Book of Abstracts: Albany 2009
June 16-20 2009
© Adenine Press (2008)
The Rational Design and Structural Analysis of a Self-Assembled Three-Dimensional DNA Crystal
The precise control of the 3D structure of matter is a central concern of the natural sciences. To this end, numerous investigators have developed self-assembling systems to produce targets of interest (1). Taking its cue from biological systems, structural DNA nanotechnology has used branched DNA motifs combined with the molecular recognition properties of cohesive ends to produce objects (2), nanomechanical devices (3) and designed 2D lattices (4). The details of these 2D lattices have been characterized primarily by atomic force microscopy, whose resolution is typically >4 nm. The criteria for 3D lattices (crystals) are stricter, because they are analyzed by x-ray crystallography, which can provide atomic resolution. Previous efforts to generate designed self-assembled 3D lattices have produced crystals that conformed to the design, but whose resolution was no better than 10 Å. Here, we report the crystal structure at 4 Å resolution of a designed, self-assembled, 3D crystal based on the tensegrity triangle. 5 This motif contains three helices that propagate in three linearly independent directions, producing a rhombohedral crystalline motif, with a = b = c = 68.3 Å; α=β=γ=102.4°. The stereoscopic image below shows the environment of a central tensegrity triangle and its six nearest neighbors. The resulting structure contains rhombohedral cavities with a volume of about 100 nm3 and a cross-sectional area of 19 nm2. The data demonstrate clearly that it is possible to design a 3D lattice using the techniques of self-assembly based on molecular recognition.
This research has been supported by grants from NIGMS, NSF, ARO, ONR and the W.M. Keck Foundation.
Dept of Chemistry