Programmable Transformations of DNA Origami Made of Small Modular Dynamic Units.

Dynamic DNA origami has been employed for generating a rich repository of molecular nanomachines that are capable of sensing various cues and changing their conformations accordingly. The common design principle of the existing DNA origami nanomachines is that each dynamic DNA origami is programmed to transform in a specific manner, and the nanomachine needs to be redesigned to achieve a different form of transformation. However, it remains challenging to enable a multitude of controlled transformations in a single design of dynamic DNA nanomachine. Here we report a modular design method to programmatically tune the shapes of a DNA origami nanomachine. The DNA origami consists of small, modular DNA units, and the length of each unit can be selectively changed by toehold-mediated strand displacement. By use of different combinations of trigger DNA strands, modular DNA units can be selectively transformed, leading to the programmable reconfiguration of the overall dimensions and curvatures of DNA origami. The modular design of programmable shape transformation of DNA origami can find potential applications in more sophisticated molecular nanorobots and smart drug delivery nanocarriers.