ACID ORIGAMI Single-stranded DNA and RNA origami

INTRODUCTION: Self-foldingofan informationcarrying polymer into a compact particle with defined structure and function (for example, folding of a polypeptide into a protein) is foundational to biology and offers attractive potential as a synthetic strategy. Over the past three decades, nucleic acids have been used to create a variety of complex nanoscale shapes and devices. In particular, multiple DNA strands have beendesigned to self-assemble intouser-specified structures, with or without the help of a long scaffold strand. In recent years, RNA has also emerged as a unique, programmable material, offering distinct advantages for molecular selfassembly. On the other hand, biological macromolecules, such as proteins (or protein domains), typically fold from a single polymer into a welldefined compact structure. The ability to fold de novo designed nucleic acid nanostructures in a similar manner would enable unimolecular folding instead ofmultistrandassembly and even replication of such structures. However, a general strategy to construct large [>1000 nucleotides (nt)] single-stranded origami (ssOrigami) remains tobedemonstratedwhereasingle-stranded nucleic acid folds into a user-specified shape.