A poly(thymine)–melamine duplex for the assembly of DNA nanomaterials

July 30, 2020


A poly(thymine)–melamine duplex for the assembly of DNA nanomaterials


Qian Li, Jiemin Zhao, Longfei Liu, Sagun Jonchhe, Felix J. Rizzuto, Shankar Mandal, Huawei He, Sansen Wei, Hanadi F. Sleiman, Hanbin Mao, Chengde Mao




Nature Materials


The diversity of DNA duplex structures is limited by a binary pair of hydrogen-bonded motifs. Here we show that poly(thymine) self-associates into antiparallel, right-handed duplexes in the presence of melamine, a small molecule that presents a triplicate set of the hydrogen-bonding face of adenine. X-ray crystallography shows that in the complex two poly(thymine) strands wrap around a helical column of melamine, which hydrogen bonds to thymine residues on two of its three faces. The mechanical strength of the thymine–melamine–thymine triplet surpasses that of adenine–thymine base pairs, which enables a sensitive detection of melamine at 3 pM. The poly(thymine)–melamine duplex is orthogonal to native DNA base pairing and can undergo strand displacement without the need for overhangs. Its incorporation into two-dimensional grids and hybrid DNA–small-molecule polymers highlights the poly(thymine)–melamine duplex as an additional tool for DNA nanotechnology.




Circular dichroism, DNA structure, Secondary structure, Ligand binding, Nanostructures, Materials, Biochemistry