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与流动性的双边相互作用可以增强Pol IV介导的TLS

Seungwoo Chang¹, Luisa Laureti², Elizabeth S Thrall¹

¹Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115.

Proceedings of the National Academy of Sciences of the United States of America

|February 24, 2025

概括

DNA聚合酶IV (Pol IV) 与β2流动性的边缘接触对于通过困难的DNA块的转化合成 (TLS) 至关重要,有助于快速修复和减少突变.

科学领域:

分子生物学分子生物学
在DNA复制和修复过程中,
生物化学生物化学

背景情况:

渐进性,如大肠杆菌中的β2,对于DNA聚合酶至关重要,特别是在转化合成 (TLS) 过程中.
包括Pol IV在内的TLS聚合酶通过保留的结基因 (CBM) 与β2子相互作用.
此外,Pol IV与的边缘的相互作用较弱,由非CBM残留物介导,其功能意义尚不清楚.

研究的目的:

为了研究Pol IV与TLS中的β2流动性之间的非CBM边缘接触的作用.
确定这种边缘相互作用如何有助于解决不同类型的DNA损伤中的停滞复制分叉.

主要方法:

在实验室中复制大肠杆菌复制体以研究TLS动力学.
位点定向的突变发生来切除Pol IV边缘接触.
在强 (3-deaza-methyl dA) 和弱 (N2-furfuryl dG) DNA 损伤后的TLS效率分析.
在体内研究使用单复制基因组病变的大肠杆菌细胞.

主要成果:

切除Pol IV边缘接触显著损害了经过强大的复制块 (3-deaza-methyl dA) 的TLS,但对经过弱块 (N2-furfuryl dG) 的TLS的影响很小.
在体外和体内实验证实了边缘相互作用对于在具有挑战性的病变中有效的TLS的关键作用.
单链DNA结合蛋白促进Pol IV的低亲和力边缘结合在停滞的叉子上,增强其与可复制的Pol III竞争的能力.

结论:

波尔IV与β2的双重相互作用 (CBM和边缘接触) 对于高效的TLS至关重要,特别是在强大的DNA块上.
边缘接触允许Pol IV有效地与Pol III竞争,确保快速解决停滞不前的复制叉.
这种机制增强了Pol IV在困难的病变中执行TLS的能力,从而最大限度地减少了DNA损伤引起的突变发生.

关键词:

对DNA损伤的反应反应复制DNA复制DNA复制DNA复制突变发生的突变发生.压制是指压制,压制就是压制.转化合成的转化合成

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