Roche S, Albertini A A V, Lepault J, Bressanelli S, Gaudin Y
CNRS, UMR2472, INRA, UMR1157, IFR 115, Virologie Moléculaire et Structurale, Gif sur Yvette, France.
Cell Mol Life Sci. 2008 Jun;65(11):1716-28. doi: 10.1007/s00018-008-7534-3.
Glycoprotein G of the vesicular stomatitis virus (VSV) is involved in receptor recognition at the host cell surface and then, after endocytosis of the virion, triggers membrane fusion via a low pH-induced structural rearrangement. G is an atypical fusion protein, as there is a pH-dependent equilibrium between its pre- and post-fusion conformations. The atomic structures of these two conformations reveal that it is homologous to glycoprotein gB of herpesviruses and that it combines features of the previously characterized class I and class II fusion proteins. Comparison of the structures of G pre- and postfusion states shows a dramatic reorganization of the molecule that is reminiscent of that of paramyxovirus fusion protein F. It also allows identification of conserved key residues that constitute pH-sensitive molecular switches. Besides the similarities with other viral fusion machineries, the fusion properties and structures of G also reveal some striking particularities that invite us to reconsider a few dogmas concerning fusion proteins.
水泡性口炎病毒（VSV）的糖蛋白G参与宿主细胞表面的受体识别，然后在病毒粒子内吞后，通过低pH诱导的结构重排触发膜融合。G是一种非典型融合蛋白，因为其融合前和融合后构象之间存在pH依赖性平衡。这两种构象的原子结构表明，它与疱疹病毒的糖蛋白gB同源，并且结合了先前表征的I类和II类融合蛋白的特征。G融合前和融合后状态的结构比较显示出分子的剧烈重组，这让人联想到副粘病毒融合蛋白F的重组。它还允许识别构成pH敏感分子开关的保守关键残基。除了与其他病毒融合机制的相似性外，G的融合特性和结构还揭示了一些引人注目的特殊性，促使我们重新审视一些关于融合蛋白的教条。
