State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China.
National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China.
Nat Commun. 2023 Jun 17;14(1):3609. doi: 10.1038/s41467-023-39220-y.
Tailed bacteriophages (order, Caudovirales) account for the majority of all phages. However, the long flexible tail of siphophages hinders comprehensive investigation of the mechanism of viral gene delivery. Here, we report the atomic capsid and in-situ structures of the tail machine of the marine siphophage, vB_DshS-R4C (R4C), which infects Roseobacter. The R4C virion, comprising 12 distinct structural protein components, has a unique five-fold vertex of the icosahedral capsid that allows genome delivery. The specific position and interaction pattern of the tail tube proteins determine the atypical long rigid tail of R4C, and further provide negative charge distribution within the tail tube. A ratchet mechanism assists in DNA transmission, which is initiated by an absorption device that structurally resembles the phage-like particle, RcGTA. Overall, these results provide in-depth knowledge into the intact structure and underlining DNA delivery mechanism for the ecologically important siphophages.
长尾噬菌体（目，长尾病毒目）占所有噬菌体的大多数。然而，噬菌体型的长尾柔性阻碍了对病毒基因传递机制的全面研究。在这里，我们报告了海洋噬菌体 vB_DshS-R4C（R4C）的原子衣壳和原位结构，该噬菌体感染玫瑰杆菌。R4C 病毒体由 12 种不同的结构蛋白组成，具有独特的二十面体衣壳五重顶点，允许基因组传递。尾管蛋白的特定位置和相互作用模式决定了 R4C 的非典型长刚性尾，并且进一步提供了尾管内的负电荷分布。棘轮机制有助于 DNA 传递，该机制由一个吸收装置启动，该装置在结构上类似于噬菌体样颗粒 RcGTA。总体而言，这些结果为生态重要的噬菌体型提供了完整结构和潜在的 DNA 传递机制的深入了解。
