Recombinational branch migration by the RadA/Sms paralog of RecA in Escherichia coli
Recombinational branch migration by the RadA/Sms paralog of RecA in Escherichia coli
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DOI：
10.7554/elife.10807
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发表时间：
2016-02-04
期刊：
影响因子：
7.7
通讯作者：
Lovett, Susan T.
中科院分区：
文献类型：
--
作者：
Cooper, Deani L.;Lovett, Susan T.
RadA（也称为“Sms”）是一种高度保守的蛋白质，存在于几乎所有的真细菌和植物中，与RecA链交换蛋白具有序列相似性，并在同源重组中发挥作用。我们在这里调查的生化特性的E。coliRadA蛋白和几种突变形式。RadA是一种DNA依赖性ATP酶，一种DNA结合蛋白，可刺激RecA介导的链转移反应的分支迁移相。RadA不能介导同源DNA分子之间的突触配对，但可以驱动分支迁移以延伸异源双链DNA的区域，即使没有RecA。与其他分支迁移因子RecG和RuvAB不同，RadA在RecA介导的链交换的方向上刺激RecA细丝背景下的分支迁移。我们提出RadA介导的分支迁移通过允许3'侵入链被并入异源双链DNA并被DNA聚合酶延伸来帮助重组。
RadA (also known as 'Sms') is a highly conserved protein, found in almost all eubacteria and plants, with sequence similarity to the RecA strand exchange protein and a role in homologous recombination. We investigate here the biochemical properties of the E. coli RadA protein and several mutant forms. RadA is a DNA-dependent ATPase, a DNA-binding protein and can stimulate the branch migration phase of RecA-mediated strand transfer reactions. RadA cannot mediate synaptic pairing between homologous DNA molecules but can drive branch migration to extend the region of heteroduplex DNA, even without RecA. Unlike other branch migration factors RecG and RuvAB, RadA stimulates branch migration within the context of the RecA filament, in the direction of RecA-mediated strand exchange. We propose that RadA-mediated branch migration aids recombination by allowing the 3' invading strand to be incorporated into heteroduplex DNA and to be extended by DNA polymerases.