2fxs
Yeast HSP82 in complex with the novel HSP90 Inhibitor Radamide
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 PubMedHsp90 chaperones contain an N-terminal ATP binding site that has been effectively targeted by competitive inhibitors. Despite the myriad of inhibitors, none to date have been designed to bind specifically to just one of the four mammalian Hsp90 paralogs, which are cytoplasmic Hsp90alpha and beta, endoplasmic reticulum GRP94, and mitochondrial Trap-1. Given that each of the Hsp90 paralogs is responsible for chaperoning a distinct set of client proteins, specific targeting of one Hsp90 paralog may result in higher efficacy and therapeutic control. Specific inhibitors may also help elucidate the biochemical roles of each Hsp90 paralog. Here, we present side-by-side comparisons of the structures of yeast Hsp90 and mammalian GRP94, bound to the pan-Hsp90 inhibitors geldanamycin (Gdm) and radamide. These structures reveal paralog-specific differences in the Hsp90 and GRP94 conformations in response to Gdm binding. We also report significant variation in the pose and disparate binding affinities for the Gdm-radicicol chimera radamide when bound to the two paralogs, which may be exploited in the design of paralog-specific inhibitors. Different poses for ligand and chaperone in inhibitor-bound Hsp90 and GRP94: implications for paralog-specific drug design.,Immormino RM, Metzger LE 4th, Reardon PN, Dollins DE, Blagg BS, Gewirth DT J Mol Biol. 2009 May 22;388(5):1033-42. Epub 2009 Apr 8. PMID:19361515[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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