Split conformation of Chaetomium thermophilum Hsp104 disaggregase
Split conformation of Chaetomium thermophilum Hsp104 disaggregase
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DOI：
10.1016/j.str.2021.02.002
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发表时间：
2021-07-01
期刊：
影响因子：
5.7
通讯作者：
Yohda, Masafumi
中科院分区：
文献类型：
--
作者：
Inoue, Yosuke;Hanazono, Yuya;Yohda, Masafumi
Hsp104和它的细菌同源物ClpB形成六聚环结构并介导蛋白质解聚。解聚的多肽被认为穿过环的中央通道。然而，热休克蛋白104在解聚过程中的动态行为仍不清楚。本文利用X射线晶体学、冷冻电镜和高速原子力显微镜研究了热毛壳菌Hsp 104解聚酶（CtHsp 104）在ADP存在下的随机构象动力学和断裂构象。ADP结合的CtHsp104在晶体结构中以2.7 A度的分辨率组装成65左手螺旋丝。丝的单位是分裂螺旋结构的六聚体。在冷冻电镜图像中，观察到交错和分裂的六聚体环。此外，高速AFM观察表明，底物的加入增强了构象的变化，并增加了分裂结构的频率。我们的数据表明，分裂构象是一个关闭的路径状态的CtHsp104在解聚。
Hsp104 and its bacterial homolog ClpB form hexameric ring structures and mediate protein disaggregation. The disaggregated polypeptide is thought to thread through the central channel of the ring. However, the dynamic behavior of Hsp104 during disaggregation remains unclear. Here, we reported the stochastic conformational dynamics and a split conformation ofHsp104 disaggregase fromChaetomiumthermophilum(CtHsp104) in the presence of ADP by X-ray crystallography, cryo-electron microscopy (EM), and high-speed atomic force microscopy (AFM). ADP-bound CtHsp104 assembles into a 65 left-handed spiral filament in the crystal structure at a resolution of 2.7 A degrees. The unit of the filament is a hexamer of the split spiral structure. In the cryo-EM images, staggered and split hexameric rings were observed. Further, high-speed AFM observations showed that a substrate addition enhanced the conformational change and increased the split structure's frequency. Our data suggest that split conformation is an off-pathway state of CtHsp104 during disaggregation.