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Published on: July 30, 2014
The mechanism of type IA topoisomerases
N H Dekker1, V V Rybenkov, M Duguet
1Laboratoire de Physique Statistique et Département de Biologie, Ecole Normale Supérieure, Unité Mixte de Recherche 8550 Centre National de la Recherche Scientifique, 24 Rue Lhomond, 75231 Paris, France. Nynke.Dekker@lps.ens.fr
Abstract:
The topology of cellular DNA is carefully controlled by enzymes called topoisomerases. By using single-molecule techniques, we monitored the activity of two type IA topoisomerases in real time under conditions in which single relaxation events were detected. The strict one-at-a-time removal of supercoils we observed establishes that these enzymes use an enzyme-bridged strand-passage mechanism that is well suited to their physiological roles and demonstrates a mechanistic unity with type II topoisomerases.
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