Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
J Biol Chem. 2012 Apr 6;287(15):12343-7. doi: 10.1074/jbc.C112.352161. Epub 2012 Feb 27.
Homologous recombination catalyzed by the RAD51 recombinase is essential for maintaining genome integrity upon the induction of DNA double strand breaks and other DNA lesions. By enhancing the recombinase activity of RAD51, RAD51AP1 (RAD51-associated protein 1) serves a key role in homologous recombination-mediated chromosome damage repair. We show here that RAD51AP1 harbors two distinct DNA binding domains that are both needed for maximal protein activity under physiological conditions. We have finely mapped the two DNA binding domains in RAD51AP1 and generated mutant variants that are impaired in either or both of the DNA binding domains. Examination of these mutants reveals that both domains are indispensable for RAD51AP1 function in cells. These and other results illuminate the mechanistic basis of RAD51AP1 action in homologous DNA repair.
由 RAD51 重组酶催化的同源重组对于在诱导 DNA 双链断裂和其他 DNA 损伤后维持基因组完整性至关重要。RAD51AP1（RAD51 相关蛋白 1）通过增强 RAD51 的重组酶活性，在同源重组介导的染色体损伤修复中发挥关键作用。我们在这里表明，RAD51AP1 具有两个不同的 DNA 结合结构域，这两个结构域在生理条件下均需要最大的蛋白活性。我们已经精细地绘制了 RAD51AP1 中的这两个 DNA 结合结构域，并生成了在一个或两个 DNA 结合结构域中均有缺陷的突变变体。对这些突变体的研究表明，两个结构域对于 RAD51AP1 在细胞中的功能都是不可或缺的。这些和其他结果阐明了 RAD51AP1 在同源 DNA 修复中的作用的机制基础。
