Structure of HSP90 bound with a noval fragment.
[HS90A_HUMAN] Molecular chaperone that promotes the maturation, structural maintenance and proper regulation of specific target proteins involved for instance in cell cycle control and signal transduction. Undergoes a functional cycle that is linked to its ATPase activity. 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. 
Publication Abstract from PubMed
Heat shock protein 90 (Hsp90) plays a key role in stress response and protection of the cell against the effects of mutation. Herein we report the identification of an Hsp90 inhibitor identified by fragment screening using a high-concentration biochemical assay, as well as its optimisation by in silico searching coupled with a structure-based drug design (SBDD) approach.
Fragment-based identification of Hsp90 inhibitors.,Barker JJ, Barker O, Boggio R, Chauhan V, Cheng RK, Corden V, Courtney SM, Edwards N, Falque VM, Fusar F, Gardiner M, Hamelin EM, Hesterkamp T, Ichihara O, Jones RS, Mather O, Mercurio C, Minucci S, Montalbetti CA, Muller A, Patel D, Phillips BG, Varasi M, Whittaker M, Winkler D, Yarnold CJ ChemMedChem. 2009 Jun;4(6):963-6. PMID:19301319
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.