GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:10077571

From GONUTS
Jump to: navigation, search
Citation

Horowitz, PM, Lorimer, GH and Ybarra, J (1999) GroES in the asymmetric GroEL14-GroES7 complex exchanges via an associative mechanism. Proc. Natl. Acad. Sci. U.S.A. 96:2682-6

Abstract

The interaction of the chaperonin GroEL14 with its cochaperonin GroES7 is dynamic, involving stable, asymmetric 1:1 complexes (GroES7.GroEL7-GroEL7) and transient, metastable symmetric 2:1 complexes [GroES7.GroEL7-GroEL7.GroES7]. The transient formation of a 2:1 complex permits exchange of free GroES7 for GroES7 bound in the stable 1:1 complex. Electrophoresis in the presence of ADP was used to resolve free GroEL14 from the GroES7-GroEL14 complex. Titration of GroEL14 with radiolabeled GroES7 to molar ratios of 32:1 demonstrated a 1:1 limiting stoichiometry in a stable complex. No stable 2:1 complex was detected. Preincubation of the asymmetric GroES7.GroEL7-GroEL7 complex with excess unlabeled GroES7 in the presence of ADP demonstrated GroES7 exchange. The rates of GroES7 exchange were proportional to the concentration of unlabeled free GroES7. This concentration dependence points to an associative mechanism in which exchange of GroES7 occurs by way of a transient 2:1 complex and excludes a dissociative mechanism in which exchange occurs by way of free GroEL14. Exchange of radiolabeled ADP from 1:1 complexes was much slower than the exchange of GroES7. In agreement with recent structural studies, this indicates that conformational changes in GroEL14 following the dissociation of GroES7 must precede ADP release. These results explain how the GroEL14 cavity can become reversibly accessible to proteins under in vivo conditions that favor 2:1 complexes.

Links

PubMed PMC15829

Keywords

Chaperonin 10/chemistry; Chaperonin 10/metabolism; Chaperonin 60/chemistry; Chaperonin 60/metabolism; Escherichia coli/chemistry; Escherichia coli/metabolism; Protein Binding

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

ECOLI:CH60

enables

GO:0005515: protein binding

ECO:0000353: physical interaction evidence used in manual assertion

UniProtKB:P0A6F9

F

Seeded From UniProt

complete

ECOLI:CH10

enables

GO:0005515: protein binding

ECO:0000353: physical interaction evidence used in manual assertion

UniProtKB:P0A6F5

F

Seeded From UniProt

complete

ECOLI:CH10

enables

GO:0042802: identical protein binding

ECO:0000353: physical interaction evidence used in manual assertion

UniProtKB:P0A6F9

F

Seeded From UniProt

complete


See also

References

See Help:References for how to manage references in GONUTS.