G, Katz A, Leumann C, Polacek N. Oxidative stress damages rRNA inside the ribosome and differentially affects the catalytic center. Nucleic Acids Res 2019; 46:1945-1957. [PMID: 29309687 PMCID: PMC5829716 DOI: 10.1093/nar/gkx1308] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 12/20/2017] [Indexed: 01/19/2023] Open
Abstract
Intracellular levels of reactive oxygen species (ROS) increase as a consequence of oxidative stress and represent a major source of damage to biomolecules. Due to its high cellular abundance RNA is more frequently the target for oxidative damage than DNA. Nevertheless the functional consequences of damage on stable RNA are poorly understood. Using a genome-wide approach, based on 8-oxo-guanosine immunoprecipitation, we present evidence that the most abundant non-coding RNA in a cell, the ribosomal RNA (rRNA), is target for oxidative nucleobase damage by ROS. Subjecting ribosomes to oxidative stress, we demonstrate that oxidized 23S rRNA inhibits the ribosome during protein biosynthesis. Placing single oxidized nucleobases at specific position within the ribosome's catalytic center by atomic mutagenesis resulted in markedly different functional outcomes. While some active site nucleobases tolerated oxidative damage well, oxidation at others had detrimental effects on protein synthesis by inhibiting different sub-steps of the ribosomal elongation cycle. Our data provide molecular insight into the biological consequences of RNA oxidation in one of the most central cellular enzymes and reveal mechanistic insight on the role of individual active site nucleobases during translation.
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Affiliation(s)
- Jessica Willi
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Pascal Küpfer
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Damien Evéquoz
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Guillermo Fernandez
- Programa de Biología Celular y Molecular, ICBM, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Assaf Katz
- Programa de Biología Celular y Molecular, ICBM, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Christian Leumann
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Norbert Polacek
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
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15
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Abstract
This review summarizes our current understanding of translation in prokaryotes, focusing on the mechanistic and structural aspects of each phase of translation: initiation, elongation, termination, and ribosome recycling. The assembly of the initiation complex provides multiple checkpoints for messenger RNA (mRNA) and start-site selection. Correct codon-anticodon interaction during the decoding phase of elongation results in major conformational changes of the small ribosomal subunit and shapes the reaction pathway of guanosine triphosphate (GTP) hydrolysis. The ribosome orchestrates proton transfer during peptide bond formation, but requires the help of elongation factor P (EF-P) when two or more consecutive Pro residues are to be incorporated. Understanding the choreography of transfer RNA (tRNA) and mRNA movements during translocation helps to place the available structures of translocation intermediates onto the time axis of the reaction pathway. The nascent protein begins to fold cotranslationally, in the constrained space of the polypeptide exit tunnel of the ribosome. When a stop codon is reached at the end of the coding sequence, the ribosome, assisted by termination factors, hydrolyzes the ester bond of the peptidyl-tRNA, thereby releasing the nascent protein. Following termination, the ribosome is dissociated into subunits and recycled into another round of initiation. At each step of translation, the ribosome undergoes dynamic fluctuations between different conformation states. The aim of this article is to show the link between ribosome structure, dynamics, and function.
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Affiliation(s)
- Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen 37077, Germany
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16
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Koch M, Willi J, Pradère U, Hall J, Polacek N. Critical 23S rRNA interactions for macrolide-dependent ribosome stalling on the ErmCL nascent peptide chain. Nucleic Acids Res 2017; 45:6717-6728. [PMID: 28369621 PMCID: PMC5499644 DOI: 10.1093/nar/gkx195] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/14/2017] [Indexed: 12/25/2022] Open
Abstract
The nascent peptide exit tunnel has recently been identified as a functional region of ribosomes contributing to translation regulation and co-translational protein folding. Inducible expression of the erm resistance genes depends on ribosome stalling at specific codons of an upstream open reading frame in the presence of an exit tunnel-bound macrolide antibiotic. The molecular basis for this translation arrest is still not fully understood. Here, we used a nucleotide analog interference approach to unravel important functional groups on 23S rRNA residues in the ribosomal exit tunnel for ribosome stalling on the ErmC leader peptide. By replacing single nucleobase functional groups or even single atoms we were able to demonstrate the importance of A2062, A2503 and U2586 for drug-dependent ribosome stalling. Our data show that the universally conserved A2062 and A2503 are capable of forming a non-Watson–Crick base pair that is critical for sensing and transmitting the stalling signal from the exit tunnel back to the peptidyl transferase center of the ribosome. The nucleobases of A2062, A2503 as well as U2586 do not contribute significantly to the overall mechanism of protein biosynthesis, yet their elaborate role for co-translational monitoring of nascent peptide chains inside the exit tunnel can explain their evolutionary conservation.
