Download MendeleyAllosteric Signalling of ATP Hydrolysis in Groel-Groes Complexes.
Ranson, N.A., Clare, D.K., Farr, G.W., Houldershaw, D., Horwich, A.L., Saibil, H.R.(2006) Nat Struct Mol Biol 13: 147-152
- PubMed: 16429154
- DOI: https://doi.org/10.1038/nsmb1046
- Primary Citation of Related Structures:
2C7C, 2C7D - PubMed Abstract:
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.
Organizational Affiliation:
Astbury Centre for Structural Molecular Biology and Institute of Molecular & Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK.
