Activation and Densensitization in Bacterial Chemotaxis
Bacterial chemotaxis allows cells to respond to over 35 different There are transmembrane cell surface The bound state of the receptor intracellular protein kinase that can phosphorylate two chemotaxis system components, the CheY and the CheB proteins. When CheY is phosphorylated it modulates bacterial flagellar rotation and thus effects the cells' movement. When CheB is phosphorylated it increases its ability to modify the cell surface receptor and change its sensitivity. A model for the integration of these steps into a scheme that can explain the dynamic range, rapid response and sensitivity of the bacterial sensory system is described. This represents one example of a much larger group of "two component" sensory systems in bacteria.