Structure of a flavivirus envelope glycoprotein in its low-pH-induced membrane fusion conformation
Structure of a flavivirus envelope glycoprotein in its low-pH-induced membrane fusion conformation
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DOI：
10.1038/sj.emboj.7600064
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发表时间：
2004-02-25
期刊：
影响因子：
11.4
通讯作者：
Rey, FA
中科院分区：
文献类型：
--
作者：
Bressanelli, S;Stiasny, K;Rey, FA
包膜病毒通过由特定病毒包膜蛋白的构象变化驱动的膜融合反应进入细胞。我们在这里报告的蜱传脑炎病毒包膜糖蛋白，E，一个典型的II类融合蛋白，在其三聚体低pH诱导的构象的胞外域的结构。我们发现，在构象转变中，中性pH形式的三个域被保持，但它们的相对取向被改变。类似于融合后I类蛋白，亚基重排使得融合肽环聚集在伸长分子的一端，并且连接到病毒跨膜区的C-末端区段沿着指向融合肽环的三聚体的侧面延伸。与低pH诱导形式的甲病毒II类融合蛋白的比较揭示了携带融合肽的分子末端的显著差异，表明缺失的膜连接片段的重要构象效应。
Enveloped viruses enter cells via a membrane fusion reaction driven by conformational changes of specific viral envelope proteins. We report here the structure of the ectodomain of the tick-borne encephalitis virus envelope glycoprotein, E, a prototypical class II fusion protein, in its trimeric low-pH-induced conformation. We show that, in the conformational transition, the three domains of the neutral-pH form are maintained but their relative orientation is altered. Similar to the postfusion class I proteins, the subunits rearrange such that the fusion peptide loops cluster at one end of an elongated molecule and the C-terminal segments, connecting to the viral transmembrane region, run along the sides of the trimer pointing toward the fusion peptide loops. Comparison with the low-pH-induced form of the alphavirus class II fusion protein reveals striking differences at the end of the molecule bearing the fusion peptides, suggesting an important conformational effect of the missing membrane connecting segment.