Exonuclease III is an enzyme that specifically targets double-stranded DNA (dsDNA) and is involved in DNA repair processes. It possesses both endonuclease activity, with apurinic/apyrimidinic (AP) endonuclease function, and 3'→5' exonuclease activity. Exonuclease III can cleave single-stranded DNA at the 5' phosphodiester bonds from the 3' end to the 5' end.