PMID:12453214
| Citation |
Yoshida, T, Qin, L and Inouye, M (2002) Formation of the stoichiometric complex of EnvZ, a histidine kinase, with its response regulator, OmpR. Mol. Microbiol. 46:1273-82 |
|---|---|
| Abstract |
EnvZ, a histidine kinase, and its cognate response regulator OmpR of Escherichia coli are responsible for adaptation to external osmotic changes by regulating the levels of the outer membrane porin proteins, OmpF and OmpC. The osmosensor, EnvZ, has dual enzymatic functions with OmpR kinase and OmpR-P phosphatase. Here, we demonstrate that the cytoplasmic kinase domain of EnvZ (EnvZc) and OmpR are able to form a 1:1 complex detected by native PAGE. This indicates that two OmpR molecules can bind to one EnvZc dimer. As this 1:1 EnvZc/OmpR complex is formed even in the presence of a large excess of EnvZc, OmpR binding to EnvZc is co-operative. The complex formation is also observed between EnvZc and phosphorylated OmpR for the phosphatase reaction. OmpR-P bound to EnvZc was readily released upon the addition of OmpR, indicating that OmpR and OmpR-P can compete for the binding to EnvZ. On the basis of these results, a model is discussed to explain how cellular OmpR-P concentrations are regulated in response to medium osmolarity. |
| Links | |
| Keywords |
Adenosine Triphosphate/metabolism; Bacterial Outer Membrane Proteins/chemistry; Bacterial Outer Membrane Proteins/genetics; Bacterial Outer Membrane Proteins/metabolism; Bacterial Proteins; Cations, Divalent; Electrophoresis, Polyacrylamide Gel; Escherichia coli/genetics; Escherichia coli/metabolism; Escherichia coli/physiology; Escherichia coli Proteins/genetics; Escherichia coli Proteins/metabolism; Gene Expression Regulation, Bacterial; Multienzyme Complexes/chemistry; Multienzyme Complexes/genetics; Multienzyme Complexes/metabolism; Osmolar Concentration; Porins/genetics; Porins/metabolism; Protein Kinases/chemistry; Protein Kinases/genetics; Protein Kinases/metabolism; Signal Transduction; Trans-Activators/chemistry; Trans-Activators/genetics; Trans-Activators/metabolism |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.