A diverse set of prophage-mediated mechanisms protecting bacterial hosts from infection has been recently uncovered within cluster N mycobacteriophages isolated on the host, Mycobacterium smegmatis mc²155. In that context, we unveil a novel defense mechanism in cluster N prophage Butters. By using bioinformatics analyses, phage plating efficiency experiments, microscopy, and immunoprecipitation assays, we show that Butters genes located in the central region of the genome play a key role in the defense against heterotypic viral attack. Our study suggests that a two-component system, articulated by interactions between protein products of genes 30 and 31, confers defense against heterotypic phage infection by PurpleHaze (cluster A/subcluster A3) or Alma (cluster A/subcluster A9) but is insufficient to confer defense against attack by the heterotypic phage Island3 (cluster I/subcluster I1). Therefore, based on heterotypic phage plating efficiencies on the Butters lysogen, additional prophage genes required for defense are implicated and further show specificity of prophage-encoded defense systems.

中文翻译：

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分枝杆菌噬菌体黄油编码蛋白有助于宿主防御病毒攻击


最近在宿主耻垢分枝杆菌mc ² 155 上分离的 N 簇分枝杆菌噬菌体中发现了一组不同的原噬菌体介导的保护细菌宿主免受感染的机制。在这种背景下，我们揭示了 N 簇原噬菌体 Butters 中的一种新型防御机制。通过使用生物信息学分析、噬菌体铺板效率实验、显微镜检查和免疫沉淀测定，我们表明位于基因组中心区域的巴特斯基因在防御异型病毒攻击中发挥着关键作用。我们的研究表明，由基因30和31的蛋白质产物之间的相互作用连接起来的双组分系统，可以防御 PurpleHaze（簇 A/亚簇 A3）或 Alma（簇 A/亚簇 A9）的异型噬菌体感染，但不足以防御异型噬菌体感染。赋予防御异型噬菌体 Island3（簇 I/亚簇 I1）攻击的能力。因此，基于巴特斯溶原上的异型噬菌体铺板效率，涉及防御所需的额外原噬菌体基因，并进一步显示了原噬菌体编码的防御系统的特异性。