Pastrana…Moreno-Herrero {Nucleic Acids Res 44: 8885}

Force and twist dependence of RepC nicking activity on torsionally-constrained DNA molecules. Nucleic Acids Res. 2016 Oct 14;44(18):8885-8896.
Magnetic Tweezers allows mimicking the in-vivo torsional state of a plasmid. Here we show that initiation of replication by the rolling circle mechanism requires a particular degree of negatively-supercoiled DNA.