1. Repair of DNA Dewar Photoproduct to (6-4) Photoproduct in (6-4) Photolyase.
- Author
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Ai, Yue-Jie, Liao, Rong-Zhen, Chen, Shi-Lu, Hua, Wei-Jie, Fang, Wei-Hai, and Luo, Yi
- Subjects
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DNA repair , *PHOTOCHEMISTRY , *DEOXYRIBODIPYRIMIDINE photolyase , *ISOMERS , *COMPARATIVE studies , *DENSITY functional theory , *ISOMERIZATION - Abstract
Dewar photoproduct (Dewar PP) is the valence isomer of (6-4) photoproduct ((6-4)PP) in photodamaged DNA. Compared to the extensive studied CPD photoproducts, the underlying repair mechanisms for the (6-4)PP, and especially for the Dewar PP, are not well-established to date. In this paper, the repair mechanism of DNA Dewar photoproduct T(dew)C in (6-4) photolyase was elucidated using hybrid density functional theory. Our results showed that, during the repair process, the T(dew)C has to isomerize to T(6-4)C photolesion first via direct C6â²âN3â² bond cleavage facilitated by electron injection. This isomerization mechanism is energetically much more efficient than other possible rearrangement pathways. The calculations provide a theoretical interpretation to recent experimental observations. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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