Mode of Host Cell Penetration by Bacteriophage φX174
Mode of Host Cell Penetration by Bacteriophage φX174
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噬菌体 φX174 的宿主细胞穿透模式
DOI：
10.1128/jvi.7.6.836-846.1971
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发表时间：
1971
影响因子：
5.4
通讯作者：
M. Bayer
中科院分区：
文献类型：
--
作者：
Dennis T. Brown;J. Mackenzie;M. Bayer
噬菌体φX174是一种二十面体噬菌体，它不需要复杂的尾部装配就能附着在宿主细胞上。当φX174与从细菌宿主分离的细胞壁混合时，附着在壁碎片上的病毒粒子和噬菌体脱氧核糖核酸（DNA）被释放。如果用氯仿处理细胞壁，则可以防止附着。如果用溶菌酶孵育细胞壁或用甲醛灭活病毒体，则可以防止噬菌体DNA的释放，但不能防止病毒附着。用溶菌酶处理细胞壁释放出大小均匀（6.5 × 25 nm）的结构。这些结构附着在φX174的12个顶点之一的尖端，但病毒DNA没有释放出来。附着在这些结构上的病毒体的五重对称轴垂直于结构的长轴。没有病毒粒子通过一个以上的顶点附着于这些结构。吸附在完整细菌上的φX174的冷冻蚀刻制备物显示，病毒粒子被淹没在宿主细胞壁中，其直径为一半，并且五重对称轴垂直于细胞表面。第二个细胞不能附着到吸附的噬菌体的面向外的顶点，因此噬菌体不能交联两个细胞。当病毒粒子标记的3 H-亮氨酸，纯化，并吸附到大肠杆菌细胞，约15%的放射性回收作为低分子量材料从由溶菌酶-乙二胺四乙酸形成的原生质球。其他实验显示，在新形成的子代病毒中可以回收约7%的总亲本病毒蛋白标记。
Bacteriophage φX174 is an icosahedral phage which attaches to host cells without the aid of a complex tail assembly. When φX174 was mixed with cell walls isolated from the bacterial host, the virions attached to the wall fragments and the phage deoxyribonucleic acid (DNA) was released. Attachment was prevented if the cell walls were treated with chloroform. Release of phage DNA, but not viral attachment, was prevented if the cell walls were incubated with lysozyme or if the virions were inactivated with formaldehyde. Treatment of the cell walls with lysozyme released structures which were of uniform size (6.5 by 25 nm). These structures attached φX174 at the tip of one of its 12 vertices, but the viral DNA was not released. The virions attached to these structures were oriented with their fivefold axis of symmetry normal to the long axis of the structure. No virions were attached to these structures by more than one vertex. Freeze-etch preparations of φX174 adsorbed to intact bacteria showed that the virions were submerged to one half their diameter into the host cell wall, and the fivefold axis of symmetry was normal to the cell surface. A second cell could not be attached to the outwardly facing vertex of the adsorbed phage and thus the phage could not cross-link two cells. When the virions were labeled with 3H-leucine, purified, and adsorbed to Escherichia coli cells, about 15% of the radioactivity was recovered as low-molecular-weight material from spheroplasts formed by lysozyme-ethylenediaminetetraacetic acid. Other experiments revealed that about 7% of the total parental virus protein label could be recovered in newly formed progeny virus.