Nucleotide insertion in the anticodon loop of a glycine transfer RNA causes missense suppression.

AUTOR(ES)

Prather, N E

RESUMO

We have determined the nucleotide sequences of two unusual UGG-suppressing glycine tRNAs from Escherichia coli and, as a result, have discovered a new mechanism for the generation of missense suppressors. The suppressor tRNAs translate UGG but not UGA. Each arose as a consequence of spontaneous mutational alteration of glyT, the gene for the GGA/G-reading glycine tRNA of E. coli. In each mutant tRNA, the change in primary structure involved the insertion of an adenylate residue on the 3' side of the anticodon and the loss of a modification of the uridylate residue at the 5' end of the anticodon. A "shift" of the effective anticodon by one nucleotide in the 3' direction can account for the new coding specificity of these tRNAs.

Documentos Relacionados

• Anticodon shift in tRNA: a novel mechanism in missense and nonsense suppression.
• A nucleotide change in the anticodon of an Escherichia coli serine transfer RNA results in supD-amber suppression.
• The nucleotide in position 32 of the tRNA anticodon loop determines ability of anticodon UCC to discriminate among glycine codons.
• A novel type of + 1 frameshift suppressor: a base substitution in the anticodon stem of a yeast mitochondrial serine-tRNA causes frameshift suppression.
• Insertion (sufB) in the anticodon loop or base substitution (sufC) in the anticodon stem of tRNA(Pro)2 from Salmonella typhimurium induces suppression of frameshift mutations.