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Dulin D. An Introduction to Magnetic Tweezers. Methods Mol Biol 2024; 2694:375-401. [PMID: 37824014 DOI: 10.1007/978-1-0716-3377-9_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Magnetic tweezers are a single-molecule force and torque spectroscopy technique that enable the mechanical interrogation in vitro of biomolecules, such as nucleic acids and proteins. They use a magnetic field originating from either permanent magnets or electromagnets to attract a magnetic particle, thus stretching the tethering biomolecule. They nicely complement other force spectroscopy techniques such as optical tweezers and atomic force microscopy (AFM) as they operate as a very stable force clamp, enabling long-duration experiments over a very broad range of forces spanning from 10 fN to 1 nN, with 1-10 milliseconds time and sub-nanometer spatial resolution. Their simplicity, robustness, and versatility have made magnetic tweezers a key technique within the field of single-molecule biophysics, being broadly applied to study the mechanical properties of, e.g., nucleic acids, genome processing molecular motors, protein folding, and nucleoprotein filaments. Furthermore, magnetic tweezers allow for high-throughput single-molecule measurements by tracking hundreds of biomolecules simultaneously both in real-time and at high spatiotemporal resolution. Magnetic tweezers naturally combine with surface-based fluorescence spectroscopy techniques, such as total internal reflection fluorescence microscopy, enabling correlative fluorescence and force/torque spectroscopy on biomolecules. This chapter presents an introduction to magnetic tweezers including a description of the hardware, the theory behind force calibration, its spatiotemporal resolution, combining it with other techniques, and a (non-exhaustive) overview of biological applications.
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Affiliation(s)
- David Dulin
- LaserLaB Amsterdam and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.
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2
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Yang C, Song X, Feng Y, Zhao G, Liu Y. Stability of DNA and RNA hairpins: a comparative study based on ox-DNA. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 35:265101. [PMID: 36972608 DOI: 10.1088/1361-648x/acc7eb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 03/27/2023] [Indexed: 06/18/2023]
Abstract
Advances in single-molecule experiments on macromolecular crowding urgently need an efficient simulation method to resolve their discrepancies quantitatively. Ox-DNA model has been since reworked to treat the thermodynamics and mechanical properties of DNA/RNA hairpin at a stretching force. In hopping experiments, the critical forces of RNA hairpins at different temperatures are greater than those of DNA hairpins, in addition, the Gibbs free energy at a fixed temperature required to convert an RNA hairpin into a single-stranded molecule at zero force is obviously greater than that of DNA hairpin and gradually decreases by increasing the temperature. As far as force-ramping experiments are concerned, the first-rupture forces of RNA/DNA hairpins corresponding to the maximum probability density linearly pertain to the force-loading rate, with those of RNA hairpins being greater. The extended ox-DNA model could potentially identify the interaction between biologically inert polymer and RNA/DNA hairpins in crowded environments.
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Affiliation(s)
- Chao Yang
- College of Physics, Guizhou University, Guiyang, Guizhou 550025, People's Republic of China
| | - Xiaoya Song
- College of Physics, Guizhou University, Guiyang, Guizhou 550025, People's Republic of China
| | - Yuyu Feng
- College of Physics, Guizhou University, Guiyang, Guizhou 550025, People's Republic of China
| | - Guangju Zhao
- College of Physics, Guizhou University, Guiyang, Guizhou 550025, People's Republic of China
| | - Yanhui Liu
- College of Physics, Guizhou University, Guiyang, Guizhou 550025, People's Republic of China
- Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education (Guizhou University), Guiyang, Guizhou 550025, People's Republic of China
- State Key Laboratory of Public Big Data, Guizhou University, Guiyang 550025, People's Republic of China
- Kechuang Industrial Development Company Limited,Gui'an New Area, Guiyang 550025, People's Republic of China
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3
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Bokolia NP, Gadepalli R. Identification of consensus hairpin loop structure among the negative sense subgenomic RNAs of SARS-CoV-2. BULLETIN OF THE NATIONAL RESEARCH CENTRE 2023; 47:28. [PMID: 36852284 PMCID: PMC9947893 DOI: 10.1186/s42269-023-01002-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND SARS-CoV-2 is the causative agent of worldwide pandemic disease coronavirus disease 19. SARS-CoV-2 bears positive sense RNA genome that has organized and complex pattern of replication/transcription process including the generation of subgenomic RNAs. Transcription regulatory sequences have important role in the pausing of replication/transcription and generation of subgenomic RNAs. RESULTS In the present bioinformatics analysis, a consensus secondary structure was identified among negative sense subgenomic RNAs of SARS-CoV-2. This consensus region is present at the adjacent of initiation codon. CONCLUSIONS This study proposed that consensus structured domain could involve in mediating the long pausing of replication/transcription complex and responsible for subgenomic RNA production. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1186/s42269-023-01002-3.
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Affiliation(s)
- Naveen Prakash Bokolia
- Viral Research and Diagnostic Laboratory, Microbiology Department, All India Institute of Medical Sciences, Jodhpur, 342001 India
| | - Ravisekhar Gadepalli
- Viral Research and Diagnostic Laboratory, Microbiology Department, All India Institute of Medical Sciences, Jodhpur, 342001 India
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4
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Duan X, Lacko LA, Chen S. Druggable targets and therapeutic development for COVID-19. Front Chem 2022; 10:963701. [PMID: 36277347 PMCID: PMC9581228 DOI: 10.3389/fchem.2022.963701] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 07/11/2022] [Indexed: 12/15/2022] Open
Abstract
Coronavirus disease (COVID-19), which is caused by SARS-CoV-2, is the biggest challenge to the global public health and economy in recent years. Until now, only limited therapeutic regimens have been available for COVID-19 patients, sparking unprecedented efforts to study coronavirus biology. The genome of SARS-CoV-2 encodes 16 non-structural, four structural, and nine accessory proteins, which mediate the viral life cycle, including viral entry, RNA replication and transcription, virion assembly and release. These processes depend on the interactions between viral polypeptides and host proteins, both of which could be potential therapeutic targets for COVID-19. Here, we will discuss the potential medicinal value of essential proteins of SARS-CoV-2 and key host factors. We summarize the most updated therapeutic interventions for COVID-19 patients, including those approved clinically or in clinical trials.
