Molecular mechanism and structure of Trigger Factor bound to the translating ribosome.
EMBO J
; 27(11): 1622-32, 2008 Jun 04.
Article
en En
| MEDLINE
| ID: mdl-18497744
ABSTRACT
Ribosome-associated chaperone Trigger Factor (TF) initiates folding of newly synthesized proteins in bacteria. Here, we pinpoint by site-specific crosslinking the sequence of molecular interactions of Escherichia coli TF and nascent chains during translation. Furthermore, we provide the first full-length structure of TF associated with ribosome-nascent chain complexes by using cryo-electron microscopy. In its active state, TF arches over the ribosomal exit tunnel accepting nascent chains in a protective void. The growing nascent chain initially follows a predefined path through the entire interior of TF in an unfolded conformation, and even after folding into a domain it remains accommodated inside the protective cavity of ribosome-bound TF. The adaptability to accept nascent chains of different length and folding states may explain how TF is able to assist co-translational folding of all kinds of nascent polypeptides during ongoing synthesis. Moreover, we suggest a model of how TF's chaperoning function can be coordinated with the co-translational processing and membrane targeting of nascent polypeptides by other ribosome-associated factors.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Ribosomas
/
Biosíntesis de Proteínas
/
Chaperonas Moleculares
/
Isomerasa de Peptidilprolil
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Proteínas de Escherichia coli
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
EMBO J
Año:
2008
Tipo del documento:
Article
País de afiliación:
Alemania