tRNA dynamics on the ribosome during translation Academic Article uri icon


MeSH Major

  • Protein Biosynthesis
  • RNA, Transfer
  • Ribosomes


  • Using single-molecule fluorescence spectroscopy, time-resolved conformational changes between fluorescently labeled tRNA have been characterized within surface-immobilized ribosomes proceeding through a complete cycle of translation elongation. Fluorescence resonance energy transfer was used to observe aminoacyl-tRNA (aa-tRNA) stably accommodating into the aminoacyl site (A site) of the ribosome via a multistep, elongation factor-Tu dependent process. Subsequently, tRNA molecules, bound at the peptidyl site and A site, fluctuate between two configurations assigned as classical and hybrid states. The lifetime of classical and hybrid states, measured for complexes carrying aa-tRNA and peptidyl-tRNA at the A site, shows that peptide bond formation decreases the lifetime of the classical-state tRNA configuration by approximately 6-fold. These data suggest that the growing peptide chain plays a role in modulating fluctuations between hybrid and classical states. Single-molecule fluorescence resonance energy transfer was also used to observe aa-tRNA accommodation coupled with elongation factor G-mediated translocation. Dynamic rearrangements in tRNA configuration are also observed subsequent to the translocation reaction. This work underscores the importance of dynamics in ribosome function and demonstrates single-particle enzymology in a system of more than two components.

publication date

  • August 31, 2004



  • Academic Article



  • eng

PubMed Central ID

  • PMC516491

Digital Object Identifier (DOI)

  • 10.1073/pnas.0403884101

PubMed ID

  • 15317937

Additional Document Info

start page

  • 12893

end page

  • 8


  • 101


  • 35