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5
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Malone B, Urakova N, Snijder EJ, Campbell EA. Structures and functions of coronavirus replication-transcription complexes and their relevance for SARS-CoV-2 drug design. Nat Rev Mol Cell Biol 2022; 23:21-39. [PMID: 34824452 PMCID: PMC8613731 DOI: 10.1038/s41580-021-00432-z] [Citation(s) in RCA: 191] [Impact Index Per Article: 95.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2021] [Indexed: 02/08/2023]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has killed millions of people and continues to cause massive global upheaval. Coronaviruses are positive-strand RNA viruses with an unusually large genome of ~30 kb. They express an RNA-dependent RNA polymerase and a cohort of other replication enzymes and supporting factors to transcribe and replicate their genomes. The proteins performing these essential processes are prime antiviral drug targets, but drug discovery is hindered by our incomplete understanding of coronavirus RNA synthesis and processing. In infected cells, the RNA-dependent RNA polymerase must coordinate with other viral and host factors to produce both viral mRNAs and new genomes. Recent research aiming to decipher and contextualize the structures, functions and interplay of the subunits of the SARS-CoV-2 replication and transcription complex proteins has burgeoned. In this Review, we discuss recent advancements in our understanding of the molecular basis and complexity of the coronavirus RNA-synthesizing machinery. Specifically, we outline the mechanisms and regulation of RNA translation, replication and transcription. We also discuss the composition of the replication and transcription complexes and their suitability as targets for antiviral therapy.
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Affiliation(s)
- Brandon Malone
- grid.134907.80000 0001 2166 1519Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY USA
| | - Nadya Urakova
- grid.10419.3d0000000089452978Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - Eric J. Snijder
- grid.10419.3d0000000089452978Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - Elizabeth A. Campbell
- grid.134907.80000 0001 2166 1519Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY USA
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6
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Piccolo JG, Méndez Harper J, McCalla D, Xu W, Miller S, Doan J, Kovari D, Dunlap D, Finzi L. Force spectroscopy with electromagnetic tweezers. JOURNAL OF APPLIED PHYSICS 2021; 130:134702. [PMID: 38681504 PMCID: PMC11055633 DOI: 10.1063/5.0060276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 09/07/2021] [Indexed: 05/01/2024]
Abstract
Force spectroscopy using magnetic tweezers (MTs) is a powerful method to probe the physical characteristics of single polymers. Typically, molecules are functionalized for specific attachment to a glass surface at one end and a micrometer-scale paramagnetic bead at the other end. By applying an external magnetic field, multiple molecules can be stretched and twisted simultaneously without exposure to potentially damaging radiation. The majority of MTs utilize mobile, permanent magnets to produce forces on the beads (and the molecule under test). However, translating and rotating the permanent magnets may require expensive precision actuators, limit the rate at which force can be changed, and may induce vibrations that disturb tether dynamics and bead tracking. Alternatively, the magnetic field can be produced with an electromagnet, which allows fast force modulation and eliminates motor-associated vibration. Here, we describe a low-cost quadrapolar electromagnetic tweezer design capable of manipulating DNA-tethered MyOne paramagnetic beads with forces as high as 15 pN. The solid-state nature of the generated B-field modulated along two axes is convenient for accessing the range of forces and torques relevant for studying the activity of DNA motor enzymes like polymerases and helicases. Our design specifically leverages technology available at an increasing number of university maker spaces and student-run machine shops. Thus, it is an accessible tool for undergraduate education that is applicable to a wide range of biophysical research questions.
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Affiliation(s)
- Joseph G. Piccolo
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - Joshua Méndez Harper
- Department of Earth Science, University of Oregon, 1272 University of Oregon, Eugene, Oregon 97403, USA
| | - Derrica McCalla
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - Wenxuan Xu
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - Sam Miller
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - Jessie Doan
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - Dan Kovari
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - David Dunlap
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - Laura Finzi
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
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7
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Seifert M, Bera SC, van Nies P, Kirchdoerfer RN, Shannon A, Le TTN, Meng X, Xia H, Wood JM, Harris LD, Papini FS, Arnold JJ, Almo S, Grove TL, Shi PY, Xiang Y, Canard B, Depken M, Cameron CE, Dulin D. Inhibition of SARS-CoV-2 polymerase by nucleotide analogs from a single-molecule perspective. eLife 2021; 10:e70968. [PMID: 34617885 PMCID: PMC8497053 DOI: 10.7554/elife.70968] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/24/2021] [Indexed: 12/14/2022] Open
Abstract
The absence of 'shovel-ready' anti-coronavirus drugs during vaccine development has exceedingly worsened the SARS-CoV-2 pandemic. Furthermore, new vaccine-resistant variants and coronavirus outbreaks may occur in the near future, and we must be ready to face this possibility. However, efficient antiviral drugs are still lacking to this day, due to our poor understanding of the mode of incorporation and mechanism of action of nucleotides analogs that target the coronavirus polymerase to impair its essential activity. Here, we characterize the impact of remdesivir (RDV, the only FDA-approved anti-coronavirus drug) and other nucleotide analogs (NAs) on RNA synthesis by the coronavirus polymerase using a high-throughput, single-molecule, magnetic-tweezers platform. We reveal that the location of the modification in the ribose or in the base dictates the catalytic pathway(s) used for its incorporation. We show that RDV incorporation does not terminate viral RNA synthesis, but leads the polymerase into backtrack as far as 30 nt, which may appear as termination in traditional ensemble assays. SARS-CoV-2 is able to evade the endogenously synthesized product of the viperin antiviral protein, ddhCTP, though the polymerase incorporates this NA well. This experimental paradigm is essential to the discovery and development of therapeutics targeting viral polymerases.
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Affiliation(s)
- Mona Seifert
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU)ErlangenGermany
| | - Subhas C Bera
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU)ErlangenGermany
| | - Pauline van Nies
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU)ErlangenGermany
| | - Robert N Kirchdoerfer
- Department of Biochemistry and Institute of Molecular Virology, University of Wisconsin-MadisonMadisonUnited States
| | - Ashleigh Shannon
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Aix-Marseille UniversitéMarseilleFrance
| | - Thi-Tuyet-Nhung Le
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Aix-Marseille UniversitéMarseilleFrance
| | - Xiangzhi Meng
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San AntonioSan AntonioUnited States
| | - Hongjie Xia
- Department of Biochemistry and Molecular Biology, University of Texas Medical BranchGalvestonUnited States
| | - James M Wood
- The Ferrier Research Institute, Victoria University of WellingtonWellingtonNew Zealand
| | - Lawrence D Harris
- The Ferrier Research Institute, Victoria University of WellingtonWellingtonNew Zealand
| | - Flavia S Papini
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU)ErlangenGermany
| | - Jamie J Arnold
- Department of Microbiology and Immunology, University of North Carolina School of MedicineChapel HillUnited States
| | - Steven Almo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, Institute for Protein InnovationBostonUnited States
| | - Tyler L Grove
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, Institute for Protein InnovationBostonUnited States
| | - Pei-Yong Shi
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Institute for Human Infections and Immunity, University of Texas Medical Branch, Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical BranchGalvestonUnited States
| | - Yan Xiang
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San AntonioSan AntonioUnited States
| | - Bruno Canard
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Aix-Marseille UniversitéMarseilleFrance
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of TechnologyDelftNetherlands
| | - Craig E Cameron
- Department of Microbiology and Immunology, University of North Carolina School of MedicineChapel HillUnited States
| | - David Dulin
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU)ErlangenGermany
- Department of Physics and Astronomy, and LaserLaB Amsterdam, Vrije Universiteit AmsterdamAmsterdamNetherlands
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8
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The nucleotide addition cycle of the SARS-CoV-2 polymerase. Cell Rep 2021; 36:109650. [PMID: 34433083 PMCID: PMC8367775 DOI: 10.1016/j.celrep.2021.109650] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/10/2021] [Accepted: 08/11/2021] [Indexed: 12/29/2022] Open
Abstract
Coronaviruses have evolved elaborate multisubunit machines to replicate and transcribe their genomes. Central to these machines are the RNA-dependent RNA polymerase subunit (nsp12) and its intimately associated cofactors (nsp7 and nsp8). We use a high-throughput magnetic-tweezers approach to develop a mechanochemical description of this core polymerase. The core polymerase exists in at least three catalytically distinct conformations, one being kinetically consistent with incorporation of incorrect nucleotides. We provide evidence that the RNA-dependent RNA polymerase (RdRp) uses a thermal ratchet instead of a power stroke to transition from the pre- to post-translocated state. Ultra-stable magnetic tweezers enable the direct observation of coronavirus polymerase deep and long-lived backtracking that is strongly stimulated by secondary structures in the template. The framework we present here elucidates one of the most important structure-dynamics-function relationships in human health today and will form the grounds for understanding the regulation of this complex.
