Neil A Ranson / Daniel K Clare / George W Farr / David Houldershaw / Arthur L Horwich / Helen R Saibil /
PubMed 要旨
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 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.
EMDB-1180: Allosteric signaling of ATP hydrolysis in GroEL-GroES complexes. PDB-2c7c: FITTED COORDINATES FOR GROEL-ATP7-GROES CRYO-EM COMPLEX (EMD-1180) 手法: EM (単粒子) / 解像度: 7.7 Å
EMDB-1181: Allosteric signaling of ATP hydrolysis in GroEL-GroES complexes. PDB-2c7d: Fitted coordinates for GroEL-ADP7-GroES Cryo-EM complex (EMD-1181) 手法: EM (単粒子) / 解像度: 8.7 Å