Direct reversal of DNA damage is one repair mechanism used to restore damaged DNA. Although this is the most energy efficient method, few types of damaged DNA are repaired in this way. The formation of pyrimidine dimmers, the major type of damage caused by UV light, distorts the double helix and blocks transcription or replication past the damaged site. The process of photoreactivation causes direct reversal of the dimerized reaction, thus the original pyrimidine bases are restored. Direct reversal of O6 adducts caused by chemotherapy agents is accomplished in mammalian cells by the protein O6-methylguanine DNA methyltransferase (MGMT). Some tumors overexpress MGMT and are resistance to alkylator therapy.
All Direct Reversal of DNA Damage Antibodies, Lysates, Proteins, and RNAi