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9
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Malone B, Chen J, Wang Q, Llewellyn E, Choi YJ, Olinares PDB, Cao X, Hernandez C, Eng ET, Chait BT, Shaw DE, Landick R, Darst SA, Campbell EA. Structural basis for backtracking by the SARS-CoV-2 replication-transcription complex. Proc Natl Acad Sci U S A 2021; 118:e2102516118. [PMID: 33883267 PMCID: PMC8126829 DOI: 10.1073/pnas.2102516118] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Backtracking, the reverse motion of the transcriptase enzyme on the nucleic acid template, is a universal regulatory feature of transcription in cellular organisms but its role in viruses is not established. Here we present evidence that backtracking extends into the viral realm, where backtracking by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA-dependent RNA polymerase (RdRp) may aid viral transcription and replication. Structures of SARS-CoV-2 RdRp bound to the essential nsp13 helicase and RNA suggested the helicase facilitates backtracking. We use cryo-electron microscopy, RNA-protein cross-linking, and unbiased molecular dynamics simulations to characterize SARS-CoV-2 RdRp backtracking. The results establish that the single-stranded 3' segment of the product RNA generated by backtracking extrudes through the RdRp nucleoside triphosphate (NTP) entry tunnel, that a mismatched nucleotide at the product RNA 3' end frays and enters the NTP entry tunnel to initiate backtracking, and that nsp13 stimulates RdRp backtracking. Backtracking may aid proofreading, a crucial process for SARS-CoV-2 resistance against antivirals.
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Affiliation(s)
- Brandon Malone
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065
| | - James Chen
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065
| | - Qi Wang
- D. E. Shaw Research, New York, NY 10036
| | - Eliza Llewellyn
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065
| | - Young Joo Choi
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065
| | - Paul Dominic B Olinares
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, 10065
| | - Xinyun Cao
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
| | - Carolina Hernandez
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027
| | - Edward T Eng
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027
| | - Brian T Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, 10065
| | - David E Shaw
- D. E. Shaw Research, New York, NY 10036
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706
| | - Seth A Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065;
| | - Elizabeth A Campbell
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065;
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10
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Seifert M, Bera SC, van Nies P, Kirchdoerfer RN, Shannon A, Le TTN, Meng X, Xia H, Wood JM, Harris LD, Papini FS, Arnold JJ, Almo SC, Grove TL, Shi PY, Xiang Y, Canard B, Depken M, Cameron CE, Dulin D. Inhibition of SARS-CoV-2 polymerase by nucleotide analogs: a single molecule perspective. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2020.08.06.240325. [PMID: 33851161 PMCID: PMC8043451 DOI: 10.1101/2020.08.06.240325] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
The nucleotide analog Remdesivir (RDV) is the only FDA-approved antiviral therapy to treat infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The physical basis for efficient utilization of RDV by SARS-CoV-2 polymerase is unknown. Here, we characterize the impact of RDV and other nucleotide analogs on RNA synthesis by the polymerase using a high-throughput, single-molecule, magnetic-tweezers platform. The location of the modification in the ribose or in the base dictates the catalytic pathway(s) used for its incorporation. We reveal that RDV incorporation does not terminate viral RNA synthesis, but leads the polymerase into deep backtrack, which may appear as termination in traditional ensemble assays. SARS-CoV-2 is able to evade the endogenously synthesized product of the viperin antiviral protein, ddhCTP, though the polymerase incorporates this nucleotide analog well. This experimental paradigm is essential to the discovery and development of therapeutics targeting viral polymerases. TEASER We revise Remdesivir's mechanism of action and reveal SARS-CoV-2 ability to evade interferon-induced antiviral ddhCTP.
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Affiliation(s)
- Mona Seifert
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Subhas Chandra Bera
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Pauline van Nies
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Robert N. Kirchdoerfer
- Department of Biochemistry and Institute of Molecular Virology, University of Wisconsin-Madison, Madison, WI 53706
| | - Ashleigh Shannon
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Aix-Marseille Université, UMR 7257, Polytech Case 925, 13009 Marseille, France
| | - Thi-Tuyet-Nhung Le
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Aix-Marseille Université, UMR 7257, Polytech Case 925, 13009 Marseille, France
| | - Xiangzhi Meng
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Hongjie Xia
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - James M. Wood
- The Ferrier Research Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Lawrence D. Harris
- The Ferrier Research Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Flávia S. Papini
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Jamie J. Arnold
- Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC 27599 USA
| | - Steven C. Almo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, USA Institute for Protein Innovation, Boston, MA, USA
| | - Tyler L. Grove
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, USA Institute for Protein Innovation, Boston, MA, USA
| | - Pei-Yong Shi
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA; Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Yan Xiang
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Bruno Canard
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Aix-Marseille Université, UMR 7257, Polytech Case 925, 13009 Marseille, France
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Craig E. Cameron
- Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC 27599 USA
| | - David Dulin
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
- Department of Physics and Astronomy, and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
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11
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Bera SC, Seifert M, Kirchdoerfer RN, van Nies P, Wubulikasimu Y, Quack S, Papini FS, Arnold JJ, Canard B, Cameron CE, Depken M, Dulin D. The nucleotide addition cycle of the SARS-CoV-2 polymerase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2021.03.27.437309. [PMID: 33791706 PMCID: PMC8010733 DOI: 10.1101/2021.03.27.437309] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Coronaviruses have evolved elaborate multisubunit machines to replicate and transcribe their genomes. Central to these machines are the RNA-dependent RNA polymerase subunit (nsp12) and its intimately associated cofactors (nsp7 and nsp8). We have used a high-throughput magnetic-tweezers approach to develop a mechanochemical description of this core polymerase. The core polymerase exists in at least three catalytically distinct conformations, one being kinetically consistent with incorporation of incorrect nucleotides. We provide the first evidence that an RdRp uses a thermal ratchet instead of a power stroke to transition from the pre- to post-translocated state. Ultra-stable magnetic tweezers enables the direct observation of coronavirus polymerase deep and long-lived backtrack that are strongly stimulated by secondary structure in the template. The framework presented here elucidates one of the most important structure-dynamics-function relationships in human health today, and will form the grounds for understanding the regulation of this complex.
