Changes to the length of the flexible linker region of the Rieske protein impair the interaction of ubiquinol with the cytochrome bc1 complex.
Changes to the length of the flexible linker region of the Rieske protein impair the interaction of ubiquinol with the cytochrome bc1 complex.
复制标题
Rieske 蛋白柔性接头区域长度的变化会损害泛醇与细胞色素 bc1 复合物的相互作用。
DOI：
10.1046/j.1432-1327.2000.01650.x
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Trumpower,BL
中科院分区：
文献类型：
--
作者：
Nett,JH;Hunte,C;Trumpower,BL
cytochromebc 1复合物的晶体结构表明，携带[2Fe−2S]簇的Rieske铁硫蛋白的催化结构域通过柔性接头区域连接到跨膜锚。这种灵活的连接体允许催化结构域在两个位置之间移动，靠近细胞色素带cytochromec 1。在Rieske蛋白的柔性连接区添加丙氨酸残基会使线粒体膜的泛醇-细胞色素还原酶活性降低一半，并导致泛醇的表观Km从9.3 μ m降低到2.6 μm。 添加两个丙氨酸残基使活性降低90%，表观Km降低至1.9 µm。 丙氨酸残基的缺失使活性降低约40%，表观Km降低至5.0 µm。 丙氨酸残基的添加或缺失也会导致豆磷蛋白抑制泛醇-细胞色素还原酶活性的效力显著降低，豆磷蛋白与泛醇氧化的反应中间体类似地结合。这些结果表明，灵活的连接区的长度是关键的相互作用泛醇与thebc 1复合物，与电子转移机制，泛醇必须同时与铁硫蛋白和细胞色素b相互作用一致。
Crystal structures of the cytochromebc1complex indicate that the catalytic domain of the Rieske iron–sulfur protein, which carries the [2Fe−2S] cluster, is connected to a transmembrane anchor by a flexible linker region. This flexible linker allows the catalytic domain to move between two positions, proximal to cytochromeband cytochromec1. Addition of an alanine residue to the flexible linker region of the Rieske protein lowers the ubiquinol‐cytochromecreductase activity of the mitochondrial membranes by one half and causes the apparentKmfor ubiquinol to decrease from 9.3 to 2.6 µm. Addition of two alanine residues lowers the activity by 90% and the apparentKmdecreases to 1.9 µm. Deletion of an alanine residue lowers the activity by ≈ 40% and the apparentKmdecreases to 5.0 µm. Addition or deletion of an alanine residue also causes a pronounced decrease in efficacy of inhibition of ubiquinol‐cytochromecreductase activity by stigmatellin, which binds analogous to reaction intermediates of ubiquinol oxidation. These results indicate that the length of the flexible linker region is critical for interaction of ubiquinol with thebc1complex, consistent with electron transfer mechanisms in which ubiquinol must simultaneously interact with the iron–sulfur protein and cytochromeb.
登录
查看更多内容
影响因子：
5.6
作者：
IPPOLITO, JA;ALEXANDER, RS;CHRISTIANSON, DW
通讯作者：
CHRISTIANSON, DW
DOI：
10.1073/pnas.97.9.4567
发表时间：
2000-04-25
影响因子：
11.1
作者：
Darrouzet, E;Valkova-Valchanova, M;Daldal, F
通讯作者：
Daldal, F
通过荧光淬灭滴定分析抑制剂与线粒体细胞色素 c 还原酶的结合。
DOI：
--
发表时间：
1991
期刊：
European Journal of Biochemistry
影响因子：
--
作者：
Ulrich Brandt;G. Jagow
通讯作者：
G. Jagow
影响因子：
14.9
作者：
THOMPSON, JD;HIGGINS, DG;GIBSON, TJ
通讯作者：
GIBSON, TJ
影响因子：
5.7
作者：
Hunte, C;Koepke, J;Michel, H
通讯作者：
Michel, H