Repair of the (6-4) photoproduct by DNA photolyase requires two photons

Angew Chem Int Ed Engl. 2013 Jul 15;52(29):7432-6. doi: 10.1002/anie.201301567. Epub 2013 Jun 12.


It takes two (photons) to tango: Single-turnover flash experiments showed that the flavoenzyme (6-4) photolyase uses a successive two-photon mechanism to repair the UV-induced T(6-4)T lesion in DNA (see picture). The intermediate (X) formed by the first photoreaction is likely to be the oxetane-bridged dimer T(ox)T. The enzyme could stabilize the normally short-lived T(ox)T, allowing repair to be completed by the second photoreaction.

Keywords: (6-4) photoproducts; DNA damage; DNA repair; enzyme catalysis; photolyases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • DNA Damage / radiation effects
  • DNA Repair*
  • Deoxyribodipyrimidine Photo-Lyase / metabolism*
  • Photons
  • Pyrimidine Dimers / chemistry
  • Ultraviolet Rays
  • Xenopus laevis / metabolism


  • Pyrimidine Dimers
  • Deoxyribodipyrimidine Photo-Lyase