The structure of bovine IF1, the regulatory subunit of mitochondrial F-ATPase
The structure of bovine IF1, the regulatory subunit of mitochondrial F-ATPase
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DOI：
10.1093/emboj/20.24.6990
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发表时间：
2001-12-17
期刊：
影响因子：
11.4
通讯作者：
Walker, JE
中科院分区：
文献类型：
--
作者：
Cabezón, E;Runswick, MJ;Walker, JE
在线粒体中，ATP合酶的水解活性由抑制蛋白IF 1调节。它与ATP合酶的结合取决于pH值，在中性以下，IF 1是二聚体，与酶形成稳定的复合物。在较高的pH值下，IF 1形成四聚体并且无活性。在这里描述的牛IF 1的2.2埃结构中，不对称单元中的四个单体排列为二聚体的二聚体。单体通过C-末端区域中的反平行α-螺旋卷曲螺旋形成二聚体。二聚体通过N-末端和抑制区域（残基14-47）中的卷曲螺旋相互作用结合成低聚物并在晶格中形成长纤维。因此，四聚体的形成掩盖了抑制区域，阻止IF 1与ATP合酶结合。
In mitochondria, the hydrolytic activity of ATP synthase is regulated by an inhibitor protein, IF1. Its binding to ATP synthase depends on pH, and below neutrality, IF1 is dimeric and forms a stable complex with the enzyme. At higher pH values, IF1 forms tetramers and is inactive. In the 2.2 Angstrom structure of the bovine IF1 described here, the four monomers in the asymmetric unit are arranged as a dimer of dimers. Monomers form dimers via an antiparallel alpha -helical coiled coil in the C-terminal region. Dimers are associated into oligomers and form long fibres in the crystal lattice, via coiled-coil interactions in the N-terminal and inhibitory regions (residues 14-47). Therefore, tetramer formation masks the inhibitory region, preventing IF1 binding to ATP synthase.