[Encoded by human TOP2A Gene (TOPII Family), alternative homodimeric nuclear DNA Topoisomerase II, Alpha isoforms 1 (1531-aa, 174.4-kD), 2 (1557-aa), 3 (1567-aa), and 4 (1612-aa) control DNA topology. TOP2A catalyzes transient ATP-dependent double-strand breakage/relaxation and rejoining of negative/positive supercoiled DNA during transcription, replication, chromosome condensation, and chromatid separation. TOPII reactions likely involve crossing-over. TOP2A is associated with Pol II holoenzyme. Inhibited by intercalating amsacrine, TOP2A is a target for several anticancer agents. Mutations are linked with drug resistance and perhaps ataxia-telangiectasia. (from LocusLink, Swiss-Prot, OMIM, and NCI) ( NCI )]
UMLS (NCI) C0256022 - Amino Acid, Peptide, or Protein
- Enzyme