(6-4) photolyases repair carcinogenic pyrimidine(6-4)pyrimidone photoproducts, a process that requires two successive photons but whose mechanistic details remain elusive. Here, the authors use time-resolved ultraviolet and infrared spectroscopy to identify a long-lived oxetane intermediate formed within 500 µs after absorption of the first photon by Xenopus laevis (6-4) photolyase.
- Daichi Yamada
- Ai Kadono
- Minoru Kubo
