Sense Codon Reassignment

现代生物大肠杆菌的标准遗传密码的灵活性进行了实验评估。在这项研究中，新建立了基因组和密码子解码因子的广泛工程方法。E.只有几十个基因修饰的大肠杆菌细胞接受AGG的高精氨酸的重新分配。由于含有11个AGG密码子的6个必需基因功能性表达，表明高精氨酸和精氨酸在很大程度上是相容的。我之前已经证明了E。具有10个突变的大肠杆菌细胞接受终止密码子TAG的重新分配。因此，遗传密码仍然是灵活的，可能是因为蛋白质组本质上比人们想象的更能容忍改变的分配。

The flexibility of the standard genetic code in a modern organism Escherichia coli was experimentally evaluated. In this study, methods for the extensive engineering of the genome and codon-decoding factors were newly established. E. coli cells with only few dozens of genetic modifications accepted the reassignment of AGG to homoarginine. Since six essential genes containing eleven AGG codons were functionally expressed, it was indicated that homoarginine and arginine were largely compatible. I have previously demonstrated that E. coli cells with ten mutations accepted the reassignment of a stop codon TAG. Thus, the genetic code is still flexible, probably because the proteome is intrinsically more tolerant to the altered assignment than believed.