GO:0052822

Catalysis of the reaction: DNA containing 3-methylguanine + H2O = DNA with abasic site + 3-methylguanine. This reaction is the hydrolysis of DNA by cleavage of the N-C1' glycosidic bond between the damaged DNA 3-methylguanine and the deoxyribose sugar to remove the 3-methylguanine, leaving an abasic site. [EC:3.2.2.21, GOC:elh, PMID:10872450, PMID:9224623]