aflatoxin-FapyG

FULL NAME: aflatoxin-bound imidazole ring-opened guanine


DESCRIPTION:
Cytochrome P-450 isoenzymes metabolize aflatoxin B1 to the 8,9-epoxide, which can react with DNA. While a number of products are formed, the initial major adduct from reaction of the aflatoxin B1 epoxide with the N7 position of guanine in DNA. This adduct has a destabilized glycosyl bond and can depurinate to form AP site. Alternatively, the primary adduct can undergo opening of the imidazole ring, giving rise to the chemically and biologically stable formamidopyrimidine adduct, aflatoxin B1-Fapy.

DAMAGE TYPE: bulky adduct


DNA DAMAGE SOURCE(S) (MAIN):
aflatoxin


DNA DAMAGE EFFECT(S) (MAIN):
carcinogen
DNA backbone distortion
stalled replication fork


PATHWAYS:
Fanconi anemia (FA) pathway
base excision repair (BER)
nucleotide excision repair (NER)


DNA repair protein(s) related to damage:
Fpg (MutM)
ERCC5 (XPG)
ERCC4 (XPF)


Last modification date: Oct. 10, 2011