PX DNA triangle oligomerized using a novel three-domain motif.

Structural DNA nanotechnology is directed at building objects, lattices, and arrays from cohesive interactions between DNA molecules. The predominant means of doing this takes advantage of the information inherent in Watson-Crick base pairing in duplex formation and in sticky-ended cohesion. Nevertheless, other forms of nucleic acid cohesion are also known, particularly paranemic edge-sharing interactions (PX). Here we report the formation of a triangular species that has four strands per edge, held together by PX interactions. We demonstrate by nondenaturing gel electrophoresis and by atomic force microscopy (AFM) that we can combine a partial triangle with other strands to form a four-stranded molecule that is robust. By combining them with a new mixed-fusion type of three-domain molecule, we demonstrate by AFM that these triangles can be self-assembled into a linear array.