1us7
From Proteopedia
Complex of Hsp90 and P50
Structural highlights
FunctionHSP82_YEAST Molecular chaperone that promotes the maturation, structural maintenance and proper regulation of specific target proteins involved in cell cycle control and signal transduction. Undergoes a functional cycle that is linked to its ATPase activity. The nucleotide-free form of the dimer is found in an open conformation in which the N-termini are not dimerized and the complex is ready for client protein binding. Binding of ATP induces large conformational changes, resulting in the formation of a ring-like closed structure in which the N-terminal domains associate intramolecularly with the middle domain and also dimerize with each other, stimulating their intrinsic ATPase activity and acting as a clamp on the substrate. Finally, ATP hydrolysis results in the release of the substrate. This cycle probably induces conformational changes in the client proteins, thereby causing their activation. Interacts dynamically with various co-chaperones that modulate its substrate recognition, ATPase cycle and chaperone function. Required for growth at high temperatures.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedRecruitment of protein kinase clients to the Hsp90 chaperone involves the cochaperone p50(cdc37) acting as a scaffold, binding protein kinases via its N-terminal domain and Hsp90 via its C-terminal region. p50(cdc37) also has a regulatory activity, arresting Hsp90's ATPase cycle during client-protein loading. We have localized the binding site for p50(cdc37) to the N-terminal nucleotide binding domain of Hsp90 and determined the crystal structure of the Hsp90-p50(cdc37) core complex. Dimeric p50(cdc37) binds to surfaces of the Hsp90 N-domain implicated in ATP-dependent N-terminal dimerization and association with the middle segment of the chaperone. This interaction fixes the lid segment in an open conformation, inserts an arginine side chain into the ATP binding pocket to disable catalysis, and prevents trans-activating interaction of the N domains. The Mechanism of Hsp90 regulation by the protein kinase-specific cochaperone p50(cdc37).,Roe SM, Ali MM, Meyer P, Vaughan CK, Panaretou B, Piper PW, Prodromou C, Pearl LH Cell. 2004 Jan 9;116(1):87-98. PMID:14718169[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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