DNA topoisomerase

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DNA topoisomerase
EC number
CAS number 80449-01-0
IntEnz IntEnz view
ExPASy NiceZyme view
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum

DNA topoisomerase (EC, type I DNA topoisomerase, untwisting enzyme, relaxing enzyme, nicking-closing enzyme, swivelase, omega-protein, deoxyribonucleate topoisomerase) is an enzyme with systematic name DNA topoisomerase.[1] This enzyme catalyses the following chemical reaction

ATP-independent breakage of single-stranded DNA, followed by passage and rejoining

These enzymes bring about the conversion of one topological isomer of DNA into another. There are two types of DNA topoisomerase; I and II. Both of which are further classified into sub families IA, IB, IIA, and IIB. DNA topoisomerase facilitates a transesterification reaction. Through this reaction DNA topoisomerase is able to break and rejoin the phosphate backbone of DNA. [2]


  1. ^ Gellert M (1981). "DNA topoisomerases". Annual Review of Biochemistry. 50: 879–910. doi:10.1146/annurev.bi.50.070181.004311. PMID 6267993. 
  2. ^ Wang JC (June 2002). "Cellular roles of DNA topoisomerases: a molecular perspective". Nature Reviews. Molecular Cell Biology. 3 (6): 430–40. doi:10.1038/nrm831. PMID 12042765. 

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