The ATPase cycle of Hsp90 drives a molecular 'clamp' via transient dimerization of the N-terminal domains

Prodromou, Chrisostomos, Panaretou, Barry, Chohan, Shahzad, Siligardi, Giuliano, O'Brien, Ronan, Ladbury, John E, Roe, S Mark, Piper, Peter W and Pearl, Laurence H (2000) The ATPase cycle of Hsp90 drives a molecular 'clamp' via transient dimerization of the N-terminal domains. EMBO Journal, 19 (16). pp. 4383-92. ISSN 0261-4189

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How the ATPase activity of Heat shock protein 90 (Hsp90) is coupled to client protein activation remains obscure. Using truncation and missense mutants of Hsp90, we analysed the structural implications of its ATPase cycle. C-terminal truncation mutants lacking inherent dimerization displayed reduced ATPase activity, but dimerized in the presence of 5'-adenylamido-diphosphate (AMP-PNP), and AMP-PNP- promoted association of N-termini in intact Hsp90 dimers was demonstrated. Recruitment of p23/Sba1 to C-terminal truncation mutants also required AMP-PNP-dependent dimerization. The temperature- sensitive (ts) mutant T101I had normal ATP affinity but reduced ATPase activity and AMP-PNP-dependent N-terminal association, whereas the ts mutant T22I displayed enhanced ATPase activity and AMP-PNP-dependent N-terminal dimerization, indicating a close correlation between these properties. The locations of these residues suggest that the conformation of the 'lid' segment (residues 100-121) couples ATP binding to N-terminal association. Consistent with this, a mutation designed to favour 'lid' closure (A107N) substantially enhanced ATPase activity and N-terminal dimerization. These data show that Hsp90 has a molecular 'clamp' mechanism, similar to DNA gyrase and MutL, whose opening and closing by transient N-terminal dimerization are directly coupled to the ATPase cycle.

Item Type: Article
Keywords: Adenosine Triphosphatases/*metabolism Adenosine Triphosphate/metabolism Adenylyl Imidodiphosphate/metabolism Bacterial Proteins/metabolism Circular Dichroism Cross-Linking Reagents/pharmacology DNA Gyrase DNA Topoisomerases, Type II/metabolism Dimerization *Escherichia coli Proteins Fungal Proteins/metabolism HSP90 Heat-Shock Proteins/*chemistry/genetics/*metabolism Kinetics Models, Biological Models, Molecular Molecular Chaperones/metabolism Mutagenesis, Site-Directed Mutation, Missense Phenotype Plasmids/metabolism Protein Binding Protein Conformation Protein Structure, Secondary Protein Structure, Tertiary *Saccharomyces cerevisiae Proteins Spectrometry, Fluorescence Temperature Time Factors
Schools and Departments: School of Life Sciences > Biochemistry
Subjects: Q Science > QD Chemistry > QD0241 Organic chemistry > QD0415 Biochemistry
Q Science > QD Chemistry > QD0901 Crystallography
Depositing User: Chrisostomos Prodromou
Date Deposited: 24 Feb 2015 17:30
Last Modified: 24 Feb 2015 17:30
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