Structural basis for specific recognition of Lys 63-linked polyubiquitin chains by tandem UIMs of RAP80
Structural basis for specific recognition of Lys 63-linked polyubiquitin chains by tandem UIMs of RAP80
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DOI：
10.1038/emboj.2009.160
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发表时间：
2009-08-19
期刊：
影响因子：
11.4
通讯作者：
Fukai, Shuya
中科院分区：
文献类型：
--
作者：
Sato, Yusuke;Yoshikawa, Azusa;Fukai, Shuya
RAP 80在Abraxas-BRCC 36-BRCA 1-BARD 1复合物通过其串联的泛素相互作用基序（UIM）特异性识别Lys 63连接的多聚泛素化蛋白质而募集到DNA损伤灶进行DNA修复中具有关键作用。在这里，我们报告的晶体结构的RAP 80串联UIMs（RAP 80-UIM 1-UIM 2）在复杂的赖氨酸63连接的二泛素在2.2埃的分辨率。两个UIM，UIM 1和UIM 2，以及α-螺旋UIM间区域一起形成连续的60埃长的α-螺旋。UIM 1和UIM 2分别与近端和远端泛素部分结合。RAP 80的UIM 1和UIM 2都识别泛素上以Ile 44为中心的疏水补丁，但UIM都不与Lys 63连接的异肽键相互作用。我们的结构表明，间UIM区域形成一个12埃长的α-螺旋，确保UIM的安排，使特异性结合的赖氨酸63连接的双泛素。这通过使用各种长度的UIM间区域的RAP 80-UIM 1-UIM 2突变体的下拉分析来证实。此外，我们表明，Epsin 1串联UIM，它有一个inter-UIM区域类似的RAP 80-UIM 1-UIM 2，也选择性地结合赖氨酸63连接的二泛素。The EMBO Journal（2009）28，2461-2468. doi：10.1038/doj.2009.160; 2009年6月18日在线发布
RAP80 has a key role in the recruitment of the Abraxas-BRCC36-BRCA1-BARD1 complex to DNA-damage foci for DNA repair through specific recognition of Lys 63-linked polyubiquitinated proteins by its tandem ubiquitin-interacting motifs (UIMs). Here, we report the crystal structure of the RAP80 tandem UIMs (RAP80-UIM1-UIM2) in complex with Lys 63-linked di-ubiquitin at 2.2 angstrom resolution. The two UIMs, UIM1 and UIM2, and the alpha-helical inter-UIM region together form a continuous 60 angstrom-long alpha-helix. UIM1 and UIM2 bind to the proximal and distal ubiquitin moieties, respectively. Both UIM1 and UIM2 of RAP80 recognize an Ile 44-centered hydrophobic patch on ubiquitin but neither UIM interacts with the Lys 63-linked isopeptide bond. Our structure suggests that the inter-UIM region forms a 12 angstrom-long alpha-helix that ensures that the UIMs are arranged to enable specific binding of Lys 63-linked diubiquitin. This was confirmed by pull-down analyses using RAP80-UIM1-UIM2 mutants of various length inter-UIM regions. Further, we show that the Epsin1 tandem UIM, which has an inter-UIM region similar to that of RAP80-UIM1-UIM2, also selectively binds Lys 63-linked di-ubiquitin. The EMBO Journal (2009) 28, 2461-2468. doi:10.1038/emboj.2009.160; Published online 18 June 2009