Dekanin/Dekan:

Min proteins are a class of proteins that is widely conserved among bacteria. In the rod-shaped bacterium Escherichia coli, Min proteins form spatiotemporal patterns which are characterized by concentration maxima that oscillate from one cell pole to the other. In this thesis, we use theoretical and experimental tools to characterize the Min system. We consider two mean field models of the Min system that emphasize different aspects of Min protein interactions inducing a dynamic instability. The first model assumes that MinD proteins feel mutual interactions in the membranebound state leading to an aggregating current that results in the formation of concentration maxima. In the second model, MinD and MinE bind to the membrane in a self-enhanced manner thereby generating a dynamic instability in the system. We study solutions of the dynamical systems and compare them with the patterns observed in living E.coli and in vitro. Both models are able to generate patterns similar to those observed in wild type E.coli. Oscillations in filamentous cells and the stochastic switching in very short cells are better described by the first model. In vitro patterning of the Min system is more aptly captured by the second description. Using fluorescence correlation spectroscopy in vivo, we obtain characteristic time constants of the Min system. We experimentally study pattern formation of the Min system in short E.coli and find stochastic switching of Min proteins instead of oscillations. iii Zusammenfassung Min-Proteine sind ein Teil des bakteriellen Zytoskeletts. Im stäbchenförmige