Related Experiment Video
Updated: Jul 2, 2026

Simple and Fast Rolling Circle Amplification-Based Detection of Topoisomerase 1 Activity in Crude Biological Samples
Published on: December 2, 2022
The topopyrones poison human DNA topoisomerases I and II
Qasim A Khan1, Mark A Elban, Sidney M Hecht
1Center for BioEnergetics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287, USA.
Abstract:
The topopyrones are fungal natural products shown previously to act as poisons of human DNA topoisomerase I. Recent total syntheses of the four known naturally occurring members of this class of compounds have enabled more detailed biochemical characterization. Presently it is shown that in addition to topoisomerase I, topopyrones A-D also act as poisons of human DNA topoisomerase II. The topopyrones thus represent a rare example of molecules capable of interacting effectively with more than one DNA topoisomerase.
Related Concept Videos
DNA Topoisomerases
Types and Mechanism of action
Topoisomerases are divided into two main types. Type I...
Inhibitors of Bacterial DNA Synthesis
Translesion DNA Polymerases
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
DNA Helicases
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
Nucleotide Excision Repair
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...

