Involved in the cellular defense against the biological effects of O6-methylguanine (O6-MeG) in DNA. Repairs alkylated guanine in DNA by stoichiometrically transferring the alkyl group at the O-6 position to a cysteine residue in the enzyme. This is a suicide reaction: the enzyme is irreversibly inactivated.
[1] "Isolation and structural characterization of a cDNA clone encoding the human DNA repair protein for O6-alkylguanine."Tano K., Shiota S., Collier J., Foote R.S., Mitra S.Proc. Natl. Acad. Sci. U.S.A. 87:686-690(1990) [2] "cDNA clo