Fig. 5: F120 regulates Hsp90 conformational dynamics by properly positioning R380.
a Portion of the Hsp90/Cdc37/Cdk complex crystal structure (pdb: 5FWK) showing the relative positions of ATP (sticks, colored by atom), Hsp90 (cyan) residues R380 and F120 (spheres, Hsp82 numbering) and Cdc37 (magenta) Y5 (spheres). The Mg2+ ion is gray and the other Hsp90 protomer is green. b Response of Hsp82F120Y to AMPPNP (red), ATP-γ-S (blue) and ATP (black) in the PET assay. Compare to Hsp82 wild type (Fig. 1b) and Hsp82F120A (Fig. 2d). c Relative ATPase rates of Hsp82F120A and Hsp82F120Y proteins. Bars are the average rates of three reactions (each replicate is shown as a circle) and error bars are the standard deviation. Asterisks indicate significant difference from wild type (p < 0.0001 by one-way ANOVA). d Hsp90 functional assay testing all substitutions at position F120. Substitutions F120D, E, I, K, P, R, or V were lethal. Growth of cells expressing Hsp82F120G or Hsp82F120T was apparent only after extended incubation on FOA. Images were cropped from different areas of the same plate or different plates of identical composition. e Relative growth (YPD, left) and CFW sensitivity (right) of indicated viable F120 mutants recovered from FOA. Lines in images indicate where portions were cropped from different plates of identical composition.
