TRANSLATION SYSTEM WITH COMPLEXITY

点击翻译按钮获取中文摘要

We demonstrated that codon CUG is assigned simultaneously both-as serine arid leucine codons in several- Candida-species, using analyzes of tRNA-and genetic techniques. In order to evaluate biological significance of the polysemous decoding in Candid strains, we are addressing quantitative manipulation of leucine acceptance of responsible tRNA. We already showed that leucine acceptance is governed by the presence of 1-methylguanosine at the position 37 adjacent to the anticodon. Moreover it is suggested that A at 73 position is also significantly involved in leucylation. In this project/we prepared various transcripts with mutation and modification enzyme for m1G from E. coli by overexpression method. Furthermore, seryl-tRNA and leucyl-tRNA synthetases were also expressed in E. coli and purified. By determination of enzymatic parameters of leucylation reaction using mutants, it appeared that methyl group at position 37 is indispensable for leucine *. Acceptance. Furthermore, mutation G to A at position 73 increased Kcat/Km values 400-fold. Base upon these observations, we will introduce these mutants genes into Candida cells and alternation of cell function will be evaluated.