An operational RNA code for faithful assignment of AUG triplets to methionine.
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.
Jones
Thomas E
TE
Barcelona Institute for Research in Biomedicine, Barcelona Science Park, C/Samitier 1-5, Barcelona 08015, Catalonia, Spain.
Brown
Cassidy L
CL
Geslain
Renaud
R
Alexander
Rebecca W
RW
Ribas de Pouplana
Lluís
L
D049148:Aminoacylation; D000818:Animals; D000926:Anticodon; D001483:Base Sequence; D003062:Codon; D005798:Genes, Bacterial; D008715:Methionine / Q000235:genetics*; D008718:Methionine-tRNA Ligase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D009154:Mutation; D018661:Mycoplasma penetrans / Q000201:enzymology / Q000235:genetics; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames; D012313:RNA / Q000235:genetics*; D012355:RNA, Transfer, Ile / Q000235:genetics; D012358:RNA, Transfer, Met / Q000235:genetics
D000926:Anticodon; D003062:Codon; D012355:RNA, Transfer, Ile; D012358:RNA, Transfer, Met; D012313:RNA; D008715:Methionine; D008718:Methionine-tRNA Ligase