Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Mol Cell. 2008 May 9;30(3):348-59. doi: 10.1016/j.molcel.2008.03.012.

Coupling of ribosomal L1 stalk and tRNA dynamics during translation elongation.

Author information

  • 1Department of Chemistry, Columbia University, New York, NY 10027, USA.

Abstract

By using single-molecule fluorescence resonance energy transfer (smFRET), we observe the real-time dynamic coupling between the ribosome, labeled at the L1 stalk, and transfer RNA (tRNA). We find that an interaction between the ribosomal L1 stalk and the newly deacylated tRNA is established spontaneously upon peptide bond formation; this event involves coupled movements of the L1 stalk and tRNAs as well as ratcheting of the ribosome. In the absence of elongation factor G, the entire pretranslocation ribosome fluctuates between just two states: a nonratcheted state, with tRNAs in their classical configuration and no L1 stalk-tRNA interaction, and a ratcheted state, with tRNAs in an intermediate hybrid configuration and a direct L1 stalk-tRNA interaction. We demonstrate that binding of EF-G shifts the equilibrium toward the ratcheted state. Real-time smFRET experiments reveal that the L1 stalk-tRNA interaction persists throughout the translocation reaction, suggesting that the L1 stalk acts to direct tRNA movements during translocation.

PMID:
18471980
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk