Structure-function analysis of the DNA translocating portal of the bacteriophage T4 packaging machine.
Structure-function analysis of the DNA translocating portal of the bacteriophage T4 packaging machine.
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噬菌体T4包装机的DNA易位门户的结构 - 功能分析。
DOI：
10.1016/j.jmb.2013.10.011
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发表时间：
2014-03-06
影响因子：
5.6
通讯作者：
Rao VB
中科院分区：
文献类型：
--
作者：
Padilla-Sanchez V;Gao S;Kim HR;Kihara D;Sun L;Rossmann MG;Rao VB
有尾噬菌体和疱疹病毒由位于衣壳特殊五重顶点的结构上高度保守的十二聚体门户组成。该门户在头部组装、基因组包装、颈/尾附着和基因组排出中起关键作用。虽然来自P29、SPP 1和P22的通道结构已经确定，但它们的机制作用还没有很好的理解。由于噬菌体T4门户（gp 20）与大肠杆菌的不寻常的相互作用，其结构分析受到阻碍。coli内膜。在这里，我们预测T4门户单体和十二聚体的原子模型，并将十二聚体拟合到噬菌体门户顶点的cryoEM密度中。核心结构，像其他的噬菌体一样，是锥形的，较宽的一端包含噬菌体头部内的“翼”和“冠”结构域。一个长的“茎”包围着一个中央通道，一个狭窄的“柄”突出到衣壳的外面。开发了一种生物化学方法，通过将质粒表达的门户蛋白掺入噬菌体头部并确定突变对头部组装、DNA易位和病毒体产生的影响来分析门户功能。我们发现茎域的突出环参与组装DNA包装马达。连接柄和通道的环可能需要用于马达和门户之间的通信。突出到通道中的“隧道”环对于密封封装的头部是必不可少的。这些研究确定了在整个DNA包装过程中都需要门户，不同的域参与基因组包装的不同阶段。
Tailed bacteriophages and herpesviruses consist of a structurally well conserved dodecameric portal at a special five-fold vertex of the capsid. The portal plays critical roles in head assembly, genome packaging, neck/tail attachment, and genome ejection. Although the structures of portals from phages φ29, SPP1 and P22 have been determined, their mechanistic roles have not been well understood. Structural analysis of phage T4 portal (gp20) has been hampered because of its unusual interaction with the E. coli inner membrane. Here, we predict atomic models for the T4 portal monomer and dodecamer, and fit the dodecamer into the cryoEM density of the phage portal vertex. The core structure, like that from other phages, is cone-shaped with the wider end containing the “wing” and “crown” domains inside the phage head. A long “stem” encloses a central channel, and a narrow “stalk” protrudes outside the capsid. A biochemical approach was developed to analyze portal function by incorporating plasmid-expressed portal protein into phage heads and determining the effect of mutations on head assembly, DNA translocation, and virion production. We found that the protruding loops of the stalk domain are involved in assembling the DNA packaging motor. A loop that connects the stalk to the channel might be required for communication between the motor and portal. The “tunnel” loops that project into the channel are essential for sealing the packaged head. These studies established that the portal is required throughout the DNA packaging process, with different domains participating at different stages of genome packaging.
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影响因子：
14.9
作者：
Cole C;Barber JD;Barton GJ
通讯作者：
Barton GJ
影响因子：
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作者：
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作者：
DRIEDONKS, RA;ENGEL, A;VANDRIEL, R
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VANDRIEL, R
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作者：
Goetzinger, KR;Rao, VB
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作者：
Hugel, Thorsten;Michaelis, Jens;Bustamante, Carlos
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