Mechanism of Action of Exonuclease III from Escherichia Coli

Reactive oxygen species such as hydrogen peroxide, superoxide radical, and hydroxyl radical are formed during aerobic respiration (1). These reactive oxygen species can react with vital cell components such as the cell membrane, protein, as well as DNA, potentially leading to mutagenesis and cell death (1). In Escherichiacoli. repair endonucleases. such as exonuclease III (2, 4) and endonuclease IV (3) appear to be involved in the repair of oxidative damages in DNA. Further, endonuclease III was shown to recognize oxidative base damages (4).