Infrared and ultraviolet spectroscopic characterization of a key intermediate during DNA repair by (6-4) photolyase.

ABSTRACT: Ultraviolet (UV) irradiation of DNA causes genotoxic photolesions, such as carcinogenic pyrimidine(6-4)pyrimidone photoproducts ((6-4)PPs). In many organisms, (6-4)PPs are repaired by (6-4) photolyases, which contain a flavin chromophore and use blue light energy to initiate the catalytic reaction. Although (6-4)PP repair has been shown to require the input of two successive photons, details of the mechanism remain elusive. Here, we applied recently developed time-resolved UV and infrared (IR) spectroscopic techniques to capture a key intermediate that awaits the second photon in the repair reaction of Xenopus laevis (6-4) photolyase. The results indicate that the intermediate is formed within 500 μs following the initial absorption of a photon and contains a four-membered oxetane ring tha

SUBMITTER: Yamada D 

PROVIDER: S-EPMC12397333 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature