Chaperonins are a subclass of molecular chaperones that assist cellular proteins 
to fold and assemble into their native shape. Much work has been done on Type I 
chaperonins, which has elucidated their elegant mechanism. Some debate remains 
about the details in these mechanisms, but nonetheless the roles of these in 
helping protein folding have been understood in great depth. In this review we 
discuss the known functions of atypical Type I chaperonins, highlighting 
evolutionary aspects that might lead chaperonins to perform alternate functions.