Rad54 Drives ATP Hydrolysis-Dependent DNA Sequence Alignment during Homologous Recombination
Rad54 Drives ATP Hydrolysis-Dependent DNA Sequence Alignment during Homologous Recombination
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DOI：
10.1016/j.cell.2020.04.056
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发表时间：
2020-06-11
期刊：
影响因子：
64.5
通讯作者：
Greene, Eric C.
中科院分区：
文献类型：
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作者：
Crickard, J. Brooks;Moevus, Corentin J.;Greene, Eric C.
同源重组（HR）有助于维持基因组的完整性，而HR缺陷会导致疾病，尤其是癌症。在HR过程中，受损的DNA必须通过称为同源性搜索的过程与未受损的模板对齐。尽管经过了几十年的研究，但这一研究的关键方面仍然没有得到明确。在这里，我们使用单分子成像来证明Rad54，一种在所有真核生物中发现的保守的Snf2样蛋白，将搜索从基础HR机制的基于扩散的途径特征切换到一个活跃的过程，在该过程中，DNA序列通过ATP依赖的分子马达驱动机制进行对齐。我们进一步证明，Rad54破坏了供体模板链，使搜索发生在一个迁移的DNA气泡样结构，复制蛋白A（RPA）的约束。我们的研究结果表明，Rad54与RPA一起工作，从根本上改变了HR期间DNA序列的排列方式。
Homologous recombination (HR) helps maintain genome integrity, and HR defects give rise to disease, especially cancer. During HR, damaged DNA must be aligned with an undamaged template through a process referred to as the homology search. Despite decades of study, key aspects of this search remain undefined. Here, we use single-molecule imaging to demonstrate that Rad54, a conserved Snf2-like protein found in all eukaryotes, switches the search from the diffusion-based pathways characteristic of the basal HR machinery to an active process in which DNA sequences are aligned via an ATP-dependent molecular motor-driven mechanism. We further demonstrate that Rad54 disrupts the donor template strands, enabling the search to take place within a migrating DNA bubble-like structure that is bound by replication protein A (RPA). Our results reveal that Rad54, working together with RPA, fundamentally alters how DNA sequences are aligned during HR.