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Yang XY, Shen Z, Wang C, Nakanishi K, Fu TM. DdmDE eliminates plasmid invasion by DNA-guided DNA targeting. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.20.604412. [PMID: 39071313 PMCID: PMC11275911 DOI: 10.1101/2024.07.20.604412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Horizontal gene transfer is a key driver of bacterial evolution, but it also presents severe risks to bacteria by introducing invasive mobile genetic elements. To counter these threats, bacteria have developed various defense systems, including prokaryotic Argonautes (pAgo) and the D NA D efense M odule DdmDE system. Through biochemical analysis, structural determination, and in vivo plasmid clearance assays, we elucidate the assembly and activation mechanisms of DdmDE, which eliminates small, multicopy plasmids. We demonstrate that DdmE, a pAgo-like protein, acts as a catalytically inactive, DNA-guided, DNA-targeting defense module. In the presence of guide DNA, DdmE targets plasmids and recruits a dimeric DdmD, which contains nuclease and helicase domains. Upon binding to DNA substrates, DdmD transitions from an autoinhibited dimer to an active monomer, which then translocates along and cleaves the plasmids. Together, our findings reveal the intricate mechanisms underlying DdmDE-mediated plasmid clearance, offering fundamental insights into bacterial defense systems against plasmid invasions.
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Schwer B, Innokentev A, Sanchez AM, Garg A, Shuman S. Suppression of inositol pyrophosphate toxicosis and hyper-repression of the fission yeast PHO regulon by loss-of-function mutations in chromatin remodelers Snf22 and Sol1. mBio 2024; 15:e0125224. [PMID: 38899862 PMCID: PMC11253589 DOI: 10.1128/mbio.01252-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 05/06/2024] [Indexed: 06/21/2024] Open
Abstract
Inositol pyrophosphates are signaling molecules that regulate cellular phosphate homeostasis in eukaryal taxa. In fission yeast, where the phosphate regulon (comprising phosphate acquisition genes pho1, pho84, and tgp1) is repressed under phosphate-replete conditions by lncRNA-mediated transcriptional interference, mutations of inositol pyrophosphatases that increase IP8 levels derepress the PHO regulon by eliciting precocious termination of lncRNA transcription. Asp1 pyrophosphatase mutations resulting in too much IP8 are cytotoxic in YES medium owing to overexpression of glycerophosphodiester transporter Tgp1. IP8 toxicosis is ameliorated by mutations in cleavage/polyadenylation and termination factors, perturbations of the Pol2 CTD code, and mutations in SPX domain proteins that act as inositol pyrophosphate sensors. Here, we show that IP8 toxicity is alleviated by deletion of snf22+, the gene encoding the ATPase subunit of the SWI/SNF chromatin remodeling complex, by an ATPase-inactivating snf22-(D996A-E997A) allele, and by deletion of the gene encoding SWI/SNF subunit Sol1. Deletion of snf22+ hyper-repressed pho1 expression in phosphate-replete cells; suppressed the pho1 derepression elicited by mutations in Pol2 CTD, termination factor Seb1, Asp1 pyrophosphatase, and 14-3-3 protein Rad24 (that favor precocious prt lncRNA termination); and delayed pho1 induction during phosphate starvation. RNA analysis and lack of mutational synergies suggest that Snf22 is not impacting 3'-processing/termination. Using reporter assays, we find that Snf22 is important for the activity of the tgp1 and pho1 promoters, but not for the promoters that drive the synthesis of the PHO-repressive lncRNAs. Transcription profiling of snf22∆ and snf22-(D996A-E997A) cells identified an additional set of 66 protein-coding genes that were downregulated in both mutants.IMPORTANCERepression of the fission yeast PHO genes tgp1, pho1, and pho84 by lncRNA-mediated interference is sensitive to inositol pyrophosphate dynamics. Cytotoxic asp1-STF alleles derepress the PHO genes via the action of IP8 as an agonist of precocious lncRNA 3'-processing/termination. IP8 toxicosis is alleviated by mutations of the Pol2 CTD and the 3'-processing/termination machinery that dampen the impact of toxic IP8 levels on termination. In this study, a forward genetic screen revealed that IP8 toxicity is suppressed by mutations of the Snf22 and Sol1 subunits of the SWI/SNF chromatin remodeling complex. Genetic and biochemical evidence indicates that the SWI/SNF is not affecting 3'-processing/termination or lncRNA promoter activity. Rather, SWI/SNF is critical for firing the PHO mRNA promoters. Our results implicate the ATP-dependent nucleosome remodeling activity of SWI/SNF as necessary to ensure full access of PHO-activating transcription factor Pho7 to its binding sites in the PHO mRNA promoters.
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Affiliation(s)
- Beate Schwer
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, USA
| | - Aleksei Innokentev
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Ana M. Sanchez
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
- Gerstner Sloan Kettering Graduate School of Biomedical Sciences, New York, New York, USA
| | - Angad Garg
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Stewart Shuman
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
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3
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Eustermann S, Patel AB, Hopfner KP, He Y, Korber P. Energy-driven genome regulation by ATP-dependent chromatin remodellers. Nat Rev Mol Cell Biol 2024; 25:309-332. [PMID: 38081975 DOI: 10.1038/s41580-023-00683-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2023] [Indexed: 03/28/2024]
Abstract
The packaging of DNA into chromatin in eukaryotes regulates gene transcription, DNA replication and DNA repair. ATP-dependent chromatin remodelling enzymes (re)arrange nucleosomes at the first level of chromatin organization. Their Snf2-type motor ATPases alter histone-DNA interactions through a common DNA translocation mechanism. Whether remodeller activities mainly catalyse nucleosome dynamics or accurately co-determine nucleosome organization remained unclear. In this Review, we discuss the emerging mechanisms of chromatin remodelling: dynamic remodeller architectures and their interactions, the inner workings of the ATPase cycle, allosteric regulation and pathological dysregulation. Recent mechanistic insights argue for a decisive role of remodellers in the energy-driven self-organization of chromatin, which enables both stability and plasticity of genome regulation - for example, during development and stress. Different remodellers, such as members of the SWI/SNF, ISWI, CHD and INO80 families, process (epi)genetic information through specific mechanisms into distinct functional outputs. Combinatorial assembly of remodellers and their interplay with histone modifications, histone variants, DNA sequence or DNA-bound transcription factors regulate nucleosome mobilization or eviction or histone exchange. Such input-output relationships determine specific nucleosome positions and compositions with distinct DNA accessibilities and mediate differential genome regulation. Finally, remodeller genes are often mutated in diseases characterized by genome dysregulation, notably in cancer, and we discuss their physiological relevance.
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Affiliation(s)
- Sebastian Eustermann
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Avinash B Patel
- Department of Molecular Biosciences, Robert H. Lurie Comprehensive Cancer Center, Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
| | - Karl-Peter Hopfner
- Gene Center and Department of Biochemistry, Faculty of Chemistry and Pharmacy, LMU Munich, Munich, Germany
| | - Yuan He
- Department of Molecular Biosciences, Robert H. Lurie Comprehensive Cancer Center, Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA.
| | - Philipp Korber
- Biomedical Center (BMC), Molecular Biology, Faculty of Medicine, LMU Munich, Martinsried, Germany.
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Ramsey JR, Shelton PM, Heiss TK, Olinares PDB, Vostal LE, Soileau H, Grasso M, Casebeer SW, Adaniya S, Miller M, Sun S, Huggins DJ, Myers RW, Chait BT, Vinogradova EV, Kapoor TM. Using a Function-First "Scout Fragment"-Based Approach to Develop Allosteric Covalent Inhibitors of Conformationally Dynamic Helicase Mechanoenzymes. J Am Chem Soc 2024; 146:62-67. [PMID: 38134034 PMCID: PMC10958666 DOI: 10.1021/jacs.3c10581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
Helicases, classified into six superfamilies, are mechanoenzymes that utilize energy derived from ATP hydrolysis to remodel DNA and RNA substrates. These enzymes have key roles in diverse cellular processes, such as translation, ribosome assembly, and genome maintenance. Helicases with essential functions in certain cancer cells have been identified, and helicases expressed by many viruses are required for their pathogenicity. Therefore, helicases are important targets for chemical probes and therapeutics. However, it has been very challenging to develop chemical inhibitors for helicases, enzymes with high conformational dynamics. We envisioned that electrophilic "scout fragments", which have been used in chemical proteomic studies, could be leveraged to develop covalent inhibitors of helicases. We adopted a function-first approach, combining enzymatic assays with enantiomeric probe pairs and mass spectrometry, to develop a covalent inhibitor that selectively targets an allosteric site in SARS-CoV-2 nsp13, a superfamily-1 helicase. Further, we demonstrate that scout fragments inhibit the activity of two human superfamily-2 helicases, BLM and WRN, involved in genome maintenance. Together, our findings suggest an approach to discover covalent inhibitor starting points and druggable allosteric sites in conformationally dynamic mechanoenzymes.
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Affiliation(s)
- Jared R. Ramsey
- Tri-Institutional PhD Program in Chemical Biology, New York, NY 10021, United States
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, United States
| | - Patrick M.M Shelton
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, United States
| | - Tyler K. Heiss
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, United States
| | - Paul Dominic B. Olinares
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY 10065, United States
| | - Lauren E. Vostal
- Tri-Institutional PhD Program in Chemical Biology, New York, NY 10021, United States
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, United States
| | - Heather Soileau
- Tri-Institutional PhD Program in Chemical Biology, New York, NY 10021, United States
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, United States
| | - Michael Grasso
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, United States
| | - Sara W. Casebeer
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, United States
| | - Stephanie Adaniya
- Laboratory of Chemical Immunology and Proteomics, The Rockefeller University, New York, NY 10065, United States
| | - Michael Miller
- Sanders Tri-Institutional Therapeutics Discovery Institute, New York, NY 10065, United States
| | - Shan Sun
- Sanders Tri-Institutional Therapeutics Discovery Institute, New York, NY 10065, United States
| | - David J. Huggins
- Sanders Tri-Institutional Therapeutics Discovery Institute, New York, NY 10065, United States
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10021, United States
| | - Robert W. Myers
- Sanders Tri-Institutional Therapeutics Discovery Institute, New York, NY 10065, United States
| | - Brian T. Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY 10065, United States
| | - Ekaterina V. Vinogradova
- Tri-Institutional PhD Program in Chemical Biology, New York, NY 10021, United States
- Laboratory of Chemical Immunology and Proteomics, The Rockefeller University, New York, NY 10065, United States
| | - Tarun M. Kapoor
- Tri-Institutional PhD Program in Chemical Biology, New York, NY 10021, United States
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, United States
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5
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García-Martínez A, Zinovjev K, Ruiz-Pernía JJ, Tuñón I. Conformational Changes and ATP Hydrolysis in Zika Helicase: The Molecular Basis of a Biomolecular Motor Unveiled by Multiscale Simulations. J Am Chem Soc 2023; 145:24809-24819. [PMID: 37921592 PMCID: PMC10852352 DOI: 10.1021/jacs.3c09015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 09/30/2023] [Accepted: 10/17/2023] [Indexed: 11/04/2023]
Abstract
We computationally study the Zika NS3 helicase, a biological motor, using ATP hydrolysis energy for nucleic acid remodeling. Through molecular mechanics and hybrid quantum mechanics/molecular mechanics simulations, we explore the conformational landscape of motif V, a conserved loop connecting the active sites for ATP hydrolysis and nucleic acid binding. ATP hydrolysis, initiated by a meta-phosphate group formation, involves the nucleophilic attack of a water molecule activated by Glu286 proton abstraction. Motif V hydrogen bonds to this water via the Gly415 backbone NH group, assisting hydrolysis. Posthydrolysis, free energy is released when the inorganic phosphate moves away from the coordination shell of the magnesium ion, inducing a significant shift in the conformational landscape of motif V to establish a hydrogen bond between the Gly415 NH group and Glu285. According to our simulations, the Zika NS3 helicase acts as a ratchet biological motor with motif V transitions steered by Gly415's γ-phosphate sensing in the ATPase site.
