Figure 2.
DNA/RNA lesions that AlkB can repair. Exogenous or endogenous methylating agents can introduce various DNA methylations as shown, which are known substrates of AlkB. Exocyclic DNA adducts of 1,N6-ethenoadenine (εA) and 3,N4-ethenocytosine (εC) are generated by exposure to electrophilic vinyl chloride (VC) metabolites, chloroethylene oxide (CEO), or chloroacetaldehyde (CAA) introduced exogenously or endogenously from lipid peroxidation.54,55 1,N6-Ethanoadenine (EA) is produced by the reaction of adenine with the anticancer agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU).57,58 3,N4-α-Hydroxypropanocytosine is produced by lipid peroxidation.59