Dynamic interaction between the CpxA sensor kinase and the periplasmic accessory protein CpxP mediates signal recognition in E. coli.

Two-component systems, consisting of an inner membrane sensor kinase and a cytosolic response regulator, allow bacteria to respond to changes in the environment. Some two-component systems are additionally orchestrated by an accessory protein that integrates additional signals. It is assumed that spatial and temporal interaction between an accessory protein and a sensor kinase modifies the activity of a two-component system.

The sensor kinase DctS forms a tripartite sensor unit with DctB and DctA for sensing C4-dicarboxylates in Bacillus subtilis.

The DctSR two-component system of Bacillus subtilis controls the expression of the aerobic C4-dicarboxylate transporter DctA. Deletion of DctA leads to an increased dctA expression. The inactivation of DctB, an extracellular binding protein, is known to inhibit the expression of dctA.

Membrane-SPINE: a biochemical tool to identify protein-protein interactions of membrane proteins in vivo.

Unlabelled: Membrane proteins are essential for cell viability and are therefore important therapeutic targets(1-3). Since they function in complexes(4), methods to identify and characterize their interactions are necessary(5). To this end, we developed the Membrane Strep-protein interaction experiment, called Membrane-SPINE(6).