Functional dynamics and crystallization of the sensor kinase KdpD of Escherichia coli

• Applicant: Professor Dr. Karlheinz Altendorf
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2009 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 145676105

Under K+-limiting conditions in the medium E. coli is synthesizing the high-affmity K+ transport system KdpFABC (P-type ATPase). The expression of the kdpFABC operon is regulated by the histidine kinase KdpD and the response regulator KdpE, constituting a typical bacterial two-component system. Since the stimulus, which is perceived by KdpD, is still not known, we would like to test the hypothesis that changes in the membrane potential are sensed by KdpD. In this context we will also search for interaction partners of KdpD, which might play a role in stimulus perception. Furthermore, we will clarify the role of the Walker A/B motif (ATP binding) in the input domain of KdpD. In addition, the dynamic interplay of the N- and C-terminal domains of KdpD during stimulus perception and signal transduction within the protein will be studied by EPR spectroscopy. Since the knowledge of the structure of KdpD forms the basis for the understanding of its function and its communication specificity, we will try to crystallize KdpD and solve the structure by X-ray crystallography. All the data obtained for KdpD will have an impact for the understanding of molecular events in stimulus perception and signal transduction in regulatory networks in bacteria.

• DFG Programme: Research Grants