Visualization of DNA-induced conformational changes in the DNA repair kinase DNA-PKcs
Visualization of DNA-induced conformational changes in the DNA repair kinase DNA-PKcs
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DOI：
10.1093/emboj/cdg555
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发表时间：
2003-11-03
期刊：
影响因子：
11.4
通讯作者：
Llorca, O
中科院分区：
文献类型：
--
作者：
Boskovic, J;Rivera-Calzada, A;Llorca, O
DNA依赖性蛋白激酶（DNA-PKcs）的催化亚基对于非同源末端连接（NHEJ）和V（D）J重组期间的双链DNA断裂（DSB）的修复是必需的。DNA-PKcs在体外结合单链和双链DNA，在体内Ku异源二聚体可能有助于以高亲和力将其募集到DSB。一旦加载到DNA上，DNA-PKcs就充当其他修复因子的支架，以产生将两个DNA末端结合在一起的多蛋白复合物。人DNA-PKcs已通过电子显微镜在双链DNA的存在和不存在下进行了分析，与未结合的蛋白质相比，DNA结合的DNA-PKcs的三维重建显示出较大的构象变化。DNA-PKcs似乎使用棕榈样结构域夹在DNA上，这种新的构象与激酶的激活相关。我们认为，所观察到的结构域的运动可能有助于结合和维持DNA-PKcs'与DNA的相互作用在损伤部位，这些构象的变化激活激酶。
The catalytic subunit of the DNA-dependent protein kinase (DNA-PKcs) is essential for the repair of double-stranded DNA breaks (DSBs) in non- homologous end joining (NHEJ) and during V(D)J recombination. DNA-PKcs binds single- and double-stranded DNA in vitro, and in vivo the Ku heterodimer probably helps recruit it to DSBs with high affinity. Once loaded onto DNA, DNA-PKcs acts as a scaffold for other repair factors to generate a multiprotein complex that brings the two DNA ends together. Human DNA-PKcs has been analysed by electron microscopy in the absence and presence of double-stranded DNA, and the three-dimensional reconstruction of DNA-bound DNA-PKcs displays large conformational changes when compared with the unbound protein. DNA-PKcs seems to use a palm-like domain to clip onto the DNA, and this new conformation correlates with the activation of the kinase. We suggest that the observed domain movements might help the binding and maintenance of DNA-PKcs' interaction with DNA at the sites of damage, and that these conformational changes activate the kinase.