On January 22, at 15.00 in PJ salen, Mark Leake from the University of York, UK, will give a seminar entitled: "From DNA Chirality to Bacterial Condensates: Single-Molecule Biophysics of Topology, Mechanics and Phase Separation".
Symmetry breaking underpins life across scales, from molecular chirality to mesoscale cellular organisation. We combine cutting-edge single-molecule manipulation and live-cell imaging to reveal how physical principles of twist, topology and phase separation govern biological function. Using our breakthrough COMBI-Tweez technology, which integrates optical and magnetic tweezers with nanoscale fluorescence microscopy, we simultaneously control and measure twist, extension and topology of individual DNA molecules in real time. This enables direct observation of reversible plectoneme formation, mechanical responses under physiological force and torque, and protein-induced perturbations of DNA topology, as well as the engineering of braided DNA as a ‘DNA rope’ smart biomaterial. In parallel, we uncover how bacterial aggresomes—mesoscale membraneless condensates formed by liquid–liquid phase separation—safeguard mRNA during stress. New data reveal that ribosomal proteins L2 and L15 reciprocally tune the condensate’s state of fluidification, modulating mRNA protection and cellular recovery. Together, these approaches reveal features of a unified biophysical framework linking molecular chirality, mechanics and phase behaviour to cellular resilience and function.
Mark is Anniversary Chair of Biological Physics, EPSRC Fellow, Coordinator Physics of Life Group and Chair of the UK Physics of Life PoLNET network. Read more here.