Open AccessThymine dimers bend DNA.
Author(s) -
Intisar Husain,
Jack D. Griffith,
Aziz Sancar
Publication year - 1988
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.85.8.2558
Subject(s) - thymine , dna , pyrimidine dimer , photolyase , chemistry , base pair , covalent bond , gel electrophoresis , biophysics , crystallography , stereochemistry , biochemistry , dna damage , biology , dna repair , organic chemistry
A 32-base-pair DNA fragment containing a thymine photodimer was constructed and ligated head-to-tail to obtain multimers of this sequence in which thymine dimers were in phase with the helix screw axis (approximately equal to 3 turns apart). The ligation products were analyzed by one- and two-dimensional gel electrophoresis and quantitative electron microscopy. These analyses show that the thymine photodimer introduces a bend of approximately equal to 30 degrees in DNA, which causes anomalously slow migration of DNA fragments in polyacrylamide gels and facilitates the formation of small covalent circles. Repair of thymine dimers by DNA photolyase abolishes the anomalous migration.