這個基因編碼一種DNA拓撲異構酶，這種酶在轉錄過程中控制和改變DNA的拓撲狀態。這種酶催化單鏈DNA的瞬間斷裂和重新結合，使單鏈DNA彼此穿過，從而改變DNA的拓撲結構。該基因定位于20號染色體，并具有位于1號和22號染色體上的假基因。
This gene encodes a DNA topoisomerase, an enzyme that controls and alters the topologic states of DNA during transcription. This enzyme catalyzes the transient breaking and rejoining of a single strand of DNA which allows the strands to pass through one another, thus altering the topology of DNA. This gene is localized to chromosome 20 and has pseudogenes which reside on chromosomes 1 and 22.