 Fpg has a preference for oxidised purines, excising oxidised purine bases such as 7,8-dihydro-8-oxoguanine (8-oxoG).Its AP (apurinic/apyrimidinic) lyase activity introduces nicks in the DNA strand, cleaving the DNA backbone by beta-delta elimination to generate a single-strand break at the site of the removed base with both 3'- and 5'-phosphates.Fpg is a monomer composed of 2 domains connected by a flexible hinge.