Part of a stress-induced multi-chaperone system, it is involved in the recovery of the cell from heat-induced damage, in cooperation with DnaK, DnaJ and GrpE. Acts before DnaK, in the processing of protein aggregates. Protein binding stimulates the ATPase activity; ATP hydrolysis unfolds the denatured protein aggregates, which probably helps expose new hydrophobic binding sites on the surface of ClpB-bound aggregates, contributing to the solubilization and refolding of denatured protein aggregates by DnaK (By similarity). Necessary for thermotolerance. Homohexamer. The oligomerization is ATP-dependent (By similarity). By heat shock. The Clp repeat (R) domain probably functions as a substrate-discriminating domain, recruiting aggregated proteins to the ClpB hexamer and/or stabilizing bound proteins. The NBD2 domain is responsible for oligomerization, whereas the NBD1 domain stabilizes the hexamer probably in an ATP-dependent manner. The movement of the coiled-coil domain is essential for ClpB ability to rescue proteins from an aggregated state, probably by pulling apart large aggregated proteins, which are bound between the coiled-coils motifs of adjacent ClpB subunits in the functional hexamer (By similarity). Also contributes to the overall thermotolerance of the bacterium. Belongs to the ClpA/ClpB family.