Localised buckling, writhing and cutting of the DNA molecule

	J. Michael T. Thompson FRS
	Department of Applied Mathematics and Theoretical Physics, Cambridge
	DNA and why it gets twisted
	Topology of writhing
	Topoisomerase: nature's cutting enzyme
	Mechanics of stretched and twisted rods
	Single-molecule magnetic tweezer experiment
	Mechanics of steady–state plying

DNA and why it gets twisted

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Topology of writhing

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The cutting enzyme
(Topo = topoisomerase)

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Mechanics of stretched and twisted rods

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The magnetic tweezer experiment

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Mechanics of steady–state plying

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