Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 102, Issue 45, Pages 16128-16132Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.0506586102
Keywords
photocycle; radical mechanism; ultrafast kinetics
Categories
Funding
- NIGMS NIH HHS [R01 GM031082, GM31082, R37 GM031082] Funding Source: Medline
Ask authors/readers for more resources
Photolyase uses light energy to split UV-induced cyclobutane dimers in damaged DNA, but its molecular mechanism has never been directly revealed. Here, we report the direct mapping of catalytic processes through femtosecond synchronization of the enzymatic dynamics with the repair function. We observed direct electron transfer from the excited flavin cofactor to the dimer in 170 ps and back electron transfer from the repaired thymines in 560 ps. Both reactions are strongly modulated by active-site solvation to achieve maximum repair efficiency. These results show that the photocycle of DNA repair by photolyase is through a radical mechanism and completed on subnanosecond time scale at the dynamic active site, with no net change in the redox state of the flavin cofactor.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available