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Affiliation(s)
| | - Kirill Zinovjev
- Departamento de Química Física, Universidad de Valencia, 46100 Bujassot, Spain
| | | | - Iñaki Tuñón
- Departamento de Química Física, Universidad de Valencia, 46100 Bujassot, Spain
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6
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Amrein F, Sarto C, Cababie LA, Gonzalez Flecha FL, Kaufman S, Arrar M. Impact of bound ssRNA length on allostery in the Dengue Virus NS3 helicase. Nucleic Acids Res 2023; 51:11213-11224. [PMID: 37823592 PMCID: PMC10639040 DOI: 10.1093/nar/gkad808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 08/20/2023] [Accepted: 09/19/2023] [Indexed: 10/13/2023] Open
Abstract
The presence of ATP is known to stimulate helicase activity of the Dengue Virus Non-structural protein 3 helicase (NS3h), and the presence of RNA stimulates NS3h ATPase activity, however this coupling is still mechanistically unclear. Here we use atomistic models and molecular dynamics simulations to evaluate the single-stranded RNA (ssRNA)-length dependence of the NS3h-ssRNA binding affinity and its modulation by bound ATP. Considering complexes with 7, 11, 16 and 26 nucleotides (nts), we observe that both the binding affinity and its modulation by bound ATP are augmented with increased ssRNA lengths. In models with at least 11 nts bound, the binding of ATP results in a shift from a tightly bound to a weakly bound state. We find that the weakly bound state persists during both the ADP-Pi- and ADP-bound stages of the catalytic cycle. We obtain the equilibrium association constants for NS3h binding to an ssRNA 10-mer in vitro, both in the absence and presence of ADP, which further support the alternation between tightly and weakly bound states during the catalytic cycle. The length of bound ssRNA is critical for understanding the NS3h-RNA interaction as well as how it is modulated during the catalytic cycle.
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Affiliation(s)
- Fernando Amrein
- Universidad de Buenos Aires, CONICET, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Junín 956, CABA 1113, Argentina
- Universidad de Buenos Aires, CONICET, Instituto de Cálculo, Intendente Guiraldes 2160, CABA 1428, Argentina
| | - Carolina Sarto
- Universidad de Buenos Aires, CONICET, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Intendente Guiraldes 2160, CABA 1428, Argentina
- Universidad de Buenos Aires, CONICET, Instituto de Cálculo, Intendente Guiraldes 2160, CABA 1428, Argentina
| | - Leila A Cababie
- Universidad de Buenos Aires, CONICET, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Junín 956, CABA 1113, Argentina
| | - F Luis Gonzalez Flecha
- Universidad de Buenos Aires, CONICET, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Junín 956, CABA 1113, Argentina
- Universidad de Buenos Aires, Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Junín 956, CABA 1113, Argentina
| | - Sergio B Kaufman
- Universidad de Buenos Aires, CONICET, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Junín 956, CABA 1113, Argentina
- Universidad de Buenos Aires, Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Junín 956, CABA 1113, Argentina
| | - Mehrnoosh Arrar
- Universidad de Buenos Aires, CONICET, Instituto de Cálculo, Intendente Guiraldes 2160, CABA 1428, Argentina
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7
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Ramsey JR, Shelton PMM, Heiss TK, Olinares PDB, Vostal LE, Soileau H, Grasso M, Warrington S, Adaniya S, Miller M, Sun S, Huggins DJ, Myers RW, Chait BT, Vinogradova EV, Kapoor TM. Using a function-first 'scout fragment'-based approach to develop allosteric covalent inhibitors of conformationally dynamic helicase mechanoenzymes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.25.559391. [PMID: 37808863 PMCID: PMC10557574 DOI: 10.1101/2023.09.25.559391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Helicases, classified into six superfamilies, are mechanoenzymes that utilize energy derived from ATP hydrolysis to remodel DNA and RNA substrates. These enzymes have key roles in diverse cellular processes, such as genome replication and maintenance, ribosome assembly and translation. Helicases with essential functions only in certain cancer cells have been identified and helicases expressed by certain viruses are required for their pathogenicity. As a result, helicases are important targets for chemical probes and therapeutics. However, it has been very challenging to develop selective chemical inhibitors for helicases, enzymes with highly dynamic conformations. We envisioned that electrophilic 'scout fragments', which have been used for chemical proteomic based profiling, could be leveraged to develop covalent inhibitors of helicases. We adopted a function-first approach, combining enzymatic assays with enantiomeric probe pairs and mass spectrometry, to develop a covalent inhibitor that selectively targets an allosteric site in SARS-CoV-2 nsp13, a superfamily-1 helicase. Further, we demonstrate that scout fragments inhibit the activity of two human superfamily-2 helicases, BLM and WRN, involved in genome maintenance. Together, our findings suggest a covalent inhibitor discovery approach to target helicases and potentially other conformationally dynamic mechanoenzymes.
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8
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Mao C, Mills M. Characterization of human XPD helicase activity with Single Molecule Magnetic Tweezers. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.07.527508. [PMID: 36798221 PMCID: PMC9934580 DOI: 10.1101/2023.02.07.527508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
XPD helicase is a DNA unwinding enzyme involved in multiple cellular processes. As part of TFIIH, XPD opens a repair bubble in DNA for access by proteins in the nucleotide excision repair pathway. XPD uses the energy from ATP hydrolysis to translocate in the 5-prime to 3-prime direction on one strand of duplex DNA, displacing the opposite strand in the process. We used magnetic tweezers assays to measure the double-stranded DNA (dsDNA) unwinding and single-stranded DNA (ssDNA) translocation activities of human XPD by itself. In our experimental setup, hXPD exhibits low unwinding processivity of ~14 bp and slow overall unwinding rate of ~0.3 bp/s. Individual unwinding and translocation events were composed of fast and slow runs and pauses. Analysis of these events gave similar mean run sizes and rates for unwinding and translocation, suggesting that unwinding is a reflection of translocation. The analysis also revealed that hXPD spent similar time stalling and unwinding. hXPD translocated on ssDNA at a similar overall rate as that of unwinding, pointing to an active helicase. However, we observed modest effects of DNA sequence on stalling and unwinding initiation position. Considering the slow unwinding rate, high probability of base pair separation at the ssDNA/dsDNA fork, and the observed DNA sequence dependences, we propose that hXPD is most likely a partially active helicase. Our results provide detailed information on the basal activity of hXPD which enhances our mechanistic understanding of hXPD activity.
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9
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Sadic M, Schneider WM, Katsara O, Medina GN, Fisher A, Mogulothu A, Yu Y, Gu M, de los Santos T, Schneider RJ, Dittmann M. DDX60 selectively reduces translation off viral type II internal ribosome entry sites. EMBO Rep 2022; 23:e55218. [PMID: 36256515 PMCID: PMC9724679 DOI: 10.15252/embr.202255218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 09/07/2022] [Accepted: 09/15/2022] [Indexed: 11/05/2022] Open
Abstract
Co-opting host cell protein synthesis is a hallmark of many virus infections. In response, certain host defense proteins limit mRNA translation globally, albeit at the cost of the host cell's own protein synthesis. Here, we describe an interferon-stimulated helicase, DDX60, that decreases translation from viral internal ribosome entry sites (IRESs). DDX60 acts selectively on type II IRESs of encephalomyocarditis virus (EMCV) and foot and mouth disease virus (FMDV), but not by other IRES types or by 5' cap. Correspondingly, DDX60 reduces EMCV and FMDV (type II IRES) replication, but not that of poliovirus or bovine enterovirus 1 (BEV-1; type I IRES). Furthermore, replacing the IRES of poliovirus with a type II IRES is sufficient for DDX60 to inhibit viral replication. Finally, DDX60 selectively modulates the amount of translating ribosomes on viral and in vitro transcribed type II IRES mRNAs, but not 5' capped mRNA. Our study identifies a novel facet in the repertoire of interferon-stimulated effector genes, the selective downregulation of translation from viral type II IRES elements.
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Affiliation(s)
| | | | | | - Gisselle N Medina
- Plum Island Animal Disease Center, ARSUSDAGreenportNYUSA,National Bio and Agro‐Defense Facility (NBAF), ARSUSDAManhattanKSUSA
| | | | - Aishwarya Mogulothu
- Plum Island Animal Disease Center, ARSUSDAGreenportNYUSA,Department of Pathobiology and Veterinary ScienceUniversity of ConnecticutStorrsCTUSA
| | - Yingpu Yu
- The Rockefeller UniversityNew YorkNYUSA
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10
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Craig JM, Mills M, Kim HC, Huang JR, Abell S, Mount J, Gundlach J, Neuman K, Laszlo A. Nanopore tweezers measurements of RecQ conformational changes reveal the energy landscape of helicase motion. Nucleic Acids Res 2022; 50:10601-10613. [PMID: 36165957 PMCID: PMC9561376 DOI: 10.1093/nar/gkac837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 09/02/2022] [Accepted: 09/19/2022] [Indexed: 11/13/2022] Open
Abstract
Helicases are essential for nearly all nucleic acid processes across the tree of life, yet detailed understanding of how they couple ATP hydrolysis to translocation and unwinding remains incomplete because their small (∼300 picometer), fast (∼1 ms) steps are difficult to resolve. Here, we use Nanopore Tweezers to observe single Escherichia coli RecQ helicases as they translocate on and unwind DNA at ultrahigh spatiotemporal resolution. Nanopore Tweezers simultaneously resolve individual steps of RecQ along the DNA and conformational changes of the helicase associated with stepping. Our data reveal the mechanochemical coupling between physical domain motions and chemical reactions that together produce directed motion of the helicase along DNA. Nanopore Tweezers measurements are performed under either assisting or opposing force applied directly on RecQ, shedding light on how RecQ responds to such forces in vivo. Determining the rates of translocation and physical conformational changes under a wide range of assisting and opposing forces reveals the underlying dynamic energy landscape that drives RecQ motion. We show that RecQ has a highly asymmetric energy landscape that enables RecQ to maintain velocity when encountering molecular roadblocks such as bound proteins and DNA secondary structures. This energy landscape also provides a mechanistic basis making RecQ an 'active helicase,' capable of unwinding dsDNA as fast as it translocates on ssDNA. Such an energy landscape may be a general strategy for molecular motors to maintain consistent velocity despite opposing loads or roadblocks.
