Toward Single-Molecule DNA Sequencing with Engineered Nanopores

Single-molecule DNA sequencing with nanopores is a promising concept for advancing the next generation of rapid and low cost sequencing technologies. A proposed approach in this field involves moving a single-stranded DNA (ssDNA) through a narrow pore under the influence of an electric field and identifying the nucleobases as they pass by a reading-head located within the pore.  A key challenge is to work out how to ratchet a DNA strand through a nanopore at the appropriate speed and time intervals that are commensurate with real-time sequential nucleobase identification. In this lecture I will highlight key recent advances in this field and in particular describe an approach that exploits the intrinsic motor function of DNA polymerases to effect stepwise DNA strand translocation through an alpha-hemolysin (aHL) protein pore. The system is based on a single-species supramolecular nanopore construct, whose configurational dynamic features provide the means for real-time monitoring of DNA strand translocation and DNA polymerase function.