Designing novel functions of proteins by using an artificial genetic code dictionary

蛋白质合成系统中内源性trna数量的限制导致遗传密码字典中出现“空密码子”。如果我们能创造出一种tRNA，它能读取“一个空密码子”，并接受一种非天然的氨基酸，那就意味着我们开发了一个人工的遗传密码词典。在这里，我从大肠杆菌中纯化了21个tRNA，并通过重新混合单个tRNA来制作最小tRNA集。实际上，在PURE系统中，用最少的tRNA集和化学合成的具有最少密码子的基因就可以合成黄色荧光蛋白。这表明含有几种非天然氨基酸的蛋白质在未来是可以有效合成的。

Restriction of the number of endogenous tRNAs in protein synthesis system causes "empty codons" in the genetic code dictionary. If we can create a tRNA that reads "an empty codon" and accepts an unnatural amino acid, it means that we develop an artificial genetic code dictionary. Here, I purified 21 tRNAs from Escherichia coli, and made a minimal tRNA set by remixing an individual tRNA. Actually, yellow fluorescent protein could be synthesized in PURE system with a minimal tRNA set and a chemically synthesized gene having minimal codons. It indicates that proteins having several unnatural amino acids can be effectively synthesized in the future.