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). Homohexamer. The oligomerization is ATP-dependent (By similarity). 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). Not induced by heat shock or other stresses, it is expressed constitutively in the cell. Belongs to the ClpA/ClpB family.