Structural basis of ubiquitin recognition by the winged-helix domain of Cockayne syndrome group B protein
Structural basis of ubiquitin recognition by the winged-helix domain of Cockayne syndrome group B protein
复制标题
DOI：
10.1093/nar/gkz081
复制
发表时间：
2019-04-23
影响因子：
14.9
通讯作者：
Fukai, Shuya
中科院分区：
文献类型：
--
作者：
Takahashi, Tomio S.;Sato, Yusuke;Fukai, Shuya
Cockayne综合征B组B（CS B，也称为ERCC 6）蛋白参与许多DNA修复过程并且是转录偶联修复（TCR）所必需的。CSB的中心区域具有解旋酶基序，而C-末端区域包含用于修复UV和氧化应激诱导的损伤和双链断裂（DSB）的重要调控元件。以前的研究表明，该区域内的一小部分（约30个残基）负责与泛素（Ub）结合。在这里，我们表明，UB结合的CSB需要一个更大的部分CSB，这是以前确定为翼螺旋结构域（WHD），并参与招聘的CSB DSB。我们还介绍了CSB WHD与Ub复合物的晶体结构。CSB WHD折叠为单个球状结构域，定义了一类不同于迄今为止鉴定的23个UBD类的UBD结合结构域（UBD）。CSB WHD的第二螺旋和C末端与Ub相互作用。结合结构指导的突变分析，我们确定了与Ub结合的关键残基。CSB突变体在Ub结合缺陷减少UV诱导的损伤的修复。本研究支持DSB修复和TCR可能与CSB的Ub结合相关的观点。
Cockayne syndrome group B (CSB, also known as ERCC6) protein is involved in many DNA repair processes and essential for transcription-coupled repair (TCR). The central region of CSB has the helicase motif, whereas the C-terminal region contains important regulatory elements for repair of UV- and oxidative stress-induced damages and double-strand breaks (DSBs). A previous study suggested that a small part (approximate to 30 residues) within this region was responsible for binding to ubiquitin (Ub). Here, we show that the Ub-binding of CSB requires a larger part of CSB, which was previously identified as a winged-helix domain (WHD) and is involved in the recruitment of CSB to DSBs. We also present the crystal structure of CSB WHD in complex with Ub. CSB WHD folds as a single globular domain, defining a class of Ub-binding domains (UBDs) different from 23 UBD classes identified so far. The second -helix and C-terminal extremity of CSB WHD interact with Ub. Together with structure-guided mutational analysis, we identified the residues critical for the binding to Ub. CSB mutants defective in the Ub binding reduced repair of UV-induced damage. This study supports the notion that DSB repair and TCR may be associated with the Ub-binding of CSB.