Heat-shock protein 90 (HSP90) is a cellular chaperone protein required for the activation of several eukaryotic protein kinases, including the cyclin-dependent kinase CDK4. Geldanamycin, an inhibitor of the protein-refolding activity of Hsp90, has been shown to have antiproliferative and antitumor activities.
Geldanamycin (in yellow) binds HSP90 (in cyan, interacting side chains in red) in a well-defined deep pocket lined by residues conserved across different species expressing HSP90.
Geldanamycin occupies the ATP-binding site on the protein.
