Current Protein & Peptide Science

Ben M. Dunn  
Department of Biochemistry and Molecular Biology University of Florida
College of Medicine, P.O. Box 100245, Gainesville
Florida, FL 32610-0245
USA

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Thermal Adaptation of Heat Shock Proteins

Author(s): A. Muga, F. Moro.

Abstract:

Heat shock proteins (Hsps) are molecular chaperones that oppose stress-induced denaturation of other proteins. Hsps are present in all organisms. Apart from assisting in the efficient folding of newly synthesized proteins they maintain pre-existing proteins in a stable conformation, preventing their aggregation, under stress conditions. The latter role, essential for thermal adaptation, requires that the chaperone system change from a folding to a storing function at heat shock temperatures. The temperature at which this change occurs depends on the presence of a thermosensor in at least one of the components of the chaperone systems. In this review, we focus on the bacterial GroE and DnaK systems, describe their temperature-sensitive protein components, and the location of the thermosensor within the structure of these components. While the thermosensor of the GroE system is located at the inter-ring interface of GroEL, that of the DnaK system occurs in its co-chaperone GrpE. Analysis of these examples demonstrates the amazing mechanistic diversity of thermal stress adaptation and of functional convergence of structurally unrelated proteins.

Keywords: DnaK, GroEL, GrpE, heat shock protein, protein folding, thermal adaptation

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Article Details

VOLUME: 9
ISSUE: 6
Year: 2008
Page: [552 - 566]
Pages: 15
DOI: 10.2174/138920308786733903
Price: $58