Kadlec Jan, Loureiro Silvia, Abrescia Nicola G A, Stuart David I, Jones Ian M
Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
Nat Struct Mol Biol. 2008 Oct;15(10):1024-30. doi: 10.1038/nsmb.1484. Epub 2008 Sep 7.
Viral fusion proteins mediate the merger of host and viral membranes during cell entry for all enveloped viruses. Baculovirus glycoprotein gp64 (gp64) is unusual in promoting entry into both insect and mammalian cells and is distinct from established class I and class II fusion proteins. We report the crystal structure of its postfusion form, which explains a number of gp64's biological properties including its cellular promiscuity, identifies the fusion peptides and shows it to be the third representative of a new class (III) of fusion proteins with unexpected structural homology with vesicular stomatitis virus G and herpes simplex virus type 1 gB proteins. We show that domains of class III proteins have counterparts in both class I and II proteins, suggesting that all these viral fusion machines are structurally more related than previously thought.
对于所有包膜病毒而言，病毒融合蛋白在细胞进入过程中介导宿主膜与病毒膜的融合。杆状病毒糖蛋白gp64在促进进入昆虫和哺乳动物细胞方面表现独特，且不同于已确定的I类和II类融合蛋白。我们报道了其融合后形式的晶体结构，该结构解释了gp64的许多生物学特性，包括其细胞嗜性，鉴定了融合肽，并表明它是融合蛋白新类别（III类）的第三个代表，与水疱性口炎病毒G蛋白和单纯疱疹病毒1型gB蛋白具有意外的结构同源性。我们表明，III类蛋白的结构域在I类和II类蛋白中都有对应物，这表明所有这些病毒融合机制在结构上的相关性比以前认为的更高。
