Third position base changes in codons 5′ and 3′ adjacent UGA codons affect UGA suppression in vivo
| Autor: | B.H. Mims, D. Brechemier-Baey, P.M. Sörensen, Kathryn A. Hijazi, Emanuel J. Murgola, Frances T. Pagel, Richard H. Buckingham |
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| Rok vydání: | 1990 |
| Předmět: |
Genetics
Base Sequence Genotype media_common.quotation_subject Nonsense mutation Nonsense Biophysics Context (language use) Biology Biochemistry Stop codon Nonsense suppressor Genes Bacterial Structural Biology Transfer RNA Escherichia coli Mutagenesis Site-Directed TRPA RNA Messenger Codon Genes Suppressor Gene media_common |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression. 1050:259-262 |
| ISSN: | 0167-4781 |
| DOI: | 10.1016/0167-4781(90)90177-4 |
| Popis: | The base sequence around nonsense codons affects the efficiency of nonsense codon suppression. Published data, comparing different nonsense sites in a mRNA, implicate the two bases downstream of the nonsense codon as major determinants of suppression efficiency. However, the results we report here indicate that the nature of the contiguous upstream codon can also affect nonsense suppression, as can the third (wobble) base of the contiguous downstream codon. These conclusions are drawn from experiments in which the two Ser codons UCU233 and UCG235 in a nonsense mutant form (UGA234) of the trpA gene in Escherichia coli have been replaced with other Ser codons by site-directed mutagenesis. Suppression of these trpA mutants has been studied in the presence of a UGA nonsense suppressor derived from glyT. We speculate that the non-site-specific effects of the two adjacent downstream bases may be largely at the level of the termination process, whereas more site-specific or codon-specific effects may operate primarily on the activity of the suppressor tRNA. |
| Databáze: | OpenAIRE |
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