DNA topoisomerase

More Like This

Show all results sharing this subject:

  • Chemistry


Show Summary Details

Quick Reference

Enzymes (EC. that control and alter the topologic states of DNA in both prokaryotes and eukaryotes. Type I topoisomerases break a single DNA strand, whereas the type II enzymes break both strands. Topoisomerase I in eukaryotic cells normally functions during transcription. Topoisomerase II catalyses the relaxation of supercoiled DNA molecules, catenation, decatenation, knotting, and unknotting of circular DNA. The topoisomerase III gene is commonly deleted in patients with the Smith–Magenis syndrome; the product of this gene apparently specifically reduces the number of supercoils in highly negatively supercoiled DNA and is found in many somatic tissues. There is a marked reduction of topoisomerase II in some cell lines from patients with ataxia-telangiectasia. Topoisomerase II of E. coli is also known as DNA gyrase.

Subjects: Chemistry.

Reference entries

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.