Structure of a viral DNA gatekeeper at 10 Å resolution by cryo-electron microscopy
Structure of a viral DNA gatekeeper at 10 Å resolution by cryo-electron microscopy
复制标题
DOI：
10.1093/emboj/cdg123
复制
发表时间：
2003-03-17
期刊：
影响因子：
11.4
通讯作者：
Tavares, P
中科院分区：
文献类型：
--
作者：
Orlova, EV;Gowen, B;Tavares, P
在尾状噬菌体和疱疹病毒中，病毒DNA通过门静脉蛋白通道被包装。通道封闭是必不可少的，以防止包装后DNA释放。在这里，我们使用冷冻电子显微镜和单粒子分析展示了噬菌体SPP1的连接器结构。多蛋白复合物包括门静脉蛋白gp6和头部完成蛋白gp15和gp16。虽然我们发现连接器中的gp6具有与分离的门脉蛋白相似的折叠，但我们观察到暴露于dna包装atp酶和gp15的gp6区域的构象变化。这种重组不会导致通道关闭。连接器通道遍历gp6和gp15的整个高度，但它在复合体的底部被gp16关闭。Gp16就像一个阀门，它的关闭可以防止DNA泄漏，而它的打开是病毒与宿主相互作用时释放DNA所必需的。
In tailed bacteriophages and herpes viruses, the viral DNA is packaged through the portal protein channel. Channel closure is essential to prevent DNA release after packaging. Here we present the connector structure from bacteriophage SPP1 using cryo-electron microscopy and single particle analysis. The multiprotein complex comprises the portal protein gp6 and the head completion proteins gp15 and gp16. Although we show that gp6 in the connector has a fold similar to that of the isolated portal protein, we observe conformational changes in the region of gp6 exposed to the DNA-packaging ATPase and to gp15. This reorganization does not cause closure of the channel. The connector channel traverses the full height of gp6 and gp15, but it is closed by gp16 at the bottom of the complex. Gp16 acts as a valve whose closure prevents DNA leakage, while its opening is required for DNA release upon interaction of the virus with its host.