Sense Codon Reassignment

对标准遗传密码在现代生物体中的灵活性进行了实验评估。在这项研究中，新建立了广泛的基因组工程和密码子解码因子的方法。只有几十个基因修饰的大肠杆菌细胞接受了AGG重新分配为高精氨酸。由于6个包含11个agg密码子的必需基因在功能上表达，表明高精氨酸和精氨酸在很大程度上是相容的。我之前已经证明过，有10个突变的大肠杆菌细胞接受了终止密码子标签的重新分配。因此，遗传密码仍然是灵活的，可能是因为蛋白质组本质上对改变的分配比人们认为的更耐受。

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.