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Photoreactivation of the thymine dimer containing DNA octamer d(GCGT TGCG)·d(CGCAACGC) by the photoreactivating enzyme from Anacystis nidulans

✍ Scribed by J. Kemmink; A.P.M. Eker; G.A. van der Marel; J.H. van Boom; R. Kaptein


Publisher
Elsevier Science
Year
1988
Tongue
English
Weight
390 KB
Volume
1
Category
Article
ISSN
1011-1344

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✦ Synopsis


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.