TOP3A gene

DNA topoisomerase III alpha

The information on this page was automatically extracted from online scientific databases.

From NCBI 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 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]

From UniProt:

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 then 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. Essential component of the RMI complex, a complex that plays an important role in the processing of homologous recombination intermediates to limit DNA crossover formation in cells. Has DNA decatenation activity.

From NCBI Gene:

  • MICROCEPHALY, GROWTH RESTRICTION, AND INCREASED SISTER CHROMATID EXCHANGE 2
  • PROGRESSIVE EXTERNAL OPHTHALMOPLEGIA WITH MITOCHONDRIAL DNA DELETIONS, AUTOSOMAL RECESSIVE 5

Cytogenetic Location: 17p11.2, which is the short (p) arm of chromosome 17 at position 11.2

Molecular Location: base pairs 18,269,958 to 18,315,092 on chromosome 17 (Homo sapiens Annotation Release 109, GRCh38.p12) (NCBI)

Cytogenetic Location: 17p11.2, which is the short (p) arm of chromosome 17 at position 11.2
  • MGRISCE2
  • PEOB5
  • TOP3
  • ZGRF7