Description
Fpg protein, a key enzyme in the DNA base excision repair pathway (BER), catalyses the excision of a broad spectrum of modified purines such as formamidopyrimidine (Fapy) and 8-oxoguanine (8-oxo-G). Fpg possess both DNA glycosylase activity that removes the mutated base and AP-lyase activity that releases ribose, leaving both 5'-and 3'-phosphorylated ends in the DNA. Several analytical methods based on Fpg protein activity in vitro were developed for detection and quantitation of oxidative damage to DNA mainly for FapyA, FapyG and 8-oxo-G. The fpg gene was cloned by Boiteux, et al. Fpg protein possess a zinc finger motif at its C-terminus (one zinc atom per molecule). This region is responsible for the DNA binding and AP-lyase activity. In addition, its N-terminal proline was found to act as a nucleophile to produce a Schiff base intermediate, which is essential for enzyme action