Three mutations in pGB-ruvAz60 are necessary and sufficient to inactivate RFR.

aSurvival of ruvA100 mutant (JJC2971) containing different plasmids after 40 Joules/m2 UV irradiation.bPlating of dnaEts recF recB ruvA100 (JJC3110) containing different plasmids at 37��C. (+) 50 to 100% plating efficiency, (?) less than 0.01% plating efficiency, (+/?) or (+/?) 0.01 to 10% plating efficiency.cPercentage of DNA entering pulse field gels in dnaEts recF recB ruvA100 cells containing different plasmids (42��C). Results are the average of 2 or 3 independent experiments except pGB-ruvAz3 (H29R K129E F140S) which was tested 5 times, pF1m-F3m (H29R E40G K129E F140S) 7 times, and pF4m (S177G D184N) which was tested once.dThis triple mutant was called ruvAz3 and was used for further analysis.eThis mutant was fortuitously obtained during the construction of pF1m1�CF3m1 by site directed mutagenesis.