Three-dimensional structure of bovine NADH:Ubiquinone oxidoreductase (Complex I) at 22 Å in ice
Three-dimensional structure of bovine NADH:Ubiquinone oxidoreductase (Complex I) at 22 Å in ice
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DOI：
10.1006/jmbi.1998.1668
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发表时间：
1998-04-17
影响因子：
5.6
通讯作者：
Grigorieff, N
中科院分区：
文献类型：
--
作者：
Grigorieff, N
NADH：泛氨基酮氧化还原酶（复合物I）是线粒体电子传输链中的第一个也是最大的复合物。从心肌纯化的牛复合物由至少42个不同的亚基组成，共同分子质量约为890 kDa。使用电子冷冻微观显微镜从嵌入玻璃化冰中的单个颗粒中确定复合物的三维结构。使用新程序来对齐颗粒，校正显微镜的对比度传递函数，并进行复合物的三维重建，从而计算结构。该牛复合物具有从Neurospora crassa的紧密相关复合物I的早期研究中发现的总体L形外观，但通过将膜结合的球形臂与固有膜结构域连接的薄茎区域不同。因此，直径约为30盎司的茎很可能包含一部分电子转移途径，将球状臂中NADH结合位点与膜结构域中的泛素酮结合位点联系起来。牛I的球状结构域明显大于Crassa酶的球状结构域，这表明牛酶的明显附加亚基复杂性与球形部分相关。 （c）1998 Academic Press Limited。
NADH:ubiquinone oxidoreductase (complex I) is the first and largest complex in the electron transport chain of mitochondria. The bovine complex purified from cardiac muscle consists of at least 42 different subunits with a combined molecular mass of about 890 kDa. The three-dimensional structure of the complex was determined at 22 Angstrom from single particles embedded in vitrified ice using electron cryo-microscopy. The structure was calculated using a new program to align particles, to correct for the contrast transfer function of the microscope, and to carry out the three-dimensional reconstruction of the complex. The bovine complex has the overall L-shaped appearance found in earlier studies of the closely related complex I from Neurospora crassa, but it differs by having a thin stalk region Linking the membrane-bound globular arm with the intrinsic membrane domain. Thus, the stalk which measures about 30 Angstrom in diameter is likely to contain part of the electron transfer pathway linking the NADH binding site in the globular arm with the ubiquinone binding site in the membrane domain. The globular domain of bovine complex I is significantly bigger than that of the N. crassa enzyme, suggesting that the apparent additional subunit complexity of the bovine enzyme is associated with the globular part. (C) 1998 Academic Press Limited.