Crystal‐Structure‐Guided Design of Self‐Assembling RNA Nanotriangles

RNA nanotechnology uses RNA structural motifs to build nanosized architectures that assemble through selective base‐pair interactions. Herein, we report the crystal‐structure‐guided design of highly stable RNA nanotriangles that self‐assemble cooperatively from short oligonucleotides. The crystal structure of an 81 nucleotide nanotriangle determined at 2.6 Å resolution reveals the so‐far smallest circularly closed nanoobject made entirely of double‐stranded RNA. The assembly of the nanotriangle architecture involved RNA corner motifs that were derived from ligand‐responsive RNA switches, which offer the opportunity to control self‐assembly and dissociation.