Eliminating the type I restriction endonuclease from Pseudomonas aeruginosa PAO1 for optimized phage isolation

This is the authors' abstract. We don't add key points for this paper.

Graphical Abstract [A] The type I R-M system is comprised of a methyltransferase (one HsdS and two HsdM subunits) and a restriction endonuclease (one HsdS, two HsdM and two HsdR subunits). [B] In wildtype PAO1, the restriction endonuclease destroys phage DNA with unmethylated restriction sites, while the methyltransferase methylates host recognition sites to protect self-DNA from restriction. [C] ∆hsdR is optimised for phage isolation and propagation as it lacks the restriction endonuclease, preventing phage DNA cleavage and facilitating efficient phage proliferation. The methyltransferase remains active, so both host and phage DNA are methylated, protecting phage progeny from R-M systems in future hosts. (Created in BioRender.com)