Darracq Baptiste, Littner Eloi, Brunie Manon, Bos Julia, Kaminski Pierre Alexandre, Depardieu Florence, Slesak Weronika, Debatisse Kevin, Touchon Marie, Bernheim Aude, Bikard David, Le Roux Frédérique, Mazel Didier, Rocha Eduardo P C, Loot Céline
Institut Pasteur, Université Paris Cité, Unité Plasticité du Génome Bactérien, CNRS UMR3525, Paris, France.
Collège Doctoral, Sorbonne Université, Paris, France.
Science. 2025 May 8;388(6747):eads0768. doi: 10.1126/science.ads0768.
Integrons are genetic systems that drive bacterial adaptation by acquiring, expressing, and shuffling gene cassettes. While mobile integrons are well known for spreading antibiotic resistance genes, the functions of the hundreds of cassettes carried by sedentary integrons remain largely unexplored. We show that many of these cassettes encode small variants of known antiphage systems that favor their inclusion in the integron. We also demonstrate that nearly 10% of the integron cassettes in the pandemic strain encode novel antiphage functions. Most of these novel systems have little or no similarity to previously known ones, with several providing defense through cell lysis or growth arrest. Our work highlights the stabilization and prevalence of small antiphage systems within integrons, making them an untapped biobank of defense mechanisms.
整合子是通过获取、表达和改组基因盒来推动细菌适应的遗传系统。虽然可移动整合子因传播抗生素抗性基因而广为人知，但固定整合子携带的数百个基因盒的功能在很大程度上仍未得到探索。我们发现，这些基因盒中的许多编码已知抗噬菌体系统的小变体，这有利于它们被整合到整合子中。我们还证明，在大流行菌株中，近10%的整合子基因盒编码新的抗噬菌体功能。这些新系统中的大多数与先前已知的系统几乎没有相似之处，有几种通过细胞裂解或生长停滞提供防御。我们的工作突出了整合子内小型抗噬菌体系统的稳定性和普遍性，使其成为一个尚未开发的防御机制生物库。
