| Literature DB >> 2499882 |
Abstract
We describe an assay that converts the effects of tRNA-tRNA contacts at two particular codons into a quantitative effect on beta-galactosidase level. The assay measures the separate and combined efficiency of suppression at adjacent nonsense codons in vivo using a set of specially created homologous messages. In a survey of distal anticodon arm substitutions, we find that particular mutant tRNAs occupying the P-site reduce the apparent efficiency of the suppressor tRNA reading the A-site codon by factors of 2-170. By using measured tRNA-tRNA distances and the crystallographic tRNA structure, we propose a model of the tRNA-tRNA-mRNA complex. In the model, the anticodon loops of the P-site and A-site tRNAs contact one another in a way that is consistent with our combined tRNA efficiency data. These results suggest that tRNA-tRNA interactions that modulate tRNA action are an inevitable feature of translation.Entities:
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Year: 1989 PMID: 2499882 PMCID: PMC287276 DOI: 10.1073/pnas.86.12.4397
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN: 0027-8424 Impact factor: 11.205