Crystal structure of a Rad51 filament
Crystal structure of a Rad51 filament
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DOI：
10.1038/nsmb795
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发表时间：
2004-08-01
影响因子：
16.8
通讯作者：
Rice, PA
中科院分区：
文献类型：
--
作者：
Conway, AB;Lynch, TW;Rice, PA
Rad 51是真核生物中最主要的同源重组酶，对DNA损伤的修复以及基因组多样性和稳定性的维持具有重要作用。这种依赖DNA的ATP酶的活性形式是螺旋丝，在螺旋丝内进行同源性和链交换。在这里，我们提出了一个酿酒酵母Rad 51丝形成的功能获得性突变体的晶体结构。这条细丝的螺距比Rad 51的原核同源物RecA的晶体中所见的要长，并将ATP酶位点直接放置在原聚体之间的新界面上。虽然细丝具有近似六重对称性，但交替的蛋白质-蛋白质界面略有不同，这意味着细丝内Rad 51的功能单元可能是二聚体。此外，我们表明，突变的His 352，这是在这个新的接口，显着破坏DNA结合。
Rad51, the major eukaryotic homologous recombinase, is important for the repair of DNA damage and the maintenance of genomic diversity and stability. The active form of this DNA-dependent ATPase is a helical filament within which the search for homology and strand exchange occurs. Here we present the crystal structure of a Saccharomyces cerevisiae Rad51 filament formed by a gain-of-function mutant. This filament has a longer pitch than that seen in crystals of Rad51' s prokaryotic homolog RecA, and places the ATPase site directly at a new interface between protomers. Although the filament exhibits approximate six-fold symmetry, alternate protein-protein interfaces are slightly different, implying that the functional unit of Rad51 within the filament may be a dimer. Additionally, we show that mutation of His352, which lies at this new interface, markedly disrupts DNA binding.