果蝇钙离子通道Orai激活态的成像数据集

Orai 通道具有电压独立、低电导和高 Ca2+ 选择性的特点，在 Ca2+ 通过质膜 (PM) 流入中起重要作用。通道如何被激活并促进 Ca2+ 渗透尚不清楚。在这里，我们报告了根据电生理学组成型活跃的果蝇 Orai (dOrai) 突变体 (P288L) 通道的晶体结构和低温电子显微镜 (cryo-EM) 重建。 Orai 通道的开放状态显示六聚体组装，其中中心的 6 个跨膜 1 (TM1) 螺旋形成离子传导孔，外围的 6 个 TM4 螺旋形成延伸的长螺旋。 Orai 通道激活需要从 TM4 到 TM1 的构象转导，并最终导致 TM1 的基本部分向外扭曲。胞质侧较宽的孔聚集阴离子以增加跨膜的电位梯度，从而促进 Ca2+ 的渗透。 Orai 通道的开放状态结构提供了对通道组装、通道激活和 Ca2+ 渗透的见解。

Orai channels are voltage-independent, low-conductance, and highly Ca²⁺-selective, playing critical roles in Ca²⁺ influx across the plasma membrane (PM). The mechanisms underlying channel activation and Ca²⁺ permeation remain unclear. Here, we report the crystal structure and cryo-electron microscopy (cryo-EM) reconstruction of a constitutively active Drosophila Orai (dOrai) mutant (P288L) channel characterized via electrophysiological assays. The open state of Orai channels adopts a hexameric assembly, wherein the six central transmembrane 1 (TM1) helices form the ion-conducting pore, while the six peripheral TM4 helices form extended long helices. Channel activation requires conformational coupling from TM4 to TM1, which ultimately triggers the outward twisting of the basic segment of TM1. The wide, cytoplasm-facing pore accumulates anions to amplify the transmembrane potential gradient, thereby facilitating Ca²⁺ permeation. The structure of the Orai channel open state provides critical insights into channel assembly, activation, and Ca²⁺ permeation.

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背景与挑战

背景概述

该数据集包含果蝇钙离子通道Orai激活态的成像数据，通过晶体结构和低温电子显微镜重建揭示了通道的六聚体组装和Ca2+渗透机制。数据量为44.68MB，包含5个文件，由南开大学沈月全团队发布。