In bacteria, the genetic material is often in a crowded and congested state. For instance, the size of the bacterial nucleoid, the structure that contains the bacterial chromosome associated with proteins, is typically sub-micron whereas the length of the DNA is around 1 mm. The genome is hence compacted by a factor of thousand.

Expected breakthroughs of the PhD project are to develop and to couple methods for the investigation of nucleoprotein structures. A multidisciplinary approach will be developed at the Leon Brillouin laboratory in collaboration with a group at SOLEIL Synchrotron (DISCO beamline). The PhD student will investigate the effect of protein-mediated bridging on the structural properties of bacterial DNA. In particular, we aim to study a new way of DNA structuring by a bacterial protein forming amyloid structures, called Hfq. DNA condensation induced by amyloids associated to neuropathologies has been reported previously. Here the amyloid domain of Hfq serves the physiology of the cell to ensure DNA compaction. Examining the interaction of Hfq with DNA will thus be paramount for understanding bacterial nucleoid compaction and functional consequences. The expected benefits for this PhD project will be twice: the development of methods for the analysis of biological nanostructures, but also new opportunities for the development of antibiotics.