National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
GM43949
米国
Howard Hughes Medical Institute (HHMI)
米国
引用
ジャーナル: Nature / 年: 2017 タイトル: Structural basis for gating the high-conductance Ca-activated K channel. 著者: Richard K Hite / Xiao Tao / Roderick MacKinnon / 要旨: The precise control of an ion channel gate by environmental stimuli is crucial for the fulfilment of its biological role. The gate in Slo1 K channels is regulated by two separate stimuli, ...The precise control of an ion channel gate by environmental stimuli is crucial for the fulfilment of its biological role. The gate in Slo1 K channels is regulated by two separate stimuli, intracellular Ca concentration and membrane voltage. Slo1 is thus central to understanding the relationship between intracellular Ca and membrane excitability. Here we present the Slo1 structure from Aplysia californica in the absence of Ca and compare it with the Ca-bound channel. We show that Ca binding at two unique binding sites per subunit stabilizes an expanded conformation of the Ca sensor gating ring. These conformational changes are propagated from the gating ring to the pore through covalent linkers and through protein interfaces formed between the gating ring and the voltage sensors. The gating ring and the voltage sensors are directly connected through these interfaces, which allow membrane voltage to regulate gating of the pore by influencing the Ca sensors.
解像度: 3.8 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 粒子像の数: 60000 / 対称性のタイプ: POINT
原子モデル構築
B value: 160 / プロトコル: AB INITIO MODEL / 空間: RECIPROCAL
精密化
解像度: 3.8→147 Å / Cor.coef. Fo:Fc: 0.889 / SU B: 86.753 / SU ML: 1.047 立体化学のターゲット値: MAXIMUM LIKELIHOOD WITH PHASES 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS
Rfactor
反射数
%反射
Rwork
0.3848
-
-
obs
0.3848
26401
100 %
溶媒の処理
イオンプローブ半径: 0.8 Å / 減衰半径: 0.8 Å / VDWプローブ半径: 1.2 Å / 溶媒モデル: MASK