Molecular and mechanistic basis for spatiotemporal organization of polar flagella

• Applicants: Professor Dr. Gert Bange; Professor Dr. Kai Thormann
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms ; Cell Biology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 495924434

Many bacteria are motile by flagella, which provides them with a significant advantage in environmental proliferation. Flagella are proteinaceous fibers rotated by intricate sophisticated nanomachines, which allow bacteria to move in accordance with chemical gradients. It has long been established that place and number of flagella (flagellation pattern) vary among the species. There are two basic flagellation patterns existing: either one or more filaments emerge at one both cell poles or they occur at lateral positions away from the cell pole. The number of flagella, flagellar localization pattern and flagellar activity in a huge number of bacterial species is regulated in a spatiotemporal fashion by two interacting proteins, the SRP-type GTPase FlhF and the MinD-like ATPase FlhG. The mechanism by which the two proteins act are still mostly elusive. In this study, we will combine the complementary expertises of the two participating groups to further investigate how FlhF and FlhG establish the very common monopolar flagellation pattern using our well-developed model species Shewanella putrefaciens. More specifically, we will further determine how FlhG links flagella assembly with transcriptional control of the corresponding building blocks, and how timely flagella synthesis is regulated. Furthermore, we will investigate how FlhF directs the nascent flagellar structure to the designated cell pole, and how direct interaction between FlhF and FlhG is spatiotemporally controlled. We expect that the approaches will enable to generate the first comprehensive model of an FlhF/FlhG-mediated mechanism in bacteria and to give insights into how the two proteins may function to establish other, different flagellar patterns.

• DFG Programme: Research Grants