title: Repair of the (6-4) photoproduct by DNA photolyase requires two photons.
abstract: 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.
authors.affiliation: Division of Chemistry, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan. yamamoto@chem.es.osaka-u.ac.jp
authors.forename: Junpei
authors.initials: J
authors.lastname: Yamamoto
authors.forename: Ryan
authors.initials: R
authors.lastname: Martin
authors.forename: Shigenori
authors.initials: S
authors.lastname: Iwai
authors.forename: Pascal
authors.initials: P
authors.lastname: Plaza
authors.forename: Klaus
authors.initials: K
authors.lastname: Brettel
mesh_terms: D000818:Animals; D004249:DNA Damage / Q000528:radiation effects; D004260:DNA Repair; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000378:metabolism*; D017785:Photons; D011740:Pyrimidine Dimers / Q000737:chemistry; D014466:Ultraviolet Rays; D014982:Xenopus laevis / Q000378:metabolism
chemical_list: D011740:Pyrimidine Dimers; D004255:Deoxyribodipyrimidine Photo-Lyase
keywords: (6-4) photoproducts; DNA damage; DNA repair; enzyme catalysis; photolyases