A fast dynamic mode of the EF-G-bound ribosome. Academic Article uri icon

Overview

MeSH

  • Binding Sites
  • Fluorescence Resonance Energy Transfer
  • Macromolecular Substances
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Nucleic Acid Conformation
  • Protein Biosynthesis
  • Protein Conformation
  • Protein Stability
  • RNA Stability
  • RNA, Transfer
  • Recombinant Fusion Proteins
  • Ribosomal Proteins
  • Thermodynamics

MeSH Major

  • Peptide Elongation Factor G
  • Ribosomes

abstract

  • A key intermediate in translocation is an 'unlocked state' of the pre-translocation ribosome in which the P-site tRNA adopts the P/E hybrid state, the L1 stalk domain closes and ribosomal subunits adopt a ratcheted configuration. Here, through two- and three-colour smFRET imaging from multiple structural perspectives, EF-G is shown to accelerate structural and kinetic pathways in the ribosome, leading to this transition. The EF-G-bound ribosome remains highly dynamic in nature, wherein, the unlocked state is transiently and reversibly formed. The P/E hybrid state is energetically favoured, but exchange with the classical P/P configuration persists; the L1 stalk adopts a fast dynamic mode characterized by rapid cycles of closure and opening. These data support a model in which P/E hybrid state formation, L1 stalk closure and subunit ratcheting are loosely coupled, independent processes that must converge to achieve the unlocked state. The highly dynamic nature of these motions, and their sensitivity to conformational and compositional changes in the ribosome, suggests that regulating the formation of this intermediate may present an effective avenue for translational control.

publication date

  • February 17, 2010

has subject area

  • Binding Sites
  • Fluorescence Resonance Energy Transfer
  • Macromolecular Substances
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Nucleic Acid Conformation
  • Peptide Elongation Factor G
  • Protein Biosynthesis
  • Protein Conformation
  • Protein Stability
  • RNA Stability
  • RNA, Transfer
  • Recombinant Fusion Proteins
  • Ribosomal Proteins
  • Ribosomes
  • Thermodynamics

Research

keywords

  • Journal Article

Identity

Language

  • eng

PubMed Central ID

  • PMC2829159

Digital Object Identifier (DOI)

  • 10.1038/emboj.2009.384

PubMed ID

  • 20033061

Additional Document Info

start page

  • 770

end page

  • 781

volume

  • 29

number

  • 4