Erez Yirmiya, Azita Leavitt, Allen Lu, Adelyn E Ragucci, Carmel Avraham, Ilya Osterman, Jeremy Garb, Sadie P Antine, Sarah E Mooney, Samuel J Hobbs, Philip J Kranzusch, Gil Amitai, Rotem Sorek
It was recently shown that bacteria employ, apart from CRISPR-Cas and restriction systems, a considerable diversity of phage resistance systems1-4 , but it is largely unknown how phages cope with this multilayered bacterial immunity. Here, we analyzed groups of closely related Bacillus phages that showed differential sensitivity to bacterial defense systems, and discovered four distinct families of anti-defense proteins that inhibit the Gabija, Thoeris, and Hachiman systems. We show that these proteins Gad1, Gad2, Tad2, and Had1 efficiently cancel the defensive activity when co-expressed with the respective defense system or introduced into phage genomes...
November 22, 2023: Nature