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Catenation and knotting of duplex DNA by type 1 topoisomerases: a mechanistic parallel with type 2 topoisomerases.
Open accessAbstract
Escherichia coli omega protein, a type 1 topoisomerase, can catenate and knot duplex DNA circles. Previously, these activities were thought to be limited to type 2 topoisomerases. Catenation by omega requires a nick in one of the participating molecules, but it is not necessary that both be nicked. Catenation does not depend on sequence homology and is greatly stimulated by DNA-condensing agents such as spermidine. A eukaryotic type 1 topoisomerase can also interlock duplex DNA circles. These activities cannot easily be explained by the widely held topoisomerase model in which a reversible nick in DNA allows free rotation about the unbroken strand. We suggest instead passage of a DNA segment though a transient enzyme-bridged break in a single DNA strand. This is analogous to the sign inversion mechanism of the type 2 topoisomerases, and thus expresses an essential mechanistic unity among topoisomerases. As expected for relaxation by a single-strand passage, omega changes the linking number of DNA in steps of 1.
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Citations
Cited by
DNA Topoisomerases: Structure, Function, and Mechanism
Champoux, J. J. (2001) · Annual Review of Biochemistry · doi:10.1146/annurev.biochem.70.1.369 · Cited by 2,743
Cellular roles of DNA topoisomerases: a molecular perspective
Wang, J. C. (2002) · Nature Reviews Molecular Cell Biology · doi:10.1038/nrm831 · Cited by 2,353
DNA topoisomerases: harnessing and constraining energy to govern chromosome topology
Schoeffler, A. J., & Berger, J. M. (2008) · Quarterly Reviews of Biophysics · doi:10.1017/s003358350800468x · Cited by 490
Topoisomerases as anticancer targets
Delgado, J. L., Hsieh, C.-M., Chan, N.-L., & Hiasa, H. (2018) · Biochemical Journal · doi:10.1042/bcj20160583 · Cited by 481
Friction and torque govern the relaxation of DNA supercoils by eukaryotic topoisomerase IB
Koster, D. A., Croquette, V., Dekker, C., Shuman, S., & Dekker, N. H. (2005) · Nature · doi:10.1038/nature03395 · Cited by 324
Metadata
- Authors
- Brown, P. O., & Cozzarelli, N. R.
- Venue
- Proceedings of the National Academy of Sciences
- Published
- 1981-02
- Volume
- 78
- Issue
- 2
- Pages
- 843-847
- ISSN
- 0027-8424 (ISSN-L)
- 1091-6490
- OpenAlex
- W2040188253
- Cited by
- 164
- References
- 0
- FWCI
- 4.06
- Type
- journal article
- Language
- en
- Open access
- green
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- CoChat. (2026). Citation check: Catenation and knotting of duplex DNA by type 1 topoisomerases: a mechanistic parallel with type 2 topoisomerases. https://app.cochat.ai/papers/10.1073/pnas.78.2.843
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- Brown, P. O., & Cozzarelli, N. R. (1981). Catenation and knotting of duplex DNA by type 1 topoisomerases: a mechanistic parallel with type 2 topoisomerases. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.78.2.843
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