DNA topoisomerase IIα is a human
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
encoded by the ''TOP2A''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Topoisomerase IIα relieves topological DNA stress during transcription, condenses chromosomes, and separates chromatids. It catalyzes the transient breaking and rejoining of two strands of duplex DNA which allows the strands to pass through one another. 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 chemotherapy 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.
Interactions
TOP2A has been shown to
interact with
SMURF2,
,
CDC5L
Cell division cycle 5-like protein is a protein that in humans is encoded by the ''CDC5L'' gene.
Function
The protein encoded by this gene shares a significant similarity with '' Schizosaccharomyces pombe'' cdc5 gene product, which is a cell ...
,
,
,
and
TOPBP1
DNA topoisomerase 2-binding protein 1 (TOPBP1) is a scaffold protein that in humans is encoded by the ''TOPBP1'' gene.
TOPBP1 was first identified as a protein binding partner of DNA TOP2B, topoisomerase-IIβ by a Two-hybrid screening, yeast 2- ...
.
In other species
In ''
Drosophila
''Drosophila'' (), from Ancient Greek δρόσος (''drósos''), meaning "dew", and φίλος (''phílos''), meaning "loving", is a genus of fly, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or p ...
'' Hadlaczky et al 1988 found DNA topoisomerase II α to correlate with cell proliferation - but
β did not.
See also
*
Topoisomerase II
Type II topoisomerases are topoisomerases that cut both strands of the DNA helix simultaneously in order to manage DNA tangles and supercoils. They use the hydrolysis of Adenosine triphosphate, ATP, unlike Type I topoisomerase. In this process, t ...
*
TOP2B - Topoisomerase II beta
*
Gene duplication
Gene duplication (or chromosomal duplication or gene amplification) is a major mechanism through which new genetic material is generated during molecular evolution. It can be defined as any duplication of a region of DNA that contains a gene ...
*
Ataxia-telangiectasia
*
TOPBP1
DNA topoisomerase 2-binding protein 1 (TOPBP1) is a scaffold protein that in humans is encoded by the ''TOPBP1'' gene.
TOPBP1 was first identified as a protein binding partner of DNA TOP2B, topoisomerase-IIβ by a Two-hybrid screening, yeast 2- ...
References
Further reading
*
*
*
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