Linking allostery in chaperonins to protein folding

WCC 27

Amnon Horovitz, amnon.horovitz@weizmann.ac.il, Department of Structural Biology, Weizmann Institute, PO Box 26, 76100 Rehovot, Israel
The prokaryotic chaperonin GroEL consists of two back-to-back stacked homo-heptameric rings with a cavity at each end where protein folding can take place under confining conditions. It is a molecular machine that assists protein folding by undergoing concerted ATP-induced allosteric transitions between protein substrate binding and release states. By contrast, the eukaryotic chaperonin CCT consists of two back-to-back stacked hetero-octameric rings that undergo sequential ATP-promoted allosteric transitions. Evidence will be presented showing that concerted allosteric transitions favor all-or-none protein substrate release and folding whereas sequential transitions result in domain-by-domain substrate release and folding.