The release element of the yeast polymerase I transcription terminator can function independently of Reb1p.
The release element of the yeast polymerase I transcription terminator can function independently of Reb1p.
复制标题
酵母聚合酶 I 转录终止子的释放元件可以独立于 Reb1p 发挥作用。
DOI：
10.1128/mcb.15.11.5929
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发表时间：
1995
影响因子：
5.3
通讯作者：
Reeder,RH
中科院分区：
文献类型：
--
作者：
Jeong,SW;Lang,WH;Reeder,RH
酵母菌聚合酶I（polI）转录终止子利用DNA结合蛋白（Reb1p）作为信号的一部分，使聚合酶在从模板释放之前暂停。为了研究终止子的释放元件，不依赖于Reb1p暂停信号，我们已经将Reb1p结合位点替换为lacrepressor的结合位点，lacrepressor作为polI的独立异源暂停信号。当lacrepressor使polI在Reb1p使其暂停的位置完全相同时，释放效率最大，这表明polI必须精确定位才能发生转录物释放。突变分析表明，释放元件是一个富含T残基的区域，该区域编码转录物的最末端3′端，并且在转录成RNA时没有明显的形成发夹的能力。我们讨论了可能的机制，从而这种polI释放元件可能发挥作用。
TheSaccharomyces cerevisiaepolymerase I (polI) transcription terminator utilizes a DNA-binding protein (Reb1p) as part of a signal that causes the polymerase to pause prior to release from the template. To study the release element of the terminator, independent of the Reb1p pause signal, we have replaced the Reb1p binding site with the binding site for thelacrepressor, which acts as a self-contained heterologous pause signal for polI. Release efficiency is maximal when thelacrepressor causes polI to pause in exactly the same position that Reb1p would have caused it to pause, suggesting that polI must be precisely positioned for transcript release to occur. Mutational analysis shows that the release element is a region rich in T residues which codes for the extreme 3′ end of the transcript and which has no apparent ability to form hairpins when transcribed into RNA. We discuss possible mechanisms whereby this polI release element might function.