TOP3A（DNA topoisomerase III alpha），癌症关联基因，基因ID：7156，这个基因编码一种dna拓扑异构酶，一种在转录过程中控制和改变dna拓扑异构酶状态的酶。这种酶能催化单链dna的瞬时断裂和重新连接，从而使单链dna彼此穿过，从而减少超螺旋的数量并改变dna的拓扑结构。这种酶与blm形成复合物，在体细胞重组中起调节作用。选择性剪接导致编码不同亚型的多个转录变体。[由RefSeq提供，2016年3月]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 reducing the number of supercoils and altering the topology of DNA. This enzyme forms a complex with BLM which functions in the regulation of recombination in somatic cells. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq， Mar 2016]。