灵活性和分布式合成 调节人类DNA聚合酶α-Primase中的RNA原始化和移交
John J Cordoba1, Elwood A Mullins2, Lauren E Salay3
1Chemical and Physical Biology Program, Vanderbilt University, Nashville, TN, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN, USA.
Journal of molecular biology
|October 26, 2023
概括
细胞DNA复制原始合成涉及聚合酶α-原始酶 (pol-prim) 酶. 它的灵活结构和低酶催化域 (PRIM1) 亲和力促进RNA原始生成和转移到聚合酶α.
科学领域:
- 分子生物学分子生物学
- 生物化学 生化学
- 结构生物学 结构生物学
背景情况:
- 在真核生物中,DNA复制需要由聚合酶α-原酶 (pol-prim) 酶合成的原料.
- 聚原酶由一个原酶子单元 (PRIM1和PRIM2C) 和一个聚合酶α子单元组成.
- 原料合成涉及RNA原料 (7-10个核酸),其次是DNA延伸 (大约. 20个核酸).
研究的目的:
- 通过pol-prim.研究控制RNA原料合成的结构和动态机制.
- 阐明PRIM2C和PRIM1领域在基质结合和催化中的作用.
- 要了解从原酶到α.聚合酶的原始交换机制.
主要方法:
- 微角X射线散射 (SAXS) 和电子显微镜 (EM) 用于确定聚原体的结构和动态.
- 交叉连接与EM相结合,可视化基质参与期间的域定向.
- 微尺度热泳以测量聚原结构的基质结合亲和力.
主要成果:
- 在PRIM2C和PRIM1组织中观察到显著的结构变异,无论是带有基质还是没有基质.
- 能够有效合成的结构的数量很少,这突显了酶的动态性质.
- PRIM1催化域对模板和RNA原料模板的亲和力较低,而聚合酶α的POLA1cat域具有较高的亲和力.
结论:
- RNA原始合成和移交是由pol-prim.的高域间灵活性调节的.
- PRIM1的低亲和力促进了基质的释放和转移到聚合酶α.
- 这种机制确保了真核细胞DNA复制的有效和准确启动.
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