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Affiliation(s)
- Subhas Chandra Bera
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Mona Seifert
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Robert N. Kirchdoerfer
- Department of Biochemistry and Institute for Molecular Virology, University of Wisconsin-Madison, Madison, WI 53706
| | - Pauline van Nies
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Yibulayin Wubulikasimu
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Salina Quack
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Flávia S. Papini
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Jamie J. Arnold
- Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC 27599 USA
| | - Bruno Canard
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Aix-Marseille Université, UMR 7257, Polytech Case 925, 13009 Marseille, France
| | - Craig E. Cameron
- Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC 27599 USA
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - David Dulin
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
- Department of Physics and Astronomy, and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
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12
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Malone B, Chen J, Wang Q, Llewellyn E, Choi YJ, Olinares PDB, Cao X, Hernandez C, Eng ET, Chait BT, Shaw DE, Landick R, Darst SA, Campbell EA. Structural basis for backtracking by the SARS-CoV-2 replication-transcription complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2021.03.13.435256. [PMID: 33758867 PMCID: PMC7987028 DOI: 10.1101/2021.03.13.435256] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Backtracking, the reverse motion of the transcriptase enzyme on the nucleic acid template, is a universal regulatory feature of transcription in cellular organisms but its role in viruses is not established. Here we present evidence that backtracking extends into the viral realm, where backtracking by the SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) may aid viral transcription and replication. Structures of SARS-CoV-2 RdRp bound to the essential nsp13 helicase and RNA suggested the helicase facilitates backtracking. We use cryo-electron microscopy, RNA-protein crosslinking, and unbiased molecular dynamics simulations to characterize SARS-CoV-2 RdRp backtracking. The results establish that the single-stranded 3'-segment of the product-RNA generated by backtracking extrudes through the RdRp NTP-entry tunnel, that a mismatched nucleotide at the product-RNA 3'-end frays and enters the NTP-entry tunnel to initiate backtracking, and that nsp13 stimulates RdRp backtracking. Backtracking may aid proofreading, a crucial process for SARS-CoV-2 resistance against antivirals.
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Affiliation(s)
- Brandon Malone
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, 10065 USA
- These authors contributed equally: Brandon Malone, James Chen
| | - James Chen
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, 10065 USA
- These authors contributed equally: Brandon Malone, James Chen
| | - Qi Wang
- D. E. Shaw Research, New York, NY 10036 USA
| | - Eliza Llewellyn
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, 10065 USA
| | - Young Joo Choi
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, 10065 USA
| | - Paul Dominic B. Olinares
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, 10065 USA
| | - Xinyun Cao
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706 USA
| | - Carolina Hernandez
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, 10027 USA
| | - Edward T. Eng
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, 10027 USA
| | - Brian T. Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, 10065 USA
| | - David E. Shaw
- D. E. Shaw Research, New York, NY 10036 USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032 USA
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706 USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706 USA
| | - Seth A. Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, 10065 USA
| | - Elizabeth A. Campbell
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, 10065 USA
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13
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Han S, Ko O, Lee G, Jeong SW, Choi YJ, Lee JB. Rapid Diagnosis of Coronavirus by RNA-Directed RNA Transcription Using an Engineered RNA-based Platform. NANO LETTERS 2021; 21:462-468. [PMID: 33395304 PMCID: PMC7805305 DOI: 10.1021/acs.nanolett.0c03917] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/24/2020] [Indexed: 05/22/2023]
Abstract
A coronavirus disease (COVID-19) outbreak associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading widely through person-to-person transmission. Various detection approaches have been developed involving quantitative polymerase chain reaction (qPCR) methods, CRISPR-based systems, and direct targeting of specific coronavirus proteins. However, there have only been a few reports on the detection of RNA-dependent RNA polymerase (RdRP), the primer-independent RNA-replicable protein produced by the RNA genes of coronavirus. Here, we introduce a novel diagnostic methodology for COVID-19 using the RNA-directed and de novo RNA replicable function of RdRP. We devised an RNA platform for RdRP-induced transcription (RPRIT) that includes an RNA template that can be directly transcribed by RdRP. By utilizing RPRIT, the presence of RdRP can be readily confirmed within 30 min using isothermal incubation without PCR. This RdRP detection method can provide a new route for rapid diagnosis of RNA virus-infected patients.
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Affiliation(s)
- Sangwoo Han
- Department
of Chemical Engineering, University of Seoul, 163 Seoulsiripdaero, Dongdaemungu, Seoul 02504, Republic of Korea
| | - Ohsung Ko
- Department
of Chemical Engineering, University of Seoul, 163 Seoulsiripdaero, Dongdaemungu, Seoul 02504, Republic of Korea
| | - Geonhu Lee
- School
of Environmental Engineering, University
of Seoul, 163 Seoulsiripdaero, Dongdaemungu, Seoul 02504, Republic of Korea
| | - Sun-Wook Jeong
- School
of Environmental Engineering, University
of Seoul, 163 Seoulsiripdaero, Dongdaemungu, Seoul 02504, Republic of Korea
| | - Yong Jun Choi
- School
of Environmental Engineering, University
of Seoul, 163 Seoulsiripdaero, Dongdaemungu, Seoul 02504, Republic of Korea
| | - Jong Bum Lee
- Department
of Chemical Engineering, University of Seoul, 163 Seoulsiripdaero, Dongdaemungu, Seoul 02504, Republic of Korea
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14
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Douglas J, Drummond AJ, Kingston RL. Evolutionary history of cotranscriptional editing in the paramyxoviral phosphoprotein gene. Virus Evol 2021; 7:veab028. [PMID: 34141448 PMCID: PMC8204654 DOI: 10.1093/ve/veab028] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The phosphoprotein gene of the paramyxoviruses encodes multiple protein products. The P, V, and W proteins are generated by transcriptional slippage. This process results in the insertion of non-templated guanosine nucleosides into the mRNA at a conserved edit site. The P protein is an essential component of the viral RNA polymerase and is encoded by a faithful copy of the gene in the majority of paramyxoviruses. However, in some cases, the non-essential V protein is encoded by default and guanosines must be inserted into the mRNA in order to encode P. The number of guanosines inserted into the P gene can be described by a probability distribution, which varies between viruses. In this article, we review the nature of these distributions, which can be inferred from mRNA sequencing data, and reconstruct the evolutionary history of cotranscriptional editing in the paramyxovirus family. Our model suggests that, throughout known history of the family, the system has switched from a P default to a V default mode four times; complete loss of the editing system has occurred twice, the canonical zinc finger domain of the V protein has been deleted or heavily mutated a further two times, and the W protein has independently evolved a novel function three times. Finally, we review the physical mechanisms of cotranscriptional editing via slippage of the viral RNA polymerase.
