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. Author manuscript; available in PMC: 2013 Jul 14.
Published in final edited form as: Mol Cell. 2012 May 24;46(5):561–572. doi: 10.1016/j.molcel.2012.04.027

Figure 5. Influence of RecA, ClpP and the SOS response on DNA fragmentation, hydroxyl radical production and phosphatidylserine exposure.

Figure 5

(A) % change in DNA fragmentation detectable by TUNEL (mean ± SD at 4.5 hours post-treatment) exhibited by ΔrecA, ΔclpP, ΔclpPΔrecA and ΔsulA cells, recA56 cells and wildtype E. coli expressing the LexA3(Ind-) mutant repressor protein compared to similarly treated wildtype cells (125ng/mL norfloxacin). (B) Correlation between norfloxacin-induced DNA fragmentation and hydroxyl radical production. Data reflect % change in DNA fragmentation detectable by TUNEL and hydroxyl radical production detectable by the fluorescent dye, HPF (mean ± SD at 4.5 hours post-treatment), compared to similarly treated wildtype cells (125ng/mL norfloxacin). (C) % change in PS exposure detectable by annexin V (mean ± SD at 4.5 hours post-treatments) exhibited by above strains compared to similarly treated wildtype cells (125ng/mL norfloxacin).