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Description
DNA topology-relaxing enzymes in the cell nucleus produce simplified topology, allowing entangled duplex DNA strands to pass one through another, essential for many critical cell nuclear processes including successful DNA segregation during cell division. Here, we carry out 1-point and 2-point microrheology on a model system of DNA at physiologically-relevant concentrations with and without enzyme activity of topoisomerase II. We find that the aggregate, incoherent effect of the enzyme activity creates randomly fluctuating forces, which drive diffusive-like, non-thermal motion. We combine these measurements of random motion with independent micro mechanical measurements and show that the enzyme-driven fluctuations are quantitatively consistent with