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Affiliation(s)
- Jordan Douglas
- Centre for Computational Evolution, University of Auckland, Auckland 1010, New Zealand
- School of Computer Science, University of Auckland, Auckland 1010, New Zealand
| | - Alexei J Drummond
- Centre for Computational Evolution, University of Auckland, Auckland 1010, New Zealand
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Richard L Kingston
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
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15
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Picarazzi F, Vicenti I, Saladini F, Zazzi M, Mori M. Targeting the RdRp of Emerging RNA Viruses: The Structure-Based Drug Design Challenge. Molecules 2020; 25:E5695. [PMID: 33287144 PMCID: PMC7730706 DOI: 10.3390/molecules25235695] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 02/06/2023] Open
Abstract
The RNA-dependent RNA polymerase (RdRp) is an essential enzyme for the viral replication process, catalyzing the viral RNA synthesis using a metal ion-dependent mechanism. In recent years, RdRp has emerged as an optimal target for the development of antiviral drugs, as demonstrated by recent approvals of sofosbuvir and remdesivir against Hepatitis C virus (HCV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), respectively. In this work, we overview the main sequence and structural features of the RdRp of emerging RNA viruses such as Coronaviruses, Flaviviruses, and HCV, as well as inhibition strategies implemented so far. While analyzing the structural information available on the RdRp of emerging RNA viruses, we provide examples of success stories such as for HCV and SARS-CoV-2. In contrast, Flaviviruses' story has raised attention about how the lack of structural details on catalytically-competent or ligand-bound RdRp strongly hampers the application of structure-based drug design, either in repurposing and conventional approaches.
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Affiliation(s)
- Francesca Picarazzi
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018–2022, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy;
| | - Ilaria Vicenti
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (I.V.); (F.S.); (M.Z.)
| | - Francesco Saladini
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (I.V.); (F.S.); (M.Z.)
| | - Maurizio Zazzi
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (I.V.); (F.S.); (M.Z.)
| | - Mattia Mori
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018–2022, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy;
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16
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Chen J, Malone B, Llewellyn E, Grasso M, Shelton PM, Olinares PDB, Maruthi K, Eng ET, Vatandaslar H, Chait BT, Kapoor TM, Darst SA, Campbell EA. Structural Basis for Helicase-Polymerase Coupling in the SARS-CoV-2 Replication-Transcription Complex. Cell 2020; 182:1560-1573.e13. [PMID: 32783916 PMCID: PMC7386476 DOI: 10.1016/j.cell.2020.07.033] [Citation(s) in RCA: 299] [Impact Index Per Article: 74.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/10/2020] [Accepted: 07/22/2020] [Indexed: 01/21/2023]
Abstract
SARS-CoV-2 is the causative agent of the 2019-2020 pandemic. The SARS-CoV-2 genome is replicated and transcribed by the RNA-dependent RNA polymerase holoenzyme (subunits nsp7/nsp82/nsp12) along with a cast of accessory factors. One of these factors is the nsp13 helicase. Both the holo-RdRp and nsp13 are essential for viral replication and are targets for treating the disease COVID-19. Here we present cryoelectron microscopic structures of the SARS-CoV-2 holo-RdRp with an RNA template product in complex with two molecules of the nsp13 helicase. The Nidovirales order-specific N-terminal domains of each nsp13 interact with the N-terminal extension of each copy of nsp8. One nsp13 also contacts the nsp12 thumb. The structure places the nucleic acid-binding ATPase domains of the helicase directly in front of the replicating-transcribing holo-RdRp, constraining models for nsp13 function. We also observe ADP-Mg2+ bound in the nsp12 N-terminal nidovirus RdRp-associated nucleotidyltransferase domain, detailing a new pocket for anti-viral therapy development.
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Affiliation(s)
- James Chen
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Brandon Malone
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Eliza Llewellyn
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Michael Grasso
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, USA
| | - Patrick M.M. Shelton
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, USA
| | - Paul Dominic B. Olinares
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY 10065, USA
| | - Kashyap Maruthi
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Edward T. Eng
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Hasan Vatandaslar
- Institute of Molecular Health Sciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Brian T. Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY 10065, USA
| | - Tarun M. Kapoor
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, USA
| | - Seth A. Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA,Corresponding author
| | - Elizabeth A. Campbell
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA,Corresponding author
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17
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Chen J, Malone B, Llewellyn E, Grasso M, Shelton PMM, Olinares PDB, Maruthi K, Eng E, Vatandaslar H, Chait BT, Kapoor T, Darst SA, Campbell EA. Structural basis for helicase-polymerase coupling in the SARS-CoV-2 replication-transcription complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020. [PMID: 32676607 PMCID: PMC7359531 DOI: 10.1101/2020.07.08.194084] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
SARS-CoV-2 is the causative agent of the 2019-2020 pandemic. The SARS-CoV-2 genome is replicated-transcribed by the RNA-dependent RNA polymerase holoenzyme (subunits nsp7/nsp82/nsp12) along with a cast of accessory factors. One of these factors is the nsp13 helicase. Both the holo-RdRp and nsp13 are essential for viral replication and are targets for treating the disease COVID-19. Here we present cryo-electron microscopic structures of the SARS-CoV-2 holo-RdRp with an RNA template-product in complex with two molecules of the nsp13 helicase. The Nidovirus-order-specific N-terminal domains of each nsp13 interact with the N-terminal extension of each copy of nsp8. One nsp13 also contacts the nsp12-thumb. The structure places the nucleic acid-binding ATPase domains of the helicase directly in front of the replicating-transcribing holo-RdRp, constraining models for nsp13 function. We also observe ADP-Mg2+ bound in the nsp12 N-terminal nidovirus RdRp-associated nucleotidyltransferase domain, detailing a new pocket for anti-viral therapeutic development.
