Topoisomerase IV is essential for chromosome segregation. It relaxes supercoiled DNA. Performs the decatenation events required during the replication of a circular DNA molecule. ATP-dependent breakage, passage and rejoining of double-stranded DNA. Heterotetramer composed of ParC and ParE. Bipolarly localized. Belongs to the type II topoisomerase GyrA/ParC subunit family. ParC type 2 subfamily.