Encyclopedia of Cancer

Living Edition
| Editors: Manfred Schwab


  • Wenjian Ma
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27841-9_5861-10


DNA topoisomerases are a class of enzymes required for the regulation of DNA folding and supercoiling to maintain chromosome integrity and cellular function. They are essential for relaxing entangled DNA and modulating DNA topology by transiently breaking and rejoining DNA single or double strands. Topoisomerases play a key role during DNA replication, transcription, and chromosome segregation. They are also involved in resolving specific DNA structures and intermediates arising from other cellular processes such as DNA repair and recombination.


To fit into the tiny nucleus, cellular DNA, which has a combined length of several meters, is compacted and bound by proteins to form chromatin, which is twisted and folded into a space of only a few microns. However, excess folding of DNA poses a unique challenge to living organisms and generates topological problems when the DNA helix must be unwound to make its genetic information accessible. This highly...


Topological Problem Sister Chromosome Strand Passage Divalent Metal Binding Top2 Enzyme 
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  1. Nitiss JL (2009) DNA topoisomerase II and its growing repertoire of biological functions. Nat Rev Cancer 9(5):327–337CrossRefPubMedCentralPubMedGoogle Scholar
  2. Vos SM, Tretter EM, Schmidt BH, Berger JM (2011) All tangled up: how cells direct, manage and exploit topoisomerase function. Nat Rev Mol Cell Biol 12(12):827–841CrossRefPubMedCentralPubMedGoogle Scholar
  3. Wang JC (2002) Cellular roles of DNA topoisomerases: a molecular perspective. Nat Rev Mol Cell Biol 3(6):430–440CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.National Institute of Environmental Health Sciences (NIEHS)Research Triangle ParkUSA