Nagy Toni A, Gersabeck Gina W, Conte Amy N, Whiteley Aaron T
Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA.
bioRxiv. 2025 Jul 2:2025.07.02.662641. doi: 10.1101/2025.07.02.662641.
Bacteria have evolved sophisticated antiphage systems that halt phage replication upon detecting specific phage triggers. Identifying phage triggers is crucial to our understanding of immune signaling, however, they are challenging to predict. Here we used an expansive plasmid library that expressed 400 phage protein-coding genes from 6 different phages to identify novel triggers of known and undiscovered antiphage systems. We transformed our library into 72 diverse strains of . Each strain natively harbors a different suite of antiphage systems whose activation typically inhibits growth. By tracking plasmids that were selectively depleted, we identified over 100 candidate phage trigger- pairs. Two phage trigger proteins were investigated in detail, revealing a novel antiphage system that detects multiple phage tail fiber proteins and identifying major capsid protein as the activating ligand of the antiphage system Avs8. These experiments provide a unique dataset for continued definition of the molecular details of the bacterial immune system.
细菌已经进化出复杂的抗噬菌体系统，该系统在检测到特定的噬菌体触发因素时会阻止噬菌体复制。识别噬菌体触发因素对于我们理解免疫信号传导至关重要，然而，它们很难预测。在这里，我们使用了一个庞大的质粒文库，该文库表达来自6种不同噬菌体的400个噬菌体蛋白质编码基因，以识别已知和未发现的抗噬菌体系统的新触发因素。我们将文库转化到72种不同的菌株中。每种菌株天然携带不同的抗噬菌体系统组合，其激活通常会抑制生长。通过追踪被选择性消耗的质粒，我们鉴定出了100多个候选噬菌体触发因素对。对两种噬菌体触发蛋白进行了详细研究，揭示了一种检测多种噬菌体尾纤维蛋白的新型抗噬菌体系统，并确定主要衣壳蛋白为抗噬菌体系统Avs8的激活配体。这些实验为继续确定细菌免疫系统的分子细节提供了一个独特的数据集。
