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topoisomerase-2
Function:
- control of topological states of DNA by transient breakage & subsequent rejoining of DNA strands
- topoisomerase 2 makes double-strand breaks
- DNA cleavage by topoisomerase 2 induces reversible, protein- associated fragments of > 600 kb
- reversible cleavage into > 600 kb fragment appears to be a signal for the engagement of apoptosis [2]
- further cleavage leads to 300 & 50 kb fragments.
- formation of 50 kb fragments is irreversible
- eukaryotic topoisomerase 1 & topoisomerase 2 can relax both negative & positive supercoils, whereas prokaryotic enzymes relax only negative supercoils
Compartment:
- topoisomerase 2 occurs with a periodicity of 300 kbp along chromatin, associated with the nuclear scaffold
Specific
DNA topoisomerase-2 alpha (TOP2A)
topoisomerase-2 beta (TOP2B)
General
oligomerizing protein
pro apoptotic protein
topoisomerase
Properties
COMPARTMENT: cell nucleus
MOTIF: active site
MOTIF: tyrosine residue
S/T phosphorylation site
Database Correlations
OMIM 126430
ENZYME 5.99.1.3
References
- Martin SJ, Green DR, Cotter TG.
Dicing with death: dissecting the components of the apoptosis
machinery.
Trends Biochem Sci. 1994 Jan;19(1):26-30. Review.
PMID: 8140617
- Beere HM, Chresta CM, Alejo-Herberg A, Skladanowski A, Dive C,
Larsen AK, Hickman JA.
Investigation of the mechanism of higher order chromatin
fragmentation observed in drug-induced apoptosis.
Mol Pharmacol. 1995 May;47(5):986-96.
PMID: 7746285