Specificity of the ribosomal A site for aminoacyl-tRNAs. Journal Article uri icon



  • Although some experiments suggest that the ribosome displays specificity for the identity of the esterified amino acid of its aminoacyl-tRNA substrate, a study measuring dissociation rates of several misacylated tRNAs containing the GAC anticodon from the A site showed little indication for such specificity. In this article, an expanded set of misacylated tRNAs and two 2'-deoxynucleotide-substituted mRNAs are used to demonstrate the presence of a lower threshold in k(off) values for aa-tRNA binding to the A site. When a tRNA binds sufficiently well to reach this threshold, additional stabilizing effects due to the esterified amino acid or changes in tRNA sequence are not observed. However, specificity for different amino acid side chains and the tRNA body is observed when tRNA binding is sufficiently weaker than this threshold. We propose that uniform aa-tRNA binding to the A site may be a consequence of a conformational change in the ribosome, induced by the presence of the appropriate combination of contributions from the anticodon, amino acid and tRNA body.

publication date

  • March 1, 2009

has subject area

has restriction

  • gold

Date in CU Experts

  • March 13, 2015 12:56 PM

Full Author List

  • Dale T; Fahlman RP; Olejniczak M; Uhlenbeck OC

author count

  • 4

Other Profiles

Electronic International Standard Serial Number (EISSN)

  • 1362-4962

Additional Document Info

start page

  • 1202

end page

  • 1210


  • 37


  • 4