Tailed duplex DNA is the preferred substrate for Rad51 protein-mediated homologous pairing
Tailed duplex DNA is the preferred substrate for Rad51 protein-mediated homologous pairing
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DOI：
10.1093/emboj/19.5.1148
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发表时间：
2000-03-01
期刊：
影响因子：
11.4
通讯作者：
Kowalczykowski, SC
中科院分区：
文献类型：
--
作者：
Mazin, AV;Zaitseva, E;Kowalczykowski, SC
通过同源重组修复潜在致命的DNA双链断裂（DSB）需要将断裂的DIVA加工成具有突出的3 '-单链DNA（ssDNA）尾的切除的DNA双链体。因此，DSB修复的典型模型需要ssDNA的3 '端侵入完整的同源DNA模板，这是细菌配对蛋白RecA所具有的特征。出乎意料的是，我们发现对于真核同源物Rad 51蛋白，ssDNA的5 '端比3'端更具侵袭性。这种配对偏差不受Rad 52、Rad 54或Bad 55 -57蛋白的影响。然而，进一步的研究表明，与RecA蛋白相反，Rad 51蛋白的优选DNA底物不是ssDNA，而是具有ssDNA尾的dsDNA。这种重要的区别允许Rad 51蛋白以相似的效率使用3 '或5'末端促进DNA链侵入。
The repair of potentially lethal DNA double-stranded breaks (DSBs) by homologous recombination requires processing of the broken DIVA into a resected DNA duplex with a protruding 3'-single-stranded DNA (ssDNA) tail. Accordingly, the canonical models for DSB repair require invasion of an intact homologous DNA template by the 3'-end of the ssDNA, a characteristic that the bacterial pairing protein RecA possesses. Unexpectedly, we find that for the eukaryotic homolog, Rad51 protein, the 5'-end of ssDNA is more invasive than the 3'-end. This pairing bias is unaffected by Rad52, Rad54 or Bad55-57 proteins. However, further investigation reveals that, in contrast to RecA protein, the preferred DNA substrate for Rad51 protein is not ssDNA but rather dsDNA with ssDNA tails. This important distinction permits the Rad51 proteins to promote DNA strand invasion using either 3'; or 5'-ends with similar efficiency.