Bacterial DNA topoisomerase II and topoisomerase IV (DNA gyrase (often abbreviated as Gyrase) and topoisomerase IV (Topo IV))

DNA gyrase and DNA topoisomerase IV are essential bacterial type II topoisomerases that manage DNA topology during replication, transcription, and chromosomal segregation. DNA gyrase uniquely introduces negative supercoils and relaxes positive supercoils, while topoisomerase IV mainly decatenates intertwined daughter chromosomes and also relaxes supercoils. Both are heterotetrameric enzymes: gyrase is composed of GyrA and GyrB subunits, topoisomerase IV of ParC and ParE subunits. These enzymes are validated and clinically important antibacterial targets, especially for fluoroquinolones and newer drug classes. The widespread clinical use of these inhibitors has led to high rates of target-mediated resistance, making continued drug development against these targets a central focus in antibacterial chemotherapy.

Other names

DNA gyraseTopoisomerase IVType IIA topoisomerasesGyrA/GyrBParC/ParE

Stabilization of topoisomerase-DNA cleavage complexes leading to double-stranded DNA breaks (fluoroquinolones and related agents) Inhibition of ATPase activity (aminocoumarins) Allosteric inhibition (NBTIs)