Scholarlink

<p>Bacteriophages must overcome diverse bacterial immune systems, yet the molecular principles enabling such escape remain poorly understood. Here, we show that the phage homing endonuclease SegB facilitates immune evasion by promoting the segmental amplification of anti-defense loci. The antiphage defense Septu inhibits phage T6 replication by cleaving the variable loop of tRNA<sup>Tyr</sup>. We show that SegB enables immune evasion by amplifying a genomic segment that contains the full-length <i>tRNA</i><sup><i>Tyr</i></sup> gene. This repeat expansion increases tRNA<sup>Tyr</sup> expression, allowing the phage to overcome Septu immunity. SegB also mediates in trans amplification of distinct anti-defense genes that counteract OLD and toxin-antitoxin ToxIN defense systems. Collectively, our findings demonstrate that SegB-mediated segmental amplification represents a versatile mechanism by which phages rapidly adapt to and circumvent diverse bacterial antiphage defenses.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Phage homing endonuclease amplifies anti-defense genes to evade bacterial immunity

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年4月20日

查看全文
  • Kotaro Chihara,
  • Aa Haeruman Azam,
  • Artyom A. Egorov,
  • Ilya Terenin,
  • Masanori Hashino,
  • Koichi Watashi,
  • Kazuhiro Horiba,
  • Vasili Hauryliuk,
  • Kotaro Kiga

摘要

Bacteriophages must overcome diverse bacterial immune systems, yet the molecular principles enabling such escape remain poorly understood. Here, we show that the phage homing endonuclease SegB facilitates immune evasion by promoting the segmental amplification of anti-defense loci. The antiphage defense Septu inhibits phage T6 replication by cleaving the variable loop of tRNATyr. We show that SegB enables immune evasion by amplifying a genomic segment that contains the full-length tRNATyr gene. This repeat expansion increases tRNATyr expression, allowing the phage to overcome Septu immunity. SegB also mediates in trans amplification of distinct anti-defense genes that counteract OLD and toxin-antitoxin ToxIN defense systems. Collectively, our findings demonstrate that SegB-mediated segmental amplification represents a versatile mechanism by which phages rapidly adapt to and circumvent diverse bacterial antiphage defenses.