Concerted action of the ribosome and the associated chaperone trigger factor confines nascent polypeptide folding.
Mol Cell
; 48(1): 63-74, 2012 Oct 12.
Article
en En
| MEDLINE
| ID: mdl-22921937
How nascent polypeptides emerging from ribosomes fold into functional structures is poorly understood. Here, we monitor disulfide bond formation, protease resistance, and enzymatic activity in nascent polypeptides to show that in close proximity to the ribosome, conformational space and kinetics of folding are restricted. Folding constraints decrease incrementally with distance from the ribosome surface. Upon ribosome binding, the chaperone Trigger Factor counters folding also of longer nascent chains, to extents varying between different chain segments. Trigger Factor even binds and unfolds pre-existing folded structures, the unfolding activity being limited by the thermodynamic stability of nascent chains. Folding retardation and unfolding activities are not shared by the DnaK chaperone assisting later folding steps. These ribosome- and Trigger Factor-specific activities together constitute an efficient mechanism to prevent or even revert premature folding, effectively limiting misfolded intermediates during protein synthesis.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ribosomas
/
Pliegue de Proteína
/
Isomerasa de Peptidilprolil
/
Proteínas de Escherichia coli
Tipo de estudio:
Prognostic_studies
/
Risk_factors_studies
Idioma:
En
Revista:
Mol Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2012
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Estados Unidos