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Affiliation(s)
- Jonathan M Craig
- Department of Physics, University of Washington, 3910 15th Ave NE, Seattle, WA, USA
| | - Maria Mills
- Laboratory of Single Molecule Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Department of Physics & Astronomy, University of Missouri, 701 S College Ave, Physics Building Rm 223, Columbia, MO 65211, USA
| | - Hwanhee C Kim
- Department of Physics, University of Washington, 3910 15th Ave NE, Seattle, WA, USA
| | - Jesse R Huang
- Department of Physics, University of Washington, 3910 15th Ave NE, Seattle, WA, USA
| | - Sarah J Abell
- Department of Physics, University of Washington, 3910 15th Ave NE, Seattle, WA, USA
| | - Jonathan W Mount
- Department of Physics, University of Washington, 3910 15th Ave NE, Seattle, WA, USA
| | - Jens H Gundlach
- Department of Physics, University of Washington, 3910 15th Ave NE, Seattle, WA, USA
| | - Keir C Neuman
- Laboratory of Single Molecule Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrew H Laszlo
- Department of Physics, University of Washington, 3910 15th Ave NE, Seattle, WA, USA
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11
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Anindita PD, Halbeisen M, Řeha D, Tuma R, Franta Z. Mechanistic insight into the RNA stimulated-ATPase activity of tick-borne encephalitis virus helicase. J Biol Chem 2022; 298:102383. [PMID: 35987382 PMCID: PMC9490040 DOI: 10.1016/j.jbc.2022.102383] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 08/12/2022] [Accepted: 08/13/2022] [Indexed: 11/05/2022] Open
Abstract
The helicase domain of nonstructural protein 3 (NS3H) unwinds the double-stranded RNA replication intermediate in an ATP-dependent manner during the flavivirus life cycle. While the ATP hydrolysis mechanism of Dengue and Zika viruses NS3H has been extensively studied, little is known in the case of the tick-borne encephalitis virus NS3H. We demonstrate that ssRNA binds with nanomolar affinity to NS3H and strongly stimulates the ATP hydrolysis cycle, whereas ssDNA binds only weakly and inhibits ATPase activity in a noncompetitive manner. Thus, NS3H is an RNA-specific helicase, whereas DNA might act as an allosteric inhibitor. Using modeling, we explored plausible allosteric mechanisms by which ssDNA inhibits the ATPase via nonspecific binding in the vicinity of the active site and ATP repositioning. We captured several structural snapshots of key ATP hydrolysis stages using X-ray crystallography. One intermediate, in which the inorganic phosphate and ADP remained trapped inside the ATPase site after hydrolysis, suggests that inorganic phosphate release is the rate-limiting step. Using structure-guided modeling and molecular dynamics simulation, we identified putative RNA-binding residues and observed that the opening and closing of the ATP-binding site modulates RNA affinity. Site-directed mutagenesis of the conserved RNA-binding residues revealed that the allosteric activation of ATPase activity is primarily communicated via an arginine residue in domain 1. In summary, we characterized conformational changes associated with modulating RNA affinity and mapped allosteric communication between RNA-binding groove and ATPase site of tick-borne encephalitis virus helicase.
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Affiliation(s)
| | - Marco Halbeisen
- Department of Chemistry, Faculty of Science, University of South Bohemia, Czech Republic
| | - David Řeha
- Department of Chemistry, Faculty of Science, University of South Bohemia, Czech Republic
| | - Roman Tuma
- Department of Chemistry, Faculty of Science, University of South Bohemia, Czech Republic
| | - Zdenek Franta
- Department of Chemistry, Faculty of Science, University of South Bohemia, Czech Republic.
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12
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Mechanistic insights into the multiple activities of the Rad5 family of enzymes. J Mol Biol 2022; 434:167581. [DOI: 10.1016/j.jmb.2022.167581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 04/01/2022] [Accepted: 04/02/2022] [Indexed: 11/18/2022]
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13
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Ul Haq A, Sheikh A, Naeem S, Abidi SH. Molecular docking analysis of fluoroquinolones and other natural and synthetic compounds with the HCV NS3 helicase. Bioinformation 2022; 18:147-154. [PMID: 36518146 PMCID: PMC9722412 DOI: 10.6026/97320630018147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/07/2022] [Accepted: 03/31/2022] [Indexed: 08/10/2023] Open
Abstract
It is of an interest to document the molecular docking analysis of fluoroquinolones and other natural and synthetic compounds with the HCV NS3 helicase. Data shows that three fluoroquinolones interacted with the NS3 helicase in the catalytic region, targeting some of the amino acids known to play a crucial role in NS3 helicase activity. Similarly, binding energy shows that the fluoroquinolones were comparable to the thiazolpiperazinyl derivatives, while superior to several of the synthetic and natural derivatives. The results show three fluoroquinolones to be potent helicase inhibitors that can be repurposed as supplemental therapy against HCV especially in cases non-responsive to DAAAs.
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Affiliation(s)
- Ahtesham Ul Haq
- Department of Biochemistry, University of Karachi, Karachi-Pakistan
| | - Alisalman Sheikh
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi-Pakistan
| | - Sadaf Naeem
- Department of Biochemistry, University of Karachi, Karachi-Pakistan
| | - Syed Hani Abidi
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi-Pakistan
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14
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Du Pont KE, McCullagh M, Geiss BJ. Conserved motifs in the flavivirus NS3 RNA helicase enzyme. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1688. [PMID: 34472205 PMCID: PMC8888775 DOI: 10.1002/wrna.1688] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/29/2021] [Accepted: 08/02/2021] [Indexed: 01/04/2023]
Abstract
Flaviviruses are a major health concern because over half of the world population is at risk of infection and there are very few antiviral therapeutics to treat diseases resulting from infection. Replication is an essential part of the flavivirus survival. One of the viral proteins, NS3 helicase, is critical for unwinding the double stranded RNA intermediate during flaviviral replication. The helicase performs the unwinding of the viral RNA intermediate structure in an ATP-dependent manner. NS3 helicase is a member of the Viral/DEAH-like subfamily of the superfamily 2 helicase containing eight highly conserved structural motifs (I, Ia, II, III, IV, IVa, V, and VI) localized between the ATP-binding and RNA-binding pockets. Of these structural motifs only three are well characterized for function in flaviviruses (I, II, and VI). The roles of the other structural motifs are not well understood for NS3 helicase function, but comparison of NS3 with other superfamily 2 helicases within the viral/DEAH-like, DEAH/RHA, and DEAD-box subfamilies can be used to elucidate the roles of these structural motifs in the flavivirus NS3 helicase. This review aims to summarize the role of each conserved structural motif within flavivirus NS3 in RNA helicase function. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease.
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Affiliation(s)
- Kelly E. Du Pont
- Department of Chemistry, Colorado State University, Fort Collins, Colorado, USA
| | - Martin McCullagh
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Brian J. Geiss
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA,Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA,School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado, USA
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15
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Nodelman IM, Das S, Faustino AM, Fried SD, Bowman GD, Armache JP. Nucleosome recognition and DNA distortion by the Chd1 remodeler in a nucleotide-free state. Nat Struct Mol Biol 2022; 29:121-129. [PMID: 35173352 DOI: 10.1038/s41594-021-00719-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 12/23/2021] [Indexed: 12/12/2022]
Abstract
Chromatin remodelers are ATP-dependent enzymes that reorganize nucleosomes within all eukaryotic genomes. Here we report a complex of the Chd1 remodeler bound to a nucleosome in a nucleotide-free state, determined by cryo-EM to 2.3 Å resolution. The remodeler stimulates the nucleosome to absorb an additional nucleotide on each strand at two different locations: on the tracking strand within the ATPase binding site and on the guide strand one helical turn from the ATPase motor. Remarkably, the additional nucleotide on the tracking strand is associated with a local transformation toward an A-form geometry, explaining how sequential ratcheting of each DNA strand occurs. The structure also reveals a histone-binding motif, ChEx, which can block opposing remodelers on the nucleosome and may allow Chd1 to participate in histone reorganization during transcription.
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Affiliation(s)
- Ilana M Nodelman
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA
| | - Sayan Das
- Department of Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | | | - Stephen D Fried
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA.,Department of Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - Gregory D Bowman
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA.
| | - Jean-Paul Armache
- Department of Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA.
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16
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Lin M, Cui W, Tian H, Zhang Y, Chen C, Yang X, Chi H, Mu Z, Chen C, Wang Z, Ji X, Yang H, Lin Z. Structural Basis of Zika Virus Helicase in RNA Unwinding and ATP Hydrolysis. ACS Infect Dis 2022; 8:150-158. [PMID: 34904824 DOI: 10.1021/acsinfecdis.1c00455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The flavivirus nonstructural protein 3 helicase (NS3hel) is a multifunctional domain protein that is associated with DNA/RNA helicase, nucleoside triphosphatase (NTPase), and RNA 5'-triphosphatase (RTPase) activities. As an NTPase-dependent superfamily 2 (SF2) member, NS3hel employs an NTP-driven motor force to unwind double-stranded RNA while translocating along single-stranded RNA and is extensively involved in the viral replication process. Although the structures of SF2 helicases are widely investigated as promising drug targets, the mechanism of energy transduction between NTP hydrolysis and the RNA binding sites in ZIKV NS3hel remains elusive. Here, we report the crystal structure of ZIKV NS3hel in complex with its natural substrates ATP-Mn2+ and ssRNA. Distinct from other members of the Flavivirus genus, ssRNA binding to ZIKV NS3hel induces relocation of the active water molecules and ATP-associated metal ions in the NTP hydrolysis active site, which promotes the hydrolysis of ATP and the production of AMP. Our findings highlight the importance of the allosteric role of ssRNA on the modulation of ATP hydrolysis and energy utilization.
