Molecular Mechanisms of Ultraviolet Radiation-Induced DNA Damage and Repair

Figure 9

Photoreactivation: incidence of ultraviolet radiation (UVR) results in pyrimidine lesion (thymine dimer), which is recognized by a photoreactivating enzyme “photolyase”. The light energy (>380 nm) is trapped by the antenna molecules of photolyase (such as MTHF/8-HDF/FMN) and transfers them to catalytic cofactor FADH⁻ which becomes excited and transfers energy to the pyrimidine dimer in the form of e⁻, splitting the CPD into two monomeric unit, and then electron is transferred back to the flavin molecule.