Polymorphism of turnip yellow mosaic virus empty shells and evidence for conformational changes occurring after release of the viral RNA. A differential scanning calorimetric study.

Details

Serval ID
serval:BIB_12503
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Polymorphism of turnip yellow mosaic virus empty shells and evidence for conformational changes occurring after release of the viral RNA. A differential scanning calorimetric study.
Journal
European Journal of Biochemistry / Febs
Author(s)
Michels B., Leimkühler M., Lechner M.D., Adrian M., Lorber B., Witz J.
ISSN
0014-2956 (Print)
ISSN-L
0014-2956
Publication state
Published
Issued date
1999
Volume
264
Number
3
Pages
965-972
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
Turnip yellow mosaic virus (TYMV) is a small isometric plant virus which decapsidates by releasing its RNA through a hole in the capsid, leaving behind an empty shell [R. E. F. Matthews and J. Witz, (1985) Virology 144, 318-327]. Similar empty shells (artificial top component, ATC) can be obtained by submitting the virions to various treatments in vitro. We have used differential scanning calorimetry, analytical sedimentation, and electron microscopy to investigate the thermodenaturation of natural empty shells (NTC, natural top component) present in purified virus suspensions, and of several types of ATCs. ATCs divided in two major classes. Those obtained by alkaline titration, by the action of urea or butanol behaved as NTC: their thermograms contained only one peak corresponding to the irreversible dissociation of the shells and the denaturation of the coat protein. The temperature of this unique transition varied significantly with pH, from 71 degrees C at pH 4.5 to 84 degrees C at pH 8.5. The thermograms of ATCs obtained by freezing and thawing, or by the action of high pressure, contained two peaks: shells dissociated first into smaller protein aggregates at 57 degrees C (at pH 5.0) to 61 degrees C (at pH 8.5), which denatured at the temperature of the unique transition of NTC. Shells obtained by heating virions to 55 degrees C at pH 7.6, changed conformation after the release of the viral RNA, as upon continuous heating to 95 degrees C, their thermograms were similar to those of the shells obtained by freezing and thawing, whereas after purification they behaved like NTC. Structural implications of these observations are discussed.
Keywords
Calorimetry, Differential Scanning, Capsid/chemistry, Capsid/ultrastructure, Freezing, Hot Temperature, Hydrogen-Ion Concentration, Microscopy, Electron, Protein Conformation, Protein Denaturation, RNA, Viral/chemistry, Thermodynamics, Tymovirus/chemistry, Tymovirus/ultrastructure
Pubmed
Web of science
Open Access
Yes
Create date
19/11/2007 12:03
Last modification date
20/08/2019 12:40
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