Structure of the connexin 26 gap junction channel at 3.5 Ã… resolution
Structure of the connexin 26 gap junction channel at 3.5 Ã… resolution
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DOI：
10.1038/nature07869
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发表时间：
2009-04-02
期刊：
影响因子：
64.8
通讯作者：
Tsukihara, Tomitake
中科院分区：
文献类型：
--
作者：
Maeda, Shoji;Nakagawa, So;Tsukihara, Tomitake
缝隙连接由相邻细胞之间允许离子和小分子交换的细胞间通道阵列组成。本文报道了人连接蛋白26(Cx26，又称GJB2)在3.5埃分辨率下形成的缝隙连接通道的晶体结构，并讨论了溶质通过该通道的结构决定因素。密度图显示了两个跨膜半通道和形成每个半通道的六个原基的四个跨膜螺旋的排列。半管有一个带正电的细胞质入口、一个漏斗、一个带负电的跨膜通路和一个胞外空腔。孔在漏斗处变窄，漏斗由排列在通道壁上的六个氨基末端螺旋形成，从而决定了通道入口处的分子尺寸限制。Cx26间隙结沟道的结构对于通过跨结电压选通沟道也有影响。
Gap junctions consist of arrays of intercellular channels between adjacent cells that permit the exchange of ions and small molecules. Here we report the crystal structure of the gap junction channel formed by human connexin 26 (Cx26, also known as GJB2) at 3.5 angstrom resolution, and discuss structural determinants of solute transport through the channel. The density map showed the two membrane-spanning hemichannels and the arrangement of the four transmembrane helices of the six protomers forming each hemichannel. The hemichannels feature a positively charged cytoplasmic entrance, a funnel, a negatively charged transmembrane pathway, and an extracellular cavity. The pore is narrowed at the funnel, which is formed by the six amino-terminal helices lining the wall of the channel, which thus determines the molecular size restriction at the channel entrance. The structure of the Cx26 gap junction channel also has implications for the gating of the channel by the transjunctional voltage.