Structural rearrangements underlying K+-channel activation gating
Structural rearrangements underlying K+-channel activation gating
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DOI：
10.1126/science.285.5424.73
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发表时间：
1999-07-02
期刊：
影响因子：
56.9
通讯作者：
Cuello, LG
中科院分区：
文献类型：
--
作者：
Perozo, E;Cortes, DM;Cuello, LG
通过定点自旋标记法和电子顺磁共振谱研究了链霉菌K+通道激活门控的膜内分子事件。通道的闭合和开放构象的比较揭示了自旋-标签迁移率和亚基间自旋-自旋相互作用的周期性变化与两个跨膜螺旋TM 1和TM 2的刚体运动一致。这些变化涉及两个螺旋相对于通道对称中心的平移和逆时针旋转。TM 2的移动增加了渗透途径的直径，沿着四个亚基的会聚点，从而打开孔。尽管选择性过滤器侧翼的细胞外残基在门控期间保持不动，但在孔螺旋的C-末端检测到小的移动。可能会影响门控机制
The intramembrane molecular events underlying activation gating in the Streptomyces K+ channel were investigated by site-directed spin-labeling methods and electron paramagnetic resonance spectroscopy. A comparison of the closed and open conformations of the channel revealed periodic changes in spin-label mobility and intersubunit spin-spin interaction consistent with rigid-body movements of the two transmembrane helices TM1 and TM2. These changes involve translations and counterclockwise rotations of both helices relative to the center of symmetry of the channel. The movement of TM2 increases the diameter of the permeation pathway along the point of convergence of the four subunits, thus opening the pore, Although the extracellular residues flanking the selectivity filter remained immobile during gating, small movements were detected at the C-terminal end of the pore helix. with possible implications to the gating mechanism.