Aliases for TOP3B Gene
External Ids for TOP3B Gene
Previous GeneCards Identifiers for TOP3B Gene
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 relaxing the supercoils and altering the topology of DNA. The enzyme interacts with DNA helicase SGS1 and plays a role in DNA recombination, cellular aging and maintenance of genome stability. Low expression of this gene may be related to higher survival rates in breast cancer patients. This gene has a pseudogene on chromosome 22. Alternate splicing results in multiple transcript variants. Additional alternatively spliced transcript variants of this gene have been described, but their full-length nature is not known. [provided by RefSeq, Aug 2013]
GeneCards Summary for TOP3B Gene
TOP3B (Topoisomerase (DNA) III Beta) is a Protein Coding gene. Diseases associated with TOP3B include breast cancer. Among its related pathways are Homologous recombination and Fanconi anemia pathway (KEGG). GO annotations related to this gene include DNA topoisomerase type I activity and DNA topoisomerase activity. An important paralog of this gene is TOP3A.
UniProtKB/Swiss-Prot for TOP3B Gene
Releases the supercoiling and torsional tension of DNA introduced during the DNA replication and transcription by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(5-phosphotyrosyl)-enzyme intermediate and the expulsion of a 3-OH DNA strand. The free DNA strand than undergoes passage around the unbroken strand thus removing DNA supercoils. Finally, in the religation step, the DNA 3-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone (By similarity). Possesses negatively supercoiled DNA relaxing activity.