REASSIGNMENT OF CODONS FROM ARG TO ALA BY MULTIPLE TRNA^ALA VARIANTS

抄録

  We have recently developed “simplified genetic codes” in which only 19 amino acids are assigned to one sense codon each. In one simplified code, for example, the UGG codon for tryptophan is reassigned to alanine (Ala) by a tRNA^Ala variant. We have previously generated such codes each of which was constructed using only one kind of tRNA variant. In this study, we describe a novel simplified genetic code in which the codons of Arg were reassigned to Ala using 3 kinds of tRNA^Ala variants. The usage of multiple tRNA variants will be important to construct more simplified genetic codes containing less than 19 amino acids. A Simplified genetic code will provide not only new insights into primordial genetic codes, but also an engineering tool for the assessment of protein evolution.