The seven members of the TRP channel superfamily are divided into two main groups with five members comprising group I (TRPC/V/M/N/A) and TRPML (TRP MucoLipin) and TRPP (TRP Polycystin) making up group II. Group II channels share a high sequence homology on their transmembrane domains and are distinct from group I members as they contain a large luminal/extracellular domain between transmembrane helix 1 (S1) and S2. Since 2016, there are more than ten research papers reporting various structures of group II channels by either cryo-EM or X-ray crystallography. These studies along with recent functional analysis by the other groups have considerably strengthened our knowledge on TRPML and TRPP channels. In this review, we summarize and discuss these reports providing molecular insights into the group II TRP channel family.

中文翻译：

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对第二组TRP渠道的结构见解。

TRP通道超家族的七个成员分为两个主要组，五个成员包括I组（TRPC / V / M / N / A）和TRPML（TRP MucoLipin）和TRPP（TRP多囊蛋白），组成第二组。II组通道在其跨膜结构域上具有较高的序列同源性，并且与I组成员不同，因为它们在跨膜螺旋1（S1）和S2之间包含较大的腔/细胞外结构域。自2016年以来，已有十多篇研究论文通过冷冻EM或X射线晶体学报告了II组通道的各种结构。这些研究以及其他小组最近进行的功能分析大大增强了我们对TRPML和TRPP渠道的了解。在这篇综述中，我们总结并讨论了这些报告，从而提供了对第二类TRP通道家族的分子认识。