MGMT recognizes and binds DNA containing 6-O-methylguanine in a manner consistent with a helix-loop-wing DNA binding model, where guanine is flipped out in order to bring the methylated oxygen atom close to MGMT active site (Vora et al. 1998, Daniels et al. 2000). Weakened or distorted base-pairs formed by 6-O-methylguanine probably aid in the substrate recognition by MGMT (Duguid et al. 2005). MGMT is stabilized by Zn2+ binding (Daniels et al. 2000).