ATP dependent rotational motion of group II chaperonin observed by X-ray single molecule tracking.
ATP dependent rotational motion of group II chaperonin observed by X-ray single molecule tracking.
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DOI：
10.1371/journal.pone.0064176
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Sasaki YC
中科院分区：
文献类型：
--
作者：
Sekiguchi H;Nakagawa A;Moriya K;Makabe K;Ichiyanagi K;Nozawa S;Sato T;Adachi S;Kuwajima K;Yohda M;Sasaki YC
在真核细胞质和古生物中，第二类分子伴侣蛋白在蛋白质动态平衡中起着重要作用。这些蛋白质帮助新生多肽的折叠，也以依赖于ATP的方式重新折叠未折叠的蛋白质。伴侣蛋白介导的蛋白质折叠依赖于内置盖子的关闭和打开，这是由ATP水解循环控制的。最近的结构研究表明，伴侣蛋白的环状结构扭曲以封闭中央空洞。在这项研究中，我们通过衍射X射线跟踪(DXT)在单分子水平上用高精度的旋转轴视图证明了II组伴侣蛋白的ATP依赖动力学。紫外光触发的DXT研究表明，在三磷酸腺苷结合的1 S范围内，盖子部分关闭，随后在2-6 S范围内，从伴侣蛋白的顶部到底部，关闭的环逆时针扭曲，扭曲的环以顺时针运动恢复到原来的打开状态。我们的分析清楚地表明，两相合盖过程发生了不同步合盖和同步逆时针扭转运动。
Group II chaperonins play important roles in protein homeostasis in the eukaryotic cytosol and in Archaea. These proteins assist in the folding of nascent polypeptides and also refold unfolded proteins in an ATP-dependent manner. Chaperonin-mediated protein folding is dependent on the closure and opening of a built-in lid, which is controlled by the ATP hydrolysis cycle. Recent structural studies suggest that the ring structure of the chaperonin twists to seal off the central cavity. In this study, we demonstrate ATP-dependent dynamics of a group II chaperonin at the single-molecule level with highly accurate rotational axes views by diffracted X-ray tracking (DXT). A UV light-triggered DXT study with caged-ATP and stopped-flow fluorometry revealed that the lid partially closed within 1 s of ATP binding, the closed ring subsequently twisted counterclockwise within 2–6 s, as viewed from the top to bottom of the chaperonin, and the twisted ring reverted to the original open-state with a clockwise motion. Our analyses clearly demonstrate that the biphasic lid-closure process occurs with unsynchronized closure and a synchronized counterclockwise twisting motion.
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影响因子：
2.1
作者：
Kawashima, Y.;Sasaki, Y. C.;Okamoto, Y.
通讯作者：
Okamoto, Y.
影响因子：
2.9
作者：
Villebeck, Laila;Persson, Malin;Jonsson, Bengt-Harald
通讯作者：
Jonsson, Bengt-Harald
影响因子：
4.8
作者：
Iizuka, R;Yoshida, T;Yohda, M
通讯作者：
Yohda, M
影响因子：
64.5
作者：
Ditzel, L;Löwe, J;Steinbacher, S
通讯作者：
Steinbacher, S
影响因子：
2.4
作者：
Okumura, Y;Oka, T;Sasaki, YC
通讯作者：
Sasaki, YC