The N-terminal domain of the human Rad51 protein binds DNA: Structure and a DNA binding surface as revealed by NMR
The N-terminal domain of the human Rad51 protein binds DNA: Structure and a DNA binding surface as revealed by NMR
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DOI：
10.1006/jmbi.1999.2904
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发表时间：
1999-07-09
影响因子：
5.6
通讯作者：
Shibata, T
中科院分区：
文献类型：
--
作者：
Aihara, H;Ito, Y;Shibata, T
人RAD51蛋白(HsRad51)是大肠杆菌RecA蛋白的同源物，在DNA修复和重组中发挥重要作用。在高等真核生物中，RAD51蛋白是细胞存活所必需的。HsRad51的N-末端在真核细胞RAD51蛋白中高度保守，但在RecA中缺失，这表明该区域具有RAD51特有的功能。在这里，我们用核磁共振波谱确定了HsRad51的N-末端部分的结构。N-末端区域形成一个由五个短螺旋组成的紧凑结构域，该结构域与大肠杆菌的DNA修复酶--内切酶III的结构相似。核磁共振实验不支持N端结构域参与HsRad51-HsBrca2相互作用或HsRad51的自结合。然而，核磁共振滴定实验证明了结构域与DNA的物理相互作用，并允许绘制DNA结合表面的图谱。突变分析表明，DNA结合表面是HsRad51双链和单链DNA结合所必需的。我们的结果表明HsRad51丝的外表面存在一个DNA结合位点，并为N-末端结构域中通过磷酸化来调节DNA结合提供了可能的解释。(C)1999年学术出版社。
Human Rad51 protein (HsRad51) is a homolog of Escherichia coli RecA protein, and functions in DNA repair and recombination. Ln higher eukaryotes, Rad51 protein is essential for cell viability. The N-terminal region of HsRad51 is highly conserved among eukaryotic Rad51 proteins but is absent from RecA, suggesting a Rad51-specific function for this region. Here, we have determined the structure of the N-terminal part of HsRad51 by NMR spectroscopy. The N-terminal region forms a compact domain consisting of five short helices, which shares structural similarity with a domain of endonuclease III, a DNA repair enzyme of E. coli. NMR experiments did not support the involvement of the N-terminal domain in HsRad51-HsBrca2 interaction or the self-association of HsRad51 as proposed by previous studies. However, NMR tiration experiments demonstrated a physical interaction of the domain with DNA, and allowed mapping of the DNA binding surface. Mutation analysis showed that the DNA binding surface is essential for double-stranded and single-stranded DNA binding of HsRad51. Our results suggest the presence of a DNA binding site on the outside surface of the HsRad51 filament and provide a possible explanation for the regulation of DNA binding by phosphorylation within the N-terminal domain. (C) 1999 Academic Press.