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Affiliation(s)
- Miriam Koch
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Jessica Willi
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Ugo Pradère
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Jonathan Hall
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Norbert Polacek
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
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17
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Mechanistic Insights Into Catalytic RNA-Protein Complexes Involved in Translation of the Genetic Code. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017. [PMID: 28683922 DOI: 10.1016/bs.apcsb.2017.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
The contemporary world is an "RNA-protein world" rather than a "protein world" and tracing its evolutionary origins is of great interest and importance. The different RNAs that function in close collaboration with proteins are involved in several key physiological processes, including catalysis. Ribosome-the complex megadalton cellular machinery that translates genetic information encoded in nucleotide sequence to amino acid sequence-epitomizes such an association between RNA and protein. RNAs that can catalyze biochemical reactions are known as ribozymes. They usually employ general acid-base catalytic mechanism, often involving the 2'-OH of RNA that activates and/or stabilizes a nucleophile during the reaction pathway. The protein component of such RNA-protein complexes (RNPCs) mostly serves as a scaffold which provides an environment conducive for the RNA to function, or as a mediator for other interacting partners. In this review, we describe those RNPCs that are involved at different stages of protein biosynthesis and in which RNA performs the catalytic function; the focus of the account is on highlighting mechanistic aspects of these complexes. We also provide a perspective on such associations in the context of proofreading during translation of the genetic code. The latter aspect is not much appreciated and recent works suggest that this is an avenue worth exploring, since an understanding of the subject can provide useful insights into how RNAs collaborate with proteins to ensure fidelity during these essential cellular processes. It may also aid in comprehending evolutionary aspects of such associations.
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18
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Zhang X, Jiang Y, Mao Q, Tan H, Li X, Chen G, Jia Z. Distal Proton Shuttle Mechanism of Ribosome Catalysed Peptide Bond Formation-A Theoretical Study. Molecules 2017; 22:molecules22040571. [PMID: 28362358 PMCID: PMC6154465 DOI: 10.3390/molecules22040571] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/17/2017] [Accepted: 03/28/2017] [Indexed: 12/02/2022] Open
Abstract
In this work, we have investigated a novel distal proton shuttle mechanism of ribosome catalyzed peptide bond formation reaction. The reaction was found to follow a two-step mechanism. A distal water molecule located about 6.1 Å away from the attacking amine plays as a proton acceptor and results in a charge-separated intermediate that is stabilized by the N terminus of L27 and the A-site A76 5′-phosphate. The ribose A2451 bridges the proton shuttle pathway, thus plays critical role in the reaction. The calculated 27.64 kcal·mol−1 free energy barrier of the distal proton shuttle mechanism is lower than that of eight-membered ring transition state. The distal proton shuttle mechanism studied in this work can provide new insights into the important biological peptide synthesis process.
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Affiliation(s)
- Xiaotong Zhang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Yafei Jiang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Qiuyun Mao
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Hongwei Tan
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Xichen Li
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Guangju Chen
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Zongchao Jia
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7N 3L6, Canada .
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19
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Downey AM, Pohl R, Roithová J, Hocek M. Synthesis of Nucleosides through Direct Glycosylation of Nucleobases with 5-O-Monoprotected or 5-Modified Ribose: Improved Protocol, Scope, and Mechanism. Chemistry 2017; 23:3910-3917. [DOI: 10.1002/chem.201604955] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Indexed: 12/26/2022]
Affiliation(s)
- A. Michael Downey
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences; Flemingovo nám. 2 16610 Prague 6 Czech Republic
| | - Radek Pohl
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences; Flemingovo nám. 2 16610 Prague 6 Czech Republic
| | - Jana Roithová
- Department of Organic Chemistry; Faculty of Science; Charles University in Prague; Hlavova 8 12843 Prague 2 Czech Republic
| | - Michal Hocek
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences; Flemingovo nám. 2 16610 Prague 6 Czech Republic
- Department of Organic Chemistry; Faculty of Science; Charles University in Prague; Hlavova 8 12843 Prague 2 Czech Republic
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20
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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.
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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
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21
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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.
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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
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22
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Wang J, Dong H, Chionh YH, McBee ME, Sirirungruang S, Cunningham RP, Shi PY, Dedon PC. The role of sequence context, nucleotide pool balance and stress in 2'-deoxynucleotide misincorporation in viral, bacterial and mammalian RNA. Nucleic Acids Res 2016; 44:8962-8975. [PMID: 27365049 PMCID: PMC5062971 DOI: 10.1093/nar/gkw572] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 06/06/2016] [Indexed: 11/16/2022] Open
Abstract
The misincorporation of 2′-deoxyribonucleotides (dNs) into RNA has important implications for the function of non-coding RNAs, the translational fidelity of coding RNAs and the mutagenic evolution of viral RNA genomes. However, quantitative appreciation for the degree to which dN misincorporation occurs is limited by the lack of analytical tools. Here, we report a method to hydrolyze RNA to release 2′-deoxyribonucleotide-ribonucleotide pairs (dNrN) that are then quantified by chromatography-coupled mass spectrometry (LC-MS). Using this platform, we found misincorporated dNs occurring at 1 per 103 to 105 ribonucleotide (nt) in mRNA, rRNAs and tRNA in human cells, Escherichia coli, Saccharomyces cerevisiae and, most abundantly, in the RNA genome of dengue virus. The frequency of dNs varied widely among organisms and sequence contexts, and partly reflected the in vitro discrimination efficiencies of different RNA polymerases against 2′-deoxyribonucleoside 5′-triphosphates (dNTPs). Further, we demonstrate a strong link between dN frequencies in RNA and the balance of dNTPs and ribonucleoside 5′-triphosphates (rNTPs) in the cellular pool, with significant stress-induced variation of dN incorporation. Potential implications of dNs in RNA are discussed, including the possibilities of dN incorporation in RNA as a contributing factor in viral evolution and human disease, and as a host immune defense mechanism against viral infections.
