Distinguishing between Cl- and O22- as the bridging element between Fe3+ and Cu2+ in resting-oxidized cytochrome c oxidase

被引：15

作者：

Suga, Michihiro ^{[2
]}

Yano, Naomine ^{[1
]}

Muramoto, Kazumasa ^{[1
]}

Shinzawa-Itoh, Kyoko ^{[1
]}

Maeda, Tomoko ^{[1
]}

Yamashita, Eiki ^{[2
]}

Tsukihara, Tomitake ^{[1
,2
]}

Yoshikawa, Shinya ^{[1
]}

机构：

[1] Univ Hyogo, Dept Life Sci, Akoh, Hyogo 6781297, Japan

[2] Osaka Univ, Inst Prot Res, Suita, Osaka 5650871, Japan

来源：

ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY | 2011年 / 67卷

关键词：

SITE;

D O I：

10.1107/S0907444911022803

中图分类号：

Q5 [生物化学];

学科分类号：

071010 ; 081704 ;

摘要：

Fully oxidized cytochrome c oxidase (CcO) under enzymatic turnover is capable of pumping protons, while fully oxidized CcO as isolated is not able to do so upon one-electron reduction. The functional difference is expected to be a consequence of structural differences: [Fe3+-OH-] under enzymatic turnover versus [Fe3+-O-2(2-)-Cu2+] for the as-isolated CcO. However, the electron density for O-2(2-) is equally assignable to Cl-. An anomalous dispersion analysis was performed in order to conclusively demonstrate the absence of Cl- between the Fe3+ and Cu2+. Thus, the peroxide moiety receives electron equivalents from cytochrome c without affecting the oxidation states of the metal sites. The metal-site reduction is coupled to the proton pump.

引用

页码：742 / 744

页数：3