Podophages are, by far, the least well studied of all the bacteriophages. Despite being classified together due to their short, noncontractile tails, there is a huge amount of diversity among members of this group. Of the podophages, the N4-like Schitoviridae family is the least well studied structurally and is quite divergent from well-characterized podophages such as T7 and P22. In this work, we isolate and fully characterize two members of the Schitoviridae family by cryo–electron microscopy, genetics, and biochemistry. We describe the capsid features of Moo19 and B2, including a decoration protein. In addition, we have fully modeled the tail machinery for both phages and identify proteins with esterase activity. Genetic knockouts of the host reveal factors specific for host attachment including key modifications to the O-antigen on the lipopolysaccharide. Moo19 and B2 are both Schitoviridae members, yet some distinct differences in the genome and structure place them into distinct clades.

中文翻译：

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Moo19 和 B2：具有 T = 9 几何形状和具有酯酶活性的尾刺的 Schitoviridae 足噬菌体的结构


到目前为止，鬼软动物是所有噬菌体中研究最少的。尽管由于它们的尾巴短而不可收缩而被归类在一起，但该组的成员之间存在巨大的多样性。在足噬菌体中，N4 样 Schitoviridae 家族在结构上研究最少，并且与 T7 和 P22 等特征明确的足噬菌体有很大不同。在这项工作中，我们通过冷冻电子显微镜、遗传学和生物化学分离并完全表征了 Schitoviridae 家族的两个成员。我们描述了 Moo19 和 B2 的衣壳特征，包括装饰蛋白。此外，我们已经完全模拟了两种噬菌体的尾部机制，并鉴定了具有酯酶活性的蛋白质。宿主的基因敲除揭示了宿主附着的特异性因素，包括对脂多糖上 O 抗原的关键修饰。Moo19 和 B2 都是 Schitoviridae 成员，但基因组和结构的一些明显差异将它们分为不同的分支。