1501 K
16 pp.
 
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TitleChaperonin Polymers in Archaea: The Cytoskeleton of Prokaryotes?
Author(s)Trent, J. D.; Kagawa, H. K.; Zaluzec, N. J.
Publication DateJuly 1997
Report NumberANL/CMB/PP--88274
Unique IdentifierACC0216
Other NumbersLegacy ID: DE97007876; OSTI ID: 505321
Research OrgArgonne National Laboratory (ANL), IL (United States)
Contract NoW-31109-ENG-38
Sponsoring OrgUSDOE Office of Energy Research, Washington, DC (United States)
Subject55 Biology And Medicine, Basic Studies; Heat-Shock Proteins; Molecular Structure; Biological Functions; Experimental Data; Biological Adaptation; Molecular Biology
Related Web PagesThe Discovery of Archaea, the 'Third Branch of Life', and Its Impacts
AbstractChaperonins are protein complexes that play a critical role in folding nascent polypeptides under normal conditions and refolding damaged proteins under stress conditions. In all organisms these complexes are composed of evolutionarily conserved 60-kDa proteins arranged in double-ring structures with between 7 and 9 protein subunits per ring. These double ring structures are assumed to be the functional units in vivo, although they have never been observed inside cells. Here the authors show that the purified chaperonin from the hyperthermophilic archaeon Sulfolobus shibatae, which is closely related to chaperonins in eukaryotes, has a double ring structure at low concentrations (0.1 mg/ml), but at more physiological concentrations, the rings stack end to end to form polymers. The polymers are stable at physiological temperatures (75 C) and closely resemble structures observed inside unfixed S. shibatae cells. The authors suggest that in vivo chaperonin activity may be regulated by polymerization and that chaperonin polymers may act as a cytoskeleton-like structure in archaea and bacteria.
1501 K
16 pp.
 
View Document 
  


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