2 Evolutionary Relationships of Chaperonins

Chaperonin homologs are found in all extant species, including eubacteria, archaebacteria, and eukaryotes. In bacteria and eukaryotic cell organelles, such as mitochondria and chloroplasts, chaperonin (cpn) 10 and cpn60 are present. In contrast to the above, no proteins closely related to cpn60 (or cpn 10) have been found in the archaebacteria and the eukaryotic cell cytosol thus far. These species instead contain members of a protein family …