拉克抑制剂通过修改最初的转录复合体来起作用,使其无法离开促进体
1Department of Microbiology, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
Cell
|August 23, 1991
概括
乳糖抑制蛋白质通过增强自然暂停部位,防止RNA聚合酶在乳糖UV5促进体上延长转录. 这种机制阻断了促进子逃逸,并产生了短的,流产的RNA分子.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 生物化学 生物化学
背景情况:
- 乳酸抑制蛋白通过与乳酸运营者结合来调节基因表达.
- RNA聚合酶在促进体区域启动转录,但促进体逃脱是一个关键步骤.
- 堕胎转录发生在RNA聚合酶释放短RNA片段而不延长转录时.
研究的目的:
- 调查乳酸抑制剂抑制乳酸UV5促进体RNA聚合酶活性的机制.
- 为了确定抑制剂的作用是否涉及增加内在促进剂暂停站点.
- 探索这种机制对促进体清除和流产转录的影响.
主要方法:
- 形成RNA聚合酶和lac UV5促进体中的lac抑制剂之间的联合复合体.
- 对RNA合成的分析,重点是流产的寡合体生成和转录长度.
- 研究基质度对转录的影响.
- 利用一种特定的RNA聚合酶突变,模仿抑制剂的效果.
主要成果:
- RNA聚合酶和LAC抑制剂之间的联合复合物被阻止促进物逃逸,产生失败的RNA寡合物.
- 转录对基质度非常敏感,表明了暂停地点.
- 抑制剂增加了促进体内的自然高核度 (kNTP) 暂停点.
- 一种特定的RNA聚合酶突变会复制抑制剂的效果,阻断促进体清除并缩短堕胎产物.
结论:
- 拉克抑制剂通过增强促销器内在的暂停部位来抑制转录延长,从而防止促销器逃逸.
- 这种增强暂停点的机制可能是调节转录启动的广泛策略.
- 了解这些调节机制对于理解基因表达控制至关重要.
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