Rad54在同源重組時驅動DNA序列比對
作者:
小柯機器人發布時間:2020/6/6 21:33:46
2020年6月4日,《細胞》雜誌在線發表了美國哥倫比亞大學Eric C. Greene小組的最新成果。他們發現,Rad54在同源重組(HR)過程中驅動ATP水解依賴性的DNA序列比對。
研究人員使用單分子成像來證明了Rad54(一種在所有真核生物中均發現的保守Snf2樣蛋白)將同源性搜索從基礎HR機器的擴散途徑轉換為主動過程。在這一主動過程中,DNA序列通過 ATP依賴性分子馬達驅動的機制來對齊。
研究人員進一步證明Rad54破壞了供體模板鏈,使搜索能夠在由複製蛋白A(RPA)結合的DNA氣泡狀結構中進行。這些研究結果表明,Rad54與RPA一起可以從根本上改變HR期間DNA序列的排列方式。
據了解,HR有助於維持基因組完整性,並且HR缺陷會導致疾病,尤其是癌症。在HR期間,必須通過稱為同源性搜索的過程將受損的DNA與未損壞的模板對齊。儘管進行了數十年的研究,但此搜索的關鍵方面仍不確定。
附:英文原文
Title: Rad54 Drives ATP Hydrolysis-Dependent DNA Sequence Alignment during Homologous Recombination
Author: J. Brooks Crickard, Corentin J. Moevus, Youngho Kwon, Patrick Sung, Eric C. Greene
Issue&Volume: 2020-06-04
Abstract: Homologous recombination (HR) helps maintain genome integrity, and HR defects giverise to disease, especially cancer. During HR, damaged DNA must be aligned with anundamaged template through a process referred to as the homology search. Despite decadesof study, key aspects of this search remain undefined. Here, we use single-moleculeimaging to demonstrate that Rad54, a conserved Snf2-like protein found in all eukaryotes,switches the search from the diffusion-based pathways characteristic of the basalHR machinery to an active process in which DNA sequences are aligned via an ATP-dependentmolecular motor-driven mechanism. We further demonstrate that Rad54 disrupts the donortemplate strands, enabling the search to take place within a migrating DNA bubble-likestructure that is bound by replication protein A (RPA). Our results reveal that Rad54,working together with RPA, fundamentally alters how DNA sequences are aligned duringHR.
DOI: 10.1016/j.cell.2020.04.056
Source: https://www.cell.com/cell/fulltext/S0092-8674(20)30562-6
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