The affinity of elongation factor Tu for an aminoacyl-tRNA is modulated by the esterified amino acid
The affinity of elongation factor Tu for an aminoacyl-tRNA is modulated by the esterified amino acid
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DOI：
10.1021/bi036290o
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发表时间：
2004-05-25
期刊：
影响因子：
2.9
通讯作者：
Uhlenbeck, OC
中科院分区：
文献类型：
--
作者：
Dale, T;Sanderson, LE;Uhlenbeck, OC
当不同的突变被引入到反密码子环和 YFA2（酵母 tRNA（Phe）的衍生物）的 73 位时，单个 tRNA 体被 13 个不同的氨基酸异酰化。使用核糖核酸酶保护测定法测定这些三酰基化 tRNA 对嗜热栖热菌延伸因子 Tu (EF-Tu).GTP 的亲和力。观察到结合能范围为 2.5 kcal/mol，清楚地表明 EF-Tu 特异性识别酯化氨基酸的侧链。此外，可以通过在 EF-Tu 表面的氨基酸结合袋中引入突变来改变这种特异性。此外，当结合先前确定的 EF-Tu 对 tRNA 体的特异性进行讨论时，这些实验进一步证明 EF-Tu 使用热力学补偿来类似地结合同源氨酰基-tRNA。
When different mutations were introduced into the anticodon loop and at position 73 of YFA2, a derivative of yeast tRNA(Phe), a single tRNA body was misacylated with 13 different amino acids. The affinities of these misacylated tRNAs for Thermus thermophilus elongation factor Tu (EF-Tu).GTP were determined using a ribonuclease protection assay. A range of 2.5 kcal/mol in the binding energies was observed, clearly demonstrating that EF-Tu specifically recognizes the side chain of the esterified amino acid. Furthermore, this specificity can be altered by introducing a mutation in the amino acid binding pocket on the surface of EF-Tu. Also, when discussed in conjunction with the previously determined specificity of EF-Tu for the tRNA body, these experiments further demonstrate that EF-Tu uses thermodynamic compensation to bind cognate aminoacyl-tRNAs similarly.