Artificial synthesis of supramolecular protein complexes with synthetic DNA scaffolds

MAB Baker, AJ Tuckwell, JF Berengut, S Xu and LK Lee

The University of New South Wales

Supramolecular protein complexes such as the bacterial flagellar motor and the type III secretion injectisome assemble spontaneously from hundreds of subunits. We recently elucidated a structural and thermodynamic model for how self-assembly can be triggered and steered by a structural template (1) and seek to replicate this process by artificially constructing supramolecular protein assemblies in vitro. This entails the design and synthesis of custom nanoscale scaffolds constructed from DNA, which are structurally characterised with electron microscopy, atomic force microscopy and small-angle X-ray scattering, and the chemical conjugation of protein subunits to specific sites on DNA nanoscaffolds to initiate and steer self-assembly. Artificial synthesis allows for the direct observation and manipulation of the self-assembly of supramolecular protein structures, new avenues for high-resolution structural analysis and the design of novel complex vaccines. (1) Baker, M. A. B., Hynson, R. M. G., Ganuelas, L. A., Mohammadi, N. S., Liew, C. W., Rey, A. A., et al. (2016). Domain-swap polymerization drives the self-assembly of the bacterial flagellar motor. Nature Structural & Molecular Biology.