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Affiliation(s)
- Mengmeng Lin
- School of Life Sciences, Tianjin University, Tianjin 300072, China
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Shanghai Clinical Research and Trial Center, Shanghai 201210, China
| | - Wen Cui
- School of Life Sciences, Tianjin University, Tianjin 300072, China
- Institute of Life Sciences, Chongqing Medical University, Chongqing 400016, China
| | - Hongliang Tian
- School of Life Sciences, Tianjin University, Tianjin 300072, China
| | - Yan Zhang
- School of Life Sciences, Tianjin University, Tianjin 300072, China
| | - Chen Chen
- School of Life Sciences, Tianjin University, Tianjin 300072, China
| | - Xiaoyun Yang
- School of Life Sciences, Tianjin University, Tianjin 300072, China
| | - Heng Chi
- School of Life Sciences, Tianjin University, Tianjin 300072, China
| | - Zhongyu Mu
- School of Life Sciences, Tianjin University, Tianjin 300072, China
| | - Cheng Chen
- School of Life Sciences, Tianjin University, Tianjin 300072, China
| | - Zefang Wang
- School of Life Sciences, Tianjin University, Tianjin 300072, China
- Tianjin International Joint Academy of Biotechnology and Medicine, Tianjin 300457, China
| | - Xiaoyun Ji
- The State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Haitao Yang
- School of Life Sciences, Tianjin University, Tianjin 300072, China
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Tianjin International Joint Academy of Biotechnology and Medicine, Tianjin 300457, China
- Shanghai Clinical Research and Trial Center, Shanghai 201210, China
| | - Zhi Lin
- School of Life Sciences, Tianjin University, Tianjin 300072, China
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17
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Zhang C, Li Y, Samad A, Zheng P, Ji Z, Chen F, Zhang H, Jin T. Structure and mutation analysis of the hexameric P4 from Pseudomonas aeruginosa phage phiYY. Int J Biol Macromol 2022; 194:42-49. [PMID: 34856215 DOI: 10.1016/j.ijbiomac.2021.11.129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 11/27/2022]
Abstract
phiYY is a foremost member of Cystoviridae isolated from Pseudomonas aeruginosa. Its P4 protein with NTPase activity is a molecular motor for their genome packing during viral particle assembly. Previously studies on the P4 from four Pseudomonas phages phi6, phi8, phi12 and phi13 reveal that despite of belonging to the same protein family, they are unique in sequence, structure and biochemical properties. To better understand the structure and function of phiYY P4, four crystal structures of phiYY P4 in apo-form or combined with different ligands were solved at the resolution between 1.85 Å and 2.43 Å, which showed drastic conformation change of the H1 motif in ligand-bound forms compared with in apo-form, a four residue-mutation at the ligand binding pocket abolished its ATPase activity. Furthermore, the truncation mutation of the 50 residues at the C-terminal did not impair the hexamerization and ATP hydrolysis.
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Affiliation(s)
- Caiying Zhang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China
| | - Yuelong Li
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Abdus Samad
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Peiyi Zheng
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Zheng Ji
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Feng Chen
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Huidong Zhang
- Research Center for Environment and Female Reproductive Health, the Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen 518033, China
| | - Tengchuan Jin
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China; Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China; CAS Center for Excellence in Molecular Cell Science, Shanghai, China.
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18
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Determining translocation orientations of nucleic acid helicases. Methods 2021; 204:160-171. [PMID: 34758393 PMCID: PMC9076756 DOI: 10.1016/j.ymeth.2021.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 11/20/2022] Open
Abstract
Helicase enzymes translocate along an RNA or DNA template with a defined polarity to unwind, separate, or remodel duplex strands for a variety of genome maintenance processes. Helicase mutations are commonly associated with a variety of diseases including aging, cancer, and neurodegeneration. Biochemical characterization of these enzymes has provided a wealth of information on the kinetics of unwinding and substrate preferences, and several high-resolution structures of helicases alone and bound to oligonucleotides have been solved. Together, they provide mechanistic insights into the structural translocation and unwinding orientations of helicases. However, these insights rely on structural inferences derived from static snapshots. Instead, continued efforts should be made to combine structure and kinetics to better define active translocation orientations of helicases. This review explores many of the biochemical and biophysical methods utilized to map helicase binding orientation to DNA or RNA substrates and includes several time-dependent methods to unequivocally map the active translocation orientation of these enzymes to better define the active leading and trailing faces.
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19
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Kwon S, Motohashi K. Incentive or disincentive for research data disclosure? A large-scale empirical analysis and implications for open science policy. INTERNATIONAL JOURNAL OF INFORMATION MANAGEMENT 2021. [DOI: 10.1016/j.ijinfomgt.2021.102371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Martínez PJ, Chacón R. Ratchet universality in coupled dissipative oscillators without external bias. Phys Rev E 2021; 104:024224. [PMID: 34525664 DOI: 10.1103/physreve.104.024224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/16/2021] [Indexed: 06/13/2023]
Abstract
Directed ratchet transport is generally observed in nonautonomous systems as a result of the interplay of nonlinearity, symmetry breaking, and nonequilibrium fluctuations. Here we demonstrate that ratchet dynamics can appear in significant transporting degrees of freedom of dissipative coupled systems without external bias due to unidirectional coupling of oscillatory degrees of freedom (which are also nonbiasing in any direction), while optimal enhancement of directed ratchet transport occurs when the initial conditions and parameters of such ratcheting degrees of freedom are suitably chosen as predicted by the theory of ratchet universality. The simple case of linear oscillatory degrees of freedom is discussed in detail, and numerical experiments are described which confirm all the theoretical predictions, including the dependence of current (velocity) reversals on the initial conditions and the ratcheting degrees-of-freedom parameters. This autonomous ratchet scenario could be exploited technologically, for instance, in the context of noncontact, rack-and-pinion type, nanoscale setups with coupling from the lateral Casimir force, and is relevant for studies of molecular motors in the biological realm.
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Affiliation(s)
- Pedro J Martínez
- Instituto de Nanociencia y Materiales de Aragón, CSIC-Universidad de Zaragoza, E-50009 Zaragoza, Spain
- Departamento de Física Aplicada, E.I.N.A., Universidad de Zaragoza, E-50018 Zaragoza, Spain
| | - Ricardo Chacón
- Departamento de Física Aplicada, E.I.I., Universidad de Extremadura, Apartado Postal 382, E-06006 Badajoz, Spain
- Instituto de Computación Científica Avanzada (ICCAEx), Universidad de Extremadura, E-06006 Badajoz, Spain
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21
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Brugger C, Deaconescu AM. A Gel-Based Assay for Probing Protein Translocation on dsDNA. Bio Protoc 2021; 11:e4094. [PMID: 34395731 PMCID: PMC8329466 DOI: 10.21769/bioprotoc.4094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 04/16/2021] [Accepted: 04/22/2021] [Indexed: 11/02/2022] Open
Abstract
Protein translocation on DNA represents the key biochemical activity of ssDNA translocases (aka helicases) and dsDNA translocases such as chromatin remodelers. Translocation depends on DNA binding but is a distinct process as it typically involves multiple DNA binding states, which are usually dependent on nucleotide binding/hydrolysis and are characterized by different affinities for the DNA. Several translocation assays have been described to distinguish between these two modes of action, simple binding as opposed to directional movement on dsDNA. Perhaps the most widely used is the triplex-forming oligonucleotide displacement assay. Traditionally, this assay relies on the formation of a DNA triplex from a dsDNA segment and a short radioactively labeled oligonucleotide. Upon translocation of the protein of interest along the DNA substrate, the third DNA strand is destabilized and eventually released off the DNA duplex. This process can be visualized and quantitated by polyacrylamide electrophoresis. Here, we present an effective, sensitive, and convenient variation of this assay that utilizes a fluorescently labeled oligonucleotide, eliminating the need to radioactively label DNA. In short, our protocol provides a safe and user-friendly alternative. Graphical abstract: Figure 1.Schematic of the triplex-forming oligonucleotide displacement assay.
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Affiliation(s)
- Christiane Brugger
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - Alexandra M. Deaconescu
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02903, USA
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22
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Zhang Y, Chen S, Yuan Z, Yi Z. Bioorthogonal dissection of the replicase assembly of hepatitis C virus. Cell Chem Biol 2021; 28:1366-1378.e4. [PMID: 33798447 PMCID: PMC8444619 DOI: 10.1016/j.chembiol.2021.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/21/2021] [Accepted: 03/10/2021] [Indexed: 01/01/2023]
Abstract
Positive-strand RNA viruses such as hepatitis C virus (HCV), flaviviruses, and coronaviruses are medically important. Assembly of replicase on host membranes is a conserved replication strategy and an attractive antiviral target. The mechanisms of replicase assembly are largely unknown, due to the technical difficulties in purifying the replicase and carrying out structural studies. Here, with an HCV replicase assembly surrogate system, we employed a bioorthogonal system to introduce the photolabile unnatural amino into each residue in the cytosolic regions of NS4B and the amphipathic helix (AH) of NS5A. Photocrosslinking enabled visualization of NS4B oligomerization and NS5A dimerization at pinpointed interacting residues and identifying contacting sites among the replicase components. Characterization of the interacting sites revealed hub elements in replicase assembly by docking replicase components to prompt protein-protein interactions. The results provide information about the molecular architecture of the replicase, advancing understanding of the mechanism of replicase assembly.
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Affiliation(s)
- Yang Zhang
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Shuiye Chen
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Zhenghong Yuan
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China.
| | - Zhigang Yi
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China; Shanghai Public Health Clinical Center, Fudan University, Shanghai 201052, China.
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23
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Li HC, Yang CH, Lo SY. Hepatitis C Viral Replication Complex. Viruses 2021; 13:v13030520. [PMID: 33809897 PMCID: PMC8004249 DOI: 10.3390/v13030520] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 12/16/2022] Open
Abstract
The life cycle of the hepatitis C virus (HCV) can be divided into several stages, including viral entry, protein translation, RNA replication, viral assembly, and release. HCV genomic RNA replication occurs in the replication organelles (RO) and is tightly linked to ER membrane alterations containing replication complexes (proteins NS3 to NS5B). The amplification of HCV genomic RNA could be regulated by the RO biogenesis, the viral RNA structure (i.e., cis-acting replication elements), and both viral and cellular proteins. Studies on HCV replication have led to the development of direct-acting antivirals (DAAs) targeting the replication complex. This review article summarizes the viral and cellular factors involved in regulating HCV genomic RNA replication and the DAAs that inhibit HCV replication.
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Affiliation(s)
- Hui-Chun Li
- Department of Biochemistry, Tzu Chi University, Hualien 97004, Taiwan;
| | - Chee-Hing Yang
- Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien 97004, Taiwan;
| | - Shih-Yen Lo
- Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien 97004, Taiwan;
- Department of Laboratory Medicine, Buddhist Tzu Chi General Hospital, Hualien 97004, Taiwan
- Correspondence: ; Tel.: +886-3-8565301 (ext. 2322)
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24
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Pirinçal A, Turan K. Human DDX56 protein interacts with influenza A virus NS1 protein and stimulates the virus replication. Genet Mol Biol 2021; 44:e20200158. [PMID: 33749700 PMCID: PMC7983190 DOI: 10.1590/1678-4685-gmb-2020-0158] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 02/08/2021] [Indexed: 11/21/2022] Open
Abstract
Influenza A viruses (IAV) are enveloped viruses carrying a single-stranded negative-sense RNA genome. Detection of host proteins having a relationship with IAV and revealing of the role of these proteins in the viral replication are of great importance in keeping IAV infections under control. Consequently, the importance of human DDX56, which is determined to be associated with a viral NS1 with a yeast two-hybrid assay, was investigated for IAV replication. The viral replication in knocked down cells for the DDX56 gene was evaluated. The NS1 was co-precipitated with the DDX56 protein in lysates of cells transiently expressing DDX56 and NS1 or infected with the viruses, showing that NS1 and DDX56 interact in mammalian cells. Viral NS1 showed a tendency to co-localize with DDX56 in the cells, transiently expressing both of these proteins, which supports the IP and two-hybrid assays results. The data obtained with in silico predictions supported the in vitro protein interaction results. The viral replication was significantly reduced in the DDX56-knockdown cells comparing with that in the control cells. In conclusion, human DDX56 protein interacts with the IAV NS1 protein in both yeast and mammalian cells and has a positive regulatory effect on IAV replication. However, the mechanism of DDX56 on IAV replication requires further elucidation.
