Transmembrane Signaling in Bacillus Subtilis Chemotaxis: Determination of the Packing Organization and Structural Changes of McpB in Response to Ligand

101 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2003.In Chapter 5, we investigated the complementation and activity of a methylesterase phosphorylation point mutant, C-terminal truncated mutant, and a serine active site mutant in vivo to the attractant asparagine to determine the role CheB phosphorylation plays in regulation of receptor demethylation events. Phosphorylation was required for normal methylesterase activity and complementation in vivo; however, enhanced methanol formation occurred briefly without activation of CheB. Therefore, demethylation must involve a hyperactive receptor transition state between ligand free "relaxed" states and ligand bound "adapted" states. We speculated that the hypersensitive receptor transition is an intrinsic property of receptors which is independent of "receptor clustering" or CheB phosphorylation.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD