aflatoxin-G

FULL NAME: aflatoxin-bound 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


DNA DAMAGE EFFECT(S) (MINOR):
AP-site
cytotoxic


PATHWAYS:
Fanconi anemia (FA) pathway
nucleotide excision repair (NER)
prokaryotic (SOS) response


DNA repair protein(s) related to damage:
UvrC
UvrB
ERCC5 (XPG)
ERCC4 (XPF)


Last modification date: Oct. 10, 2011