Versatility in phospho-dependent molecular recognition of the XRCC1 and XRCC4 DNA-damage scaffolds by aprataxin-family FHA domains.
Versatility in phospho-dependent molecular recognition of the XRCC1 and XRCC4 DNA-damage scaffolds by aprataxin-family FHA domains.
复制标题
Aprataxin-Fha域对XRCC1和XRCC4 DNA破坏支架的磷酸依赖性分子识别的多功能性。
DOI：
10.1016/j.dnarep.2015.10.002
复制
发表时间：
2015-11
期刊：
影响因子：
3.8
通讯作者：
Smerdon SJ
中科院分区：
文献类型：
--
作者：
Cherry AL;Nott TJ;Kelly G;Rulten SL;Caldecott KW;Smerdon SJ
Aprataxin和APLF FHA结构域对XRCC4和XRCC1显示出不同的特异性。特异性由多位点磷酸化调节。APLF FHA和三磷酸化XRCC4肽的晶体结构揭示了核心pSpT基序结合的保守模式。Aptx家族FHA结构域蛋白的总体磷酸依赖性结合多功能性由FHA表面碱性提供。Aprataxin、Aprataxin和PNKP样因子（APLF）和多核苷酸激酶磷酸酶（PNKP）是具有不同功能的关键DNA修复蛋白，但它们都含有同源叉头相关（FHA）结构域。它们的主要结合靶标是酪蛋白激酶2磷酸化形式的XRCC1和XRCC4支架分子，其分别协调单链和双链DNA断裂修复途径。在这里，我们呈现了磷酸化XRCC4与APLF的复合物的高分辨率X射线结构，APLF是三个FHA结构域家族成员中最不同的。结合对aprataxin和APLF与XRCC1和XRCC4的单磷酸化和多磷酸化形式结合的NMR和生物化学分析，以及与PNKP的比较，揭示了由多位点磷酸化差异调节的不同但重叠的结合特异性的模式。总之，我们的数据阐明了三个磷酸结合结构域的活动之间的重要差异，尽管它们之间有密切的进化关系。
Aprataxin and APLF FHA domains show distinct specificities for XRCC4 and XRCC1. Specificity is modulated by multi-site phosphorylation. The crystal structure of APLF FHA and triphosphorylated XRCC4 peptide reveals a conserved mode of core pSpT motif binding. Overall phospho-dependent binding versatility of Aptx-family FHA domain proteins is provided by FHA surface basicity. Aprataxin, aprataxin and PNKP-like factor (APLF) and polynucleotide kinase phosphatase (PNKP) are key DNA-repair proteins with diverse functions but which all contain a homologous forkhead-associated (FHA) domain. Their primary binding targets are casein kinase 2-phosphorylated forms of the XRCC1 and XRCC4 scaffold molecules which respectively coordinate single-stranded and double-stranded DNA break repair pathways. Here, we present the high-resolution X-ray structure of a complex of phosphorylated XRCC4 with APLF, the most divergent of the three FHA domain family members. This, combined with NMR and biochemical analysis of aprataxin and APLF binding to singly and multiply-phosphorylated forms of XRCC1 and XRCC4, and comparison with PNKP reveals a pattern of distinct but overlapping binding specificities that are differentially modulated by multi-site phosphorylation. Together, our data illuminate important differences between activities of the three phospho-binding domains, in spite of a close evolutionary relationship between them.