Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Quick Search
My eDoc
Session History
Support Wiki
Direct access to
document ID:

          Institute: MPI für Biochemie     Collection: Structural Biology (W. Baumeister)     Display Documents

ID: 318717.0, MPI für Biochemie / Structural Biology (W. Baumeister)
Chaperonin-mediated protein folding: GroES binds to one end of the GroEL cylinder, which accommodates the protein substrate within its central cavity
Authors:Langer, T.; Pfeifer, G.; Martin, J.; Baumeister, W.; Hartl, F. U.
Date of Publication (YYYY-MM-DD):1992
Title of Journal:EMBO Journal.
Issue / Number:13
Start Page:4757
End Page:4765
Audience:Not Specified
Abstract / Description:The mechanism of GroEL (chaperonin)-mediated protein folding is only partially understood. We have analysed structural and functional properties of the interaction between GroEL and the co-chaperonin GroES. The stoichiometry of the GroEL 14mer and the GroES 7mer in the functional holo-chaperonin is 1:1. GroES protects half of the GroEL subunits from proteolytic truncation of the approximately 50 C-terminal residues. Removal of this region results in an inhibition of the GroEL ATPase, mimicking the effect of GroES on full-length GroEL. Image analysis of electron micrographs revealed that GroES binding triggers conspicuous conformational changes both in the GroES adjacent end and at the opposite end of the GroEL cylinder. This apparently prohibits the association of a second GroES oligomer. Addition of denatured polypeptide leads to the appearance of irregularly shaped, stain-excluding masses within the GroEL double-ring, which are larger with bound alcohol oxidase (75 kDa) than with rhodanese (35 kDa). We conclude that the functional complex of GroEL and GroES is characterized by asymmetrical binding of GroES to one end of the GroEL cylinder and suggest that binding of the substrate protein occurs within the central cavity of GroEL.
Free Keywords:*Bacterial Proteins/ch [Chemistry]; Bacterial Proteins/me [Metabolism]; Bacterial Proteins/ul [Ultrastructure]; Chromatography, Gel; Electrophoresis, Polyacrylamide Gel; Escherichia coli/me [Metabolism]; GroEL Protein; GroES Protein; *Heat-Shock Proteins/ch [Chemistry]; Heat-Shock Proteins/me [Metabolism]; Heat-Shock Proteins/ul [Ultrastructure]; Image Processing, Computer-Assisted; Microscopy, Electron; *Protein Folding; Support, Non-U.S. Gov't
External Publication Status:published
Document Type:Article
Communicated by:Anton Hillebrand
Affiliations:MPI für Biochemie/Structural Biology (W. Baumeister)/
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.