New insights into the incorporation of natural suppressor tRNAs at stop codons in Saccharomyces cerevisiae.
Bottom Line: We found that glutamine, tyrosine and lysine were inserted at UAA and UAG codons, whereas tryptophan, cysteine and arginine were inserted at UGA codon.We also found that two different glutamine tRNA(Gln) were used to insert glutamine at UAA and UAG codons.This work constitutes the first systematic analysis of the amino acids incorporated at stop codons, providing important new insights into the decoding rules used by the ribosome to read the genetic code.
Affiliation: Institut de Génétique et Microbiologie, Université Paris-Sud, UMR8621, 91400 Orsay, France.Show MeSH
Mentions: Thus, the major tRNAGln with the 3′GUU5′ anticodon is responsible for the insertion of glutamine at UAA codons, whereas the minor tRNAGln with the 3′GUC5′ anticodon is principally responsible for the insertion of glutamine at UAG codons. These results are consistent with the possibilities for base pairing between these anticodons and the two stop codons (Figure 5A).
Affiliation: Institut de Génétique et Microbiologie, Université Paris-Sud, UMR8621, 91400 Orsay, France.