title: DNA photolyase repairs the trans-syn cyclobutane thymine dimer.
abstract: DNA photolyases catalyze the splitting of the cyclobutane ring joining the two dihydropyrimidines of a pyrimidine dimer by a photoinduced electron-transfer reaction. Previous studies concluded that photolyase repairs only the cis-syn form of the eight stereoisomers of the cyclobutane pyrimidine dimer (Pyr[ ]Pyr). In this study we found that Escherichia coli photolyase binds to the trans-syn-I isomer of T[ ]T with about 10(4)-fold lower affinity than the cis-syn isomer but it repairs it relatively efficiently.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill 27599.
authors.forename: S T
authors.initials: ST
authors.lastname: Kim
authors.forename: K
authors.initials: K
authors.lastname: Malhotra
authors.forename: C A
authors.initials: CA
authors.lastname: Smith
authors.forename: J S
authors.initials: JS
authors.lastname: Taylor
authors.forename: A
authors.initials: A
authors.lastname: Sancar
mesh_terms: D001483:Base Sequence; D004260:DNA Repair; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D007536:Isomerism; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010782:Photolysis; D011740:Pyrimidine Dimers / Q000378:metabolism*; D013379:Substrate Specificity; D014466:Ultraviolet Rays
chemical_list: D009838:Oligodeoxyribonucleotides; D011740:Pyrimidine Dimers; D004255:Deoxyribodipyrimidine Photo-Lyase