Rad50 zinc hook functions as a constitutive dimerization module interchangeable with SMC hinge
Rad50 zinc hook functions as a constitutive dimerization module interchangeable with SMC hinge
复制标题
Rad50 锌钩用作本构二聚模块，可与 SMC 铰链互换
DOI：
10.1038/s41467-019-14025-0
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发表时间：
2020
影响因子：
16.6
通讯作者：
Furukohri Asako
中科院分区：
文献类型：
--
作者：
Tatebe Hisashi;Lim Chew Theng;Konno Hiroki;Shiozaki Kazuhiro;Shinohara Akira;Uchihashi Takayuki;Furukohri Asako
人类Mre 11/Rad 50复合物是基因组维持途径中的关键因子之一。先前通过原子力显微镜（AFM）进行的纳米级成像显示，人类Mre 11/Rad 50复合物的环状结构在Rad 50的锌钩处瞬时打开。然而，通过高速AFM对人类Mre 11/Rad 50复合物的成像显示，Rad 50卷曲螺旋臂始终由二聚化钩桥接，而Mre 11/Rad 50环通过断开头部结构域而打开;类似于其他SMC蛋白质，如粘附素或凝聚素。这些结构特征在酵母和细菌Mre 11/Rad 50复合物中是保守的。携带嵌合Mre 11/Rad 50复合物的酵母菌株在DNA修复中正常发挥功能，所述嵌合Mre 11/Rad 50复合物含有细菌凝聚素MukB的SMC铰链而不是RAD 50钩。我们提出Rad 50钩的基本作用类似于SMC铰链，其作为相当稳定的二聚化界面。
The human Mre11/Rad50 complex is one of the key factors in genome maintenance pathways. Previous nanoscale imaging by atomic force microscopy (AFM) showed that the ring-like structure of the human Mre11/Rad50 complex transiently opens at the zinc hook of Rad50. However, imaging of the human Mre11/Rad50 complex by high-speed AFM shows that the Rad50 coiled-coil arms are consistently bridged by the dimerized hooks while the Mre11/Rad50 ring opens by disconnecting the head domains; resembling other SMC proteins such as cohesin or condensin. These architectural features are conserved in the yeast and bacterial Mre11/Rad50 complexes. Yeast strains harboring the chimeric Mre11/Rad50 complex containing the SMC hinge of bacterial condensin MukB instead of the RAD50 hook properly functions in DNA repair. We propose that the basic role of the Rad50 hook is similar to that of the SMC hinge, which serves as rather stable dimerization interface.