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Affiliation(s)
- James Chen
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, 10065 USA
| | - Brandon Malone
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, 10065 USA
| | - Eliza Llewellyn
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, 10065 USA
| | - Michael Grasso
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY, 10065 USA
| | - Patrick M M Shelton
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY, 10065 USA
| | - Paul Dominic B Olinares
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, 10065 USA
| | - Kashyap Maruthi
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, 10027 USA
| | - Ed Eng
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, 10027 USA
| | - Hasan Vatandaslar
- Institute of Molecular Health Sciences, ETH Zurich, 8093 Zürich, Switzerland
| | - Brian T Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, 10065 USA
| | - Tarun Kapoor
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY, 10065 USA
| | - Seth A Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, 10065 USA
| | - Elizabeth A Campbell
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, 10065 USA
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18
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Seifert M, van Nies P, Papini FS, Arnold JJ, Poranen MM, Cameron CE, Depken M, Dulin D. Temperature controlled high-throughput magnetic tweezers show striking difference in activation energies of replicating viral RNA-dependent RNA polymerases. Nucleic Acids Res 2020; 48:5591-5602. [PMID: 32286652 PMCID: PMC7261197 DOI: 10.1093/nar/gkaa233] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/10/2020] [Accepted: 03/30/2020] [Indexed: 01/05/2023] Open
Abstract
RNA virus survival depends on efficient viral genome replication, which is performed by the viral RNA dependent RNA polymerase (RdRp). The recent development of high throughput magnetic tweezers has enabled the simultaneous observation of dozens of viral RdRp elongation traces on kilobases long templates, and this has shown that RdRp nucleotide addition kinetics is stochastically interrupted by rare pauses of 1-1000 s duration, of which the short-lived ones (1-10 s) are the temporal signature of a low fidelity catalytic pathway. We present a simple and precise temperature controlled system for magnetic tweezers to characterize the replication kinetics temperature dependence between 25°C and 45°C of RdRps from three RNA viruses, i.e. the double-stranded RNA bacteriophage Φ6, and the positive-sense single-stranded RNA poliovirus (PV) and human rhinovirus C (HRV-C). We found that Φ6 RdRp is largely temperature insensitive, while PV and HRV-C RdRps replication kinetics are activated by temperature. Furthermore, the activation energies we measured for PV RdRp catalytic state corroborate previous estimations from ensemble pre-steady state kinetic studies, further confirming the catalytic origin of the short pauses and their link to temperature independent RdRp fidelity. This work will enable future temperature controlled study of biomolecular complex at the single molecule level.
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Affiliation(s)
- Mona Seifert
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Pauline van Nies
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Flávia S Papini
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Jamie J Arnold
- Department of Microbiology and Immunology, School of Medicine, The University of North Carolina Chapel Hill, 6012 Marsico Hall, CB 7290 Mason Farm Road, NC 27599, USA
| | - Minna M Poranen
- Molecular and Integrative Biosciences Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikki Biocenter 1, P.O. Box 56 (Viikinkaari 9), 00014 Helsinki, Finland
| | - Craig E Cameron
- Department of Microbiology and Immunology, School of Medicine, The University of North Carolina Chapel Hill, 6012 Marsico Hall, CB 7290 Mason Farm Road, NC 27599, USA
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands,Correspondence may also be addressed to Martin Depken. Tel: +31 15 27 81305;
| | - David Dulin
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany,To whom correspondence should be addressed. Tel: +49 9131 85 70347; Fax: +49 9131 85 35903;
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19
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Papini FS, Seifert M, Dulin D. High-yield fabrication of DNA and RNA constructs for single molecule force and torque spectroscopy experiments. Nucleic Acids Res 2020; 47:e144. [PMID: 31584079 PMCID: PMC6902051 DOI: 10.1093/nar/gkz851] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/20/2019] [Accepted: 10/02/2019] [Indexed: 12/19/2022] Open
Abstract
Single molecule biophysics experiments have enabled the observation of biomolecules with a great deal of precision in space and time, e.g. nucleic acids mechanical properties and protein–nucleic acids interactions using force and torque spectroscopy techniques. The success of these experiments strongly depends on the capacity of the researcher to design and fabricate complex nucleic acid structures, as the outcome and the yield of the experiment also strongly depend on the high quality and purity of the final construct. Though the molecular biology techniques involved are well known, the fabrication of nucleic acid constructs for single molecule experiments still remains a difficult task. Here, we present new protocols to generate high quality coilable double-stranded DNA and RNA, as well as DNA and RNA hairpins with ∼500–1000 bp long stems. Importantly, we present a new approach based on single-stranded DNA (ssDNA) annealing and we use magnetic tweezers to show that this approach simplifies the fabrication of complex DNA constructs, such as hairpins, and converts more efficiently the input DNA into construct than the standard PCR-digestion-ligation approach. The protocols we describe here enable the design of a large range of nucleic acid construct for single molecule biophysics experiments.
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Affiliation(s)
- Flávia S Papini
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Cauerstrasse 3, 91058 Erlangen, Germany
| | - Mona Seifert
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Cauerstrasse 3, 91058 Erlangen, Germany
| | - David Dulin
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Cauerstrasse 3, 91058 Erlangen, Germany
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20
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Chen YT, Yang H, Chu JW. Structure-mechanics statistical learning unravels the linkage between local rigidity and global flexibility in nucleic acids. Chem Sci 2020; 11:4969-4979. [PMID: 34122953 PMCID: PMC8159235 DOI: 10.1039/d0sc00480d] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The mechanical properties of nucleic acids underlie biological processes ranging from genome packaging to gene expression, but tracing their molecular origin has been difficult due to the structural and chemical complexity. We posit that concepts from machine learning can help to tackle this long-standing challenge. Here, we demonstrate the feasibility and advantage of this strategy through developing a structure-mechanics statistical learning scheme to elucidate how local rigidity in double-stranded (ds)DNA and dsRNA may lead to their global flexibility in bend, stretch, and twist. Specifically, the mechanical parameters in a heavy-atom elastic network model are computed from the trajectory data of all-atom molecular dynamics simulation. The results show that the inter-atomic springs for backbone and ribose puckering in dsRNA are stronger than those in dsDNA, but are similar in strengths for base-stacking and base-pairing. Our analysis shows that the experimental observation of dsDNA being easier to bend but harder to stretch than dsRNA comes mostly from the respective B- and A-form topologies. The computationally resolved composition of local rigidity indicates that the flexibility of both nucleic acids is mostly due to base-stacking. But for properties like twist-stretch coupling, backbone springs are shown to play a major role instead. The quantitative connection between local rigidity and global flexibility sets foundation for understanding how local binding and chemical modification of genetic materials effectuate longer-ranged regulatory signals. The mechanical properties of nucleic acids underlie biological processes ranging from genome packaging to gene expression. We devise structural mechanics statistical learning method to reveal their molecular origin in terms of chemical interactions.![]()
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Affiliation(s)
- Yi-Tsao Chen
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University Hsinchu Taiwan 30068 Republic of China
| | - Haw Yang
- Department of Chemistry, Princeton University Princeton NJ 08544 USA
| | - Jhih-Wei Chu
- Institute of Bioinformatics and Systems Biology, Department of Biological Science and Technology, Institute of Molecular Medicine and Bioengineering, National Chiao Tung University Hsinchu Taiwan 30068 Republic of China +886 3 5712121 ext. 56996
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21
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Carrasco C, Pastrana CL, Aicart-Ramos C, Leuba SH, Khan S, Moreno-Herrero F. Dynamics of DNA nicking and unwinding by the RepC-PcrA complex. Nucleic Acids Res 2020; 48:2013-2025. [PMID: 31930301 PMCID: PMC7038956 DOI: 10.1093/nar/gkz1200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 12/10/2019] [Accepted: 12/18/2019] [Indexed: 01/22/2023] Open
Abstract
The rolling-circle replication is the most common mechanism for the replication of small plasmids carrying antibiotic resistance genes in Gram-positive bacteria. It is initiated by the binding and nicking of double-stranded origin of replication by a replication initiator protein (Rep). Duplex unwinding is then performed by the PcrA helicase, whose processivity is critically promoted by its interaction with Rep. How Rep and PcrA proteins interact to nick and unwind the duplex is not fully understood. Here, we have used magnetic tweezers to monitor PcrA helicase unwinding and its relationship with the nicking activity of Staphylococcus aureus plasmid pT181 initiator RepC. Our results indicate that PcrA is a highly processive helicase prone to stochastic pausing, resulting in average translocation rates of 30 bp s-1, while a typical velocity of 50 bp s-1 is found in the absence of pausing. Single-strand DNA binding protein did not affect PcrA translocation velocity but slightly increased its processivity. Analysis of the degree of DNA supercoiling required for RepC nicking, and the time between RepC nicking and DNA unwinding, suggests that RepC and PcrA form a protein complex on the DNA binding site before nicking. A comprehensive model that rationalizes these findings is presented.