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Affiliation(s)
- Ayşegül Pirinçal
- Marmara University, Institute of Health Sciences, Istanbul, Turkey
| | - Kadir Turan
- Marmara University, Faculty of Pharmacy, Department of Basic Pharmaceutical Sciences, Istanbul, Turkey
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25
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Ge M, Molt RW, Jenkins HT, Blackburn GM, Jin Y, Antson AA. Octahedral Trifluoromagnesate, an Anomalous Metal Fluoride Species, Stabilizes the Transition State in a Biological Motor. ACS Catal 2021; 11:2769-2773. [PMID: 33717640 PMCID: PMC7944477 DOI: 10.1021/acscatal.0c04500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 12/26/2020] [Indexed: 01/11/2023]
Abstract
![]()
Isoelectronic metal
fluoride transition state analogue (TSA) complexes,
MgF3– and AlF4–, have proven to be immensely useful in understanding mechanisms
of biological motors utilizing phosphoryl transfer. Here we report
a previously unobserved octahedral TSA complex, MgF3(H2O)−, in a 1.5 Å resolution Zika virus
NS3 helicase crystal structure. 19F NMR provided independent
validation and also the direct observation of conformational tightening
resulting from ssRNA binding in solution. The TSA stabilizes the two
conformations of motif V of the helicase that link ATP hydrolysis
with mechanical work. DFT analysis further validated the MgF3(H2O)− species, indicating the significance
of this TSA for studies of biological motors.
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Affiliation(s)
- Mengyu Ge
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, YO10 5DD, United Kingdom
| | - Robert W. Molt
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States
- ENSCO, Inc., 4849 North Wickham Road, Melbourne, Florida 32940, United States
| | - Huw T. Jenkins
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, YO10 5DD, United Kingdom
| | - G. Michael Blackburn
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Yi Jin
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff, CF10 3AT, United Kingdom
| | - Alfred A. Antson
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, YO10 5DD, United Kingdom
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26
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Lu H, Zhan Y, Li X, Bai X, Yuan F, Ma L, Wang X, Xie M, Wu W, Chen Z. Novel insights into the function of an N-terminal region of DENV2 NS4B for the optimal helicase activity of NS3. Virus Res 2021; 295:198318. [PMID: 33485995 DOI: 10.1016/j.virusres.2021.198318] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/19/2020] [Accepted: 01/17/2021] [Indexed: 10/22/2022]
Abstract
Dengue virus NS3 is a prototypical DEx(H/D) helicase that binds and hydrolyzes NTP to translocate along and unwind double-stranded nucleic acids. NS3 and NS4B are essential components of the flavivirus replication complex. Evidences showed that NS4B interacted with NS3 and modulated the helicase activity of NS3. Despite important insights into structural, mechanistic, and cellular aspects of the NS3 function, there is still a gap in understanding how it coordinates the helicase activities within the replicase complex for efficient replication. Here, using the DENV2 as a model, we redefined the critical region of NS4B required for NS3 function by pull-down and MST assays. The FRET-based unwinding assay showed that NS3 would accelerate unwinding duplex nucleic acids in the presence of NS4B (51-83). The simulated NS3-NS4B complex models based on the rigid-body docking delineated the potential interaction sites located in the conserved motif within the core domain of NS3. Mutations in motif I (I190A) and motif III (P319L) of NS3 interfered with the unwinding activity stimulated by NS4B. Upon binding to the NS3 helicase, NS4B assisted NS3 to dissociate from single-stranded nucleic acid and enabled NS3 helicase to keep high activity at high ATP concentrations. These results suggest that NS4B probably serves as an essential cofactor for NS3 to coordinate the ATP cycles and nucleic acid binding during viral genome replication.
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Affiliation(s)
- Hongyun Lu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yumeng Zhan
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xiaorong Li
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xuehui Bai
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Feifei Yuan
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Lulu Ma
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xue Wang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Mengjia Xie
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Wei Wu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Zhongzhou Chen
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.
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27
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Shen M, Dhingra N, Wang Q, Cheng C, Zhu S, Tian X, Yu J, Gong X, Li X, Zhang H, Xu X, Zhai L, Xie M, Gao Y, Deng H, He Y, Niu H, Zhao X, Xiang S. Structural basis for the multi-activity factor Rad5 in replication stress tolerance. Nat Commun 2021; 12:321. [PMID: 33436623 PMCID: PMC7804152 DOI: 10.1038/s41467-020-20538-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 12/04/2020] [Indexed: 12/17/2022] Open
Abstract
The yeast protein Rad5 and its orthologs in other eukaryotes promote replication stress tolerance and cell survival using their multiple activities, including ubiquitin ligase, replication fork remodeling and DNA lesion targeting activities. Here, we present the crystal structure of a nearly full-length Rad5 protein. The structure shows three distinct, but well-connected, domains required for Rad5’s activities. The spatial arrangement of these domains suggest that different domains can have autonomous activities but also undergo intrinsic coordination. Moreover, our structural, biochemical and cellular studies demonstrate that Rad5’s HIRAN domain mediates interactions with the DNA metabolism maestro factor PCNA and contributes to its poly-ubiquitination, binds to DNA and contributes to the Rad5-catalyzed replication fork regression, defining a new type of HIRAN domains with multiple activities. Our work provides a framework to understand how Rad5 integrates its various activities in replication stress tolerance. Rad5 is a hub connecting three replication stress tolerance pathways. Here, the authors present the 3.3 Å crystal structure of a N-terminal truncated K.lactis Rad5 construct that reveals the spatial arrangement of the HIRAN, Snf2 and RING domains and structure-guided in vitro and in vivo experiments reveal multiple activities of the yeast Rad5 HIRAN domain among them a role in binding PCNA and supporting its ubiquitination.
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Affiliation(s)
- Miaomiao Shen
- Department of Biochemistry and Molecular Biology, Tianjin Medical University, 300070, Tianjin, P. R. China.,Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, 300070, Tianjin, P. R. China.,The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Medical University, 300070, Tianjin, P. R. China
| | - Nalini Dhingra
- Molecular Biology Department, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Quan Wang
- Department of Molecular and Cellular Biochemistry, Indiana University Bloomington, Bloomington, IN, 47405, USA
| | - Chen Cheng
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, 201210, Shanghai, P. R. China
| | - Songbiao Zhu
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systematic Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, P. R. China
| | - Xiaolin Tian
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systematic Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, P. R. China
| | - Jun Yu
- CAS Key Laboratory of Nutrition, Metabolism and Food safety, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031, Shanghai, P. R. China
| | - Xiaoxin Gong
- Department of Biochemistry and Molecular Biology, Tianjin Medical University, 300070, Tianjin, P. R. China.,Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, 300070, Tianjin, P. R. China.,The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Medical University, 300070, Tianjin, P. R. China
| | - Xuzhichao Li
- Department of Biochemistry and Molecular Biology, Tianjin Medical University, 300070, Tianjin, P. R. China.,Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, 300070, Tianjin, P. R. China.,The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Medical University, 300070, Tianjin, P. R. China
| | - Hongwei Zhang
- CAS Key Laboratory of Nutrition, Metabolism and Food safety, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031, Shanghai, P. R. China
| | - Xin Xu
- Department of Biochemistry and Molecular Biology, Tianjin Medical University, 300070, Tianjin, P. R. China.,Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, 300070, Tianjin, P. R. China.,The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Medical University, 300070, Tianjin, P. R. China
| | - Liting Zhai
- CAS Key Laboratory of Nutrition, Metabolism and Food safety, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031, Shanghai, P. R. China
| | - Min Xie
- CAS Key Laboratory of Nutrition, Metabolism and Food safety, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031, Shanghai, P. R. China
| | - Ying Gao
- CAS Key Laboratory of Nutrition, Metabolism and Food safety, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031, Shanghai, P. R. China
| | - Haiteng Deng
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systematic Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, P. R. China
| | - Yongning He
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, 201210, Shanghai, P. R. China
| | - Hengyao Niu
- Department of Molecular and Cellular Biochemistry, Indiana University Bloomington, Bloomington, IN, 47405, USA
| | - Xiaolan Zhao
- Molecular Biology Department, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Song Xiang
- Department of Biochemistry and Molecular Biology, Tianjin Medical University, 300070, Tianjin, P. R. China. .,Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, 300070, Tianjin, P. R. China. .,The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Medical University, 300070, Tianjin, P. R. China.
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Abstract
As primary carriers of epigenetic information and gatekeepers of genomic DNA, nucleosomes are essential for proper growth and development of all eukaryotic cells. Although they are intrinsically dynamic, nucleosomes are actively reorganized by ATP-dependent chromatin remodelers. Chromatin remodelers contain helicase-like ATPase motor domains that can translocate along DNA, and a long-standing question in the field is how this activity is used to reposition or slide nucleosomes. In addition to ratcheting along DNA like their helicase ancestors, remodeler ATPases appear to dictate specific alternating geometries of the DNA duplex, providing an unexpected means for moving DNA past the histone core. Emerging evidence supports twist-based mechanisms for ATP-driven repositioning of nucleosomes along DNA. In this review, we discuss core experimental findings and ideas that have shaped the view of how nucleosome sliding may be achieved.
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Affiliation(s)
- Ilana M Nodelman
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA;
| | - Gregory D Bowman
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA;
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29
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Anwar MF, Khalid R, Hasanain A, Naeem S, Zarina S, Abidi SH, Ali S. Integrated Cheminformatics-Molecular Docking Approach to Drug Discovery Against Viruses. Infect Disord Drug Targets 2020; 20:150-159. [PMID: 30345931 DOI: 10.2174/1871526518666181019162359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 08/03/2018] [Accepted: 10/11/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND In the current study, we present an integrated in silico cheminformaticsmolecular docking approach to screen and test potential therapeutic compounds against viruses. Fluoroquinolones have been shown to inhibit HCV replication by targeting HCV NS3-helicase. Based on this observation, we hypothesized that natural analogs of fluoroquinolones will have similar or superior inhibitory potential while having potentially fewer adverse effects. METHODS To screen for natural analogs of fluoroquinolones, we devised an integrated in silico Cheminformatics-Molecular Docking approach. We used 17 fluoroquinolones as bait reference, to screen large databases of natural analogs. 10399 natural compounds and their derivatives were retrieved from the databases. From these compounds, molecules bearing physicochemical similarities with fluoroquinolones were analyzed using a cheminformatics-docking approach. RESULTS From the 10399 compounds screened using our cheminformatics approach, only 20 compounds were found to share physicochemical similarities with fluoroquinolones, while the remaining 10379 compounds were physiochemically different from fluoroquinolones. Molecular docking analysis showed 32 amino acids in the HCV NS3 active site that were most frequently targeted by fluoroquinolones and their natural analogues, indicating a functional similarity between the two groups of compounds. CONCLUSION This study describes a speedy and inexpensive approach to complement drug discovery and design against viral agents. The in silico analyses we used here can be employed to shortlist promising compounds/putative drugs that can be further tested in wet-lab.
