Figure 3.

Efficient Hsp90 stimulation requires Hop but not the ATPase activity of Hsp90. P–Dε RNA complexes were reconstituted from GrpDP and Hsc70/Hsp40 in the absence of Hsp90 and Hop, or in the additional presence of Hop and wild-type yeast Hsp90 (lane wt), or the yeast Hsp90 variants ΔMEEVD or yHsp90Δ16 (lanes Δ16). The stimulatory activity of yHsp90Δ16 was abolished when Hop was omitted (lane Δ16–Hop). Complex formation was monitored by priming assays as in Figure 2. Relative signal intensities are given below each lane, with the signal from the unsupplemented reaction set at 1.0.