Cherrier Mickaël V, Kostyuchenko Victor A, Xiao Chuan, Bowman Valorie D, Battisti Anthony J, Yan Xiaodong, Chipman Paul R, Baker Timothy S, Van Etten James L, Rossmann Michael G
Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054, USA.
Proc Natl Acad Sci U S A. 2009 Jul 7;106(27):11085-9. doi: 10.1073/pnas.0904716106. Epub 2009 Jun 18.
Paramecium bursaria Chlorella virus-1 is an icosahedrally shaped, 1,900-A-diameter virus that infects unicellular eukaryotic green algae. A 5-fold symmetric, 3D reconstruction using cryoelectron microscopy images has now shown that the quasiicosahedral virus has a unique vertex, with a pocket on the inside and a spike structure on the outside of the capsid. The pocket might contain enzymes for use in the initial stages of infection. The unique vertex consists of virally coded proteins, some of which have been identified. Comparison of shape, size, and location of the spike with similar features in bacteriophages T4 and P22 suggests that the spike might be a cell-puncturing device. Similar asymmetric features may have been missed in previous analyses of many other viruses that had been assumed to be perfectly icosahedral.
草履虫小球藻病毒-1是一种呈二十面体形状、直径为1900埃的病毒,可感染单细胞真核绿藻。利用冷冻电子显微镜图像进行的五重对称三维重建现已表明,这种准二十面体病毒有一个独特的顶点,衣壳内部有一个口袋,外部有一个刺突结构。这个口袋可能含有用于感染初始阶段的酶。这个独特的顶点由病毒编码的蛋白质组成,其中一些已被识别。将刺突的形状、大小和位置与噬菌体T4和P22中的类似特征进行比较表明,刺突可能是一种细胞穿刺装置。在之前对许多被认为是完美二十面体的其他病毒的分析中,可能忽略了类似的不对称特征。