An expanded protein folding cage in the GroEL-gp31 complex.
J Mol Biol
; 358(3): 905-11, 2006 May 05.
Article
em En
| MEDLINE
| ID: mdl-16549073
ABSTRACT
Bacteriophage T4 produces a GroES analogue, gp31, which cooperates with the Escherichia coli GroEL to fold its major coat protein gp23. We have used cryo-electron microscopy and image processing to obtain three-dimensional structures of the E.coli chaperonin GroEL complexed with gp31, in the presence of both ATP and ADP. The GroEL-gp31-ADP map has a resolution of 8.2 A, which allows accurate fitting of the GroEL and gp31 crystal structures. Comparison of this fitted structure with that of the GroEL-GroES-ADP structure previously determined by cryo-electron microscopy shows that the folding cage is expanded. The enlarged volume for folding is consistent with the size of the bacteriophage coat protein gp23, which is the major substrate of GroEL-gp31 chaperonin complex. At 56 kDa, gp23 is close to the maximum size limit of a polypeptide that is thought to fit inside the GroEL-GroES folding cage.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas Virais
/
Dobramento de Proteína
/
Chaperonina 60
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article