Zhang Wei, Chipman Paul R, Corver Jeroen, Johnson Peter R, Zhang Ying, Mukhopadhyay Suchetana, Baker Timothy S, Strauss James H, Rossmann Michael G, Kuhn Richard J
Department of Biological Sciences, Lilly Hall, 915 W. State Street, Purdue University, West Lafayette, Indiana 47907, USA.
Nat Struct Biol. 2003 Nov;10(11):907-12. doi: 10.1038/nsb990. Epub 2003 Oct 5.
Improved technology for reconstructing cryo-electron microscopy (cryo-EM) images has now made it possible to determine secondary structural features of membrane proteins in enveloped viruses. The structure of mature dengue virus particles was determined to a resolution of 9.5 A by cryo-EM and image reconstruction techniques, establishing the secondary structural disposition of the 180 envelope (E) and 180 membrane (M) proteins in the lipid envelope. The alpha-helical 'stem' regions of the E molecules, as well as part of the N-terminal section of the M proteins, are buried in the outer leaflet of the viral membrane. The 'anchor' regions of E and the M proteins each form antiparallel E-E and M-M transmembrane alpha-helices, leaving their C termini on the exterior of the viral membrane, consistent with the predicted topology of the unprocessed polyprotein. This is one of only a few determinations of the disposition of transmembrane proteins in situ and shows that the nucleocapsid core and envelope proteins do not have a direct interaction in the mature virus.
用于重建冷冻电子显微镜（cryo-EM）图像的技术改进，现已使确定包膜病毒中膜蛋白的二级结构特征成为可能。通过冷冻电子显微镜和图像重建技术，确定了成熟登革病毒颗粒的结构，分辨率达到9.5埃，确定了脂质包膜中180个包膜（E）蛋白和180个膜（M）蛋白的二级结构布局。E分子的α螺旋“茎”区域以及M蛋白N端部分埋在病毒膜的外小叶中。E和M蛋白的“锚定”区域各自形成反平行的E-E和M-M跨膜α螺旋，其C端留在病毒膜的外部，这与未加工多蛋白的预测拓扑结构一致。这是仅有的几个原位确定跨膜蛋白布局的研究之一，表明在成熟病毒中核衣壳核心蛋白和包膜蛋白没有直接相互作用。
