A limited number of non-canonical genetic codes have been described in eukaryotic nuclear genomes. Most involve reassignment of one or two termination codons as sense ones [1-4], but no code variant is known that would have reassigned all three termination codons. Here, we describe such a variant that we discovered in a clade of trypanosomatids comprising nominal Blastocrithidia species. In the...

PURPOSE Lacritin is a prosecretory mitogen in tears and, although a tear protein, it promotes basal tearing and lacrimal gland secretion. Since scale up is relevant to its potential use in the treatment of dry eye, we explored various mutagenic strategies to alter the stability, solubility, and translational efficiency of nascent lacritin, and discovered 3' clustering of rare human codons. ME...

In this paper, we analyzed the UL43 gene of duck plague virus (DPV) of codon usage bias. The results may provide a basis for understanding the evolution and pathogenesis of DPV and for selecting appropriate host expression systems to improve the expression of target gene in vitro. In this study, the synonymous codon usage bias of UL43 gene in the 24 herpesviruses have been analyzed and the resu...

Mutagenesis of protooncogenes has been postulated to contribute to the initiation and progression of human cancer. Activating mutations in the H-ras gene are predominantly single-base substitutions and are most fre quently identified at codons 12, 13, and 61. We have analyzed the effects of DNA sequence context at specific codons that are hot spots for raj mutation with respect to abnormalities...

When a ribosome translates mRNA sequences, the ribosome often stalls at certain codons because it is hard to translate. Consecutive proline codons are such examples that induce ribosome stalling and elongation factor P (EF-P) is required for the stalled ribosome to continue translation at those consecutive proline codons. We found that EF-P is required for translation of the mgtB gene encoding ...

Multiple-site-specific incorporation of a noncanonical amino acid into a recombinant protein would be a very useful technique to generate multiple chemical handles for bioconjugation and multivalent binding sites for the enhanced interaction. Previously combination of a mutant yeast phenylalanyl-tRNA synthetase variant and the yeast phenylalanyl-tRNA containing the AAA anticodon was used to inc...

Termination of protein synthesis is triggered by the recognition of a stop codon at the ribosomal A site and is mediated by class I release factors (RFs). Whereas in bacteria, RF1 and RF2 promote termination at UAA/UAG and UAA/UGA stop codons, respectively, eukaryotes only depend on one RF (eRF1) to initiate peptide release at all three stop codons. Based on several structural as well as bioche...