Introns containing homing endonucleases are widespread in nature and have long been assumed to be selfish elements that provide no benefit to the host organism. These genetic elements are common in viruses, but whether they confer a selective advantage is unclear. In this work, we studied intron-encoded homing endonuclease gp210 in bacteriophage ΦPA3 and found that it contributes to viral competition by interfering with the replication of a coinfecting phage, ΦKZ. We show that gp210 targets a specific sequence in ΦKZ, which prevents the assembly of progeny viruses. This work demonstrates how a homing endonuclease can be deployed in interference competition among viruses and provide a relative fitness advantage. Given the ubiquity of homing endonucleases, this selective advantage likely has widespread evolutionary implications in diverse plasmid and viral competition as well as virus-host interactions.

中文翻译：

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内含子核酸内切酶促进共感染病毒之间的干扰竞争


含有归巢核酸内切酶的内含子在自然界中广泛存在，长期以来一直被认为是对宿主生物体没有任何好处的自私元素。这些遗传元件在病毒中很常见，但它们是否具有选择优势尚不清楚。在这项工作中，我们研究了噬菌体 ΦPA3 中内含子编码的归巢核酸内切酶 gp210，发现它通过干扰共感染噬菌体 ΦKZ 的复制来促进病毒竞争。我们发现 gp210 以 ΦKZ 中的特定序列为目标，从而阻止子代病毒的组装。这项工作展示了如何在病毒之间的干扰竞争中部署归巢核酸内切酶并提供相对的适应性优势。鉴于归巢核酸内切酶的普遍存在，这种选择性优势可能在不同的质粒和病毒竞争以及病毒与宿主的相互作用中具有广泛的进化意义。