title: ATP-driven molecular chaperone machines.
abstract: This review is focused on the mechanisms by which ATP binding and hydrolysis drive chaperone machines assisting protein folding and unfolding. A survey of the key, general chaperone systems Hsp70 and Hsp90, and the unfoldase Hsp100 is followed by a focus on the Hsp60 chaperonin machine which is understood in most detail. Cryo-electron microscopy analysis of the E. coli Hsp60 GroEL reveals intermediate conformations in the ATPase cycle and in substrate folding. These structures suggest a mechanism by which GroEL can forcefully unfold and then encapsulate substrates for subsequent folding in isolation from all other binding surfaces.
authors.affiliation: Department of Crystallography, Institute of Structural and Molecular Biology, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK.
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Clare
authors.forename: Helen R
authors.initials: HR
authors.lastname: Saibil
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry; D018834:Chaperonin 60 / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism; D018832:Molecular Chaperones / Q000737:chemistry; D017510:Protein Folding
chemical_list: D018834:Chaperonin 60; D018832:Molecular Chaperones; D000255:Adenosine Triphosphate
keywords: ATP driven; Cryo-EM; GroEL; chaperones; machines