Adenine glycosylase active on G:A and C:A mispairs, as well as processing 7,8-dihydro-8-oxoguanine:A (8-oxoG) mismatches. Minor activity against 8-oxoG:G and 8-oxo:T mismatches is also seen. Bind dsDNA oligonucleotides containing the above mismatches. Hydrolyzes free adenine bases from 7,8-dihydro-8-oxoguanine:adenine mismatched double-stranded DNA, leaving an apurinic site. Binds 1 [4Fe-4S] cluster. The cluster does not appear to play a role in catalysis, but is probably involved in the proper positioning of the enzyme along the DNA strand. Belongs to the Nth/MutY family.