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Light-induced reactions of Escherichia coli DNA photolyase monitored by Fourier transform infrared spectroscopy.
- Source :
-
The FEBS journal [FEBS J] 2005 Apr; Vol. 272 (8), pp. 1855-66. - Publication Year :
- 2005
-
Abstract
- Cyclobutane-type pyrimidine dimers generated by ultraviolet irradiation of DNA can be cleaved by DNA photolyase. The enzyme-catalysed reaction is believed to be initiated by the light-induced transfer of an electron from the anionic FADH- chromophore of the enzyme to the pyrimidine dimer. In this contribution, first infrared experiments using a novel E109A mutant of Escherichia coli DNA photolyase, which is catalytically active but unable to bind the second cofactor methenyltetrahydrofolate, are described. A stable blue-coloured form of the enzyme carrying a neutral FADH radical cofactor can be interpreted as an intermediate analogue of the light-driven DNA repair reaction and can be reduced to the enzymatically active FADH- form by red-light irradiation. Difference Fourier transform infrared (FT-IR) spectroscopy was used to monitor vibronic bands of the blue radical form and of the fully reduced FADH- form of the enzyme. Preliminary band assignments are based on experiments with 15N-labelled enzyme and on experiments with D2O as solvent. Difference FT-IR measurements were also used to observe the formation of thymidine dimers by ultraviolet irradiation and their repair by light-driven photolyase catalysis. This study provides the basis for future time-resolved FT-IR studies which are aimed at an elucidation of a detailed molecular picture of the light-driven DNA repair process.
- Subjects :
- Bacillus subtilis genetics
Catalysis radiation effects
DNA Damage radiation effects
DNA Repair radiation effects
Deoxyribodipyrimidine Photo-Lyase genetics
Deoxyribodipyrimidine Photo-Lyase isolation & purification
Enzyme Activation radiation effects
Escherichia coli genetics
Flavin-Adenine Dinucleotide chemistry
Flavin-Adenine Dinucleotide metabolism
Folic Acid metabolism
Mutation genetics
Photochemistry
Spectroscopy, Fourier Transform Infrared
Thymine chemistry
Thymine metabolism
Thymine radiation effects
Uridine chemistry
Uridine metabolism
Uridine radiation effects
Deoxyribodipyrimidine Photo-Lyase chemistry
Deoxyribodipyrimidine Photo-Lyase metabolism
Escherichia coli enzymology
Flavin-Adenine Dinucleotide analogs & derivatives
Folic Acid analogs & derivatives
Light
Uridine analogs & derivatives
Subjects
Details
- Language :
- English
- ISSN :
- 1742-464X
- Volume :
- 272
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- The FEBS journal
- Publication Type :
- Academic Journal
- Accession number :
- 15819881
- Full Text :
- https://doi.org/10.1111/j.1742-4658.2005.04617.x