An operational RNA code for faithful assignment of AUG triplets to methionine

Mol Cell. 2008 Feb 15;29(3):401-7. doi: 10.1016/j.molcel.2007.12.021.

Abstract

The assignment of AUG codons to methionine remains a central question of the evolution of the genetic code. We have unveiled a strategy for the discrimination among tRNAs containing CAU (AUG-decoding) anticodons. Mycoplasma penetrans methionyl-tRNA synthetase can directly differentiate between tRNA(Ile)(CAU) and tRNA(Met)(CAU) transcripts (a recognition normally achieved through the modification of anticodon bases). This discrimination mechanism is based only on interactions with the acceptor stems of tRNA(Ile)(CAU) and tRNA(Met)(CAU). Thus, in certain species, the fidelity of translation of methionine codons requires a discrimination mechanism that is independent of the information contained in the anticodon.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aminoacylation
  • Animals
  • Anticodon
  • Base Sequence
  • Codon*
  • Genes, Bacterial
  • Methionine / genetics*
  • Methionine-tRNA Ligase / genetics
  • Methionine-tRNA Ligase / isolation & purification
  • Methionine-tRNA Ligase / metabolism
  • Mutation
  • Mycoplasma penetrans / enzymology
  • Mycoplasma penetrans / genetics
  • Nucleic Acid Conformation
  • Open Reading Frames
  • RNA / genetics*
  • RNA, Transfer, Ile / genetics
  • RNA, Transfer, Met / genetics

Substances

  • Anticodon
  • Codon
  • RNA, Transfer, Ile
  • RNA, Transfer, Met
  • RNA
  • Methionine
  • Methionine-tRNA Ligase