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Affiliation(s)
- Jin Wang
- Infectious Disease Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore 138602
| | - Hongping Dong
- Novartis Institute for Tropical Diseases, Singapore 138670
| | - Yok Hian Chionh
- Infectious Disease Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore 138602 Department of Microbiology & Immunology Programme, Center for Life Sciences, National University of Singapore, Singapore 117545
| | - Megan E McBee
- Infectious Disease Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore 138602
| | - Sasilada Sirirungruang
- Infectious Disease Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore 138602
| | - Richard P Cunningham
- Department of Biological Sciences, The University at Albany, Albany, NY 12222, USA
| | - Pei-Yong Shi
- Departments of Biochemistry & Molecular Biology and Phamarcology & Toxicology, and Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Peter C Dedon
- Infectious Disease Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore 138602 Department of Biological Engineering & Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, USA
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23
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Koch M, Clementi N, Rusca N, Vögele P, Erlacher M, Polacek N. The integrity of the G2421-C2395 base pair in the ribosomal E-site is crucial for protein synthesis. RNA Biol 2015; 12:70-81. [PMID: 25826414 PMCID: PMC4615901 DOI: 10.1080/15476286.2015.1017218] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
During the elongation cycle of protein biosynthesis, tRNAs traverse through the ribosome by consecutive binding to the 3 ribosomal binding sites (A-, P-, and E- sites). While the ribosomal A- and P-sites have been functionally well characterized in the past, the contribution of the E-site to protein biosynthesis is still poorly understood in molecular terms. Previous studies suggested an important functional interaction of the terminal residue A76 of E-tRNA with the nucleobase of the universally conserved 23S rRNA residue C2394. Using an atomic mutagenesis approach to introduce non-natural nucleoside analogs into the 23S rRNA, we could show that removal of the nucleobase or the ribose 2'-OH at C2394 had no effect on protein synthesis. On the other hand, our data disclose the importance of the highly conserved E-site base pair G2421-C2395 for effective translation. Ribosomes with a disrupted G2421-C2395 base pair are defective in tRNA binding to the E-site. This results in an impaired translation of genuine mRNAs, while homo-polymeric templates are not affected. Cumulatively our data emphasize the importance of E-site tRNA occupancy and in particular the intactness of the 23S rRNA base pair G2421-C2395 for productive protein biosynthesis.
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Affiliation(s)
- Miriam Koch
- a Department of Chemistry and Biochemistry; University of Bern ; Bern , Switzerland
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24
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Fried SD, Schmied WH, Uttamapinant C, Chin JW. Ribosome Subunit Stapling for Orthogonal Translation in E. coli. Angew Chem Int Ed Engl 2015; 54:12791-4. [PMID: 26465656 PMCID: PMC4678508 DOI: 10.1002/anie.201506311] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 07/27/2015] [Indexed: 11/13/2022]
Abstract
The creation of orthogonal large and small ribosomal subunits, which interact with each other but not with endogenous ribosomal subunits, would extend our capacity to create new functions in the ribosome by making the large subunit evolvable. To this end, we rationally designed a ribosomal RNA that covalently links the ribosome subunits via an RNA staple. The stapled ribosome is directed to an orthogonal mRNA, allowing the introduction of mutations into the large subunit that reduce orthogonal translation, but have minimal effects on cell growth. Our approach provides a promising route towards orthogonal subunit association, which may enable the evolution of key functional centers in the large subunit, including the peptidyl-transferase center, for unnatural polymer synthesis in cells.
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Affiliation(s)
- Stephen D Fried
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH (UK)
| | - Wolfgang H Schmied
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH (UK)
| | - Chayasith Uttamapinant
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH (UK)
| | - Jason W Chin
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH (UK).
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25
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Fried SD, Schmied WH, Uttamapinant C, Chin JW. Ribosome Subunit Stapling for Orthogonal Translation in E. coli. ACTA ACUST UNITED AC 2015; 127:12982-12985. [PMID: 27570300 PMCID: PMC4985662 DOI: 10.1002/ange.201506311] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 07/27/2015] [Indexed: 11/06/2022]
Abstract
The creation of orthogonal large and small ribosomal subunits, which interact with each other but not with endogenous ribosomal subunits, would extend our capacity to create new functions in the ribosome by making the large subunit evolvable. To this end, we rationally designed a ribosomal RNA that covalently links the ribosome subunits via an RNA staple. The stapled ribosome is directed to an orthogonal mRNA, allowing the introduction of mutations into the large subunit that reduce orthogonal translation, but have minimal effects on cell growth. Our approach provides a promising route towards orthogonal subunit association, which may enable the evolution of key functional centers in the large subunit, including the peptidyl‐transferase center, for unnatural polymer synthesis in cells.
