PAXX binding to the NHEJ machinery explains functional redundancy with XLF.
PAXX binding to the NHEJ machinery explains functional redundancy with XLF.
复制标题
DOI：
10.1126/sciadv.adg2834
复制
发表时间：
2023-06-02
期刊：
影响因子：
13.6
通讯作者：
Chaplin, Amanda K.
中科院分区：
文献类型：
--
作者：
Seif-El-Dahan, Murielle;Kefala-Stavridi, Antonia;Frit, Philippe;Hardwick, Steven W.;Chirgadze, Dima Y.;De Oliviera, Taiana Maia;Britton, Sebastien;Barboule, Nadia;Bossaert, Madeleine;Pandurangan, Arun Prasad;Meek, Katheryn;Blundell, Tom L.;Ropars, Virginie;Calsou, Patrick;Charbonnier, Jean -Baptiste;Chaplin, Amanda K.
非同源末端连接是修复人类细胞中DNA双链断裂的关键机制。在这项工作中，我们解决了辅助蛋白PAXX [X射线修复交叉互补蛋白4（XRCC 4）和XRCC 4样因子（XLF）的paraminase]在这一机制中的结构和功能作用。在这里，我们报告高分辨率冷冻电子显微镜（cryo-EM）和X射线晶体学结构的PAXX C-末端Ku结合基序结合Ku 70/80和cryo-EM结构的PAXX结合两个交替的DNA依赖性蛋白激酶（DNA-PK）末端桥接二聚体，介导的Ku 80或XLF。我们确定的Ku 70/PAXX在体外和细胞中的相互作用的关键残基。我们证明，PAXX和XLF可以同时结合Ku异源二聚体，并作为结构桥梁的DNA-PK二聚体的替代形式。最后，我们表明，这两种蛋白质的参与为DNA末端突触和细胞中的末端连接提供了互补优势。PAXX和XLF在结构上桥接DNA-PK二聚体的替代形式，解释了NHEJ中XLF和PAXX之间的冗余。
Nonhomologous end joining is a critical mechanism that repairs DNA double-strand breaks in human cells. In this work, we address the structural and functional role of the accessory protein PAXX [paralog of x-ray repair cross-complementing protein 4 (XRCC4) and XRCC4-like factor (XLF)] in this mechanism. Here, we report high-resolution cryo–electron microscopy (cryo-EM) and x-ray crystallography structures of the PAXX C-terminal Ku-binding motif bound to Ku70/80 and cryo-EM structures of PAXX bound to two alternate DNA-dependent protein kinase (DNA-PK) end-bridging dimers, mediated by either Ku80 or XLF. We identify residues critical for the Ku70/PAXX interaction in vitro and in cells. We demonstrate that PAXX and XLF can bind simultaneously to the Ku heterodimer and act as structural bridges in alternate forms of DNA-PK dimers. Last, we show that engagement of both proteins provides a complementary advantage for DNA end synapsis and end joining in cells. PAXX and XLF structurally bridge alternate forms of DNA-PK dimers, explaining the redundancy between XLF and PAXX in NHEJ.
登录
查看更多内容
影响因子：
14.9
作者：
Biard, D. S. F.
通讯作者：
Biard, D. S. F.
影响因子：
3.7
作者：
Fu C;Donovan WP;Shikapwashya-Hasser O;Ye X;Cole RH
通讯作者：
Cole RH
影响因子：
5
作者：
Arora M;Kumari S;Singh J;Chopra A;Chauhan SS
通讯作者：
Chauhan SS
影响因子：
16.8
作者：
Chaplin, Amanda K.;Hardwick, Steven W.;Blundell, Tom L.
通讯作者：
Blundell, Tom L.
影响因子：
10.5
作者：
Balmus G;Barros AC;Wijnhoven PW;Lescale C;Hasse HL;Boroviak K;le Sage C;Doe B;Speak AO;Galli A;Jacobsen M;Deriano L;Adams DJ;Blackford AN;Jackson SP
通讯作者：
Jackson SP