由S. cerevisiaeRNA聚合酶II催化的多核酸添加的可逆动力学揭示了缓慢的酸盐释放
Kaila B Fuller1, Ruth Q Jacobs2, David A Schneider2
1Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
Journal of molecular biology
|May 10, 2024
概括
取决于DNA的RNA聚合酶II (Pol II) 通过火溶解逆转RNA键的形成,这表明一种古老的校对机制. 这与Pol I和Pol III形成鲜明对比,Pol I和Pol III使用核酶活性进行错误校正.
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:
- 细胞利用三个核DNA依赖的RNA聚合酶 (Pols):rRNA的Pol I,mRNA的Pol II和tRNA的Pol III.
- 聚合物I和聚合物III具有内在的核酶活性,而聚合物II需要转录因子IIS (TFIIS) 来实现强大的核酶功能.
- 缺少A12.2亚单元的Pol I表现出热溶解,在没有外部热酸盐 (PPi) 的情况下逆转键形成.
研究的目的:
- 调查RNA聚合酶II (Pol II) 是否也表现出 pyrophosphorolysis,假设它在没有 TFIIS 中介核酶活动的情况下可以作为校对机制.
- 探索火溶解作为RNA聚合酶的潜在古老校对机制的进化影响.
主要方法:
- 进行过渡状态的动力实验.
- 研究人员检查了由Pol II催化增长的RNA链中9个核酸的添加.
主要成果:
- 观察到Pol II可以通过铁溶解逆转RNA键的形成.
- 这种反应发生在没有添加的酸盐 (PPi) 的情况下.
结论:
- 聚合物II利用热溶解进行键反转,可能作为动力校对机制.
- 酸溶解可能代表一种祖先的校对策略,后来在进化过程中被其他RNA聚合酶的核酶活性所取代.
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