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Affiliation(s)
- Stephen D Fried
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH (UK)
| | - Wolfgang H Schmied
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH (UK)
| | - Chayasith Uttamapinant
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH (UK)
| | - Jason W Chin
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH (UK)
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26
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Role of a ribosomal RNA phosphate oxygen during the EF-G-triggered GTP hydrolysis. Proc Natl Acad Sci U S A 2015; 112:E2561-8. [PMID: 25941362 DOI: 10.1073/pnas.1505231112] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Elongation factor-catalyzed GTP hydrolysis is a key reaction during the ribosomal elongation cycle. Recent crystal structures of G proteins, such as elongation factor G (EF-G) bound to the ribosome, as well as many biochemical studies, provide evidence that the direct interaction of translational GTPases (trGTPases) with the sarcin-ricin loop (SRL) of ribosomal RNA (rRNA) is pivotal for hydrolysis. However, the precise mechanism remains elusive and is intensively debated. Based on the close proximity of the phosphate oxygen of A2662 of the SRL to the supposedly catalytic histidine of EF-G (His87), we probed this interaction by an atomic mutagenesis approach. We individually replaced either of the two nonbridging phosphate oxygens at A2662 with a methyl group by the introduction of a methylphosphonate instead of the natural phosphate in fully functional, reconstituted bacterial ribosomes. Our major finding was that only one of the two resulting diastereomers, the SP methylphosphonate, was compatible with efficient GTPase activation on EF-G. The same trend was observed for a second trGTPase, namely EF4 (LepA). In addition, we provide evidence that the negative charge of the A2662 phosphate group must be retained for uncompromised activity in GTP hydrolysis. In summary, our data strongly corroborate that the nonbridging proSP phosphate oxygen at the A2662 of the SRL is critically involved in the activation of GTP hydrolysis. A mechanistic scenario is supported in which positioning of the catalytically active, protonated His87 through electrostatic interactions with the A2662 phosphate group and H-bond networks are key features of ribosome-triggered activation of trGTPases.
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27
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A theoretical model investigation of peptide bond formation involving two water molecules in ribosome supports the two-step and eight membered ring mechanism. Chem Phys 2015. [DOI: 10.1016/j.chemphys.2015.01.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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28
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Bernhardt HS. The Juxtaposition of Ribose Hydroxyl Groups: The Root of Biological Catalysis and the RNA World? ORIGINS LIFE EVOL B 2015; 45:15-9. [DOI: 10.1007/s11084-015-9403-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Accepted: 10/10/2014] [Indexed: 10/24/2022]
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29
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A proton wire to couple aminoacyl-tRNA accommodation and peptide-bond formation on the ribosome. Nat Struct Mol Biol 2014; 21:787-93. [PMID: 25132179 PMCID: PMC4156881 DOI: 10.1038/nsmb.2871] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 07/14/2014] [Indexed: 11/12/2022]
Abstract
During peptide bond formation on the ribosome the α-amine of an aminoacyl-tRNA attacks the ester carbonyl carbon of a peptidyl-tRNA to yield a peptide lengthened by one amino acid. Although the ribosome's contribution to catalysis is predominantly entropic, the lack of high-resolution structural data for the complete active site in complex with full-length ligands has made it difficult to assess how the ribosome might influence the pathway of the reaction. Here, we present crystal structures of pre-attack and post-catalysis complexes of the Thermus thermophilus 70S ribosome at ∼2.6 Å resolution. These structures reveal a network of hydrogen bonds along which proton transfer could take place to ensure the concerted, rate-limiting formation of a tetrahedral intermediate. Unlike earlier models, we propose that the ribosome and the A-site tRNA facilitate the deprotonation of the nucleophile through the activation of a water molecule.
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30
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Mondal S, Pathak BK, Ray S, Barat C. Impact of P-Site tRNA and antibiotics on ribosome mediated protein folding: studies using the Escherichia coli ribosome. PLoS One 2014; 9:e101293. [PMID: 25000563 PMCID: PMC4085065 DOI: 10.1371/journal.pone.0101293] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 06/04/2014] [Indexed: 12/22/2022] Open
Abstract
Background The ribosome, which acts as a platform for mRNA encoded polypeptide synthesis, is also capable of assisting in folding of polypeptide chains. The peptidyl transferase center (PTC) that catalyzes peptide bond formation resides in the domain V of the 23S rRNA of the bacterial ribosome. Proper positioning of the 3′ –CCA ends of the A- and P-site tRNAs via specific interactions with the nucleotides of the PTC are crucial for peptidyl transferase activity. This RNA domain is also the center for ribosomal chaperoning activity. The unfolded polypeptide chains interact with the specific nucleotides of the PTC and are released in a folding competent form. In vitro transcribed RNA corresponding to this domain (bDV RNA) also displays chaperoning activity. Results The present study explores the effects of tRNAs, antibiotics that are A- and P-site PTC substrate analogs (puromycin and blasticidin) and macrolide antibiotics (erythromycin and josamycin) on the chaperoning ability of the E. coli ribosome and bDV RNA. Our studies using mRNA programmed ribosomes show that a tRNA positioned at the P-site effectively inhibits the ribosome's chaperoning function. We also show that the antibiotic blasticidin (that mimics the interaction between 3′–CCA end of P/P-site tRNA with the PTC) is more effective in inhibiting ribosome and bDV RNA chaperoning ability than either puromycin or the macrolide antibiotics. Mutational studies of the bDV RNA could identify the nucleotides U2585 and G2252 (both of which interact with P-site tRNA) to be important for its chaperoning ability. Conclusion Both protein synthesis and their proper folding are crucial for maintenance of a functional cellular proteome. The PTC of the ribosome is attributed with both these abilities. The silencing of the chaperoning ability of the ribosome in the presence of P-site bound tRNA might be a way to segregate these two important functions.
