Human FAN1 promotes strand incision in 5'-flapped DNA complexed with RPA.
Human FAN1 promotes strand incision in 5'-flapped DNA complexed with RPA.
复制标题
人类 FAN1 促进与 RPA 复合的 5 瓣 DNA 的链切割。
DOI：
10.1093/jb/mvv043
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发表时间：
2015
期刊：
影响因子：
2.7
通讯作者：
Kurumizaka H.
中科院分区：
文献类型：
--
作者：
Takahashi D;Sato K;Hirayama E;Takata M;Kurumizaka H.
范可尼贫血（FA）是一种婴儿隐性遗传病。17种FA致病蛋白在DNA链间交联（ICL）修复途径中协同发挥作用。交联周围的双DNA链切口是ICL修复的关键步骤。FA相关核酸酶1（FAN 1）是DNA结构特异性核酸内切酶，被认为参与停滞复制叉处的DNA切割。复制蛋白A（RPA）在停滞的分叉的单链DNA区域上快速组装。然而，RPA对FAN 1介导的DNA切割的影响尚未确定。在这项研究中，我们纯化人FAN 1，作为细菌表达的重组蛋白。FAN 1对在停滞复制叉处形成的5′-flapped DNA表现出强大的内切酶活性。我们发现FAN 1有效地促进了RPA包被的5′-flapped DNA的适当位点的DNA切割。因此，FAN 1具有促进RPA覆盖的5′-flapped DNA的ICL修复的能力。
Fanconi anaemia (FA) is a human infantile recessive disorder. Seventeen FA causal proteins cooperatively function in the DNA interstrand crosslink (ICL) repair pathway. Dual DNA strand incisions around the crosslink are critical steps in ICL repair. FA-associated nuclease 1 (FAN1) is a DNA structure-specific endonuclease that is considered to be involved in DNA incision at the stalled replication fork. Replication protein A (RPA) rapidly assembles on the single-stranded DNA region of the stalled fork. However, the effect of RPA on the FAN1-mediated DNA incision has not been determined. In this study, we purified human FAN1, as a bacterially expressed recombinant protein. FAN1 exhibited robust endonuclease activity with 5′-flapped DNA, which is formed at the stalled replication fork. We found that FAN1 efficiently promoted DNA incision at the proper site of RPA-coated 5′-flapped DNA. Therefore, FAN1 possesses the ability to promote the ICL repair of 5′-flapped DNA covered by RPA.