Fig. 2: Phage tail assembly chaperone triggers pSlfn5-mediated phage defence.
a–c, The growth kinetics of E. coli K-12 MG1655 cells without the defence (a), with RorSlfn5 (b) or the nuclease-dead RorSlfn5E15A, D20A mutant (c) following T5 bacteriophage infection at various MOIs. Each line shows a biological replicate (n = 4). d,e, The ECOI (d) and average burst size (e) of T5 phage in RorSlfn5-expressing E. coli MG1655 cells compared with the EV control. The data are shown as the mean of three biological replicates ± s.d. A two-sided Welch’s t-test was used to compare the experimental and control groups. f, An experimental approach to identify viral triggers of RorSlfn5. g, Top: plaque assays with RorSlfn5-escaping T5 phages (esc1–esc4). Bottom: mapping of mutations in T5 phage escapers compared with a reference phage genome. The vertical lines indicate mutations found in the laboratory T5 phage stock compared with the reference NCBI sequence. Vertical orange box highlights mutations present in escaper phages but not in the original viral stock. h, A toxicity assay in MG1655 cells co-transformed with the RorSlfn5 plasmid and a plasmid for arabinose-inducible expression of T5.142 protein. Tenfold serial dilutions were spotted on agar plates with 0.2% glucose (−) or 0.2% arabinose (ara) (+). pBAD-GFP was used as a control for arabinose-dependent induction.
