Three-dimensional map of the plasma membrane H+-ATPase in the open conformation
Three-dimensional map of the plasma membrane H+-ATPase in the open conformation
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DOI：
10.1038/33967
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发表时间：
1998-04-23
期刊：
影响因子：
64.8
通讯作者：
Kühlbrandt, W
中科院分区：
文献类型：
--
作者：
Auer, M;Scarborough, GA;Kühlbrandt, W
来自粗糙脉孢菌质膜的H+-ATP酶是相对分子质量100K的整合膜蛋白，属于P型ATP酶家族，包括质膜Na+/K+-ATP酶和肌浆网Ca2+-ATP酶。 H+-ATP 酶使用 ATP 作为能源将质子泵过细胞质膜，产生超过 200 mV 的膜电位（参考文献 1-3）。尽管 P 型 ATP 酶在控制膜电位和细胞内离子浓度方面很重要，但人们对它们用于离子转运的分子机制知之甚少。这主要是由于生长有序晶体的困难以及导致这些大膜蛋白的三维结构缺乏细节。我们现在通过直接在电子显微镜网格上生长的二维晶体的电子晶体学获得了 H+-ATP酶的三维图。在 8 埃的平面内分辨率下，该图显示了膜结构域中的 10 个跨膜 α 螺旋，以及未结合配体的酶开放构象中的 4 个主要细胞质结构域。
The H+-ATPase from the plasma membrane of Neurospora crassa is an integral membrane protein of relative molecular mass 100K, which belongs to the P-type ATPase family that includes the plasma membrane Na+/K+-ATPase and the sarcoplasmic reticulum Ca2+-ATPase. The H+-ATPase pumps protons across the cell's plasma membrane using ATP as an energy source, generating a membrane potential in excess of 200 mV (refs 1-3). Despite the importance of P-type ATPases in controlling membrane potential and intracellular ion concentrations, little is known about the molecular mechanism they use for ion transport. This is largely due to the difficulty in growing well ordered crystals and the resulting lack of detail in the three-dimensional structure of these large membrane proteins. We have now obtained a three-dimensional map of the H+-ATPase by electron crystallography of two-dimensional crystals grown directly on electron microscope grids. At an in-plane resolution of 8 Angstrom, this map reveals ten membrane-spanning alpha-helices in the membrane domain, and four major cytoplasmic domains in the open conformation of the enzyme without bound ligands.