|Synonyms: KdpE-Phosphorylated, KdpE|
KdpE is a transcriptional regulator involved in the regulation of genes involved in a high-affinity potassium (K+) uptake system |CITS:|. The genes of this system and their regulators are widely distributed among the gram-negative and gram-positive bacteria and archaea |CITS:|. KdpE activates expression of the kdpFABC operon encoding the P-type ATPase KdpFABC, a high-affinity potassium transport system.
KdpE belongs to the two-component system KdpD/KdpE |CITS:|. The operon containing both genes, kdpE, encoding the response regulator, and kdpD, encoding the sensor kinase, is located next to and in the same direction as an operon (kdpFABC) regulated by KdpE |CITS:|. It has been suggested that sometimes the genes of the two operons are transcribed in only one transcript |CITS:|. In some species the arrangement of these genes in the genome is different than in Escherichia coli |CITS:|.
KdpD exhibits both kinase and phosphatase activities towards KdpE |CITS:|. Under K+-limiting conditions or under osmotic stress imposed by a salt, autophosphorylation of KdpD at His-673 is stimulated |CITS:|. Subsequently, the phosphate group is transferred from KdpD to Asp-52 of KdpE |CITS:|, leading to the dimerization and activation of KdpE |CITS:|. At high concentrations of K+, the kinase activity of KdpD is inhibited |CITS:|.
Under salt stress, the universal stress protein UspC binds to KdpE and stabilizes the KdpD-KdpE-DNA complex; therefore, this system can be activated even though K+ accumulates under this environmental condition |CITS:|.
In addition, expression of the kdpFABC operon is regulated by the phosphoryl group transfer chain Ntr-PTS: dephosphorylated enzyme IIANtr binds to KdpD, and this interaction strongly stimulates KdpD kinase activity |CITS:|.Read more >
KdpE is a member of the OmpR/PhoB subfamily of response regulators |CITS:| and binds a 23-bp recognition sequence |CITS:|. The crystal structure of KdpE with and without bound beryllium fluoride has been solved |CITS:|.
Overproduction of KdpE causes a drug resistance phenotype |CITS:|.
|Sensing class:||External-Two-component systems|
|Connectivity class:||Local Regulator|
|Length:||678 bp / 225 aa|
|TU(s) encoding the TF:||
|Regulated gene(s)||kdpA, kdpB, kdpC, kdpF|
|Multifun term(s) of regulated gene(s)||
MultiFun Term (List of genes associated to the multifun term)
The P-type ATPase (P-ATPase) Superfamily (4)
kdpA, kdpB, kdpC, kdpF
kdpA, kdpB, kdpC
|First gene in the operon(s)||kdpF|
|Simple and complex regulons|
|Simple and complex regulatory phrases||
Regulatory phrase (List of promoters regulated by the phrase)
|Functional conformation||Function||Promoter||Sigma factor||Central Rel-Pos||Distance to first Gene||Genes||Sequence||LeftPos||RightPos||Evidence (Confirmed, Strong, Weak)||References|
|KdpE-Phosphorylated||activator||kdpFp||Sigma70||-63.0||-91.0||kdpF, kdpA, kdpB, kdpC||
|728904||728920||[BPP], [GEA], [HIBSCS], [SM]||, |
|Evolutionary conservation of regulatory elements|
 Heermann R., Weber A., Mayer B., Ott M., Hauser E., Gabriel G., Pirch T., Jung K., 2009, The universal stress protein UspC scaffolds the KdpD/KdpE signaling cascade of Escherichia coli under salt stress., J Mol Biol. 386(1):134-48
 Yamamoto K., Hirao K., Oshima T., Aiba H., Utsumi R., Ishihama A., 2005, Functional characterization in vitro of all two-component signal transduction systems from Escherichia coli., J Biol Chem. 280(2):1448-56
 Narayanan A., Paul LN., Tomar S., Patil DN., Kumar P., Yernool DA., 2012, Structure-function studies of DNA binding domain of response regulator KdpE reveals equal affinity interactions at DNA half-sites., PLoS One. 7(1):e30102