Placing molecules with Bohr radius resolution using DNA origami.

Area of Science:

• Nanotechnology and Molecular Engineering
• Biomolecular Design and Self-Assembly

Background:

• Molecular self-assembly using nucleic acids allows fabrication of discrete objects with defined sizes and shapes.
• Current research focuses on large, complex objects with limited design accuracy (typically >5 nm), with subnanometer precision achieved only in DNA crystals.
• Achieving atomic-scale placement accuracy, similar to biological machines, remains a challenge in nucleic acid-based self-assembly.

Purpose of the Study:

• To develop a molecular positioning device using DNA origami with controlled angular adjustments.
• To test and demonstrate the device's capability for atomic-resolution molecular placement.
• To achieve precise control over distances between molecular components at the subnanometer scale.

Main Methods:

• Designed a hinged DNA origami object with adjustable structural units controlled by adjuster helices.
• Employed photophysical and crosslinking assays for atomic-resolution analysis of molecular positioning.
• Quantified displacement steps and fluctuation amplitudes to assess positioning accuracy.

Main Results:

• Demonstrated rational adjustment of average distances between fluorescent molecules and reactive groups from 1.5 to 9 nm.
• Achieved 123 discrete displacement steps with a minimum step size of 0.04 nm (less than the Bohr radius).
• Observed small fluctuation amplitudes (±0.5 nm) in the distance coordinate, comparable to protein structures.

Conclusions:

• The DNA origami molecular positioning device offers unprecedented control over nanoscale spatial arrangements.
• The achieved subnanometer precision and low fluctuation amplitudes approach the capabilities of protein machines.
• This technology opens new avenues for designing and fabricating complex nanoscale structures with high accuracy.