Edge-sharing motifs in structural DNA nanotechnology

Structural DNA nanotechnology is a system whereby it is possible to construct objects, nanomechanical devices and patterned periodic arrays from unusual DNA components. These components are motifs based on DNA molecules that contain branching at the secondary structure level. The construction of these targets has entailed the covalent or non-covalent cohesion of individual units to build up larger constructs. The intermolecular interactions have in all cases been mediated directly or indirectly by sticky-ended cohesion between two double helices. From a structural standpoint, sticky-ended cohesion is equivalent to a corner-sharing mode of interaction. Here, we have explored the DNA equivalent of an edge-sharing interaction. We have used a DNA double crossover motif for this purpose. We demonstrate that it is possible to assemble edge-sharing DNA constructs containing two or three fused triangles, and to characterize them by restriction analysis. We have produced one-dimensional arrays of these molecules and have characterized them by atomic force microscopy.