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Title: Crystallization of the avian reovirus double-stranded RNA-binding and core protein σA

Abstract

The avian reovirus double-stranded RNA-binding and core protein σA has been crystallized in space group P1, with unit-cell parameters a = 103.2, b = 129.9, c = 144.0 Å, α = 93.8, β = 105.1, γ = 98.2°. A complete data set has been collected to 2.3 Å resolution and analyzed. The avian reovirus protein σA plays a dual role: it is a structural protein forming part of the transcriptionally active core, but it has also been implicated in the resistance of the virus to interferon by strongly binding double-stranded RNA and thus inhibiting the double-stranded RNA-dependent protein kinase. The σA protein has been crystallized from solutions containing ammonium sulfate at pH values around 6. Crystals belonging to space group P1, with unit-cell parameters a = 103.2, b = 129.9, c = 144.0 Å, α = 93.8, β = 105.1, γ = 98.2° were grown and a complete data set has been collected to 2.3 Å resolution. The self-rotation function suggests that σA may form symmetric arrangements in the crystals.

Authors:
;  [1];  [2];  [3]; ; ;  [1];  [1];  [4]
  1. Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Santiago de Compostela, Campus Sur, E-15782 Santiago de Compostela (Spain)
  2. Unidad de Difracción de Rayos X, Laboratorio Integral de Dinámica y Estructura de Biomoléculas José R. Carracido, Edificio CACTUS, Universidad de Santiago de Compostela, Campus Sur, E-15782 Santiago de Compostela (Spain)
  3. Spanish CRG Beamline BM16, European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz, BP 220, F-38043 Grenoble (France)
  4. (Spain)
Publication Date:
OSTI Identifier:
22363935
Resource Type:
Journal Article
Resource Relation:
Journal Name: Acta Crystallographica. Section F; Journal Volume: 63; Journal Issue: Pt 5; Other Information: PMCID: PMC2335010; PMID: 17565188; PUBLISHER-ID: ll5111; OAI: oai:pubmedcentral.nih.gov:2335010; Copyright (c) International Union of Crystallography 2007; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United Kingdom
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AMMONIUM SULFATES; CRYSTALLIZATION; CRYSTALS; MATHEMATICAL SOLUTIONS; PH VALUE; RESOLUTION; ROTATION; SOLUTIONS; SPACE GROUPS

