Chaperonin GroEL uses asymmetric and symmetric reaction cycles in response to the concentration of non-native substrate proteins.

ABSTRACT: The Escherichia coli chaperonin GroEL is an essential molecular chaperone that mediates protein folding in association with its cofactor, GroES. It is widely accepted that GroEL alternates the GroES-sealed folding-active rings during the reaction cycle. In other words, an asymmetric GroEL-GroES complex is formed during the cycle, whereas a symmetric GroEL-(GroES)₂ complex is not formed. However, this conventional view has been challenged by the recent reports indicating that such symmetric complexes can be formed in the GroEL-GroES reaction cycle. In this review, we discuss the studies of the symmetric GroEL-(GroES)₂ complex, focusing on the molecular mechanism underlying its formation. We also suggest that GroEL can be involved in two types of reaction cycles

SUBMITTER: Iizuka R 

PROVIDER: S-EPMC5042173 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature