Fig. 7
Conservation of the conformational dynamics of L1,2 in DnaK. a The fully closed conformation of L1,2 is the dominant form for DnaK in the ATP-bound state. Emission spectra of the TMR-labeled DnaK in the absence of nucleotide (Apo, black) or in the presence of ADP (blue) or ATP (red) were collected with excitation at 547 nm. b Fluorescence changes of the TMR-labeled DnaK in response to nucleotides. c Hsp40 co-chaperone DnaJ drastically increased the fluorescence intensity of the TMR-labeled DnaK in the presence of ATP. The assays were carried out as in Fig. 6a with DnaJ and the TMR-labeled DnaK. The concentrations of DnaJ were labeled on the right. The spectra of Apo and ATP alone were used as controls. d The DnaJ-induced opening of DnaK’s L1,2 is faster than ATP hydrolysis. Stopped-flow experiments were used to determine the rates of DnaJ-induced opening of L1,2 (k obs), and single-turnover ATPase assays were carried out under the same condition to determine the ATPase rate (k cat)
