Loading…

Dynamic Behavior of Trigger Factor on the Ribosome

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 riboso...

Full description

Saved in:
Bibliographic Details
Published in:Journal of molecular biology 2016-09, Vol.428 (18), p.3588-3602
Main Authors: Deeng, J., Chan, K.Y., van der Sluis, E.O., Berninghausen, O., Han, W., Gumbart, J., Schulten, K., Beatrix, B., Beckmann, R.
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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. [Display omitted] •Trigger factor's interaction with NCs on the ribosome is studied.•We have analyzed TF–ribosome–NC complexes via cryo-electron microscopy.•When bound to the ribosome, TF's flexibility depends on the NC length.•The rearranged RBD of TF provides a first landing platform for the NC.•Conformational dynamics of TF on the ribosome are coordinated with NC binding.
ISSN:0022-2836
1089-8638
DOI:10.1016/j.jmb.2016.06.007