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Publication Abstract from PubMed

Hsp90 is an abundant molecular chaperone involved in many biological systems. We report here the crystal structures of the unliganded and ADP bound fragments containing the N-terminal and middle domains of HtpG, an E. coli Hsp90. These domains are not connected through a flexible linker, as often portrayed in models, but are intimately associated with one another. The individual HtpG domains have similar folding to those of DNA gyrase B but assemble differently, suggesting somewhat different mechanisms for the ATPase superfamily. ADP binds to a subpocket of a large site that is jointly formed by the N-terminal and middle domains and induces conformational changes of the N-terminal domain. We speculate that this large pocket serves as a putative site for binding of client proteins/cochaperones. Modeling shows that ATP is not exposed to the molecular surface, thus implying that ATP activation of hsp90 chaperone activities is accomplished via conformational changes.

Structures of the N-terminal and middle domains of E. coli Hsp90 and conformation changes upon ADP binding.,Huai Q, Wang H, Liu Y, Kim HY, Toft D, Ke H Structure. 2005 Apr;13(4):579-90. PMID:15837196^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.