TOP2A

This gene encodes a DNA topoisomerase, an enzyme that controls and alters the topologic states of DNA during transcription. This nuclear enzyme is involved in processes such as chromosome condensation, chromatid separation, and the relief of torsional stress that occurs during DNA transcription and replication. It catalyzes the transient breaking and rejoining of two strands of duplex DNA which allows the strands to pass through one another, thus altering the topology of DNA. Two forms of this enzyme exist as likely products of a gene duplication event. The gene encoding this form, alpha, is localized to chromosome 17 and the beta gene is localized to chromosome 3. The gene encoding this enzyme functions as the target for several anticancer agents and a variety of mutations in this gene have been associated with the development of drug resistance. Reduced activity of this enzyme may also play a role in ataxia-telangiectasia. [provided by RefSeq, Jul 2010]

本基因编码一种DNA拓扑异构酶，该酶在转录过程中调控并改变DNA的拓扑状态。该核酶参与染色体凝聚、染色单体分离以及DNA转录和复制过程中产生的扭转应力的缓解等过程。它催化双链DNA的短暂断裂与重新连接，从而使双链能够相互穿过，从而改变DNA的拓扑结构。该酶存在两种形式，这可能是基因复制事件的产物。编码此酶的α型基因定位于染色体17，而β型基因定位于染色体3。编码此酶的基因作为多种抗癌药物的作用靶点，且该基因的多种突变与药物耐药性的发展相关。此酶活性的降低也可能在遗传性感觉神经性共济失调中发挥作用。[资料来源：RefSeq，2010年7月]