Expression of RecA, RumA and RumA’ in wild-type recA+
lexA+ cells after exposure to the SOS-inducing antibiotic, Ciprofloxacin.
Western blot analysis was performed on whole-cell protein extracts from RW520 (recA+
lexA+) harboring pRLH421 derivatives (pJM1355, pJM1356, pJM1359 or pJM1360), with various croSR391 or setRR391 wild-type, or deletion combinations as indicated. To induce the SOS response, cells were treated with 30 ng ml−1 Ciprofloxacin for various times, as indicated in the figure. Levels of RecA and RumA/ RumA’ were detected using affinity purified polyclonal rabbit antibodies to RecA and RumA proteins. The number reported for the level of RumA or RumA’ are relative to a cross-reacting band in the same track.