Abstract
The interaction between calf thymus topoisomerase II and DNA has been characterized using a transcription assay. A highly preferred recognition sequence for topoisomerase II was inserted in either direction downstream from a promoter specific for a bacteriophage RNA polymerase. The presence of topoisomerase II-DNA complexes on the template provoked blockage of transcription, yielding RNA transcripts terminated 5' to the topoisomerase II binding site. A footprint of topoisomerase II, derived from transcription towards the complex from either side, revealed that eukaryotic topoisomerase II binds a region of 28 base-pairs with a highly protected central core of 22 base-pairs. The binding region was located symmetrically around the topoisomerase II-mediated cleavage site. In agreement with this result, optimal topoisomerase II-mediated cleavage was observed with a DNA substrate consisting of a 28-mer oligonucleotide homologous to the protected region. Stepwise removal of base-pairs from the ends of the 28-mer gradually reduced the level of enzyme-mediated cleavage.
| Original language | English |
|---|---|
| Journal | Journal of Molecular Biology |
| Volume | 215 |
| Issue | 2 |
| Pages (from-to) | 237-44 |
| Number of pages | 8 |
| ISSN | 0022-2836 |
| DOIs | |
| Publication status | Published - 20 Sept 1990 |
Keywords
- Acetanilides
- Animals
- Base Sequence
- Binding Sites
- Cattle
- DNA
- DNA Topoisomerases, Type I
- DNA-Binding Proteins
- In Vitro Techniques
- Molecular Sequence Data
- Nitroimidazoles
- Transcription, Genetic
- Journal Article
- Research Support, Non-U.S. Gov't