Folding RNA–protein complex into designed nanostructures

RNA–protein (RNP) complexes are promising biomaterials for the fields of nanotechnology and synthetic biology. Protein-responsive RNA sequences (RNP motifs) can be integrated into various RNAs, such as messenger RNA, short-hairpin RNA, and synthetic RNA nano-objects for a variety of purposes. Direct observation of RNP interaction in solution at high resolution is important in the design and construction of RNP-mediated nanostructures. Here we describe a method to construct and visualize RNP nanostructures that precisely arrange a target protein on the RNA scaffold with nanometer scale. High-speed AFM (HS-AFM) images of RNP nanostructures show that the folding of RNP complexes of defined sizes can be directly visualized at single RNP resolution in solution.