Saturday, January 17, 2009
A bilingual genetic code
Messenger RNA is used as a template to assemble proteins by means of three-letter sequences called codons. Each codon corresponds to either a single amino acid or a 'stop' signal. However, Vadim Gladyshev of the University of Nebraska in Lincoln and his colleagues found that in E. crassus, the codon UGA could encode two amino acids: cysteine or selenocysteine.
The codon could be read in both ways within the same gene, depending on its location within the mRNA strand and the presence and exposure of a specific sequence near the end of the mRNA molecule. The results suggest that the genetic code can be evolutionarily expanded.
Full article @ Nature
The codon could be read in both ways within the same gene, depending on its location within the mRNA strand and the presence and exposure of a specific sequence near the end of the mRNA molecule. The results suggest that the genetic code can be evolutionarily expanded.
Full article @ Nature
