Characterization of (6-4) photoproduct DNA photolyase.

Kim, Sang‐Tae; Malhotra, Khushbeer; Smith, Colin A.; Taylor, John Stephen; Sancar, Aziz

doi:10.1016/s0021-9258(17)37228-9

Cited by 146 publications

(80 citation statements)

References 26 publications

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“…A chemical mechanism was proposed that involves an oxetane intermediate and an electron transfer reaction for repair by 6-4 photolyase. 58 In contrast, two articles published shortly after this report showed that the apoproteins of the blue-light photoreceptors (cryptochrome) of Arabidopsis thaliana 69 and mustard (Sinapis alba) 70 are very similar to the microbial CPD photolyase and are structurally related, although the photoreceptors function in signal transduction and not in DNA repair. The purified photoreceptors contained the folate and flavin chromophores characteristic of the folate class of photolyases.…”

Section: Photoreactivationmentioning

confidence: 94%

“…They demonstrated that the 6-4 photolyase restores biological activity to UV-irradiated DNA. Kim et al 58 obtained direct evidence that the 6-4 photolyase converted this photoproduct to unmodified bases. A chemical mechanism was proposed that involves an oxetane intermediate and an electron transfer reaction for repair by 6-4 photolyase.…”

Section: Photoreactivationmentioning

confidence: 99%

See 1 more Smart Citation

UV-induced DNA damage and repair: a review

Sinha

Häder

2002

Photochem Photobiol Sci

1,632

1,169

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Increases in ultraviolet radiation at the Earth's surface due to the depletion of the stratospheric ozone layer have recently fuelled interest in the mechanisms of various effects it might have on organisms. DNA is certainly one of the key targets for UV-induced damage in a variety of organisms ranging from bacteria to humans. UV radiation induces two of the most abundant mutagenic and cytotoxic DNA lesions such as cyclobutane-pyrimidine dimers (CPDs) and 6-4 photoproducts (6-4PPs) and their Dewar valence Isomers. However, cells have developed a number of repair or tolerance mechanism to counteract the DNA damage caused by UV or any other stressors. Photoreactivation with the help of the enzyme photolyase is one of the most important and frequently occurring repair mechanisms in a variety of organisms. Excision repair, which can be distinguished into base excision repair (BER) and nucleotide excision repair (NER), also plays an important role in DNA repair in several organisms with the help of a number of glycosylases and polymerases, respectively. In addition, mechanisms such as mutagenic repair or dimer bypass, recombinational repair, cell-cycle checkpoints, apoptosis and certain alternative repair pathways are also operative in various organisms. This review deals with UV-induced DNA damage and the associated repair mechanisms as well as methods of detecting DNA damage and its future perspectives.

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Section: Photoreactivationmentioning

confidence: 94%

Section: Photoreactivationmentioning

confidence: 99%

UV-induced DNA damage and repair: a review

Sinha

Häder

2002

Photochem Photobiol Sci

1,632

1,169

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“…10-14 These proteins bind to the (6-4) photoproducts and, under the action of visible or UV-A light, effect a repair reaction, restoring the original bases. Kim et al [15][16][17][18] and others 19-21 have argued that the repair mechanism is analogous to the reductive electron transfer pathway established for cyclobutane pyrimidine dimer DNA photolyases. In the case of the (6-4) enzyme it is proposed that the initial binding step is coupled to reversal of the (6-4) photoproduct to the oxetane or azetidine intermediate, and the photochemical step involves transfer of one electron from an FADH Ϫ cofactor to the oxetane.…”

Section: Introductionmentioning

confidence: 93%

Photoinduced electron transfer cleavage of oxetane adducts of uracil and cytosine

Joseph

Falvey

2002

Photochem Photobiol Sci

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Oxetane adducts of 1,3-dimethyluracil and 1,N4,N4-trimethylcytosine were prepared and their behavior under photoinduced electron transfer was examined by fluorescence quenching, laser flash photolysis and product analysis. The excited state electron donor, N,N,N',N'-tetramethylbenzidine, was shown to photosensitize a net cycloreversion of these oxetanes to give the pyrimidine derivative and benzophenone. It is demonstrated that this reaction occurs via the anion radical of the oxetane and that the latter cleaves very rapidly (>10(7) s(-1)).

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“…have developed efficient photorepair mechanisms [10][11][12][13] that involve binding of a specific enzyme to the DNA lesion and reactivation through a photoinduced electron transfer process. [14][15][16][17][18][19][20][21] Previously, the photoinduced cycloreversion of oxetanes generated from 1,3-dimethylthymine (DMT) and carbonyl compounds has been investigated as a model for the photoenzymatic repair of DNA PPs. [22][23][24][25][26][27][28][29][30] Direct photolysis of some oxetane derivatives was observed to result in a rare adiabatic cleavage leading to the triplet excited state of the corresponding carbonyl species, along with ground state DMT.…”

Section: Introductionmentioning

confidence: 99%