Photoreactivation of the thymine dimer containing DNA octamer d(GCGTTGCG).d(CGCAACGC) by the photoreactivating enzyme from Anacystis nidulans.
Irradiation of the double-stranded octamer d(GCGTTGCG).d(CGCAACGC) with UV light causes dimerization of the two central thymine residues. Proton NMR data reveal that this photodimer has the same chemical structure as the photodimer, which is formed upon UV irradiation of the single strand d(GCGTTGCG), a cis-syn-cyclobutane-type thymine dimer. Irradiation of the purified thymine dimer double-stranded octamer d(GCGTTGCG).d(CGCAACGC) with visible light in the presence of photoreactivating enzyme isolated from Anacystis nidulans leads to an increase in absorbance at 260 nm, which is characteristic for the repair of thymine dimers. The NMR spectrum recorded after the photoreactivating treatment indeed shows that a complete conversion to the starting octamer has occurred.
Kemmink
J
J
Department of Physical Chemistry, University of Groningen, The Netherlands.
Eker
A P
AP
van der Marel
G A
GA
van Boom
J H
JH
Kaptein
R
R
D000458:Cyanobacteria / Q000201:enzymology*; D004247:DNA / Q000378:metabolism*; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000378:metabolism*; D008190:Lyases / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D010777:Photochemistry; D011740:Pyrimidine Dimers / Q000378:metabolism*
D011740:Pyrimidine Dimers; D004247:DNA; D008190:Lyases; D004255:Deoxyribodipyrimidine Photo-Lyase