Structural and functional analysis of Nup120 suggests ring formation of the Nup84 complex
Structural and functional analysis of Nup120 suggests ring formation of the Nup84 complex
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DOI：
10.1073/pnas.0907453106
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发表时间：
2009-08-25
影响因子：
11.1
通讯作者：
Hoelz, Andre
中科院分区：
文献类型：
--
作者：
Seo, Hyuk-Soo;Ma, Yingli;Hoelz, Andre
Nup84复合物是核孔复合物（NPC）的关键组成部分。在这里，我们展示了它的7个组成部分之一Nup120的晶体结构，它揭示了一个β螺旋桨和一个代表新褶皱的α螺旋结构域。我们发现了Nup120与Nup133之间先前未被发现的相互作用，并证实了它们在体内的生理相关性。由于Nup84复合体中单个组分的定位将Nup120和Nup133置于七聚体的两端，我们的研究结果表明，细长的Nup84复合体首尾相连地排列成环状结构，与核孔膜的栅栏状外壳一致。Nup133的附着位点位于延伸的非结构化区域的最末端，这使得Nup84复合环的直径具有灵活性。这些结果阐明了核孔蛋白末端非结构化片段在NPC的结构、功能和组装中的重要作用。
The Nup84 complex constitutes a key building block in the nuclear pore complex (NPC). Here we present the crystal structure of one of its 7 components, Nup120, which reveals a beta propeller and an alpha-helical domain representing a novel fold. We discovered a previously unidentified interaction of Nup120 with Nup133 and confirmed the physiological relevance in vivo. As mapping of the individual components in the Nup84 complex places Nup120 and Nup133 at opposite ends of the heptamer, our findings indicate a head-to-tail arrangement of elongated Nup84 complexes into a ring structure, consistent with a fence-like coat for the nuclear pore membrane. The attachment site for Nup133 lies at the very end of an extended unstructured region, which allows for flexibility in the diameter of the Nup84 complex ring. These results illuminate important roles of terminal unstructured segments in nucleoporins for the architecture, function, and assembly of the NPC.