Dynamic Behavior of Trigger Factor on the Ribosome.
J Mol Biol
; 428(18): 3588-602, 2016 09 11.
Article
in En
| MEDLINE
| ID: mdl-27320387
ABSTRACT
Trigger factor (TF) is the only ribosome-associated chaperone in bacteria. It interacts with hydrophobic segments in nascent chain (NCs) as they emerge from the ribosome. TF binds via its N-terminal ribosome-binding domain (RBD) mainly to ribosomal protein uL23 at the tunnel exit on the large ribosomal subunit. Whereas earlier structural data suggested that TF binds as a rigid molecule to the ribosome, recent comparisons of structural data on substrate-bound, ribosome-bound, and TF in solution from different species suggest that this chaperone is a rather flexible molecule. Here, we present two cryo-electron microscopy structures of TF bound to ribosomes translating an mRNA coding for a known TF substrate from Escherichia coli of a different length. The structures reveal distinct degrees of flexibility for the different TF domains, a conformational rearrangement of the RBD upon ribosome binding, and an increase in rigidity within TF when the NC is extended. Molecular dynamics simulations agree with these data and offer a molecular basis for these observations.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ribosomes
/
Peptidylprolyl Isomerase
/
Escherichia coli Proteins
/
Escherichia coli
Language:
En
Journal:
J Mol Biol
Year:
2016
Document type:
Article
Affiliation country:
Alemania