Dataset contains (predominantly) pre-processed data for single-molecule FRET (smFRET) and luciferase refolding assays. For smFRET experiments, the conformation of individual luciferase (FlucIDS) proteins was monitored in real-time and incubated either in the presence of chemical denaturant or in the presence of various combinations and concentrations of molecular chaperones from the bacterial Hsp70 system (i.e., DnaJ, DnaK and GrpE). Similarly, the ability of this chaperone system to refold FlucIDS to an enzymatically active state was assessed using luciferase refolding assays. Owing to the size of the raw .TIF images generated during smFRET experiments, only a subset of these representative raw images are provided (see figure 1C, 2M GdHCl treatment) that can be used to perform the analysis from its earliest starting point. Note: data required for Figures S4, S5 and S6 are provided in Figure 2, 3 and 4, respectively. Note 2: Within each figure is a txt document that outlines the format and meaning of each dataset.