Protein synthesis editing by a DNA aptamer
Protein synthesis editing by a DNA aptamer
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DOI：
10.1073/pnas.93.7.2755
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发表时间：
1996-04-02
影响因子：
11.1
通讯作者：
Schimmel, P
中科院分区：
文献类型：
--
作者：
Hale, SP;Schimmel, P
解码遗传信息时的潜在错误可通过编辑反应表现出的依赖于 tRNA 的氨基酸识别过程来纠正。一个例子是 tRNA 合成酶通过水解反应排斥难以区分的失活氨基酸。尽管存在多种 tRNA 合成酶和合成酶-tRNA 复合物的晶体结构，但它们都没有提供对编辑反应的深入了解。其他研究表明，编辑需要 tRNA 效应子 3' 端的活性氨基酸受体羟基。我们在此描述了 DNA 适体的分离，该适体特异性诱导与 tRNA 合成酶结合的失活氨基酸的水解。适体对正确激活的氨基酸的稳定性没有影响，并且几乎与 tRNA 诱导编辑活性一样有效。该适体与tRNA效应子没有序列相似性，并且不能折叠成类似tRNA的结构。这些和其他数据表明，tRNA效应子和tRNA样结构中的活性受体羟基对于编辑不是必需的。因此，核酸效应子中的特定碱基触发编辑反应。
Potential errors in decoding genetic information are corrected by tRNA-dependent amino acid recognition processes manifested through editing reactions. One example is the rejection of difficult-to-discriminate misactivated amino acids by tRNA synthetases through hydrolytic reactions. Although several crystal structures of tRNA synthetases and synthetase-tRNA complexes exist, none of them have provided insight into the editing reactions. Other work suggested that editing required active amino acid acceptor hydroxyl groups at the 3' end of a tRNA effector. We describe here the isolation of a DNA aptamer that specifically induced hydrolysis of a misactivated amino acid bound to a tRNA synthetase. The aptamer had no effect on the stability of the correctly activated amino acid and was almost as efficient as the tRNA for inducing editing activity. The aptamer has no sequence similarity to that of the tRNA effector and cannot be folded into a tRNA-like structure. These and additional data show that active acceptor hydroxyl groups in a tRNA effector and a tRNA-like structure are not essential for editing, Thus, specific bases in a nucleic acid effector trigger the editing response.