Claesson C, Samuelsson T, Lustig F, Borén T
Department of Medical Biochemistry, University of Göteborg, Sweden.
FEBS Lett. 1990 Oct 29;273(1-2):173-6. doi: 10.1016/0014-5793(90)81077-2.
We have previously shown that the Mycoplasma mycoides glycine tRNA (anticodon UCC) effectively reads the codons GGU and GGC in violation of the classic codon reading rules. We have attempted to elucidate what structural elements in this tRNA molecule confer this translational property and in the course of this investigation T7 RNA polymerase transcription of the corresponding gene was used to produce a tRNA devoid of modified nucleosides. Using an in vitro translation system the ability of this tRNA to read the 4 glycine codons (GGU, GGC, and GGG) was tested and it was shown to be as efficient as its normal, fully modified counterpart in the reading of all four codons. This result demonstrates that a tRNA devoid of modified nucleosides is able to efficiently sustain protein synthesis in vitro and, furthermore, that the normal modification pattern of the Mycoplasma glycine tRNA is not essential for the ability of this tRNA to read the glycine codons GGU and GGC effectively.
我们之前已经表明，蕈状支原体甘氨酸tRNA（反密码子UCC）违反经典密码子阅读规则，能有效识别密码子GGU和GGC。我们试图阐明该tRNA分子中的哪些结构元件赋予了这种翻译特性，在这项研究过程中，利用T7 RNA聚合酶转录相应基因来产生一种不含修饰核苷的tRNA。使用体外翻译系统测试了这种tRNA识别4种甘氨酸密码子（GGU、GGC和GGG）的能力，结果表明它在识别所有4种密码子时与正常的、完全修饰的对应物一样高效。这一结果表明，不含修饰核苷的tRNA能够在体外有效地维持蛋白质合成，此外，蕈状支原体甘氨酸tRNA的正常修饰模式对于该tRNA有效识别甘氨酸密码子GGU和GGC的能力并非必不可少。
