通过RNA聚合酶II进行转录忠实性和校对
M J Thomas1, A A Platas, D K Hawley
1Institute of Molecular Biology, Department of Biology, University of Oregon, Eugene 97403, USA.
Cell
|May 30, 1998
概括
人类RNA聚合酶II (pol II) 具有内在的校对能力. 在蛋白质SII的帮助下,pol II在转录过程中有效地去除不正确的核酸,确保RNA的准确性.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 遗传学 是一个遗传学.
背景情况:
- RNA聚合酶II (pol II) 对于基因转录至关重要.
- 在转录过程中,pol II的内在校对能力尚未完全被理解.
- 已知SII蛋白调节核酶活动.
研究的目的:
- 为了研究人类pol II的3'-->5'核酶活性,在转录期间进行校对.
- 确定蛋白SII在增强PolII校对中的作用.
- 了解由pol II进行核酸歧视的机制.
主要方法:
- 使用人类RNA聚合酶II的体外转录试验.
- 使用蛋白SII来刺激3'-->5'核酶活动.
- 评估从新生的RNA转录中去除错误结合的核酸.
- 采用 inosine monophosphate 合并来探测核酸添加动力学.
主要成果:
- 人类pol II在SII.II的存在下证明了误纳入的核酸的定量去除.
- 正确和不正确的基之间的区别是基于后续核酸添加的速度.
- 纳入伊诺辛单酸盐 (IMP) 显著抑制了下一个核酸添加,类似于不匹配的基.
- 添加了SII改变的RNA基组成,有利于正确的 (GMP) 与不正确的 (IMP) 核酸合并.
结论:
- 人类RNA聚合酶II具有由其3'-->5'核酶活性介导的内在校对机制.
- 蛋白SII在转录过程中显著提高了这种校对能力.
- 核酸添加率是pol II区分和去除不正确基的能力的一个关键因素,确保RNA忠实性.
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