Project Details
Projekt
Structural Analysis of the Escherichia coli KdpFABC Holoenzyme and its Funktional Domains
Applicant
Professor Dr. Karlheinz Altendorf
Subject Area
Metabolism, Biochemistry and Genetics of Microorganisms
Term
from 1999 to 2006
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 5175070
In the case of changes in turgor across the cell membrane of Escherichia coli the cell induces the high-affinity K+-translocating KdpFABC complex, a P-type transport ATPase of unique structure. Since a high resolution structure of any of the P-type ATPases is so far not available, the KdpFABC complex and a functionally important, but soluble domain of KdpB (catalytic subunit) should be crystallized and the structure should be solved by X-ray crystallography. The dynamics (ATP binding, phosphorylation) of the soluble domain should be determined in solution by NMR. The expression of the kdpFABC operon is regulated by the sensor kinase KdpD (membrane-bound) and the response regulator KdpE (soluble). The communication between these two regulatory proteins occurs via phosphorylation and dephosphorylation reactions. Both proteins, as well as a functionally important, but soluble domain of KdpD, should be crystallized and their structure should be solved by X-ray crystallography. Crystals of KdpE have already been obtained and diffract to a resolution of 2.2 A. Since the N-terminal, soluble domain of KdpD plays an important role in the regulation of the phosphatase activity (ATP binding), the dynamics of this part should be determined in solution by NMR. Since the regulatory proteins involved in environmental signalling all exhibit a similar structure (modular design), the information obtained for KdpD and KdpE are pertinent for the understanding of the signal transduction mechanism at the molecular level.
DFG Programme
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