Electron microscopic evidence of two stalks linking the F1 and F0 parts of the Escherichia coli ATP synthase.
Electron microscopic evidence of two stalks linking the F1 and F0 parts of the Escherichia coli ATP synthase.
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DOI：
10.1016/s0005-2728(98)00048-6
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发表时间：
1998-06
期刊：
影响因子：
--
通讯作者：
S. Wilkens;R. Capaldi
中科院分区：
文献类型：
--
作者：
S. Wilkens;R. Capaldi
用电镜对大肠杆菌（ECF1F0）单分散ATP合成酶的结构进行了检测。f1部分由两根杆连接。一个位于中心位置，包括γ和λ亚基。第二茎，在ECF1F0中观察到，排列在周围。它可能包含δ和b亚基，除了γ和λ之外，它们是结合复合物的f1和f0部分所必需的。可以看出f1f0复合体的其他新特征。在第一部分的顶部有一个帽，第二茎可以在帽上结合。这可能包括α亚基的三个拷贝的n端延伸和δ亚基的一部分。f0部分显然不对称。在复合体中存在两个柄具有重要的功能意义。有充分的证据表明，γ和λ亚基的中心柄是一个可移动的结构域，通过f0部分的质子通道旋转，依次连接β亚基上的三个催化位点。δ和b亚基的第二个茎是定子，它使这种旋转成为可能。
The structure of monodisperse ATP synthase from Escherichia coli (ECF1F0) has been examined by electron microscopy after negative staining of specimens. The F1part is seen to be connected by two stalks. One is more centrally located and includes the γ and ϵ subunits. The second stalk, observed here in ECF1F0, is arranged peripherally. It probably contains the δ and b subunits which, in addition to γ and ϵ, are required for binding of the F1and F0parts of the complex. Other novel features of the F1F0complex can be discerned. There is a cap at the top of the F1part at which the second stalk may bind. This likely includes N-terminal stretches of the three copies of the α subunit and a part of the δ subunit. The F0part is clearly asymmetric. The presence of two stalks in the complex has important functional implications. There is good evidence that the more central stalk of γ and ϵ subunits is a mobile domain that rotates to link the three catalytic sites on β subunits in turn, with the proton channel of the F0part. The second stalk of δ and b subunits is then the stator which makes this rotation possible.