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Affiliation(s)
- Surojit Mondal
- Department of Biotechnology, St. Xavier's College, Kolkata, West Bengal, India
| | - Bani Kumar Pathak
- Department of Biotechnology, St. Xavier's College, Kolkata, West Bengal, India
| | - Sutapa Ray
- Dr. B.C Guha Centre for Genetic Engineering and Department of Biotechnology, Calcutta University, Kolkata, West Bengal, India
| | - Chandana Barat
- Department of Biotechnology, St. Xavier's College, Kolkata, West Bengal, India
- * E-mail:
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Blaisdell TP, Lee S, Kasaplar P, Sun X, Tan KL. Practical silyl protection of ribonucleosides. Org Lett 2013; 15:4710-3. [PMID: 24000770 DOI: 10.1021/ol402023c] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Herein we report the site-selective silylation of the ribonucelosides. The method enables a simple and efficient procedure for accessing suitably protected monomers for automated RNA synthesis. Switching to the opposite enantiomer of the catalyst allows for the selective silylation of the 3'-hydroxyl, which could be used in the synthesis of unnatural RNA or for the analoging of ribonucelosides. Lastly, the procedure was extended to ribavirin a potent antiviral therapeutic.
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Affiliation(s)
- Thomas P Blaisdell
- Institute of Chemical Research of Catalonia , Av. Paisos Catalans 16, 43007 Tarragona, Spain, and Boston College , 2609 Beacon Street, Chestnut Hill, Massachusetts 02467-3860, United States
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32
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Acosta-Silva C, Bertran J, Branchadell V, Oliva A. Quantum-Mechanical Study on the Mechanism of Peptide Bond Formation in the Ribosome. J Am Chem Soc 2012; 134:5817-31. [DOI: 10.1021/ja209558d] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Carles Acosta-Silva
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Joan Bertran
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Vicenç Branchadell
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Antoni Oliva
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
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33
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Erlacher MD, Polacek N. Probing functions of the ribosomal peptidyl transferase center by nucleotide analog interference. Methods Mol Biol 2012; 848:215-26. [PMID: 22315072 DOI: 10.1007/978-1-61779-545-9_14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The ribosome is a huge ribonucleoprotein complex in charge of protein synthesis in every living cell. The catalytic center of this dynamic molecular machine is entirely built up of 23S ribosomal RNA and therefore the ribosome can be referred to as the largest natural ribozyme known so far. The in vitro reconstitution approach of large ribosomal subunits described herein allows nucleotide analog interference studies to be performed. The approach is based on the site-specific introduction of nonnatural nucleotide analogs into the peptidyl transferase center, the active site located on the interface side of the large ribosomal subunit. This method combined with standard tests of ribosomal functions broadens the biochemical repertoire to investigate the mechanism of diverse aspects of translation considerably and adds another layer of molecular information on top of structural and mutational studies of the ribosome.
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Affiliation(s)
- Matthias D Erlacher
- Division of Genomics and RNomics, Innsbruck Biocenter, Medical University of Innsbruck, Innsbruck, Austria
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34
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Carrasco N, Hiller DA, Strobel SA. Minimal Transition State Charge Stabilization of the Oxyanion during Peptide Bond Formation by the Ribosome. Biochemistry 2011; 50:10491-8. [DOI: 10.1021/bi201290s] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Nicolas Carrasco
- Departments of Molecular Biophysics & Biochemistry and Chemistry, Yale University, 260 Whitney Ave., New Haven, Connecticut 06520-81114, United States
| | - David A. Hiller
- Departments of Molecular Biophysics & Biochemistry and Chemistry, Yale University, 260 Whitney Ave., New Haven, Connecticut 06520-81114, United States
| | - Scott A. Strobel
- Departments of Molecular Biophysics & Biochemistry and Chemistry, Yale University, 260 Whitney Ave., New Haven, Connecticut 06520-81114, United States
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35
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Rangelov MA, Petrova GP, Yomtova VM, Vayssilov GN. Determination of the optimal position of adjacent proton-donor centers for the activation or inhibition of peptide bond formation – A computational model study. J Mol Graph Model 2011; 30:10-4. [DOI: 10.1016/j.jmgm.2011.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2011] [Revised: 05/24/2011] [Accepted: 05/24/2011] [Indexed: 10/18/2022]
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36
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Affiliation(s)
- Norbert Polacek
- Innsbruck Biocenter, Medical University, Division of Genomics and RNomics, Fritz-Pregl-Strasse 3, 6020 Innsbruck, Austria.
