Topoisomerase I inhibitors

Patent Pending Human DNA topoisomerase I (Top1) is an essential enzyme that relaxes DNA supercoiling during replication and transcription. Top1 generates DNA single-strand breaks that allow rotation of the cleaved strand around the double helix axis. Top1 also religates the cleaved strand to reestablish intact duplex DNA. The Top1-DNA intermediates, known as cleavage complexes, are transient and at low levels under normal circumstances.