A four-helix bundle DNA nanostructure with binding pockets for pyrimidine nucleotides.

Area of Science:

• Biochemistry
• Nanotechnology
• Molecular Biology

Background:

• Designed DNA nanostructures have achieved impressive sizes.
• However, creating DNA nanostructures comparable in size to enzymes for specific ligand binding remains a challenge.

Purpose of the Study:

• To design and characterize a small, folded DNA nanostructure capable of selective molecular recognition.
• To investigate the binding capabilities of internal cavities within the DNA nanostructure.

Main Methods:

• Construction of a four-helix DNA motif using three synthetic strands (65 base pairs, 165 nucleotides).
• Characterization of the nanostructure's folding and internal cavity formation.
• Assessment of pyrimidine nucleotide binding affinity and specificity.

Main Results:

• The designed four-helix DNA motif demonstrates robust folding.
• Internal cavities within the nanostructure bind pyrimidine nucleotides (thymidine and cytidine derivatives) with micromolar affinity.
• Binding affinity is sequence- and position-dependent, indicating specific recognition.

Conclusions:

• A novel, small DNA nanostructure motif has been successfully designed and synthesized.
• This DNA nanostructure exhibits specific binding of pyrimidine nucleotides, mimicking enzyme-like recognition.
• The developed motif offers a new platform for advancing DNA nanotechnology in selective molecular recognition.