Structural DNA nanotechnology: Studies of two dimensional lattices and crystallization of a DNA decamer

One of the goals of structural DNA nanotechnology is to create larger more rigid structures that can be used as building blocks for two-dimensional arrays. Two-dimensional DNA crystals have been designed and constructed from Holliday junction analogues that have been combined in groups of four to form parallelogram-like structures. Two new two-dimensional parallelogram lattices were designed and formed each consisting of four eight-turn helices. In one of the designs called the 4+4 x 4+4 parallelogram there were four turns on the inside and the outside of the parallelogram tile. In the other design, 6+2 x 6+2, there were six turns on the inside and two turns on the outside of the tile. Another larger parallelogram tile has also been created consisting of four twelve turn helices. In order to create a more rigid parallelogram tile double crossover molecules were incorporated into this structure to reinforce each of the helices and to provide double the connection points at the sticky ends, called the DX (double cross-over) parallelogram. Each of the above described two-dimensional parallelogram arrays had the expected periodicity when imaged on the AFM.; Another goal of structural DNA nanotechnology is to create a two dimensional array using the mix and split method, using TX (triple cross-over) tiles with Bowtie junctions (junctions with a 3'-3' and 5'-5' linkage) was created. Connecting the tiles using linkers with the polarity reversed as sticky ends was attempted instead of conventional sticky-ended cohesion. The linker in the TX system was crystallized in an attempt to diagnose the source of problems in forming this array.