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Affiliation(s)
- Muhammad Faraz Anwar
- National Center for Proteomics, University of Karachi, Karachi, Pakistan.,Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
| | - Ramsha Khalid
- Department of Biochemistry, University of Karachi, Karachi, Pakistan
| | | | - Sadaf Naeem
- Department of Biochemistry, University of Karachi, Karachi, Pakistan
| | - Shamshad Zarina
- National Center for Proteomics, University of Karachi, Karachi, Pakistan
| | - Syed Hani Abidi
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan.,Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Syed Ali
- Department of Biomedical Sciences, Nazarbayev University School of Medicine, Nazarbayev University, Astana, Kazakhstan
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30
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An in silico approach to analyze HCV genotype-specific binding-site variation and its effect on drug-protein interaction. Sci Rep 2020; 10:20885. [PMID: 33257748 PMCID: PMC7705671 DOI: 10.1038/s41598-020-77720-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 09/18/2020] [Indexed: 01/06/2023] Open
Abstract
Genotype variation in viruses can affect the response of antiviral treatment. Several studies have established approaches to determine genotype-specific variations; however, analyses to determine the effect of these variations on drug–protein interactions remain unraveled. We present an in-silico approach to explore genotype-specific variations and their effect on drug–protein interaction. We have used HCV NS3 helicase and fluoroquinolones as a model for drug–protein interaction and have investigated the effect of amino acid variations in HCV NS3 of genotype 1a, 1b, 2b and 3a on NS3-fluoroquinolone interaction. We retrieved 687, 667, 101 and 248 nucleotide sequences of HCV NS3 genotypes 1a, 1b, 2b, and 3a, respectively, and translated these into amino acid sequences and used for genotype variation analysis, and also to construct 3D protein models for 2b and 3a genotypes. For 1a and 1b, crystal structures were used. Drug–protein interactions were determined using molecular docking analyses. Our results revealed that individual genotype-specific HCV NS3 showed substantial sequence heterogeneity that resulted in variations in docking interactions. We believe that our approach can be extrapolated to include other viruses to study the clinical significance of genotype-specific variations in drug–protein interactions.
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31
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Linke H, Höcker B, Furuta K, Forde NR, Curmi PMG. Synthetic biology approaches to dissecting linear motor protein function: towards the design and synthesis of artificial autonomous protein walkers. Biophys Rev 2020; 12:1041-1054. [PMID: 32651904 PMCID: PMC7429643 DOI: 10.1007/s12551-020-00717-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 07/02/2020] [Indexed: 12/20/2022] Open
Abstract
Molecular motors and machines are essential for all cellular processes that together enable life. Built from proteins with a wide range of properties, functionalities and performance characteristics, biological motors perform complex tasks and can transduce chemical energy into mechanical work more efficiently than human-made combustion engines. Sophisticated studies of biological protein motors have provided many structural and biophysical insights and enabled the development of models for motor function. However, from the study of highly evolved, biological motors, it remains difficult to discern detailed mechanisms, for example, about the relative role of different force generation mechanisms, or how information is communicated across a protein to achieve the necessary coordination. A promising, complementary approach to answering these questions is to build synthetic protein motors from the bottom up. Indeed, much effort has been invested in functional protein design, but so far, the "holy grail" of designing and building a functional synthetic protein motor has not been realized. Here, we review the progress made to date, and we put forward a roadmap for achieving the aim of constructing the first artificial, autonomously running protein motor. Specifically, we propose to break down the task into (i) enzymatic control of track binding, (ii) the engineering of asymmetry and (iii) the engineering of allosteric control for internal communication. We also propose specific approaches for solving each of these challenges.
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Affiliation(s)
- Heiner Linke
- NanoLund and Solid State Physics, Lund University, Box 118, SE 22100, Lund, Sweden
| | - Birte Höcker
- Department of Biochemistry, University of Bayreuth, 95447, Bayreuth, Germany
| | - Ken'ya Furuta
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe, Hyogo, 651-2492, Japan
| | - Nancy R Forde
- Department of Physics, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - Paul M G Curmi
- School of Physics, University of New South Wales, Sydney, NSW, 2052, Australia.
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32
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Brugger C, Zhang C, Suhanovsky MM, Kim DD, Sinclair AN, Lyumkis D, Deaconescu AM. Molecular determinants for dsDNA translocation by the transcription-repair coupling and evolvability factor Mfd. Nat Commun 2020; 11:3740. [PMID: 32719356 PMCID: PMC7385628 DOI: 10.1038/s41467-020-17457-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 07/01/2020] [Indexed: 11/15/2022] Open
Abstract
Mfd couples transcription to nucleotide excision repair, and acts on RNA polymerases when elongation is impeded. Depending on impediment severity, this action results in either transcription termination or elongation rescue, which rely on ATP-dependent Mfd translocation on DNA. Due to its role in antibiotic resistance, Mfd is also emerging as a prime target for developing anti-evolution drugs. Here we report the structure of DNA-bound Mfd, which reveals large DNA-induced structural changes that are linked to the active site via ATPase motif VI. These changes relieve autoinhibitory contacts between the N- and C-termini and unmask UvrA recognition determinants. We also demonstrate that translocation relies on a threonine in motif Ic, widely conserved in translocases, and a family-specific histidine near motif IVa, reminiscent of the “arginine clamp” of RNA helicases. Thus, Mfd employs a mode of DNA recognition that at its core is common to ss/ds translocases that act on DNA or RNA. Transcription-repair coupling factors (TRCFs) are large ATPases that mediate the preferential repair of the transcribed DNA strand. Here the authors reveal the cryo-EM structure of DNA-bound Mfd, the bacterial TRCF, and provide molecular insights into its mode of action.
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Affiliation(s)
- Christiane Brugger
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - Cheng Zhang
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, 92093, USA
| | - Margaret M Suhanovsky
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - David D Kim
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - Amy N Sinclair
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - Dmitry Lyumkis
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, 92093, USA.,Department of Computational and Structural Biology, The Scripps Research Institute, La Jolla, CA, 92093, USA
| | - Alexandra M Deaconescu
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02903, USA.
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33
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Kose HB, Xie S, Cameron G, Strycharska MS, Yardimci H. Duplex DNA engagement and RPA oppositely regulate the DNA-unwinding rate of CMG helicase. Nat Commun 2020; 11:3713. [PMID: 32709841 PMCID: PMC7382467 DOI: 10.1038/s41467-020-17443-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 07/01/2020] [Indexed: 01/09/2023] Open
Abstract
A ring-shaped helicase unwinds DNA during chromosome replication in all organisms. Replicative helicases generally unwind duplex DNA an order of magnitude slower compared to their in vivo replication fork rates. However, the origin of slow DNA unwinding rates by replicative helicases and the mechanism by which other replication components increase helicase speed are unclear. Here, we demonstrate that engagement of the eukaryotic CMG helicase with template DNA at the replication fork impairs its helicase activity, which is alleviated by binding of the single-stranded DNA binding protein, RPA, to the excluded DNA strand. Intriguingly, we found that, when stalled due to interaction with the parental duplex, DNA rezipping-induced helicase backtracking reestablishes productive helicase-fork engagement, underscoring the significance of plasticity in helicase action. Our work provides a mechanistic basis for relatively slow duplex unwinding by replicative helicases and explains how replisome components that interact with the excluded DNA strand stimulate fork rates.
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Affiliation(s)
- Hazal B Kose
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, NW1 1AT, London, UK
| | - Sherry Xie
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, NW1 1AT, London, UK
| | - George Cameron
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, NW1 1AT, London, UK
| | - Melania S Strycharska
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, NW1 1AT, London, UK
| | - Hasan Yardimci
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, NW1 1AT, London, UK.
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34
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Blessing C, Knobloch G, Ladurner AG. Restraining and unleashing chromatin remodelers - structural information guides chromatin plasticity. Curr Opin Struct Biol 2020; 65:130-138. [PMID: 32693313 DOI: 10.1016/j.sbi.2020.06.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/06/2020] [Accepted: 06/16/2020] [Indexed: 12/21/2022]
Abstract
Chromatin remodeling enzymes are large molecular machines that guard the genome by reorganizing chromatin structure. They can reposition, space and evict nucleosomes and thus control gene expression, DNA replication and repair. Recent cryo-electron microscopy (cryo-EM) analyses have captured snapshots of various chromatin remodelers as they interact with nucleosomes. In this review, we summarize and discuss the advances made in our understanding of the regulation of chromatin remodelers, the mode of DNA translocation, as well as the influence of associated protein domains and remodeler subunits on the specific functions of chromatin remodeling complexes. The emerging structural information will help our understanding of disease mechanisms and guide our knowledge toward innovative therapeutic interventions.
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Affiliation(s)
- Charlotte Blessing
- Department of Physiological Chemistry, Biomedical Center (BMC), Faculty of Medicine, LMU Munich, 82152 Planegg-Martinsried, Germany; International Max Planck Research School for Molecular Life Sciences, Am Klopferspitz 18, 82152 Planegg-Martinsried, Germany
| | - Gunnar Knobloch
- Eisbach Bio GmbH, Am Klopferspitz 19, 82152, Planegg-Martinsried, Germany
| | - Andreas G Ladurner
- Department of Physiological Chemistry, Biomedical Center (BMC), Faculty of Medicine, LMU Munich, 82152 Planegg-Martinsried, Germany; International Max Planck Research School for Molecular Life Sciences, Am Klopferspitz 18, 82152 Planegg-Martinsried, Germany; Eisbach Bio GmbH, Am Klopferspitz 19, 82152, Planegg-Martinsried, Germany.
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35
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Chand MK, Carle V, Anuvind KG, Saikrishnan K. DNA-mediated coupling of ATPase, translocase and nuclease activities of a Type ISP restriction-modification enzyme. Nucleic Acids Res 2020; 48:2594-2603. [PMID: 31974580 PMCID: PMC7049714 DOI: 10.1093/nar/gkaa023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 01/06/2020] [Accepted: 01/13/2020] [Indexed: 12/20/2022] Open
Abstract
Enzymes involved in nucleic acid transactions often have a helicase-like ATPase coordinating and driving their functional activities, but our understanding of the mechanistic details of their coordination is limited. For example, DNA cleavage by the antiphage defense system Type ISP restriction-modification enzyme requires convergence of two such enzymes that are actively translocating on DNA powered by Superfamily 2 ATPases. The ATPase is activated when the enzyme recognizes a DNA target sequence. Here, we show that the activation is a two-stage process of partial ATPase stimulation upon recognition of the target sequence by the methyltransferase and the target recognition domains, and complete stimulation that additionally requires the DNA to interact with the ATPase domain. Mutagenesis revealed that a β-hairpin loop and motif V of the ATPase couples DNA translocation to ATP hydrolysis. Deletion of the loop inhibited translocation, while mutation of motif V slowed the rate of translocation. Both the mutations inhibited the double-strand (ds) DNA cleavage activity of the enzyme. However, a translocating motif V mutant cleaved dsDNA on encountering a translocating wild-type enzyme. Based on these results, we conclude that the ATPase-driven translocation not only brings two nucleases spatially close to catalyze dsDNA break, but that the rate of translocation influences dsDNA cleavage.
