Selectivity and proofreading both contribute significantly to the fidelity of RNA polymerase III transcription
Selectivity and proofreading both contribute significantly to the fidelity of RNA polymerase III transcription
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DOI：
10.1073/pnas.0704116104
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发表时间：
2007-06-19
影响因子：
11.1
通讯作者：
Carles, Christophe
中科院分区：
文献类型：
--
作者：
Alic, Nazif;Ayoub, Nayla;Carles, Christophe
我们在这里检查的机制，确保RNA聚合酶III（Pol III）的RNA合成的保真度。只有使用内在RNA切割活性缺陷的Pol III变体才能观察到错误掺入。结合计算方法，确定在tRNA基因上特定位置产生正确和错误转录本的反应的相对速率，表明Pol III具有高效的校对活性，其转录保真度比仅由选择性确定的错误率（1.8 × 10（-4））提高了10（3）倍。我们表明，锅III减慢合成过去的错误纳入，以实现有效的校对。我们讨论了我们的研究结果的背景下进行RNA聚合物的转录保真度的研究，提出转录的保真度是更重要的聚合物III比聚合物II。
We examine here the mechanisms ensuring the fidelity of RNA synthesis by RNA polymerase III (Pol III). Misincorporation could only be observed by using variants of Pol III deficient in the intrinsic RNA cleavage activity. Determination of relative rates of the reactions producing correct and erroneous transcripts at a specific position on a tRNA gene, combined with computational methods, demonstrated that Pol III has a highly efficient proofreading activity increasing its transcriptional fidelity by a factor of 10(3) over the error rate determined solely by selectivity (1.8 x 10(-4)). We show that Pot III slows down synthesis past a misincorporation to achieve efficient proofreading. We discuss our findings in the context of transcriptional fidelity studies performed on RNA Pols, proposing that the fidelity of transcription is more crucial for Pol III than Pol II.