katE Complementation on katG Background has Negative or No Effect on the Ability to Protect against UV-A-Mediated Killing in Escherichia coli

In a previous study, katE complementation of an E. coli katG mutant suggested that an overexpression of katE was the cause for low survival after UV-A treatment. In this study, when JW strains lacked either katE or katG were complemented with katE, this overexpression was not observed. Rather, there were no differences between the two complemented JW strains after UV-A treatment. A possible theory on these phenomena suggests interference with other essential antioxidant genes or antioxidant inducer genes, such as ahpC, oxyR and rpoS, that need to be functional for katE and katG to be properly transcribed.