In direct repair, specific enzymes recognize and revert the altered DNA back to its original state. One of the most well-known enzymes involved in this process is O6-methylguanine-DNA methyltransferase (MGMT), which removes alkyl groups from the O6 position of guanine, a common site of damage caused by alkylating agents. Another example is photolyase, which repairs UV-induced cyclobutane pyrimidine dimers.
