Ruojie Sha and the Seeman Group published a study, "The Formation and Displacement of Ordered DNA Triplexes in Self-Assembled Three-Dimensional DNA Crystals" in the Journal of the American Chemical Society. The authors list includes: Yue Zhao, Arun Richard Chandrasekaran (Albany), David A. Rusling (Portsmouth), Karol Woloszyn, Yudong Hao, Carina Hernandez, Simon Vecchioni, Yoel P. Ohayon, Chengde Mao (Purdue), Nadrian C. Seeman, and Ruojie Sha.
Abstract: Reconfigurable structures engineered through DNA hybridization and self-assembly offer both structural and dynamic applications in nanotechnology. Here, we have demonstrated that strand displacement of triplex-forming oligonucleotides (TFOs) can be translated to a robust macroscopic DNA crystal by coloring the crystals with covalently attached fluorescent dyes. We show that three different types of triplex strand displacement are feasible within the DNA crystals and the bound TFOs can be removed and/or replaced by (a) changing the pH from 5 to 7, (b) the addition of the Watson–Crick complement to a TFO containing a short toehold, and (c) the addition of a longer TFO that uses the duplex edge as a toehold. We have also proved by X-ray diffraction that the structure of the crystals remains as designed in the presence of the TFOs.
This research was supported by the Office of Naval Research, the Department of Energy, and the National Science Foundation.
Note that Ned Seeman is dearly missed, but the work continues.
