The RAD51 family member, RAD51L3, is a DNA-stimulated ATPase that forms a complex with XRCC2
The RAD51 family member, RAD51L3, is a DNA-stimulated ATPase that forms a complex with XRCC2
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DOI：
10.1074/jbc.m002075200
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发表时间：
2000-09-15
影响因子：
4.8
通讯作者：
Hickson, ID
中科院分区：
文献类型：
--
作者：
Braybrooke, JP;Spink, KG;Hickson, ID
真核细胞中的Rad51蛋白是大肠杆菌RecA的结构和功能同源物，在DNA修复和遗传重组中起作用。先前在酵母和人类细胞中鉴定出与Rad51具有序列相似性的几种蛋白。在酿酒酵母中，这些蛋白质中的两个，Rad55p和Rad57p，形成异二聚体，可以刺激Rad51介导的DNA链交换，在这里，我们报告的纯化的RAD51家族在人类细胞中的代表之一。我们证明，纯化的RAD 51 L3蛋白具有单链DNA结合活性和DNA刺激的ATP酶活性，与推导的RAD 51 L3序列中存在的“步行者盒”基序一致。我们已经在人类细胞中发现了一种蛋白质复合物，其中含有RAD51L3和第二个RAD51家族成员XRCC2。通过使用纯化的蛋白质，我们证明了RAD51L3和XRCC 2之间的相互作用是直接的。鉴于XRCC2在基因重组和保护DNA损伤剂中的要求，我们认为RAD51L3和XRCC2的复合物可能对人类细胞中的这些功能很重要。
The Rad51 protein in eukaryotic cells is a structural and functional homolog of Escherichia coli RecA with a role in DNA repair and genetic recombination, Several proteins showing sequence similarity to Rad51 have previously been identified in both yeast and human cells. In Saccharomyces cerevisiae, two of these proteins, Rad55p and Rad57p, form a heterodimer that can stimulate Rad51-mediated DNA strand exchange, Here, we report the purification of one of the representatives of the RAD51 family in human cells. We demonstrate that the purified RAD51L3 protein possesses single-stranded DNA binding activity and DNA-stimulated ATPase activity, consistent with the presence of "Walker box" motifs in the deduced RAD51L3 sequence. We have identified a protein complex in human cells containing RAD51L3 and a second RAD51 family member, XRCC2. By using purified proteins, we demonstrate that the interaction between RAD51L3 and XRCC2 is direct. Given the requirements for XRCC2 in genetic recombination and protection against DNA-damaging agents, we suggest that the complex of RAD51L3 and XRCC2 is likely to be important for these functions in human cells.