Assembly of a tailed bacterial virus and its genome release studied in three dimensions
Assembly of a tailed bacterial virus and its genome release studied in three dimensions
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DOI：
10.1016/s0092-8674(00)81773-0
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发表时间：
1998-10-30
期刊：
影响因子：
64.5
通讯作者：
Baker, TS
中科院分区：
文献类型：
--
作者：
Tao, YZ;Olson, NH;Baker, TS
我们提出了第一个三维重建的长尾噬菌体，和它的空前体的冷冻电子显微镜。头尾接头，DNA包装机的中心部件，首次在枯草芽孢杆菌dsDNA噬菌体phi 29中原位可视化。连接器具有12或13倍的对称，看起来松散地适合头部的五聚体顶点，这种对称不匹配可能需要旋转连接器来封装DNA。φ 29的长头在其柱面赤道区有10个六聚体单元，其中11个五聚体和20个六聚体单元由T=3准对称的二十面体端帽组成。一个空的噬菌体颗粒的重建表明，连接器和颈部/尾部组装发生显著构象变化后，喷出的DNA。
We present the first three-dimensional reconstruction of a prolate, tailed phage, and its empty prohead precursor by cryo-electron microscopy. The head-tail connector, the central component of the DNA packaging machine, is visualized for the first time in situ within the Bacillus subtilis dsDNA phage phi 29. The connector, with 12- or 13-fold symmetry, appears to fit loosely into a pentameric vertex of the head, a symmetry mismatch that may be required to rotate the connector to package DNA. The prolate head of phi 29 has 10 hexameric units in its cylindrical equatorial region, and 11 pentameric and 20 hexameric units comprise icosahedral end-caps with T=3 quasi-symmetry. Reconstruction of an emptied phage particle shows that the connector and neck/tail assembly undergo significant conformational changes upon ejection of DNA.