聚合酶活性位点中的相互作用网络是沃森-克里克基配对在Pol γ中的先决条件
Joon Park1,2, Geoffrey K Herrmann1,2, Arkanil Roy3
1Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.
Science advances
|May 24, 2024
概括
DNA聚合酶玛 (Pol γ) arginine-853突变通过破坏活性位点关闭来阻止线粒体DNA复制. 这种结构缺陷解释了Pol γ突变与神经疾病之间的联系.
科学领域:
- 生物化学 生化学
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
背景情况:
- 线粒体基因组完整性依赖于DNA聚合酶玛 (Pol γ) 精确的DNA复制.
- 人类Pol γ的突变,特别是氨酸-853的突变,与神经系统疾病有关.
- 尽管它不是一种催化残留物,但氨酸-853的突变使得Pol γ变得不活跃.
研究的目的:
- 阐明Pol γ arginine-853突变体中聚合酶活性丧失的结构基础.
- 了解Pol γ中的突变如何导致神经系统疾病.
主要方法:
- 确定了与2'-脱氧化丁5'-三酸盐 (dCTP) 结合的Pol γ突变三元复合物的晶体结构.
- 将突变复合物的结构和构造变化与野生类型酶进行了比较.
主要成果:
- 在结合dCTP时,Pol γ arginine-853突变复合体未能经历必要的开放到闭合的形状变化.
- 与野生类型不同,突变复合物没有促进dCTP和模板之间的沃森-克里克基配对.
- 氨酸-853对于一个相互作用网络至关重要,该网络正确地将原始3'-end和传入的核酸定位在活性位点内.
结论:
- 氨酸-853介导的相互作用网络的干扰阻止了活性位点的关闭和沃森-克里克基配对.
- 这种结构缺陷解释了在Pol γ arginine-853突变体中观察到的聚合酶不活性.
- 这些发现为与Pol γ突变相关的神经疾病提供了结构基础.
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