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Affiliation(s)
- Mahesh Kumar Chand
- Division of Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Vanessa Carle
- Division of Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - K G Anuvind
- Division of Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Kayarat Saikrishnan
- Division of Biology, Indian Institute of Science Education and Research, Pune 411008, India
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36
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Nucleotide-dependent dynamics of the Dengue NS3 helicase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1868:140441. [PMID: 32371149 DOI: 10.1016/j.bbapap.2020.140441] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 04/22/2020] [Accepted: 04/29/2020] [Indexed: 11/21/2022]
Abstract
Dengue represents a substantial public health burden, particularly in low-resource countries. Non-structural protein 3 (NS3) is a multifunctional protein critical in the virus life cycle and has been identified as a promising anti-viral drug target. Despite recent crystallographic studies of the NS3 helicase domain, only subtle structural nucleotide-dependent differences have been identified, such that its coupled ATPase and helicase activities remain mechanistically unclear. Here we use molecular dynamics simulations to explore the nucleotide-dependent conformational landscape of the Dengue virus NS3 helicase and identify substantial changes in the protein flexibility during the ATP hydrolysis cycle. We relate these changes to the RNA-protein interactions and proposed translocation models for other monomeric helicases. Furthermore, we report a novel open-loop conformation with a likely escape route for Pi after hydrolysis, providing new insight into the conformational changes that underlie the ATPase activity of NS3.
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37
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Tabata K, Neufeldt CJ, Bartenschlager R. Hepatitis C Virus Replication. Cold Spring Harb Perspect Med 2020; 10:cshperspect.a037093. [PMID: 31570388 DOI: 10.1101/cshperspect.a037093] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Replication and amplification of the viral genome is a key process for all viruses. For hepatitis C virus (HCV), a positive-strand RNA virus, amplification of the viral genome requires the synthesis of a negative-sense RNA template, which is in turn used for the production of new genomic RNA. This process is governed by numerous proteins, both host and viral, as well as distinct lipids and specific RNA elements within the positive- and negative-strand RNAs. Moreover, this process requires specific changes to host cell ultrastructure to create microenvironments conducive to viral replication. This review will focus on describing the processes and factors involved in facilitating or regulating HCV genome replication.
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Affiliation(s)
- Keisuke Tabata
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, 69120 Heidelberg, Germany
| | - Christopher J Neufeldt
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, 69120 Heidelberg, Germany
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, 69120 Heidelberg, Germany.,Division of Virus-Associated Carcinogenesis, German Cancer Research Center, 69120 Heidelberg, Germany.,German Center for Infection Research, Heidelberg Partner Site, 69120 Heidelberg, Germany
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38
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Srinivasan S, Liu Z, Chuenchor W, Xiao TS, Jankowsky E. Function of Auxiliary Domains of the DEAH/RHA Helicase DHX36 in RNA Remodeling. J Mol Biol 2020; 432:2217-2231. [PMID: 32087197 DOI: 10.1016/j.jmb.2020.02.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/28/2020] [Accepted: 02/07/2020] [Indexed: 01/06/2023]
Abstract
The DEAH/RHA helicase DHX36 has been linked to cellular RNA and DNA quadruplex structures and to AU-rich RNA elements. In vitro, DHX36 remodels DNA and RNA quadruplex structures and unwinds DNA duplexes in an ATP-dependent manner. DHX36 contains the superfamily 2 helicase core and several auxiliary domains that are conserved in orthologs of the enzyme. The role of these auxiliary domains for the enzymatic function of DHX36 is not well understood. Here, we combine structural and biochemical studies to define the function of three auxiliary domains that contact nucleic acid. We first report the crystal structure of mouse DHX36 bound to ADP. The structure reveals an overall architecture of mouse DHX36 that is similar to previously reported architectures of fly and bovine DHX36. In addition, our structure shows conformational changes that accompany stages of the ATP-binding and hydrolysis cycle. We then examine the roles of the DHX36-specific motif (DSM), the OB-fold, and a conserved β-hairpin (β-HP) in mouse DHX36 in the remodeling of RNA structures. We demonstrate and characterize RNA duplex unwinding for DHX36 and examine the remodeling of inter- and intramolecular RNA quadruplex structures. We find that the DSM not only functions as a quadruplex binding adaptor but also promotes the remodeling of RNA duplex and quadruplex structures. The OB-fold and the β-HP contribute to RNA binding. Both domains are also essential for remodeling RNA quadruplex and duplex structures. Our data reveal roles of auxiliary domains for multiple steps of the nucleic acid remodeling reactions.
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Affiliation(s)
| | - Zhonghua Liu
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | | | - Tsan Sam Xiao
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Eckhard Jankowsky
- Center for RNA Science and Therapeutics, USA; Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
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Du Pont KE, Davidson RB, McCullagh M, Geiss BJ. Motif V regulates energy transduction between the flavivirus NS3 ATPase and RNA-binding cleft. J Biol Chem 2020; 295:1551-1564. [PMID: 31914411 PMCID: PMC7008374 DOI: 10.1074/jbc.ra119.011922] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/22/2019] [Indexed: 01/01/2023] Open
Abstract
The unwinding of dsRNA intermediates is critical for the replication of flavivirus RNA genomes. This activity is provided by the C-terminal helicase domain of viral nonstructural protein 3 (NS3). As a member of the superfamily 2 (SF2) helicases, NS3 requires the binding and hydrolysis of ATP/NTP to translocate along and unwind double-stranded nucleic acids. However, the mechanism of energy transduction between the ATP- and RNA-binding pockets is not well-understood. Previous molecular dynamics simulations conducted by our group have identified Motif V as a potential "communication hub" for this energy transduction pathway. To investigate the role of Motif V in this process, here we combined molecular dynamics, biochemistry, and virology approaches. We tested Motif V mutations in both the replicon and recombinant protein systems to investigate viral genome replication, RNA-binding affinity, ATP hydrolysis activity, and helicase-mediated unwinding activity. We found that the T407A and S411A substitutions in NS3 reduce viral replication and increase the helicase-unwinding turnover rates by 1.7- and 3.5-fold, respectively, suggesting that flaviviruses may use suboptimal NS3 helicase activity for optimal genome replication. Additionally, we used simulations of each mutant to probe structural changes within NS3 caused by each mutation. These simulations indicate that Motif V controls communication between the ATP-binding pocket and the helical gate. These results help define the linkage between ATP hydrolysis and helicase activities within NS3 and provide insight into the biophysical mechanisms for ATPase-driven NS3 helicase function.
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Affiliation(s)
- Kelly E Du Pont
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523; Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523
| | - Russell B Davidson
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523
| | - Martin McCullagh
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523.
| | - Brian J Geiss
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523; School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado 80523.
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40
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Xie P. Non-tight and tight chemomechanical couplings of biomolecular motors under hindering loads. J Theor Biol 2020; 490:110173. [PMID: 31982418 DOI: 10.1016/j.jtbi.2020.110173] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 01/17/2020] [Accepted: 01/21/2020] [Indexed: 10/25/2022]
Abstract
Biomolecular motors make use of free energy released from chemical reaction (typically ATP hydrolysis) to perform mechanical motion or work. An important issue is whether a molecular motor exhibits tight or non-tight chemomechanical (CM) coupling. The tight CM coupling refers to that each ATPase activity is coupled with a mechanical step, while the non-tight CM coupling refers to that an ATPase activity is not necessarily coupled with a mechanical step. Here, we take kinesin, monomeric DNA helicase, ring-shaped hexameric DNA helicase and ribosome as examples to study this issue. Our studies indicate that some motors such as kinesin, monomeric helicase and ribosome exhibit non-tight CM coupling under hindering forces, while others such as the ring-shaped hexameric helicase exhibit tight or nearly tight CM coupling under any force. For the former, the reduction of the velocity caused by the hindering force arises mainly from the reduction of the CM coupling efficiency, while the ATPase rate is independent or nearly independent of the force. For the latter, the reduction of the velocity caused by the hindering force arises mainly from the reduction of the ATPase rate, while the CM coupling efficiency is independent or nearly independent of the force.
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Affiliation(s)
- Ping Xie
- Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
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41
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Takada S, Brandani GB, Tan C. Nucleosomes as allosteric scaffolds for genetic regulation. Curr Opin Struct Biol 2020; 62:93-101. [PMID: 31901887 DOI: 10.1016/j.sbi.2019.11.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 12/11/2022]
Abstract
Nucleosomes are stable yet highly dynamic complexes exhibiting diverse types of motions, such as sliding, DNA unwrapping, and disassembly, encoding a landscape with a large number of metastable states. In this review, describing recent studies on these nucleosome structure changes, we propose that the nucleosome can be viewed as an ideal allosteric scaffold: regulated by effector molecules such as transcription factors and chromatin remodelers, the nucleosome controls the downstream gene activity. Binding of transcription factors to the nucleosome can enhance DNA unwrapping or slide the DNA, altering either the binding or the unbinding of other transcription factors to nearby sites. ATP-dependent chromatin remodelers induce a series of DNA deformations, which allosterically propagate throughout the nucleosome to induce DNA sliding or histone exchange.
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Affiliation(s)
- Shoji Takada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo Kyoto, 606-8502, Japan.
| | - Giovanni B Brandani
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo Kyoto, 606-8502, Japan
| | - Cheng Tan
- RIKEN Center for Computational Science, 7-1-26 Minatojima-minamimachi, Chuo, Kobe, 650-0047 Japan
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Molecular Mechanism Underlying Inhibition of Intrinsic ATPase Activity in a Ski2-like RNA Helicase. Structure 2019; 28:236-243.e3. [PMID: 31859026 DOI: 10.1016/j.str.2019.11.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/06/2019] [Accepted: 11/22/2019] [Indexed: 11/20/2022]
Abstract
RNA-dependent NTPases can act as RNA/RNA-protein remodeling enzymes and typically exhibit low NTPase activity in the absence of RNA/RNA-protein substrates. How futile intrinsic NTP hydrolysis is prevented is frequently not known. The ATPase/RNA helicase Brr2 belongs to the Ski2-like family of nucleic acid-dependent NTPases and is an integral component of the spliceosome. Comprehensive nucleotide binding and hydrolysis studies are not available for a member of the Ski2-like family. We present crystal structures of Chaetomium thermophilum Brr2 in the apo, ADP-bound, and ATPγS-bound states, revealing nucleotide-induced conformational changes and a hitherto unknown ATPγS binding mode. Our results in conjunction with Brr2 structures in other molecular contexts reveal multiple molecular mechanisms that contribute to the inhibition of intrinsic ATPase activity, including an N-terminal region that restrains the RecA-like domains in an open conformation and exclusion of an attacking water molecule, and suggest how RNA substrate binding can lead to ATPase stimulation.
