Conserved and divergent chaperoning effects of Hsp60/10 chaperonins on protein folding landscapes

Abstract

Significance Hsp60/10 chaperonins are critical for cellular proteostasis in all kingdoms of life. In this study, we present that Hsp60/10 across different species have differences in the cavity properties and correlatively in their capability to remove entropic traps in folding pathways of GroEL/ES substrates; this is affected majorly by differences in the negative-charge density inside the chaperonin cavity. This dissimilarity leads to a remarkable difference between Hsp60/10 homologs in buffering mutational variations. However, most of them can remove nonnative contacts during folding of their substrates and alter the way the polypeptide chain undergoes hydrophobic collapse. We show that these homologs may have evolved specific modes of folding assistance by modulating cavity properties according to the requirements of their substrates.