2c7c

Publication Abstract from PubMed

The double-ring chaperonin GroEL and its lid-like cochaperonin GroES form asymmetric complexes that, in the ATP-bound state, mediate productive folding in a hydrophilic, GroES-encapsulated chamber, the so-called cis cavity. Upon ATP hydrolysis within the cis ring, the asymmetric complex becomes able to accept non-native polypeptides and ATP in the open, trans ring. Here we have examined the structural basis for this allosteric switch in activity by cryo-EM and single-particle image processing. ATP hydrolysis does not change the conformation of the cis ring, but its effects are transmitted through an inter-ring contact and cause domain rotations in the mobile trans ring. These rigid-body movements in the trans ring lead to disruption of its intra-ring contacts, expansion of the entire ring and opening of both the nucleotide pocket and the substrate-binding domains, admitting ATP and new substrate protein.

Allosteric signaling of ATP hydrolysis in GroEL-GroES complexes.,Ranson NA, Clare DK, Farr GW, Houldershaw D, Horwich AL, Saibil HR Nat Struct Mol Biol. 2006 Feb;13(2):147-52. Epub 2006 Jan 22. PMID:16429154^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.