Induction of the SOS function sfiA in E. coli by systems which generate triplet ketones.

Generation of triplet ketones, either chemically through thermal decomposition of 3-hydroxymethyl-3,4,4-trimethyl-1,2-dioxetane and 3-[N-(pyridino)carbamoyl]methyl-3,4,4-trimethyl-1,2-dioxetane++ + or enzymatically via the aerobic oxidation of isobutyraldehyde trimethylsilyl enol ether catalyzed by horse-radish peroxidase, triggers the SOS function sfiA in E. coli. Although the observed effects are relatively weak and the triplet ketone scavenger tryptophan was ineffective in this system, our results provide evidence for the involvement of triplet ketones in this type of DNA damage. Possible mechanisms are discussed.