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37
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Leung EKY, Suslov N, Tuttle N, Sengupta R, Piccirilli JA. The Mechanism of Peptidyl Transfer Catalysis by the Ribosome. Annu Rev Biochem 2011; 80:527-55. [DOI: 10.1146/annurev-biochem-082108-165150] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Nikolai Suslov
- Department of Biochemistry and Molecular Biology, Chicago, Illinois 60637
| | - Nicole Tuttle
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637;
| | - Raghuvir Sengupta
- Department of Biochemistry, Stanford University, Stanford, California 94305
| | - Joseph Anthony Piccirilli
- Department of Biochemistry and Molecular Biology, Chicago, Illinois 60637
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637;
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38
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Rakauskaite R, Dinman JD. Mutations of highly conserved bases in the peptidyltransferase center induce compensatory rearrangements in yeast ribosomes. RNA (NEW YORK, N.Y.) 2011; 17:855-864. [PMID: 21441349 PMCID: PMC3078735 DOI: 10.1261/rna.2593211] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 02/18/2011] [Indexed: 05/30/2023]
Abstract
Molecular dynamics simulation identified three highly conserved rRNA bases in the large subunit of the ribosome that form a three-dimensional (3D) "gate" that induces pausing of the aa-tRNA acceptor stem during accommodation into the A-site. A nearby fourth base contacting the "tryptophan finger" of yeast protein L3, which is involved in the coordinating elongation factor recruitment to the ribosome with peptidyltransfer, is also implicated in this process. To better understand the functional importance of these bases, single base substitutions as well as deletions at all four positions were constructed and expressed as the sole forms of ribosomes in yeast Saccharomyces cerevisiae. None of the mutants had strong effects on cell growth, translational fidelity, or on the interactions between ribosomes and tRNAs. However, the mutants did promote strong effects on cell growth in the presence of translational inhibitors, and differences in viability between yeast and Escherichia coli mutants at homologous positions suggest new targets for antibacterial therapeutics. Mutant ribosomes also promoted changes in 25S rRNA structure, all localized to the core of peptidyltransferase center (i.e., the proto-ribosome area). We suggest that a certain degree of structural plasticity is built into the ribosome, enabling it to ensure accurate translation of the genetic code while providing it with the flexibility to adapt and evolve.
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Affiliation(s)
- Rasa Rakauskaite
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742, USA
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39
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Generation of chemically engineered ribosomes for atomic mutagenesis studies on protein biosynthesis. Nat Protoc 2011; 6:580-92. [PMID: 21527916 DOI: 10.1038/nprot.2011.306] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The protocol describes the site-specific chemical modification of 23S rRNA of Thermus aquaticus ribosomes. The centerpiece of this 'atomic mutagenesis' approach is the site-specific incorporation of non-natural nucleoside analogs into 23S rRNA in the context of the entire 70S ribosome. This technique exhaustively makes use of the available crystallographic structures of the ribosome for designing detailed biochemical experiments aiming at unraveling molecular insights of ribosomal functions. The generation of chemically engineered ribosomes carrying a particular non-natural 23S rRNA residue at the site of interest, a procedure that typically takes less than 2 d, allows the study of translation at the molecular level and goes far beyond the limits of standard mutagenesis approaches. This methodology, in combination with the presented tests for ribosomal functions adapted to chemically engineered ribosomes, allows unprecedented molecular insight into the mechanisms of protein biosynthesis.
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40
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Abstract
Metal ions are the salt in the soup of essentially every biological system. Also in the ribosome, the largest natural ribozyme that produces all proteins in every living cell, metal ions have been found contributing significantly to the highly dynamic and accurate process of translation. The ribosome is considered a molecular fossil of the 'RNA world' and it could be shown that the evolutionarily oldest parts of the particle, which build the catalytic center and surrounding domains, are densely packed with divalent metal ions. Nevertheless, metal ions do not seem to directly participate in ribosomal catalysis, their important roles in the ribosome, however, cannot be denied. It is probable that mono- and divalent metal ions primarily promote the functionally competent architecture of the ribosomal RNAs, but more direct roles in mRNA decoding and reading frame maintenance are likely. Decades of biochemical studies and the recent high resolution crystallographic structures of the ribosome strongly indicate that metal ions are involved in essentially every phase of the ribosomal elongation cycle, thus contributing significantly to the precise translation of the genetic code.
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Affiliation(s)
- Krista Trappl
- Innsbruck Biocenter, Division of Genomics and RNomics, Medical University Innsbruck, Fritz-Pregl-Strasse 3, 6020 Innsbruck, Austria.
