Crystal structures of a group II chaperonin reveal the open and closed states associated with the protein folding cycle.
J Biol Chem
; 285(36): 27958-66, 2010 Sep 03.
Article
em En
| MEDLINE
| ID: mdl-20573955
ABSTRACT
Chaperonins are large protein complexes consisting of two stacked multisubunit rings, which open and close in an ATP-dependent manner to create a protected environment for protein folding. Here, we describe the first crystal structure of a group II chaperonin in an open conformation. We have obtained structures of the archaeal chaperonin from Methanococcus maripaludis in both a peptide acceptor (open) state and a protein folding (closed) state. In contrast with group I chaperonins, in which the equatorial domains share a similar conformation between the open and closed states and the largest motions occurs at the intermediate and apical domains, the three domains of the archaeal chaperonin subunit reorient as a single rigid body. The large rotation observed from the open state to the closed state results in a 65% decrease of the folding chamber volume and creates a highly hydrophilic surface inside the cage. These results suggest a completely distinct closing mechanism in the group II chaperonins as compared with the group I chaperonins.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Dobramento de Proteína
/
Chaperoninas do Grupo II
Tipo de estudo:
Risk_factors_studies
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article