( A ) DNA-damage induced upregulation of RecA is impaired in Msm Δ pafBC . Msm wild type, the pafBC deletion mutant and a complemented strain were grown in 7H9 to an OD 600 between 0.8 to 1.0 at 37 °C. Cultures were split, supplemented with mitomycin C (80 ng/ml) as indicated and were incubated for another 4 h. RecA levels of cell-free lysates were analysed by an anti-RecA immunoblot. Full-length blots are shown in Supplementary Fig. S8 . To control for equal loading, an anti-RpoB immunoblot was performed. ( B ) Levels of PafBC do not alter under DNA damaging growth conditions. Samples of Msm wild type cells were prepared as described in ( A ) and were analysed by an anti-PafBC immunoblot.