Distinct DNA conformations during forward and backward translocations through a conical nanopore

Area of Science:

• Biophysics
• Genomics
• Nanotechnology

Background:

• DNA conformations are critical for genome regulation.
• DNA translocation through nanopores involves complex interactions affecting current signatures.
• Conical nanopores introduce unique geometric constraints on DNA movement.

Purpose of the Study:

• To investigate DNA conformations during translocation in conical nanopores.
• To analyze the influence of translocation direction and pore geometry on DNA behavior.
• To understand DNA folding dynamics in confined environments for technological advancement.

Main Methods:

• Utilizing molecular ping-pong methods to confine and study DNA.
• Analyzing DNA translocation dynamics through conical nanopores.
• Measuring current signatures and translocation times under varying conditions.

Main Results:

• Forward DNA translocation (cis to trans) shows reduced resistance, shorter times, and higher currents.
• Backward DNA translocation (trans to cis) exhibits longer times and complex conformations due to drag and geometry.
• DNA folding is a common conformation influencing nanopore current signals.

Conclusions:

• Nanopore geometry and translocation direction significantly alter DNA conformations and translocation dynamics.
• Understanding these dynamics is key for advancing nanopore-based sensing and sequencing.
• Insights contribute to genome regulation studies and biomedical applications.