The C-terminal tails of GroEL and its mitochondrial and chloroplastic homologs adopt polyproline II helices.

ABSTRACT: The chaperonin GroEL and its mitochondrial and chloroplastic homologs mHsp60 and Cpn60 are large barrel-like oligomeric proteins. Chaperonins facilitate folding by isolating nascent chains in their hollow interior and undergoing ATP-powered conformational transitions. Due to their vital importance, the structures of GroEL and its homologs were extensively studied by x-ray crystallography and CryoEM, revealing rings containing seven subunits. Each subunit has three folded domains and a 24 residue C-terminal extension. Whereas this C-terminal tail has been reported to bind and stimulate the folding of client proteins, it appears to be blurry or invisible, which suggests disorder. The objective of this study is to characterize conformational preferences in the C-terminal tails of GroEL, mHsp6

SUBMITTER: Rodriguez CS 

PROVIDER: S-EPMC12571646 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature