DNA supercoiling is an inherent consequence of twisting DNA and is critical for regulating gene expression and DNA replication. However, DNA supercoiling at a genomic scale in human cells is uncharacterized. To map supercoiling, we used biotinylated trimethylpsoralen as a DNA structure probe to show that the human genome is organized into supercoiling… (More)
The ability to monitor DNA polymerase activity with single-nucleotide resolution has been the cornerstone of a number of advanced single-molecule DNA sequencing concepts. Toward this goal, we report the first observation of the base-by-base DNA polymerase activity with single-base resolution at the single-molecule level. We describe the design and… (More)
Synthetic supramolecular zipper complexes have been used to quantify substituent effects on the free energies of aromatic stacking interactions. The conformational properties of the complexes have been characterised using NMR spectroscopy in CDCl(3), and by comparison with the solid state structures of model compounds. The structural similarity of the… (More)
The synthetic biology toolbox lacks extendable and conformationally controllable yet easy-to-synthesize building blocks that are long enough to span membranes. To meet this need, an iterative synthesis of α-aminoisobutyric acid (Aib) oligomers was used to create a library of homologous rigid-rod 310-helical foldamers, which have incrementally increasing… (More)
We examine an unusual case where a neutral hydrogen atom acts as a hydrogen-bond acceptor. The association constant between trihexylsilane and perfluoro-tert-butanol was measured as ∼0.8 M(-1) in cyclohexane. Computations and experimental NMR data are consistent with a weak, but favourable Si-H···HO interaction.