Coordination of chromosome unlinking and segregation

The objective is to understand mechanistically how the bacterial chromosome is organized and processed throughout the cell cycle, by addressing the molecular mechanism by which the SMC complex, MukBEF, acts in chromosome organisation and segregation. This will also generally inform mechanisms of SMC action, a crucial process in normal and pathological chromosome management in all organisms. The proposed research will use state-of-the-art methods to minimise ensemble averaging. By using quantitative live-cell single-molecule imaging that allows visualization of the assembly and action of molecular machines, alongside methods that allow the rapid production and removal of specific proteins, and which interfere with normal protein interactions, it will enable mechanistic in vivo biochemistry that will be complemented by elegant genetics and in vitro biochemistry. We will progress our work showing that the interaction between MukBEF and, TopoIV, is essential for timely chromosome unlinking, and that MatP, which binds multiple sites within the replication termination region, regulates the spatial cellular distribution of MukBEF and TopoIV. Finally, we will characterize the mechanism by which localised MukBEF clusters act to position and segregate newly replicated oris, while leading to global chromosome organization, timely chromosome segregation and efficient repair.