Functional elucidation of a key contact between tRNA and the large ribosomal subunit rRNA during decoding

RNA. 2010 Oct;16(10):2002-13. doi: 10.1261/rna.2232710. Epub 2010 Aug 25.

Abstract

The selection of cognate tRNAs during translation is specified by a kinetic discrimination mechanism driven by distinct structural states of the ribosome. While the biochemical steps that drive the tRNA selection process have been carefully documented, it remains unclear how recognition of matched codon:anticodon helices in the small subunit facilitate global rearrangements in the ribosome complex that efficiently promote tRNA decoding. Here we use an in vitro selection approach to isolate tRNA(Trp) miscoding variants that exhibit a globally perturbed tRNA tertiary structure. Interestingly, the most substantial distortions are positioned in the elbow region of the tRNA that closely approaches helix 69 (H69) of the large ribosomal subunit. The importance of these specific interactions to tRNA selection is underscored by our kinetic analysis of both tRNA and rRNA variants that perturb the integrity of this interaction.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites / genetics
  • Codon / chemistry
  • Codon / genetics
  • Codon / metabolism
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Kinetics
  • Models, Molecular
  • Mutation
  • Nucleic Acid Conformation
  • Peptide Chain Elongation, Translational
  • RNA, Bacterial / chemistry
  • RNA, Bacterial / genetics
  • RNA, Bacterial / metabolism
  • RNA, Ribosomal / chemistry*
  • RNA, Ribosomal / genetics
  • RNA, Ribosomal / metabolism*
  • RNA, Transfer / chemistry*
  • RNA, Transfer / genetics
  • RNA, Transfer / metabolism*
  • RNA, Transfer, Trp / chemistry
  • RNA, Transfer, Trp / genetics
  • RNA, Transfer, Trp / metabolism
  • Ribosome Subunits, Large, Bacterial / chemistry
  • Ribosome Subunits, Large, Bacterial / genetics
  • Ribosome Subunits, Large, Bacterial / metabolism
  • Thermodynamics

Substances

  • Codon
  • RNA, Bacterial
  • RNA, Ribosomal
  • RNA, Transfer, Trp
  • RNA, Transfer