A nanosecond time-resolved XFEL analysis of structural changes associated with CO release from cytochrome c oxidase.
A nanosecond time-resolved XFEL analysis of structural changes associated with CO release from cytochrome c oxidase.
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DOI：
10.1126/sciadv.1603042
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发表时间：
2017-07
期刊：
影响因子：
13.6
通讯作者：
Tsukihara T
中科院分区：
文献类型：
--
作者：
Shimada A;Kubo M;Baba S;Yamashita K;Hirata K;Ueno G;Nomura T;Kimura T;Shinzawa-Itoh K;Baba J;Hatano K;Eto Y;Miyamoto A;Murakami H;Kumasaka T;Owada S;Tono K;Yabashi M;Yamaguchi Y;Yanagisawa S;Sakaguchi M;Ogura T;Komiya R;Yan J;Yamashita E;Yamamoto M;Ago H;Yoshikawa S;Tsukihara T
XFEL和IR分析表明，O2绑定在CuB块质子回流单向H+运输水通道关闭。牛细胞色素c氧化酶（CcO），一种420 kDa的膜蛋白，利用通过水通道转移的质子之间的静电排斥和血红素a（Fea）氧化血红素a3（Fea 3）还原O2产生的净正电荷来泵送质子。为了使这一过程正常运行，时间是必不可少的：在收集要泵送的质子之后和Fea氧化之前，必须关闭通道。如果通道保持开放，收集的质子将发生自发回流。为了阐明的通道关闭机制，开放的通道，发生在CO从CCO释放，研究了新开发的时间分辨的X射线自由电子激光和红外技术与纳秒时间分辨率。开放过程表明，CuB感测质子收集的完成，并结合O2，然后结合Fea 3，使用构象中继系统关闭水通道，该系统包括CuB，血红素a3和跨膜螺旋，以阻止收集的质子的回流。
XFEL and IR analyses suggest that O2 bound at CuB blocks proton backflow for unidirectional H+ transport by water channel closure. Bovine cytochrome c oxidase (CcO), a 420-kDa membrane protein, pumps protons using electrostatic repulsion between protons transferred through a water channel and net positive charges created by oxidation of heme a (Fea) for reduction of O2 at heme a3 (Fea3). For this process to function properly, timing is essential: The channel must be closed after collection of the protons to be pumped and before Fea oxidation. If the channel were to remain open, spontaneous backflow of the collected protons would occur. For elucidation of the channel closure mechanism, the opening of the channel, which occurs upon release of CO from CcO, is investigated by newly developed time-resolved x-ray free-electron laser and infrared techniques with nanosecond time resolution. The opening process indicates that CuB senses completion of proton collection and binds O2 before binding to Fea3 to close the water channel using a conformational relay system, which includes CuB, heme a3, and a transmembrane helix, to block backflow of the collected protons.
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影响因子：
2.9
作者：
Qin, Ling;Liu, Jian;Ferguson-Miller, Shelagh
通讯作者：
Ferguson-Miller, Shelagh
影响因子：
4.8
作者：
Mochizuki, M;Aoyama, H;Yoshikawa, S
通讯作者：
Yoshikawa, S
DOI：
10.1073/pnas.78.1.234
发表时间：
1981-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
ALBEN, JO;MOH, PP;ALTSCHULD, RA
通讯作者：
ALTSCHULD, RA
DOI：
10.1107/s0907444913018027
发表时间：
2013-09-01
影响因子：
2.2
作者：
Baba, Seiki;Hoshino, Takeshi;Kumasaka, Takashi
通讯作者：
Kumasaka, Takashi
影响因子：
3.9
作者：
Rich, Peter R.;Marechal, Amandine
通讯作者：
Marechal, Amandine