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Affiliation(s)
- Carolina Carrasco
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, CSIC, Darwin 3, 28049 Cantoblanco, Madrid, Spain
| | - Cesar L Pastrana
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, CSIC, Darwin 3, 28049 Cantoblanco, Madrid, Spain
| | - Clara Aicart-Ramos
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, CSIC, Darwin 3, 28049 Cantoblanco, Madrid, Spain
| | - Sanford H Leuba
- Departments of Cell Biology and Bioengineering, UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, 5117 Centre Avenue, Pittsburgh, PA 15213, USA
| | - Saleem A Khan
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219, USA
| | - Fernando Moreno-Herrero
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, CSIC, Darwin 3, 28049 Cantoblanco, Madrid, Spain
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22
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mSphere of Influence: Resolution of the Structure of an Influenza Virus Polymerase Is a Game Changer. mSphere 2019; 4:4/4/e00473-19. [PMID: 31434746 PMCID: PMC6706468 DOI: 10.1128/msphere.00473-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mathilde Richard works in the field of virology, more specifically on the evolution and pathogenesis of influenza viruses. In this mSphere of Influence article, she reflects on how the two articles “Structure of Influenza A Polymerase Bound to the Viral RNA Promoter” by A. Pflug, D. Guilligay, S. Reich, and S. Cusack (Nature 516:355–360, 2014, https://doi.org/10.1038/nature14008) and “Structural Insight into Cap-Snatching and RNA Synthesis by Influenza Polymerase” by S. Reich, D. Guilligay, A. Pflug, H. Malet, I. Berger, et al. (Nature 516:361–366, 2014, https://doi.org/10.1038/nature14009) made an impact on her by providing new grounds to study the influenza virus polymerase and its role in virus biology and evolution. Mathilde Richard works in the field of virology, more specifically on the evolution and pathogenesis of influenza viruses. In this mSphere of Influence article, she reflects on how the two articles “Structure of Influenza A Polymerase Bound to the Viral RNA Promoter” by A. Pflug, D. Guilligay, S. Reich, and S. Cusack (Nature 516:355–360, 2014, https://doi.org/10.1038/nature14008) and “Structural Insight into Cap-Snatching and RNA Synthesis by Influenza Polymerase” by S. Reich, D. Guilligay, A. Pflug, H. Malet, I. Berger, et al. (Nature 516:361–366, 2014, https://doi.org/10.1038/nature14009) made an impact on her by providing new grounds to study the influenza virus polymerase and its role in virus biology and evolution.
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23
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Te Velthuis AJW, Long JC, Bauer DLV, Fan RLY, Yen HL, Sharps J, Siegers JY, Killip MJ, French H, Oliva-Martín MJ, Randall RE, de Wit E, van Riel D, Poon LLM, Fodor E. Mini viral RNAs act as innate immune agonists during influenza virus infection. Nat Microbiol 2018; 3:1234-1242. [PMID: 30224800 PMCID: PMC6203953 DOI: 10.1038/s41564-018-0240-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 08/07/2018] [Indexed: 12/17/2022]
Abstract
The molecular processes that determine the outcome of influenza virus infection in humans are multifactorial and involve a complex interplay between host, viral and bacterial factors1. However, it is generally accepted that a strong innate immune dysregulation known as 'cytokine storm' contributes to the pathology of infections with the 1918 H1N1 pandemic or the highly pathogenic avian influenza viruses of the H5N1 subtype2-4. The RNA sensor retinoic acid-inducible gene I (RIG-I) plays an important role in sensing viral infection and initiating a signalling cascade that leads to interferon expression5. Here, we show that short aberrant RNAs (mini viral RNAs (mvRNAs)), produced by the viral RNA polymerase during the replication of the viral RNA genome, bind to and activate RIG-I and lead to the expression of interferon-β. We find that erroneous polymerase activity, dysregulation of viral RNA replication or the presence of avian-specific amino acids underlie mvRNA generation and cytokine expression in mammalian cells. By deep sequencing RNA samples from the lungs of ferrets infected with influenza viruses, we show that mvRNAs are generated during infection in vivo. We propose that mvRNAs act as the main agonists of RIG-I during influenza virus infection.
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Affiliation(s)
- Aartjan J W Te Velthuis
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
- Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
| | - Joshua C Long
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - David L V Bauer
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Rebecca L Y Fan
- School of Public Health, University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Hui-Ling Yen
- School of Public Health, University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Jane Sharps
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Jurre Y Siegers
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Marian J Killip
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- Biomedical Sciences Research Complex, North Haugh, University of St Andrews, St Andrews, UK
| | - Hollie French
- Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | | | - Richard E Randall
- Biomedical Sciences Research Complex, North Haugh, University of St Andrews, St Andrews, UK
| | - Emmie de Wit
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Debby van Riel
- Department of Viroscience, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Leo L M Poon
- School of Public Health, University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Ervin Fodor
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
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24
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Ostrofet E, Papini FS, Dulin D. Correction-free force calibration for magnetic tweezers experiments. Sci Rep 2018; 8:15920. [PMID: 30374099 PMCID: PMC6206022 DOI: 10.1038/s41598-018-34360-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 10/12/2018] [Indexed: 11/09/2022] Open
Abstract
Magnetic tweezers are a powerful technique to perform high-throughput and high-resolution force spectroscopy experiments at the single-molecule level. The camera-based detection of magnetic tweezers enables the observation of hundreds of magnetic beads in parallel, and therefore the characterization of the mechanochemical behavior of hundreds of nucleic acids and enzymes. However, magnetic tweezers experiments require an accurate force calibration to extract quantitative data, which is limited to low forces if the deleterious effect of the finite camera open shutter time (τsh) is not corrected. Here, we provide a simple method to perform correction-free force calibration for high-throughput magnetic tweezers at low image acquisition frequency (fac). By significantly reducing τsh to at least 4-fold the characteristic times of the tethered magnetic bead, we accurately evaluated the variance of the magnetic bead position along the axis parallel to the magnetic field, estimating the force with a relative error of ~10% (standard deviation), being only limited by the bead-to-bead difference. We calibrated several magnets - magnetic beads configurations, covering a force range from ~50 fN to ~60 pN. In addition, for the presented configurations, we provide a table with the mathematical expressions that describe the force as a function of the magnets position.
