Figure 4. Proposed mechanism for voltage-facilitated dissociation of DNA from KF/DNA or KF/DNA/dNTP complexes.

a, Representative trace at 180 mV showing the current levels associated with nanopore capture of the ternary complex, and illustration of the molecular events proposed to occur at each step. i, The long 24 pA blockade arises from the initial capture of the ternary complex, with the duplex DNA held on top the pore vestibule because of association with the KF. ii, The shorter 20 pA terminal step occurs upon KF dissociation, when duplex DNA is pulled into the nanopore vestibule. iii, Finally, primer and template strands are dissociated, translocating through the nanopore as single-stranded molecules and resulting in a return to the open channel current. b, Current trace from an experiment with DNA and KF in the nanopore chamber, showing two translocation events. i, Trace shows the 20 pA signature characteristic of events in the presence of DNA only. ii, Trace is characteristic of events that only occur in the presence of both KF and DNA (without the correct dNTP). c–h, Two-dimensional plots show event clusters for 20-bp DNA hairpin translocation at 180 mV (c); 20-bp DNA hairpin/KF/dGTP complex terminal step at 180 mV (d); 14-bp DNA hairpin translocation at 180 mV (e); 14-bp DNA hairpin/KF/dGTP complex terminal step at 180 mV (f); 14-bp DNA hairpin translocation at 165 mV (g); 14-bp DNA hairpin/KF/dGTP complex terminal step at 165 mV (h).