The flagellum is a unique molecular machine driving bacterial movement through liquid environments. Bacteria are propelled forward by rotation of an external long whip-like flagellar filament. Rotation of the filament is achieved via the action of a universal joint known as the hook and a basal motor anchored into the bacterial cell envelope. The flagellar filament is a major antigen recognized by hosts during bacterial infections. A significant number of bacterial species encode multiple copies of the filament building block - flagellin. A complex regulatory network controls the assembly of the flagellum and the number per cell, which varies between different species.
Our research focuses on the fundamental understanding of how bacteria regulate flagellar assembly and how a cell coordinates the assembly of unrelated molecular machines. We study how bacterial species such as the pathogen Salmonella enterica maintain a discrete number of flagellar per cell during cell growth and division. We complement our study of flagellar abundance with research to understanding how a filament is assembled from multiple flagellins, a trait maintained by many bacterial species. We are also using our work on flagellar systems to begin to investigate the distribution and localization of other molecular machines in the bacterial cell envelope and how they spatially interact with each other to maintain their functional output.
