The PM2 virion has a novel organization with an internal membrane and pentameric receptor binding spikes
The PM2 virion has a novel organization with an internal membrane and pentameric receptor binding spikes
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DOI：
10.1038/nsmb807
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发表时间：
2004-09-01
影响因子：
16.8
通讯作者：
Butcher, SJ
中科院分区：
文献类型：
--
作者：
Huiskonen, JT;Kivelä, HM;Butcher, SJ
众所周知，生物膜对结构分析具有抵抗力。原位解决这个问题的最佳候选者是含膜病毒，其中膜受到二十面体衣壳的限制。噬菌体 PM2 的冷冻电镜和图像重建揭示了衣壳内表面后面的双层膜。病毒基因组与内部小叶密切相互作用。衣壳分辨率为 8.4 埃，显示 200 个三聚衣壳，具有伪 T = 21 右旋组织。五聚体受体结合尖峰从表面突出。从结构上可以明显看出，PM2膜在生命周期中至少有两个重要作用。首先，它充当使衣壳组装成核的支架。其次，在宿主识别后，它与宿主外膜融合以促进基因组进入。该结构还揭示了病毒超螺旋环状双链DNA基因组如何包装和释放。
Biological membranes are notoriously resistant to structural analysis. Excellent candidates to tackle this problem in situ are membrane-containing viruses where the membrane is constrained by an icosahedral capsid. Cryo-EM and image reconstruction of bacteriophage PM2 revealed a membrane bilayer following the internal surface of the capsid. The viral genome closely interacts with the inner leaflet. The capsid, at a resolution of 8.4 Angstrom, reveals 200 trimeric capsomers with a pseudo T = 21 dextro organization. Pentameric receptor-binding spikes protrude from the surface. It is evident from the structure that the PM2 membrane has at least two important roles in the life cycle. First, it acts as a scaffold to nucleate capsid assembly. Second, after host recognition, it fuses with the host outer membrane to promote genome entry. The structure also sheds light on how the viral supercoiled circular double-stranded DNA genome might be packaged and released.