The genetic code can be interpreted during translation as 21 amino acids and three termination signals. Recent advances at the interface of chemistry and molecular biology are extending the genetic code to allow assignment of new amino acids to existing codons, providing new functional groups for protein synthesis.

A structure-activity relationship (SAR) study was carried out to identify novel, small molecular weight compounds which induce readthrough of premature termination codons. In particular, analogs of RTC13, 1, were evaluated. In addition, hypothesizing that these compounds exhibit their activity by binding to the ribosome, we prepared the hybrid analogs 13 containing pyrimidine bases and these al...

The lsa gene confers intrinsic resistance to lincosamides and streptogramins A in Enterococcus faecalis, probably by active efflux. The lsa-like genes of two clinical isolates of E. faecalis susceptible to lincosamides and dalfopristin contained mutations that produced premature termination codons. Revertant mutants were obtained by selection on agar plates containing clindamycin.

Modified trinucleotides, 3MeU-A-G+, 3MeU-A-A, 5MeUA-G, 5MeU-A-A, BrU-A-G, hU-A-G, and U-A-I (see J. BioZ. Chem., 241, 527 (1966)), were synthesized by a combination of organic and enzymatic methods. The activity of each trinucleotide as a template for peptide chain termination was determined. The attachment of a methyl group to the NB position of uracil eliminates the template activity of termi...

The efficiency of translation termination is influenced by local contexts surrounding stop codons. In Saccharomyces cerevisiae, upstream and downstream sequences act synergistically to influence the translation termination efficiency. By analysing derivatives of a leaky stop codon context, we initially demonstrated that at least six nucleotides after the stop codon are a key determinant of read...