Citation Formats

Hermo-Parrado, X. Lois, Guardado-Calvo, Pablo, Llamas-Saiz, Antonio L., Fox, Gavin C., Vazquez-Iglesias, Lorena, Martínez-Costas, José, Benavente, Javier, Raaij, Mark J. van, E-mail: vanraaij@usc.es, and Unidad de Difracción de Rayos X, Laboratorio Integral de Dinámica y Estructura de Biomoléculas José R. Carracido, Edificio CACTUS, Universidad de Santiago de Compostela, Campus Sur, E-15782 Santiago de Compostela. Crystallization of the avian reovirus double-stranded RNA-binding and core protein σA. United Kingdom: N. p., 2007. Web. doi:10.1107/S1744309107017988.
Hermo-Parrado, X. Lois, Guardado-Calvo, Pablo, Llamas-Saiz, Antonio L., Fox, Gavin C., Vazquez-Iglesias, Lorena, Martínez-Costas, José, Benavente, Javier, Raaij, Mark J. van, E-mail: vanraaij@usc.es, & Unidad de Difracción de Rayos X, Laboratorio Integral de Dinámica y Estructura de Biomoléculas José R. Carracido, Edificio CACTUS, Universidad de Santiago de Compostela, Campus Sur, E-15782 Santiago de Compostela. Crystallization of the avian reovirus double-stranded RNA-binding and core protein σA. United Kingdom. doi:10.1107/S1744309107017988.
Hermo-Parrado, X. Lois, Guardado-Calvo, Pablo, Llamas-Saiz, Antonio L., Fox, Gavin C., Vazquez-Iglesias, Lorena, Martínez-Costas, José, Benavente, Javier, Raaij, Mark J. van, E-mail: vanraaij@usc.es, and Unidad de Difracción de Rayos X, Laboratorio Integral de Dinámica y Estructura de Biomoléculas José R. Carracido, Edificio CACTUS, Universidad de Santiago de Compostela, Campus Sur, E-15782 Santiago de Compostela. Tue . "Crystallization of the avian reovirus double-stranded RNA-binding and core protein σA". United Kingdom. doi:10.1107/S1744309107017988.
@article{osti_22363935,
title = {Crystallization of the avian reovirus double-stranded RNA-binding and core protein σA},
author = {Hermo-Parrado, X. Lois and Guardado-Calvo, Pablo and Llamas-Saiz, Antonio L. and Fox, Gavin C. and Vazquez-Iglesias, Lorena and Martínez-Costas, José and Benavente, Javier and Raaij, Mark J. van, E-mail: vanraaij@usc.es and Unidad de Difracción de Rayos X, Laboratorio Integral de Dinámica y Estructura de Biomoléculas José R. Carracido, Edificio CACTUS, Universidad de Santiago de Compostela, Campus Sur, E-15782 Santiago de Compostela},
abstractNote = {The avian reovirus double-stranded RNA-binding and core protein σA has been crystallized in space group P1, with unit-cell parameters a = 103.2, b = 129.9, c = 144.0 Å, α = 93.8, β = 105.1, γ = 98.2°. A complete data set has been collected to 2.3 Å resolution and analyzed. The avian reovirus protein σA plays a dual role: it is a structural protein forming part of the transcriptionally active core, but it has also been implicated in the resistance of the virus to interferon by strongly binding double-stranded RNA and thus inhibiting the double-stranded RNA-dependent protein kinase. The σA protein has been crystallized from solutions containing ammonium sulfate at pH values around 6. Crystals belonging to space group P1, with unit-cell parameters a = 103.2, b = 129.9, c = 144.0 Å, α = 93.8, β = 105.1, γ = 98.2° were grown and a complete data set has been collected to 2.3 Å resolution. The self-rotation function suggests that σA may form symmetric arrangements in the crystals.},
doi = {10.1107/S1744309107017988},
journal = {Acta Crystallographica. Section F},
number = Pt 5,
volume = 63,
place = {United Kingdom},
year = {Tue May 01 00:00:00 EDT 2007},
month = {Tue May 01 00:00:00 EDT 2007}
}
  • By atomic absorption analysis, the authors determined that the reovirus outer capsid protein sigma3, which binds double-stranded RNA (dsRNA), is a zinc metalloprotein. Using Northwestern blots and a novel zinc blotting technique, the authors localized the zinc- and dsRNA-binding activities of sigma3 to distinct V8 protease-generated fragments. Zinc-binding activity was contained within an amino-terminal fragment that contained a transcription factor IIIA-like zinc-binding sequence, and dsRNA-binding activity was associated with a carboxy-terminal fragment. By these techniques, new zinc- and dsRNA-binding activities were also detected in reovirus core proteins. A sequence similarity was observed between the catalytic site of the picornavirus proteasesmore » and the transcription factor IIIA-like zinc-binding site within sigma3. The authors suggest that the zinc- and dsRNA-binding activities of sigma3 may be important for its proposed regulatory effects on viral and host cell transcription and translation.« less
