Chaperonins are a diverse family of molecular chaperones that are present in the plastids, mitochondria, and cytoplasm of eukaryotes, bacteria and archaea. The family is divided into group I (CPN60, also known as Hsp60 or GroEL, found in bacteria, some archaea, mitochondria and plastids) and group II (CCT, TriC or thermosome, found in archaea and the eukaryotic cytoplasm).