Site-specific mutagenesis of Escherichia coli gltT yields a weak, glutamic acid-inserting ochre suppressor.
Site-specific mutagenesis of Escherichia coli gltT yields a weak, glutamic acid-inserting ochre suppressor.
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大肠杆菌 gltT 的位点特异性诱变产生弱的谷氨酸插入赭石抑制剂。
DOI：
10.1016/0022-2836(85)90385-7
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发表时间：
1985
影响因子：
5.6
通讯作者：
Yarus,M
中科院分区：
文献类型：
--
作者：
Raftery,LA;Yarus,M
在所有可以通过单核苷酸突变产生琥珀或赭色抑制物的大肠杆菌RNA基因中，只有tRNAGlug基因没有被观察到这样做。对tRNAs序列和它们翻译的密码子之间关系的研究预测，来自tRNAGluc的Ochre抑制因子在核糖体上的作用非常差。为了验证这一预测，我们使用了定点突变来创建这样一种tRNA的基因。我们将tRNAGlu-Suoc基因克隆到一个高拷贝数的表达载体中，并将其置于启动子的控制下。突变体tRNA同时抑制琥珀和赭色无义突变。正如预测的那样，它的效率低于在类似条件下表达的其他抑制子。
Of all theEscherichia colitRNA genes that can give rise to an amber or an ochre suppressor by a single-nucleotide mutation, only the tRNAGlugenes have not been observed to do so. A study of the relationship between the sequences of tRNAs and the codons they translate predicts that the ochre suppressor derived from tRNAGluwould function very poorly on the ribosome. We have used site-specific mutagenesis to create the gene for such a tRNA in order to test this prediction. We cloned the tRNAGlu-Suocgene into a high copy number plasmid, under control of thelacUV5 promoter. The mutant tRNA suppresses both amber and ochre nonsense mutations. As predicted, it is less efficient than other suppressors expressed under similar conditions.