Structure and mechanism of DNA topoisomerase II.
Berger, J.M., Gamblin, S.J., Harrison, S.C., Wang, J.C.(1996) Nature 379: 225-232
- PubMed: 8538787 
- DOI: https://doi.org/10.1038/379225a0
- PubMed Abstract: 
The crystal structure of a large fragment of yeast type II DNA topoisomerase reveals a heart-shaped dimeric protein with a large central hole. It provides a molecular model of the enzyme as an ATP-modulated clamp with two sets of jaws at opposite ends, connected by multiple joints. An enzyme with bound DNA can admit a second DNA duplex through one set of jaws, transport it through the cleaved first duplex, and expel it through the other set of jaws.
Organizational Affiliation: 
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.