OGG1

Harvard Gazette: Repairing DNA damage: "As described in the April 1 issue of the scientific journal Nature, OGG1 moves up and down long segments of DNA looking for aberrations in a base known as guanine. If everything is normal, the enzyme moves on. But if it detects an abnormal mutation, or change, it removes the damaged part. Other enzymes then follow up and install a replacement. "