  • The cytoplasm of cells infected with rovirus contains 8 of the 10 polypeptides coded by this virus in free form in amounts equivalent to 1 to 10 percent of the progeny virus yield. All of these polypeptides exist in monomeric form except polypeptides ..mu..l and ..mu..2 which occur as dimers, the form in which they are present in virions. One of these polypeptides, sigma3, a constituent of the outer capsid shell, binds strongly to double-stranded RNA; it can be isolated in high yield in pure form by passing extracts of infected cells through columns of poly(IC)-cellulose and eluting. Another polypeptide,more » sigma2A, a nonstructural polypeptide, binds strongly to single-stranded RNA and appears to exist in infected cells complexed with RNA. It can be isolated in high yield in pure form by passing extracts of infected cells, suitably treated to dissociate these complexes, through columns of poly(A)-cellulose and eluting. The possible significance of the highly specific nucleic acid affinities of these two reovirus-coded polypeptides is discussed.« less
  • A comparative analysis of the intracellular distribution of avian reovirus (ARV) core protein sigmaA in cells of avian and mammalian origin revealed that, whereas the viral protein accumulates in the cytoplasm and nucleolus of avian cells, most sigmaA concentrates in the nucleoplasm of mammalian cells in tight association with the insoluble nuclear matrix fraction. Our results further showed that sigmaA becomes arrested in the nucleoplasm of mammalian cells via association with mammalian cell-specific factors and that this association prevents nucleolar targeting. Inhibition of RNA polymerase II activity, but not of RNA polymerase I activity, in infected mammalian cells induces nucleus-to-cytoplasmmore » sigmaA translocation through a CRM1- and RanGTP-dependent mechanism, yet a heterokaryon assay suggests that sigmaA does not shuttle between the nucleus and cytoplasm. The scarcity of sigmaA in cytoplasmic viral factories of infected mammalian cells could be one of the factors contributing to limited ARV replication in mammalian cells.« less
  • Influenza A viruses cause a highly contagious respiratory disease in humans and are responsible for periodic widespread epidemics with high mortality rates. The influenza A virus NS1 protein (NS1A) plays a key role in countering host antiviral defense and in virulence. The 73-residue N-terminal domain of NS1A (NS1A-(1-73)) forms a symmetric homodimer with a unique six-helical chain fold. It binds canonical A-form double-stranded RNA (dsRNA). Mutational inactivation of this dsRNA binding activity of NS1A highly attenuates virus replication. Here, we have characterized the unique structural features of the dsRNA binding surface of NS1A-(1-73) using NMR methods and describe the 2.1-{angstrom}more » x-ray crystal structure of the corresponding dsRNA binding domain from human influenza B virus NS1B-(15-93). These results identify conserved dsRNA binding surfaces on both NS1A-(1-73) and NS1B-(15-93) that are very different from those indicated in earlier 'working models' of the complex between dsRNA and NS1A-(1-73). The combined NMR and crystallographic data reveal highly conserved surface tracks of basic and hydrophilic residues that interact with dsRNA. These tracks are structurally complementary to the polyphosphate backbone conformation of A-form dsRNA and run at an {approx}45{sup o} angle relative to the axes of helices {alpha}2/{alpha}2'. At the center of this dsRNA binding epitope, and common to NS1 proteins from influenza A and B viruses, is a deep pocket that includes both hydrophilic and hydrophobic amino acids. This pocket provides a target on the surface of the NS1 protein that is potentially suitable for the development of antiviral drugs targeting both influenza A and B viruses.« less
  • Under suitable conditions of denaturation, the double-stranded (ds) RNA segments of reovirus can be translated in cell-free protein synthesizing systems. Since all 10 segments of reovirus ds RNA can be isolated in virtually pure form, this provides a means for determining the nature of the polypeptide encoded by each individual segment. The complete coding assignment set was determined for the Dearing strain of reovirus serotype 3. Polypeptide identification was made not only on the basis of electrophoretic migration rates in both the phosphate- and Tri-glycine (Laemmli)-based polyacrylamide gel systems, but also on the basis of comparing peptide profiles of inmore » vitro translation products and authentic reovirus polypeptides after digestion with staphylococcal V8 protease. The latter method provides absolute identification. The assignment set is (using the commonly accepted designation for the ds RNA segments, but a newly proposed nomenclature for the polypeptides); segment L1 codes for the minor virion components lambda 3, and segments L2 and L3 code for the two major virion core components lambda 2 and lambda 1, respectively; segment M1 codes for a minor virion component ..mu..2, segment M2 codes for the polypeptide that is present in virions both in the form of the minor component ..mu..1 and as the major component ..mu..1C which is derived from it by cleavage, and segment M3 codes for the nonstructural polypeptide ..mu..NS; and segment S1 codes for the minor outer capsid shell component sigma 1, segment S2 codes for the core component sigma 2, segment S3 codes for the nonstructural polypeptide sigma NS, and segment S4 codes for the major outer capsid shell component sigma 3.« less