Structure of the transmembrane regions of a bacterial cyclic nucleotide-regulated channel
Structure of the transmembrane regions of a bacterial cyclic nucleotide-regulated channel
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DOI：
10.1073/pnas.0711533105
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发表时间：
2008-02-05
影响因子：
11.1
通讯作者：
Morais-Cabral, Joao H.
中科院分区：
文献类型：
--
作者：
Clayton, Gina M.;Altieri, Steve;Morais-Cabral, Joao H.
六跨膜螺旋（6tm）四聚体阳离子通道构成了最大的离子通道家族，其中一些成员是电压门控的，而另一些则不是。没有报道的通道结构与非电压门控成员的丰富功能数据相匹配。我们确定了细菌环核苷酸调节通道MIotiK1的跨膜区域结构，这是一个非电压门控的6 TM通道。该结构显示了S1-S4结构域及其相关连接体如何作为钳子约束孔门，并可能与配体结合结构域协同作用以调节孔的打开。该结构还使我们假设了一种新的机制，通过这种机制，S6内螺旋的运动可以在比典型螺旋束交叉更接近选择性过滤器的孔中形成离子传导途径。
The six-transmembrane helix (6 TM) tetrameric cation channels form the largest ion channel family, some members of which are voltage-gated and others are not. There are no reported channel structures to match the wealth of functional data on the non-voltage-gated members. We determined the structure of the transmembrane regions of the bacterial cyclic nucleotide-regulated channel MIotiK1, a non-voltage-gated 6 TM channel. The structure showed how the S1-S4 domain and its associated linker can serve as a clamp to constrain the gate of the pore and possibly function in concert with ligand-binding domains to regulate the opening of the pore. The structure also led us to hypothesize a new mechanism by which motions of the S6 inner helices can gate the ion conduction pathway at a position along the pore closer to the selectivity filter than the canonical helix bundle crossing.