Host RNA polymerase inhibitors encoded by ϕKMV-like phages of pseudomonas

► We report host RNA polymerase inhibitors encoded by Pseudomonas phiKMV phages. ► These inhibitors substitute for phage T7 gp2 host RNA polymerase inhibitor in vivo. ► PhiKMV phages inhibitors have the same RNA polymerase binding site as T7 gp2. ► Some PhiKMV phage inhibitors activity is cryptic.