SPECIFIC INTERACTION OF MODEL-tRNA AND AMINO ACIDS

为了探讨遗传密码的起源，研究了RNA与氨基酸之间特异性相互作用的可能性。本文首先研究了大肠杆菌中20种tRNA的同一性决定簇，利用T7 RNA聚合酶构建了多种tRNA突变体转录本。反密码子碱基和反密码子核苷酸是大多数tRNA的重要决定子。在此基础上，构建了一个由反密码子臂和受体茎组成的小RNA，并对其氨酰化活性进行了酶促研究。只有minihelix或microhelix在某些情况下工作得很好。下一次，更多的活性氨基酸应该用于这种类型的研究。

To discuss the origin of genetic code, the possibility of a specific interaction between RNA and amino acid was studied. Identity determinants of 20 kinds of tRNAs in E.coli are at first investigated, constructing various tRNA mutant transcripts by using the T7 RNA polymerase. Anticodon bases and discriminator nucleotide are found to be the important determinant in most of tRNAs. Consequently, a small RAN composed of anticodon arm and acceptor stem was constructed and its aminoacylation activity was studied enzymatically. Only minihelix or microhelix in some cases works well. Next time, more active amino acids should be used for this type of investigations.