Bacterial type II topoisomerase (Topo II (Bacterial))

Bacterial type II topoisomerase refers to a group of essential enzymes, primarily DNA gyrase and topoisomerase IV, that regulate the topological state of the bacterial genome during DNA replication, transcription, and recombination [1, 5, 11]. DNA gyrase is unique in its ability to introduce negative supercoils into DNA, a process vital for chromosome compaction and the relief of torsional stress [5, 15]. Topoisomerase IV is primarily responsible for the decatenation of interlinked daughter chromosomes, allowing for successful cell division [5, 13]. These enzymes are heterotetrameric complexes consisting of two distinct subunits (GyrA/GyrB or ParC/ParE) and are the primary targets of fluoroquinolone antibiotics [4, 11, 13]. Fluoroquinolones function as topoisomerase poisons by trapping the enzyme in a covalent complex with DNA, leading to the accumulation of lethal double-strand breaks [2, 6, 15]. Other inhibitors, such as aminocoumarins, target the ATPase domain to block the energy-dependent catalytic cycle [1, 11]. Given the rise of antibiotic resistance, these enzymes remain critical targets for the development of novel antibacterial agents with distinct mechanisms of action [3, 13].

Other names

DNA gyraseTopoisomerase IVBacterial type IIA topoisomeraseBacterial DNA topoisomerase II

Inhibition of DNA ligation and stabilization of the enzyme-DNA cleavage complex (topoisomerase poisons); competitive inhibition of ATPase activity; inhibition of DNA supercoiling and decatenation.