About the Project
Gram-negative bacteria have evolved to survive in diverse ecological niches. Some species are pathogenic, while others colonise the mammalian gut and aid food digestion. The major distinguishing feature of Gram-negative organisms compared to their Gram-positive counterparts is the existence of an additional outer membrane (OM), which has an important barrier function for the organism. We have developed fluorescent labelling techniques that enable a specific OM protein (OMP) to be localised and tracked at the single-molecule level as a bacterial cell grows and divides . Using this biotechnology we revealed the unique spatio-temporal dynamics of OMPs; specifically, OMPs undergo very restricted two-dimensional diffusion, OMPs reside in islands containing the biogenesis (BAM) machinery that inserted them, and OMPs segregate to the poles during OM biogenesis . This demonstrates that old and new OMPs partition between the poles and mid-cell regions, respectively, of a dividing Gram-negative cell. As a consequence, bacterial cells with a completely new OM proteome can appear within only two generations. This project will investigate how this (binary) partitioning might coordinate processes required for OM integrity and maintenance, and dictate the assembly of periplasm-spanning molecular machines involved in OM biogenesis and antibiotic efflux. Cutting-edge single-molecule fluorescent labelling and imaging techniques will be used to reveal links between this newly discovered endogenous mechanism for continuous OMP turnover and how a growing Gram-negative cell interacts with and adapts to its environment.
 Rassam, P., et al. (2015) Supramolecular assemblies underpin turnover of outer membrane proteins in bacteria. Nature 523: 333-336.
 Kleanthous, C., Rassam, P. and Baumann, C.G. (2015) Protein-protein interactions and the spatiotemporal dynamics of bacterial outer membrane proteins. Curr. Opin. Struct. Biol. 35: 109-115.
This is a self-funded project. Applicants need to have adequate funds to meet the costs of a self-funded research project including tuition fees and living expenses for the duration of the research programme. Please see information on tuition fee costs, living expenses and funding opportunities.