The Min protein system, comprised of MinC, MinD and MinE, functions to ensure that the cytokinetic septum formed during bacterial binary fission is placed at midcell in gram negative bacteria. When bound to ATP, MinD binds to the cell membrane and recruits MinC, forming a complex which inhibits formation of the cell division septum. MinE plays a central role in the regulation of this process by opposing this inhibition through interactions with MinD that displace MinC and site-selectively

more »

... formation of the cell division septum at midcell. However, the amino acid residues of MinE that are important for this interaction have yet to be delineated. In this thesis, I present data from an in vitro ATPase assay where I examined the ability of MinE mutant proteins from Neisseria gonorrhoeae ( N. gonorrhoeae), and synthetic peptides corresponding to the N-terminal amino acids of N. gonorrhoeae, to stimulate the ATPase activity of MinD from N. gonorrhoeae. The in vitro experimental data suggests that a sequence of five amino acids in the N-terminus of MinE plays a crucial role in MinE's ability to stimulate MinD ATPase activity and suggests that the N-terminal region of MinE is a functionally autonomous domain. To support the in vitro data, I also present preliminary data from an in vivo assay examining select MinE mutants. The preliminary in vivo experimental data supports the in vitro data, suggesting the importance of five amino acids in the N-terminus of MinE. Finally, I present spectroscopic data to complement my findings from both in vivo and in vitro assays. The results from this study have implications for all current theories regarding the mechanism by which MinE ensures that cell division occurs exclusively at midcell in gram negative bacteria.