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41
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Krishnakumar KS, Michel BY, Nguyen-Trung NQ, Fenet B, Strazewski P. Intrinsic pKa values of 3′-N-α-l-aminoacyl-3′-aminodeoxyadenosines determined by pH dependent 1H NMR in H2O. Chem Commun (Camb) 2011; 47:3290-2. [DOI: 10.1039/c0cc05136e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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42
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Rangelov MA, Petrova GP, Yomtova VM, Vayssilov GN. Catalytic Role of Vicinal OH in Ester Aminolysis: Proton Shuttle versus Hydrogen Bond Stabilization. J Org Chem 2010; 75:6782-92. [DOI: 10.1021/jo100886p] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Miroslav A. Rangelov
- Laboratory of BioCatalysis, Institute of Organic Chemistry, Bulgarian Academy of Sciences, Str. Acad. G. Bontchev, Bl. 9, 1113 Sofia, Bulgaria
| | - Galina P. Petrova
- Faculty of Chemistry, University of Sofia, Boulevard James Bouchier 1, 1164 Sofia, Bulgaria
| | - Vihra M. Yomtova
- Laboratory of BioCatalysis, Institute of Organic Chemistry, Bulgarian Academy of Sciences, Str. Acad. G. Bontchev, Bl. 9, 1113 Sofia, Bulgaria
| | - Georgi N. Vayssilov
- Faculty of Chemistry, University of Sofia, Boulevard James Bouchier 1, 1164 Sofia, Bulgaria
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43
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Hiller DA, Zhong M, Singh V, Strobel SA. Transition states of uncatalyzed hydrolysis and aminolysis reactions of a ribosomal P-site substrate determined by kinetic isotope effects. Biochemistry 2010; 49:3868-78. [PMID: 20359191 PMCID: PMC2864349 DOI: 10.1021/bi901458x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The ester bond of peptidyl-tRNA undergoes nucleophilic attack in solution and when catalyzed by the ribosome. To characterize the uncatalyzed hydrolysis reaction, a model of peptide release, the transition state structure for hydrolysis of a peptidyl-tRNA mimic was determined. Kinetic isotope effects were measured at several atoms that potentially undergo a change in bonding in the transition state. Large kinetic isotope effects of carbonyl (18)O and alpha-deuterium substitutions on uncatalyzed hydrolysis indicate the transition state is nearly tetrahedral. Kinetic isotope effects were also measured for aminolysis by hydroxylamine to study a reaction similar to the formation of a peptide bond. In contrast to hydrolysis, the large leaving group (18)O isotope effect indicates the C-O3' bond has undergone significant scission in the transition state. The smaller carbonyl (18)O and alpha-deuterium effects are consistent with a later transition state. The assay developed here can also be used to measure isotope effects for the ribosome-catalyzed reactions. These uncatalyzed reactions serve as a basis for determining what aspects of the transition states are stabilized by the ribosome to achieve a rate enhancement.
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Affiliation(s)
- David A Hiller
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven CT 06511 USA
| | | | - Vipender Singh
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven CT 06511 USA
| | - Scott A Strobel
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven CT 06511 USA
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44
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Chirkova A, Erlacher MD, Clementi N, Zywicki M, Aigner M, Polacek N. The role of the universally conserved A2450-C2063 base pair in the ribosomal peptidyl transferase center. Nucleic Acids Res 2010; 38:4844-55. [PMID: 20375101 PMCID: PMC2919715 DOI: 10.1093/nar/gkq213] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Despite the fact that all 23S rRNA nucleotides that build the ribosomal peptidyl transferase ribozyme are universally conserved, standard and atomic mutagenesis studies revealed the nucleobase identities being non-critical for catalysis. This indicates that these active site residues are highly conserved for functions distinct from catalysis. To gain insight into potential contributions, we have manipulated the nucleobases via an atomic mutagenesis approach and have utilized these chemically engineered ribosomes for in vitro translation reactions. We show that most of the active site nucleobases could be removed without significant effects on polypeptide production. Our data however highlight the functional importance of the universally conserved non-Watson-Crick base pair at position A2450-C2063. Modifications that disrupt this base pair markedly impair translation activities, while having little effects on peptide bond formation, tRNA drop-off and ribosome-dependent EF-G GTPase activity. Thus it seems that disruption of the A2450-C2063 pair inhibits a reaction following transpeptidation and EF-G action during the elongation cycle. Cumulatively our data are compatible with the hypothesis that the integrity of this A-C wobble base pair is essential for effective tRNA translocation through the peptidyl transferase center during protein synthesis.
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Affiliation(s)
- Anna Chirkova
- Innsbruck Biocenter, Medical University Innsbruck, Division of Genomics and RNomics, Innsbruck, Austria
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45
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Clementi N, Chirkova A, Puffer B, Micura R, Polacek N. Atomic mutagenesis reveals A2660 of 23S ribosomal RNA as key to EF-G GTPase activation. Nat Chem Biol 2010; 6:344-51. [PMID: 20348921 DOI: 10.1038/nchembio.341] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Accepted: 01/21/2010] [Indexed: 11/09/2022]
Abstract
Following ribosomal peptide bond formation, the reaction products, peptidyl-tRNA and deacylated tRNA, need to be translocated from the A- and P-sites to the P- and E-sites, respectively. This process is facilitated by the GTPase elongation factor G (EF-G). The mechanism describing how the ribosome activates GTP hydrolysis is poorly understood in molecular terms. By using an 'atomic mutagenesis' approach, which allows the manipulation of specific functional groups on 23S rRNA nucleotides in the context of the entire ribosome, we disclose the adenine exocyclic N6 amino group at A2660 of the sarcin-ricin loop as a key determinant for triggering GTP hydrolysis on EF-G. We show that the purine pi system-expanding characteristics of the exocyclic functional group at the C6 position of A2660 are essential. We propose that stacking interactions of A2660 with EF-G may act as a molecular trigger to induce repositioning of suspected functional amino acids in EF-G that in turn promote GTP hydrolysis.
