Homooligomeric Nanostructure Transition from RNAs to DNAs

RNAs and DNAs with identical sequences often adopt distinct structures. To understand the connection between RNA and DNA structures of an identical sequence, we used the RNA square as an experimental model to study the structural transformation from RNAs to DNAs. Interestingly, we found that the RNA square can transform into a mixture of square and triangle by gradually replacing RNA with DNA nucleotides and finally transform into a DNA triangle by total DNA nucleotide replacement. The oxDNA simulation results reveal that the RNA–DNA hybrid square becomes destabilized, while a hybrid triangle emerges. Further, by reducing the loop length of the DNA motif, it could assemble into triangles, squares, or pentagons with sufficient flexibility, similar to the RNA ones. Our experimental results have demonstrated the different self-assembly pathways of RNA and DNA with the same sequence, which provides a homoassembly strategy for studying the structural transformation from RNAs to DNAs.