Symmetry-constrained analysis of pulsed double electron-electron resonance (DEER) spectroscopy reveals the dynamic nature of the KcsA activation gate.
Symmetry-constrained analysis of pulsed double electron-electron resonance (DEER) spectroscopy reveals the dynamic nature of the KcsA activation gate.
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DOI：
10.1021/ja3069038
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发表时间：
2012-10-03
影响因子：
15
通讯作者：
Perozo E
中科院分区：
文献类型：
--
作者：
Dalmas O;Hyde HC;Hulse RE;Perozo E
由脉冲双电子-电子共振(DER)实验获得的回波强度调制来确定距离是一个数学上不适定的问题。Tikhonov正则化产生的距离分布可能很难解释，特别是在具有多个离散距离分布的系统中。在这里，我们表明，通过在对称的同聚-寡聚蛋白质系统中使用几何拟合约束，我们能够提高基于高斯分布和的基于模型的拟合解的精度。我们的方法在两个已知低聚态的不同离子通道上得到了验证，KCSA(四聚体)和CORA(五聚体)。我们的方法集成了对所得拟合的统计分析，以帮助实验者评估对称约束分布拟合与标准模型分布拟合的重要性，并检查多距离置信度区域。该方法被用来定量评估C末端结构域(CTD)对K+通道KCSA激活门的灵活性和构象的作用。我们的分析表明，内束门在打开时的动力学显著增加。此外，它还清楚地展示了CTD在静止和激活门控期间限制下闸门运动的程度。
Distance determination from an echo intensity modulation obtained by pulsed double electron-electron resonance (DEER) experiment is a mathematically ill-posed problem. Tikhonov regularization yields distance distributions that can be difficult to interpret, especially in system with multiple discrete distance distributions. Here, we show that by using geometric fit constraints in symmetric homo-oligomeric protein systems, we were able to increase the accuracy of a model-based fit solution based on a sum of Gaussian distributions. Our approach was validated on two different ion channels of known oligomeric states, KcsA (a tetramer) and CorA (a pentamer). Statistical analysis of the resulting fits was integrated within our method to help the experimenter evaluate the significance of a symmetry-constrained vs. standard model distribution fit and to examine multi-distance confidence regions. This approach was used to quantitatively evaluate the role of the C-terminal domain (CTD) on the flexibility and conformation of the activation gate of the K+ channel KcsA. Our analysis reveals a significant increase in the dynamics of the inner bundle gate upon opening. Also, it explicitly demonstrates the degree to which the CTD restricts the motion of the lower gate at rest and during activation gating.
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影响因子：
15
作者：
Endeward, Burkhard;Butterwick, Joel A.;MacKinnon, Roderick;Prisner, Thomas F.
通讯作者：
Prisner, Thomas F.
DOI：
10.1085/jgp.200609638
发表时间：
2006-11
期刊：
The Journal of general physiology
影响因子：
--
作者：
Blunck R;Cordero-Morales JF;Cuello LG;Perozo E;Bezanilla F
通讯作者：
Bezanilla F
全长KCSA的分子结构：细胞质结构域在离子渗透和激活门口中的作用。
影响因子：
3.8
作者：
Cortes, DM;Cuello, LG;Perozo, E
通讯作者：
Perozo, E
影响因子：
56.9
作者：
Doyle, DA;Cabral, JM;MacKinnon, R
通讯作者：
MacKinnon, R
影响因子：
3.3
作者：
Jeschke, Gunnar;Sajid, Muhammad;Godt, Adelheid
通讯作者：
Godt, Adelheid