Cystic fibrosis transmembrane conductance regulator: a molecular model defines the architecture of the anion conduction path and locates a "bottleneck" in the pore.
Cystic fibrosis transmembrane conductance regulator: a molecular model defines the architecture of the anion conduction path and locates a "bottleneck" in the pore.
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DOI：
10.1021/bi201888a
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发表时间：
2012-03-20
期刊：
影响因子：
2.9
通讯作者：
Sansom, Mark S. P.
中科院分区：
文献类型：
--
作者：
Norimatsu, Yohei;Ivetac, Anthony;Alexander, Christopher;Kirkham, John;O'Donnell, Nicolette;Dawson, David C.;Sansom, Mark S. P.
我们开发了基于原核ABC转运蛋白Sav1866的CFTR氯离子通道的分子模型。在这里，我们分析预测的孔的几何形状和侧链的取向TM 3，6，9和12，特别注意的位置的限速障碍阴离子传导。通过半胱氨酸扫描测定的侧链取向被发现是从77%到90%，与模型预测的雅阁。阴离子传导路径的预测几何形状由孔隙的空间填充模型定义，并通过从分子动力学（MD）模拟中可视化水分子的分布来确认。孔的形状是不对称的沙漏形状，包括一个浅的向外的前庭，其朝向一个狭窄的“瓶颈”迅速变细，该瓶颈将外前庭连接到一个大的内腔，该内腔朝向脂质双层的细胞质范围延伸。外前庭和瓶颈之间的连接处具有由TM6中的T338和TM12中的I1131标记的面向外的边缘，这与在这两个位置处的半胱氨酸与通道渗透性和通道不渗透性的硫醇导向试剂反应的观察结果一致。相反，半胱氨酸取代的S341在TM6或T1134在TM12中，预测的模型位于瓶颈的边缘之下，被发现只与通道渗透试剂从细胞外侧应用。瓶颈的预测尺寸与Cl−拟卤阴离子、水和尿素的渗透一致。
We developed molecular models for the CFTR chloride channel based on the prokaryotic ABC transporter, Sav1866. Here we analyze predicted pore geometry and side-chain orientations for TMs 3, 6, 9 and 12; with particular attention to the location of the rate-limiting barrier for anion conduction. Side-chain orientations assayed by cysteine scanning were found to be from 77% to 90% in accord with model predictions. The predicted geometry of the anion conduction path was defined by a space-filling model of the pore and confirmed by visualizing the distribution of water molecules from a molecular dynamics (MD) simulation. Pore shape is that of an asymmetric hour glass, comprising a shallow outward-facing vestibule that tapers rapidly toward a narrow “bottleneck” linking the outer vestibule to a large inner cavity extending toward the cytoplasmic extent of the lipid bilayer. The junction between the outer vestibule and the bottleneck features an outward–facing rim marked by T338 in TM6 and I1131 in TM12, consistent with the observation that cysteines at both of these locations reacted with both channel-permeant and channel-impermeant, thiol-directed reagents. Conversely, cysteines substituted for S341 in TM6 or T1134 in TM12, predicted by the model to lie below the rim of the bottleneck, were found to react exclusively with channel-permeant reagents applied from the extracellular side. The predicted dimensions of the bottleneck are consistent with the demonstrated permeation of Cl− pseudohalide anions, water and urea.
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影响因子：
4.8
作者：
El Hiani, Yassine;Linsdell, Paul
通讯作者：
Linsdell, Paul
影响因子：
2.4
作者：
Fatehi, Mohammad;Linsdell, Paul
通讯作者：
Linsdell, Paul
影响因子：
7.3
作者：
Li, M-S;Demsey, A. F. A.;Linsdell, P.
通讯作者：
Linsdell, P.
DOI：
10.1038/nrm2668
发表时间：
2009-05
期刊：
Nature reviews. Molecular cell biology
影响因子：
--
作者：
通讯作者：
--
DOI：
10.1126/science.1168750
发表时间：
2009-03-27
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Aller SG;Yu J;Ward A;Weng Y;Chittaboina S;Zhuo R;Harrell PM;Trinh YT;Zhang Q;Urbatsch IL;Chang G
通讯作者：
Chang G