title: Context-dependent photodimerization in isolated thymine-thymine steps in DNA.
abstract: The effect of 280 nm irradiation on a family of synthetic DNA hairpins possessing an alkane linker connecting a six-base pair stem having a single T-T step located at different positions within the hairpin has been investigated. A single adduct assigned to the product of 2+2 dimerization is obtained except in the case of a T-T step located adjacent to the linker, in which case both 2+2 and 6-4 adducts are obtained. The efficiency of dimerization is similar for three hairpins having a T-T step located within the duplex interior. Lower efficiency is observed for a T-T step located at the open end of the hairpin and in T overhangs, whereas higher efficiency is observed for the T-T step adjacent to the linker and in a single T bulge. The context-dependence of dimerization efficiency is discussed.
authors.affiliation: Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, USA.
authors.forename: Mahesh
authors.initials: M
authors.lastname: Hariharan
authors.forename: Frederick D
authors.initials: FD
authors.lastname: Lewis
mesh_terms: D000473:Alkanes / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects; D019281:Dimerization; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry; D010777:Photochemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013941:Thymine / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D000473:Alkanes; D009841:Oligonucleotides; D004247:DNA; D013941:Thymine