PHOTOCHEMISTRY, PHOTOPHYSICS, AND MECHANISM OF PYRIMIDINE DIMER REPAIR BY DNA PHOTOLYASE
- 1 May 1993
- journal article
- review article
- Published by Wiley in Photochemistry and Photobiology
- Vol. 57 (5) , 895-904
- https://doi.org/10.1111/j.1751-1097.1993.tb09232.x
Abstract
— DNA photolyases photorepair pyrimidine dimers (PyroPyr) in DNA as well as RNA and thus reverse the harmful effects of UV‐A (320–400 nm) and UV‐B (280–320 nm) radiations. Photolyases from various organisms have been found to contain two noncovalently bound cofactors; one is a fully reduced flavin adenine dinucleotide (FADH‐) and the other, commonly known as second chromophore, is either methenyltetrahydrofolate (MTHF) or 8‐hydroxydeazaflavin (8‐HDF). The second chromophore in photolyase is a light‐harvesting molecule that absorbs mostly in the near‐UV and visible wavelengths (300–500 nm) with its high extinction coefficient. The second chromophore then transfers its excitation energy to the FADH‐. Subsequently, the photoexcited FADH‐ transfers an electron to the Pyr<>Pyr generating a dimer radical anion (Pyr<>Pyr‐) and a neutral flavin radical (FADH‐). The Pyr<>Pyr‐ is very unstable and undergoes spontaneous splitting followed by a back electron transfer to the FADH‐. In addition to the main catalytic cofactor FADH‐, a Trp (Trp277 in Escherichia coli) in apophotolyase, independent of other chromophores, also functions as a sensitizer to repair Pyr <> Pyr by direct electron transfer.Keywords
This publication has 64 references indexed in Scilit:
- Energy transfer (deazaflavin .fwdarw. FADH2) and electron transfer (FADH2 .fwdarw. T.ltbbrac..rtbbrac.T) kinetics in Anacystis nidulans photolyaseBiochemistry, 1992
- Mechanistic studies on DNA photolyase. 5. Secondary deuterium isotope effects on the cleavage of the uracil photodimer radical cation and anionJournal of the American Chemical Society, 1992
- Effect of base, pentose, and phosphodiester backbone structures on binding and repair of pyrimidine dimers by Escherichia coli DNA photolyaseBiochemistry, 1991
- Effect of flavin structure and redox state on catalysis by and flavin-pterin energy transfer in Escherichia coli DNA photolyaseBiochemistry, 1991
- DNA photolyases: Physical properties, action mechanism, and roles in dark repairMutation Research/DNA Repair, 1990
- Activation barriers in photosensitized pyrimidine dimer splittingJournal of Physical Organic Chemistry, 1990
- Absolute action spectrum of E-FADH2 and E-FADH2-MTHF forms of Escherichia coli DNA photolyaseBiochemistry, 1990
- Active site of Escherichia coli DNA photolyase: mutations at Trp277 alter the selectivity of the enzyme without affecting the quantum yield of photorepairBiochemistry, 1990
- Mechanistic studies on DNA photolyase. 1. Secondary deuterium isotope effects on the cleavage of 2'-deoxyuridine dinucleotide photodimersJournal of the American Chemical Society, 1989
- Escherichia coli DNA photolyase is a flavoproteinJournal of Molecular Biology, 1984