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Affiliation(s)
- Eugen Ostrofet
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Hartmannstr. 14, 91052, Erlangen, Germany
| | - Flávia Stal Papini
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Hartmannstr. 14, 91052, Erlangen, Germany
| | - David Dulin
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Hartmannstr. 14, 91052, Erlangen, Germany.
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25
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Dulin D, Arnold JJ, van Laar T, Oh HS, Lee C, Perkins AL, Harki DA, Depken M, Cameron CE, Dekker NH. Signatures of Nucleotide Analog Incorporation by an RNA-Dependent RNA Polymerase Revealed Using High-Throughput Magnetic Tweezers. Cell Rep 2018; 21:1063-1076. [PMID: 29069588 PMCID: PMC5670035 DOI: 10.1016/j.celrep.2017.10.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 09/20/2017] [Accepted: 10/02/2017] [Indexed: 11/04/2022] Open
Abstract
RNA viruses pose a threat to public health that is exacerbated by the dearth of antiviral therapeutics. The RNA-dependent RNA polymerase (RdRp) holds promise as a broad-spectrum, therapeutic target because of the conserved nature of the nucleotide-substrate-binding and catalytic sites. Conventional, quantitative, kinetic analysis of antiviral ribonucleotides monitors one or a few incorporation events. Here, we use a high-throughput magnetic tweezers platform to monitor the elongation dynamics of a prototypical RdRp over thousands of nucleotide-addition cycles in the absence and presence of a suite of nucleotide analog inhibitors. We observe multiple RdRp-RNA elongation complexes; only a subset of which are competent for analog utilization. Incorporation of a pyrazine-carboxamide nucleotide analog, T-1106, leads to RdRp backtracking. This analysis reveals a mechanism of action for this antiviral ribonucleotide that is corroborated by cellular studies. We propose that induced backtracking represents a distinct mechanistic class of antiviral ribonucleotides. Several unique conformational states of an elongating RdRp exist Only one conformation incorporates nucleotide analogs with therapeutic potential An analog thought to be a chain terminator actually promotes RdRp backtracking Distinctive behavior of backtrack-inducing analog on virus variants in cell culture
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Affiliation(s)
- David Dulin
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, the Netherlands; Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Hartmannstr. 14, 91052 Erlangen, Germany
| | - Jamie J Arnold
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Theo van Laar
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Hyung-Suk Oh
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Cheri Lee
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Angela L Perkins
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Daniel A Harki
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, the Netherlands.
| | - Craig E Cameron
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA.
| | - Nynke H Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, the Netherlands.
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26
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Understanding the mechanical response of double-stranded DNA and RNA under constant stretching forces using all-atom molecular dynamics. Proc Natl Acad Sci U S A 2017. [PMID: 28634300 DOI: 10.1073/pnas.1705642114] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Multiple biological processes involve the stretching of nucleic acids (NAs). Stretching forces induce local changes in the molecule structure, inhibiting or promoting the binding of proteins, which ultimately affects their functionality. Understanding how a force induces changes in the structure of NAs at the atomic level is a challenge. Here, we use all-atom, microsecond-long molecular dynamics to simulate the structure of dsDNA and dsRNA subjected to stretching forces up to 20 pN. We determine all of the elastic constants of dsDNA and dsRNA and provide an explanation for three striking differences in the mechanical response of these two molecules: the threefold softer stretching constant obtained for dsRNA, the opposite twist-stretch coupling, and its nontrivial force dependence. The lower dsRNA stretching resistance is linked to its more open structure, whereas the opposite twist-stretch coupling of both molecules is due to the very different evolution of molecules' interstrand distance with the stretching force. A reduction of this distance leads to overwinding in dsDNA. In contrast, dsRNA is not able to reduce its interstrand distance and can only elongate by unwinding. Interstrand distance is directly correlated with the slide base-pair parameter and its different behavior in dsDNA and dsRNA traced down to changes in the sugar pucker angle of these NAs.
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27
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Alphonse S, Ghose R. Cystoviral RNA-directed RNA polymerases: Regulation of RNA synthesis on multiple time and length scales. Virus Res 2017; 234:135-152. [PMID: 28104452 PMCID: PMC5476504 DOI: 10.1016/j.virusres.2017.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Revised: 01/04/2017] [Accepted: 01/09/2017] [Indexed: 12/18/2022]
Abstract
Role of the RNA polymerase in the cystoviral life-cycle. Spatio-temporal regulation of RNA synthesis in cystoviruses. Emerging role of conformational dynamics in polymerase function.
P2, an RNA-directed RNA polymerase (RdRP), is encoded on the largest of the three segments of the double-stranded RNA genome of cystoviruses. P2 performs the dual tasks of replication and transcription de novo on single-stranded RNA templates, and plays a critical role in the viral life-cycle. Work over the last few decades has yielded a wealth of biochemical and structural information on the functional regulation of P2, on its role in the spatiotemporal regulation of RNA synthesis and its variability across the Cystoviridae family. These range from atomic resolution snapshots of P2 trapped in functionally significant states, in complex with catalytic/structural metal ions, polynucleotide templates and substrate nucleoside triphosphates, to P2 in the context of viral capsids providing structural insight into the assembly of supramolecular complexes and regulatory interactions therein. They include in vitro biochemical studies using P2 purified to homogeneity and in vivo studies utilizing infectious core particles. Recent advances in experimental techniques have also allowed access to the temporal dimension and enabled the characterization of dynamics of P2 on the sub-nanosecond to millisecond timescale through measurements of nuclear spin relaxation in solution and single molecule studies of transcription from seconds to minutes. Below we summarize the most significant results that provide critical insight into the role of P2 in regulating RNA synthesis in cystoviruses.
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Affiliation(s)
- Sébastien Alphonse
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, United States.
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, United States; Graduate Programs in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, United States; Graduate Programs in Chemistry, The Graduate Center of CUNY, New York, NY 10016, United States; Graduate Programs in Physics, The Graduate Center of CUNY, New York, NY 10016, United States.
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