3D Hexagonal Arrangement of DNA Tensegrity Triangles

Area of Science:

• * DNA nanotechnology
• * Supramolecular chemistry
• * Materials science

Background:

• * Tensegrity triangle motifs self-assemble into rhombohedral crystal lattices via Watson-Crick base pairing.
• * Previous designs utilized specific complementary sticky ends (5'-GA and 5'-TC) for assembly.

Purpose of the Study:

• * To investigate the self-assembly of isomorphic tensegrity triangles using noncanonical sticky ends (5'-AG and 5'-TC).
• * To characterize the resulting crystal structure and its properties.

Main Methods:

• * Synthesis of tensegrity triangle DNA motifs with noncanonical sticky ends.
• * X-ray crystallography to determine the crystal structure.
• * Analysis of lattice parameters and structural features.

Main Results:

• * Self-assembly into a hexagonal crystal lattice (P63 space group) using noncanonical 5'-AG and 5'-TC sticky ends.
• * Observed DNA double helix bending at crossover positions, leading to a left-handed superstructure.
• * Formation of a microtubule-like structure with three double helices and an 11 nm central channel.
• * Larger unit cell volume (886,000 ų) compared to the rhombohedral counterpart.

Conclusions:

• * Noncanonical sticky ends enable the formation of novel hexagonal DNA crystal structures.
• * The resulting structure exhibits unique helical bending and a large central cavity.
• * This finding expands the design principles for self-assembling DNA nanomaterials.