Locating the uracil-5-yl radical formed upon photoirradiation of 5-bromouracil-substituted DNA |
| |
Authors: | Fumitaka Hashiya Abhijit Saha Seiichiro Kizaki Yue Li Hiroshi Sugiyama |
| |
Institution: | 1.Department of Chemistry, Graduate School of Science Kyoto University, Sakyo, Kyoto 606-8502, Japan;2.Institute for Integrated Cell-Materials Science (iCeMS) Kyoto University, Sakyo, Kyoto 606-8502, Japan;3.CREST, Japan Science and Technology Corporation (JST), Sanbancho, Chiyoda-ku, Tokyo 102-0075, Japan |
| |
Abstract: | In a previous study, we found that 2-deoxyribonolactone is effectively generated in the specific 5-bromouracil (BrU)-substituted sequence 5′-(G/C)A]n
= 1,2BrUBrU-3′ and proposed that a formed uracil-5-yl radical mainly abstracts the C1′ hydrogen from the 5′-side of BrUBrU under 302-nm irradiation condition. In the present work, we performed photoirradiation of BrU-substituted DNA in the presence of a hydrogen donor, tetrahydrofuran, to quench the uracil-5-yl radical to uracil and then subjected the sample to uracil DNA glycosylase digestion. Slab gel sequence analysis indicated that uracil residues were formed at the hot-spot sequence of 5′-(G/C)A]n
= 1,2BrUBrU-3′ in 302-nm irradiation of BrU-substituted DNA. Furthermore, we found that the uracil residue was also formed at the reverse sequence 5′-BrUBrUA]n
= 1,2(G/C)-3′, which suggests that both 5′-(G/C)A]n
= 1,2BrUBrU-3′ and 5′-BrUBrUA]n
= 1,2(G/C)-3′ are hot-spot sequences for the formation of the uracil-5-yl radical. |
| |
Keywords: | |
|
|