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43
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Ablenas CJ, Gidi Y, Powdrill MH, Ahmed N, Shaw TA, Mesko M, Götte M, Cosa G, Pezacki JP. Hepatitis C Virus Helicase Binding Activity Monitored through Site-Specific Labeling Using an Expanded Genetic Code. ACS Infect Dis 2019; 5:2118-2126. [PMID: 31640339 DOI: 10.1021/acsinfecdis.9b00220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mechanism of unwinding catalyzed by the hepatitis C virus nonstructural protein 3 helicase (NS3h) has been a subject of considerable interest, with NS3h serving as a prototypical enzyme in the study of helicase function. Recent studies support an ATP-fueled, inchworm-like stepping of NS3h on the nucleic acid that would result in the displacement of the complementary strand of the duplex during unwinding. Here, we describe the screening of a site of incorporation of an unnatural amino acid in NS3h for fluorescent labeling of the enzyme to be used in single-molecule Förster resonance energy transfer (FRET) experiments. From the nine potential sites identified in NS3h for incorporation of the unnatural amino acid, only one allowed for expression and fluorescent labeling of the recombinant protein. Incorporation of the unnatural amino acid was confirmed via bulk assays to not interfere with unwinding activity of the helicase. Binding to four different dsDNA sequences bearing a ssDNA overhang segment of varying length (either minimal 6 or 7 base length overhang to ensure binding or a long 24 base overhang) and sequence was recorded with the new NS3h construct at the single-molecule level. Single-molecule fluorescence displayed time intervals with anticorrelated donor and acceptor emission fluctuations associated with protein binding to the substrates. An apparent FRET value was estimated from the binding events showing a single FRET value of ∼0.8 for the 6-7 base overhangs. A smaller mean value and a broad distribution was in turn recorded for the long ssDNA overhang, consistent with NS3h exploring a larger physical space while bound to the DNA construct. Notably, intervals where NS3h binding was recorded were exhibited at time periods where the acceptor dye reversibly bleached. Protein induced fluorescence intensity enhancement in the donor channel became apparent at these intervals. Overall, the site-specific fluorescent labeling of NS3h reported here provides a powerful tool for future studies to monitor the dynamics of enzyme translocation during unwinding by single-molecule FRET.
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Affiliation(s)
- Christopher J. Ablenas
- Department of Biochemistry, McGill University, Montreal, Quebec H3G1Y6, Canada
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N6N5, Canada
| | - Yasser Gidi
- Department of Chemistry, McGill University, Montreal, Quebec H3A0B8, Canada
| | - Megan H. Powdrill
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N6N5, Canada
| | - Noreen Ahmed
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N6N5, Canada
| | - Tyler A. Shaw
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N6N5, Canada
| | - Mihai Mesko
- Department of Chemistry, McGill University, Montreal, Quebec H3A0B8, Canada
| | - Matthias Götte
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G2R7, Canada
| | - Gonzalo Cosa
- Department of Chemistry, McGill University, Montreal, Quebec H3A0B8, Canada
| | - John Paul Pezacki
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N6N5, Canada
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Application of an integrated cheminformatics-molecular docking approach for discovery for physicochemically similar analogs of fluoroquinolones as putative HCV inhibitors. Comput Biol Chem 2019; 84:107167. [PMID: 31855781 DOI: 10.1016/j.compbiolchem.2019.107167] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 10/02/2019] [Accepted: 11/16/2019] [Indexed: 01/13/2023]
Abstract
BACKGROUND Hepatitis C Virus (HCV) infection is a major public health concern across the globe. At present, direct-acting antivirals are the treatment of choice. However, the long-term effect of this therapy has yet to be ascertained. Previously, fluoroquinolones have been reported to inhibit HCV replication by targeting NS3 protein. Therefore, it is logical to hypothesize that the natural analogs of fluoroquinolones will exhibit NS3 inhibitory activity with substantially lesser side effects. METHOD In this study, we tested the application of a recently devised integrated in-silico Cheminformatics-Molecular Docking approach to identify physicochemically similar natural analogs of fluoroquinolones from the available databases (Ambinter, Analyticon, Indofines, Specs, and TimTec). Molecular docking and ROC curve analyses were performed, using PatchDock and Graphpad software, respectively, to compare and analyze drug-protein interactions between active natural analogs, Fluoroquinolones, and HCV NS3 protein. RESULT In our analysis, we were able to shortlist 18 active natural analogs, out of 10,399, that shared physicochemical properties with the template drugs (fluoroquinolones). These analogs showed comparable binding efficacy with fluoroquinolones in targeting 32 amino acids in the HCV NS3 active site that are crucial for NS3 activity. Our approach had around 80 % sensitivity and 70 % specificity in identifying physicochemically similar analogs of fluoroquinolones. CONCLUSION Our current data suggest that our approach can be efficiently applied to identify putative HCV drug inhibitors that can be taken for in vitro testing. This approach can be applied to discover physicochemically similar analogs of virtually any drug, thus providing a speedy and inexpensive approach to complement drug discovery and design, which can tremendously economize on time and money spent on the screening of putative drugs.
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Gao Y, Yang W. Different mechanisms for translocation by monomeric and hexameric helicases. Curr Opin Struct Biol 2019; 61:25-32. [PMID: 31783299 DOI: 10.1016/j.sbi.2019.10.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/12/2019] [Accepted: 10/14/2019] [Indexed: 11/24/2022]
Abstract
Helicases are ATP-dependent motor proteins that translocate along single-stranded or double-stranded nucleic acids to alter base-pairing structures or molecular interactions. Helicases can be divided to monomeric and hexameric types, each with distinct ternary structures, nucleic acid-binding modes, and translocation mechanisms. It is well established that monomeric helicases translocate by the inchworm mechanism. Recent structures of different superfamilies of hexameric helicases reveal that they use a hand-over hand mechanism for translocation. Structures of bacteriophage T7 replisome illustrate how helicase and polymerase cooperatively catalyze DNA unwinding. In this review, we survey structures of monomeric and hexameric helicases and compare different mechanisms for translocation.
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Affiliation(s)
- Yang Gao
- Department of Biosciences, Rice University, Houston, TX 77030, USA.
| | - Wei Yang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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46
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Hamann F, Enders M, Ficner R. Structural basis for RNA translocation by DEAH-box ATPases. Nucleic Acids Res 2019; 47:4349-4362. [PMID: 30828714 PMCID: PMC6486627 DOI: 10.1093/nar/gkz150] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/28/2019] [Accepted: 02/22/2019] [Indexed: 12/15/2022] Open
Abstract
DEAH-box adenosine triphosphatases (ATPases) play a crucial role in the spliceosome-mediated excision of pre-mRNA introns. Recent spliceosomal cryo-EM structures suggest that these proteins utilize translocation to apply forces on ssRNAs rather than direct RNA duplex unwinding to ensure global rearrangements. By solving the crystal structure of Prp22 in different adenosine nucleotide-free states, we identified two missing conformational snapshots of genuine DEAH-box ATPases that help to unravel the molecular mechanism of translocation for this protein family. The intrinsic mobility of the RecA2 domain in the absence of adenosine di- or triphosphate (ADP/ATP) and RNA enables DEAH-box ATPases to adopt different open conformations of the helicase core. The presence of RNA suppresses this mobility and stabilizes one defined open conformation when no adenosine nucleotide is bound. A comparison of this novel conformation with the ATP-bound state of Prp43 reveals that these ATPases cycle between closed and open conformations of the helicase core, which accommodate either a four- or five-nucleotide stack in the RNA-binding tunnel, respectively. The continuous repetition of these states enables these proteins to translocate in 3′-5′ direction along an ssRNA with a step-size of one RNA nucleotide per hydrolyzed ATP. This ATP-driven motor function is maintained by a serine in the conserved motif V that senses the catalytic state and accordingly positions the RecA2 domain.
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Affiliation(s)
- Florian Hamann
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Goettingen, Justus-von-Liebig-Weg 11, 37077 Goettingen, Germany
| | - Marieke Enders
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Goettingen, Justus-von-Liebig-Weg 11, 37077 Goettingen, Germany
| | - Ralf Ficner
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Goettingen, Justus-von-Liebig-Weg 11, 37077 Goettingen, Germany
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47
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Mohapatra S, Lin CT, Feng XA, Basu A, Ha T. Single-Molecule Analysis and Engineering of DNA Motors. Chem Rev 2019; 120:36-78. [DOI: 10.1021/acs.chemrev.9b00361] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
| | | | | | | | - Taekjip Ha
- Howard Hughes Medical Institute, Baltimore, Maryland 21205, United States
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48
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Lim WZ, Cheng PG, Abdulrahman AY, Teoh TC. The identification of active compounds in Ganoderma lucidum var. antler extract inhibiting dengue virus serine protease and its computational studies. J Biomol Struct Dyn 2019; 38:4273-4288. [DOI: 10.1080/07391102.2019.1678523] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Wui Zhuan Lim
- Bioinformatics Programme, Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia
| | - Poh Guat Cheng
- Bioinformatics Programme, Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia
| | | | - Teow Chong Teoh
- Bioinformatics Programme, Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia
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49
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Jang S, Song JJ. The big picture of chromatin biology by cryo-EM. Curr Opin Struct Biol 2019; 58:76-87. [PMID: 31233978 DOI: 10.1016/j.sbi.2019.05.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 05/10/2019] [Accepted: 05/20/2019] [Indexed: 01/07/2023]
Abstract
Modifications of chromatin structure are one of the key mechanisms regulating epigenetic gene expression. Proteins involved in chromatin modification mainly function as large multi-subunit complexes, and each component in the complex contributes to the function and activity of the complex. However, little is known about the structures of whole complexes and the mechanisms by which the chromatin-modifying complexes function, the functional roles of each component in the complexes, and how the complexes recognize the central unit of chromatin, the nucleosome. This lack of information is partially due to the lack of structural information for whole complexes. Recent advances in cryo-EM have begun to reveal the structures of whole chromatin-modifying complexes that enable us to understand the big picture of chromatin biology. In this review, we discuss the recent discoveries related to the mechanisms of chromatin-modifying complexes.
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Affiliation(s)
- Seongmin Jang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Ji-Joon Song
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
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50
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Abstract
While belonging to the nanoscale, protein machines are so complex that tracing even a small fraction of their cycle requires weeks of calculations on supercomputers. Surprisingly, many aspects of their operation can be however already reproduced by using very simple mechanical models of elastic networks. The analysis suggests that, similar to other self-organized complex systems, functional collective dynamics in such proteins is effectively reduced to a low-dimensional attractive manifold.
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Affiliation(s)
- Holger Flechsig
- 1 Nano Life Science Institute (WPI-NanoLSI), Kanazawa University , Kakuma-machi, 920-1192 Kanazawa , Japan
| | - Alexander S Mikhailov
- 1 Nano Life Science Institute (WPI-NanoLSI), Kanazawa University , Kakuma-machi, 920-1192 Kanazawa , Japan.,2 Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society , Faradayweg 4-6, 14195 Berlin , Germany
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