PKD2L1, also termed TRPP3 from the TRPP subfamily (polycystic TRP channels), is involved in the sour sensation and other pH-dependent processes. PKD2L1 is believed to be a nonselective cation channel that can be regulated by voltage, protons, and calcium. Despite its considerable importance, the molecular mechanisms underlying PKD2L1 regulations are largely unknown. Here, we determine the PKD2L1 atomic structure at 3.38 Å resolution by cryo-electron microscopy, whereby side chains of nearly all residues are assigned. Unlike its ortholog PKD2, the pore helix (PH) and transmembrane segment 6 (S6) of PKD2L1, which are involved in upper and lower-gate opening, adopt an open conformation. Structural comparisons of PKD2L1 with a PKD2-based homologous model indicate that the pore domain dilation is coupled to conformational changes of voltage-sensing domains (VSDs) via a series of π-π interactions, suggesting a potential PKD2L1 gating mechanism.

中文翻译：

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多囊肾病样通道PKD2L1的低温EM结构。

PKD2L1，也称为TRPP亚家族（多囊性TRP通道）的TRPP3，参与酸味和其他pH依赖性过程。PKD2L1被认为是可以通过电压，质子和钙调节的非选择性阳离子通道。尽管其相当重要，但PKD2L1调控的分子机制尚不清楚。在这里，我们通过冷冻电子显微镜确定分辨率为3.38Å的PKD2L1原子结构，从而确定了几乎所有残基的侧链。与它的直系同源蛋白PKD2不同，参与上，下门打开的PKD2L1的孔螺旋（PH）和跨膜片段6（S6）采用开放构象。