Together with its co-chaperonin GroES, plays an essential role in assisting protein folding. The GroEL-GroES system forms a nano-cage that allows encapsulation of the non-native substrate proteins and provides a physical environment optimized to promote and accelerate protein folding. Involved in copper homeostasis (PubMed:32812602). Binds copper and may help maintaining copper homeostasis when copper is present in excess, notably in the macrophage phagosome, by acting as a metal storage protein (PubMed:32812602). Increases copper tolerance during biofilm formation (PubMed:32812602). In vitro binds to human CD209 (DC-SIGN) and may help mediate adherence to host cells (PubMed:21203928). ATP + H2O + a folded polypeptide = ADP + phosphate + an unfolded polypeptide. Forms a cylinder of 14 subunits composed of two heptameric rings stacked back-to-back. Interacts with the co-chaperonin GroES (By similarity). Able to bind to host (human) CD209 in vitro (PubMed:21203928). Although thought of as a cytoplasmic chaperone this protein has been found to interact in vitro with a host extracellular protein. In the standard Sauton's medium containing 6% glycerol, disruption mutant displays poor growth and very poor biofilm phenotype with no full attachment on the medium-air interface at day 35 (PubMed:31244785). Mutant shows abnormal Crabtree effect. Mutant has a compromised ability to down-regulate ATP and secretes more pyruvate, acetate, succinate, and glutamate in the culture medium. Mutant has higher intracellular pyruvate and produces more toxic methylglyoxal, suggesting a glycolytic stress leading to growth stasis and consequently biofilm failure (PubMed:31244785). Deletion of the gene enhances copper susceptibility during biofilm growth (PubMed:32812602). Belongs to the chaperonin (HSP60) family.