Thermosome

A thermosome is a group II chaperonin protein complex that functions in archaea. It is the homolog of eukaryotic CCT. This group II chaperonin is an ATP-dependent chaperonin that is responsible for folding or refolding of incipient or denatured proteins. A thermosome has two rings, each consisting of eight subunits, stacked together to form a cylindrical shape with a large cavity at the center. The thermosome is also defined by its heterooligomeric nature. The complex consists of that alternate location within its two rings.
Being a Group II chaperonin, the thermosome has a similar structure to group I chaperonins. The main difference, however, lies in the existence of a helical protrusion in the thermosome which composes of a built-in lid of the hydrophilic cavity. Not only is thermosome ATP-dependent, but the mechanism in which thermosome shifts from open to close conformation is also temperature-dependent. The open conformation of the ATP-thermosome exists mainly at low temperatures. Whereas, the closed conformation of the thermosome occurs when heating to physiological temperature.