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Affiliation(s)
- Nina Clementi
- Innsbruck Biocenter, Medical University Innsbruck, Division of Genomics and RNomics, Innsbruck, Austria
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46
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The transition state for peptide bond formation reveals the ribosome as a water trap. Proc Natl Acad Sci U S A 2010; 107:1888-93. [PMID: 20080677 DOI: 10.1073/pnas.0914192107] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recent progress in elucidating the peptide bond formation process on the ribosome has led to notion of a proton shuttle mechanism where the 2'-hydroxyl group of the P-site tRNA plays a key role in mediating proton transfer between the nucleophile and leaving group, whereas ribosomal groups do not actively participate in the reaction. Despite these advances, the detailed nature of the transition state for peptidyl transfer and the role of several trapped water molecules in the peptidyl transferase center remain major open questions. Here, we employ high-level quantum chemical ab initio calculations to locate and characterize global transition states for the reaction, described by a molecular model encompassing all the key elements of the reaction center. The calculated activation enthalpy as well as structures are in excellent agreement with experimental data and point to feasibility of an eight-membered "double proton shuttle" mechanism in which an auxiliary water molecule, observed both in computer simulations and crystal structures, actively participates. A second conserved water molecule is found to be of key importance for stabilizing developing negative charge on the substrate oxyanion and its presence is catalytically favorable both in terms of activation enthalpy and entropy. Transition states calculated both for six- and eight-membered mechanisms are invariably late and do not involve significant charge development on the attacking amino group. Predicted kinetic isotope effects consistent with this picture are similar to those observed for uncatalyzed ester aminolysis reactions in solution.
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47
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Bracci A, Colombo G, Ronchetti F, Compostella F. 2′-O-Alkyl Derivatives and 5′-Analogues of 5-Aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) as Potential Hsp90 Inhibitors. European J Org Chem 2009. [DOI: 10.1002/ejoc.200900797] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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48
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Simonović M, Steitz TA. A structural view on the mechanism of the ribosome-catalyzed peptide bond formation. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2009; 1789:612-23. [PMID: 19595805 DOI: 10.1016/j.bbagrm.2009.06.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 06/23/2009] [Accepted: 06/25/2009] [Indexed: 10/20/2022]
Abstract
The ribosome is a large ribonucleoprotein particle that translates genetic information encoded in mRNA into specific proteins. Its highly conserved active site, the peptidyl-transferase center (PTC), is located on the large (50S) ribosomal subunit and is comprised solely of rRNA, which makes the ribosome the only natural ribozyme with polymerase activity. The last decade witnessed a rapid accumulation of atomic-resolution structural data on both ribosomal subunits as well as on the entire ribosome. This has allowed studies on the mechanism of peptide bond formation at a level of detail that surpasses that for the classical protein enzymes. A current understanding of the mechanism of the ribosome-catalyzed peptide bond formation is the focus of this review. Implications on the mechanism of peptide release are discussed as well.
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Affiliation(s)
- Miljan Simonović
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, MBRB 1170, 900 S Ashland Ave., Chicago, IL 60607, USA
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49
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Minakawa N, Kawano Y, Murata S, Inoue N, Matsuda A. Oligodeoxynucleotides containing 3-bromo-3-deazaadenine and 7-bromo-7-deazaadenine 2'-deoxynucleosides as chemical probes to investigate DNA-protein interactions. Chembiochem 2008; 9:464-70. [PMID: 18219644 DOI: 10.1002/cbic.200700580] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We describe the design and proof of concept of a pair of chemical probes for investigating DNA-protein interactions-specifically, the incorporation of 7-bromo-7-deazaadenine and 3-bromo-3-deazaadenine 2'-deoxynucleosides (Br(7)C(7)dA and Br(3)C(3)dA) into oligodeoxynucleotides (ODNs)-and their utility. Whereas the bromo substituent of the Br(7)C(7)dA unit in an ODN duplex acts sterically to inhibit binding with NF-kappaB, which interacts with the duplex in its major groove, the bromo substituent of the Br(3)C(3)dA unit acts sterically to inhibit binding with RNase H, which interacts with the duplex in its minor groove. In addition, the utilization of ODNs containing 7-deazaadenine and 3-deazaadenine 2'-deoxynucleosides (C(7)dA and C(3)dA), together with the pair of chemical probes, afforded valuable information on the requirement for nitrogen atoms located in either the major or minor grooves. Accordingly, we were able to show the utility of ODNs containing Br(7)C(7)dA, Br(3)C(3)dA, C(7)dA, and C(3)dA for the investigation of DNA-protein interactions.
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Affiliation(s)
- Noriaki Minakawa
- Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan
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50
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Huang KS, Carrasco N, Pfund E, Strobel SA. Transition state chirality and role of the vicinal hydroxyl in the ribosomal peptidyl transferase reaction. Biochemistry 2008; 47:8822-7. [PMID: 18672893 DOI: 10.1021/bi800299u] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ribosomal peptidyl transferase is a biologically essential catalyst responsible for protein synthesis. The reaction is expected to proceed through a transition state approaching tetrahedral geometry with a specific chirality. To establish that stereospecificity, we synthesized two diastereomers of a transition state inhibitor with mimics for each of the four ligands around the reactive chiral center. Preferential binding of the inhibitor that mimics a transition state with S chirality establishes the spatial position of the nascent peptide and the oxyanion and places the amine near the critical A76 2'-OH group on the P-site tRNA. Another inhibitor series with 2'-NH 2 and 2'-SH substitutions at the critical 2'-OH group was used to test the neutrality of the 2'-OH group as predicted if the hydroxyl functions as a proton shuttle in the transition state. The lack of significant pH-dependent binding by these inhibitors argues that the 2'-OH group remains neutral in the transition state. Both of these observations are consistent with a proton shuttle mechanism for the peptidyl transferase reaction.
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Affiliation(s)
- Kevin S Huang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, USA
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