Swi5-Sfr1 protein stimulates Rad51-mediated DNA strand exchange reaction through organization of DNA bases in the presynaptic filament.
Swi5-Sfr1 protein stimulates Rad51-mediated DNA strand exchange reaction through organization of DNA bases in the presynaptic filament.
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DOI：
10.1093/nar/gkt1257
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发表时间：
2014-02
影响因子：
14.9
通讯作者：
Takahashi M
中科院分区：
文献类型：
--
作者：
Fornander LH;Renodon-Cornière A;Kuwabara N;Ito K;Tsutsui Y;Shimizu T;Iwasaki H;Nordén B;Takahashi M
Swi 5-Sfr 1异源二聚体蛋白刺激Rad 51促进的DNA链交换反应，这是同源重组的关键步骤。为了阐明这种辅助蛋白如何作用于链交换反应，我们分析了主要反应中间体的结构，即在ATP存在下形成的Rad 51/单链DNA（ssDNA）复合物细丝，如何受到Swi 5-Sfr 1的影响。使用流动线性二色性光谱，我们观察到的ssDNA的核碱基更垂直对齐的丝轴Swi 5-Sfr 1的存在下，而在Swi 5-Sfr 1的情况下，碱基更随机取向。当使用天然蛋白质的修饰版本（其中Sfr 1的N末端部分被删除，其对DNA没有亲和力，但保持刺激链交换反应的能力）时，我们仍然观察到改进的垂直DNA碱基方向。这表明Swi 5-Sfr 1主要通过与Rad 51丝的相互作用而不是与DNA的相互作用来发挥其活化作用。我们提出，在突触前Rad 51/ssDNA复合物中由Swi 5-Sfr 1诱导的核碱基的共面对齐的作用是促进与入侵的双链DNA的关键匹配，从而刺激链交换反应。
The Swi5-Sfr1 heterodimer protein stimulates the Rad51-promoted DNA strand exchange reaction, a crucial step in homologous recombination. To clarify how this accessory protein acts on the strand exchange reaction, we have analyzed how the structure of the primary reaction intermediate, the Rad51/single-stranded DNA (ssDNA) complex filament formed in the presence of ATP, is affected by Swi5-Sfr1. Using flow linear dichroism spectroscopy, we observe that the nucleobases of the ssDNA are more perpendicularly aligned to the filament axis in the presence of Swi5-Sfr1, whereas the bases are more randomly oriented in the absence of Swi5-Sfr1. When using a modified version of the natural protein where the N-terminal part of Sfr1 is deleted, which has no affinity for DNA but maintained ability to stimulate the strand exchange reaction, we still observe the improved perpendicular DNA base orientation. This indicates that Swi5-Sfr1 exerts its activating effect through interaction with the Rad51 filament mainly and not with the DNA. We propose that the role of a coplanar alignment of nucleobases induced by Swi5-Sfr1 in the presynaptic Rad51/ssDNA complex is to facilitate the critical matching with an invading double-stranded DNA, hence stimulating the strand exchange reaction.
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影响因子：
14.9
作者：
Fornander, Louise H.;Frykholm, Karolin;Norden, Bengt
通讯作者：
Norden, Bengt
DOI：
10.1073/pnas.82.3.800
发表时间：
1985-01-01
影响因子：
11.1
作者：
KEITH, CH;MAXFIELD, FR;SHELANSKI, ML
通讯作者：
SHELANSKI, ML
影响因子：
14.9
作者：
LEDNEVA, RK;RAZJIVIN, AP;BOGDANOV, AA
通讯作者：
BOGDANOV, AA
DOI：
10.1073/pnas.142404499
发表时间：
2002-09-03
影响因子：
11.1
作者：
Morimatsu, K;Takahashi, M;Nordén, B
通讯作者：
Nordén, B
影响因子：
2.1
作者：
Nomme, Julian;Takizawa, Yoshimasa;Takahashi, Masayuki
通讯作者：
Takahashi, Masayuki