E. coli Fpg protein
Fpg enzyme participates in the base-excision (BER) pathway of DNA repair enzymes and acts both as a N-glycosylase and an AP-lyase. The N-glycosylase activity cleaves damaged purines from dsDNA, which creates an apurinic/apyrimidinic (AP site). The AP-lyase activity cleaves both the 3′ and 5′ phosphodiester bonds at the AP site, leaving a single-base gap in the DNA and 3′ and 5′ phosphate termini. Bases recognized and removed by Fpg include 7, 8-dihydro-8- oxoguanine (8-oxoguanine), 8-oxoadenine, fapy-guanine, methy-fapy-guanine, fapy-adenine, aflatoxin B1-fapyguanine, 5-hydroxy-cytosine and 5-hydroxy-uracil.
Fpg protein is also known as Formamidopyrimidine DNA glycosylase, Mut M, FAPY DNA Glycosylase, or 8-oxoguanine DNA glycosylase.