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KdpE DNA-binding transcriptional activator

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:[17536175][11931551][7855422]|. The genes of this system and their regulators are widely distributed among the gram-negative and gram-positive bacteria and archaea |CITS:[17536175]|. 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:[1532388]|. 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:[1532387]|. It has been suggested that sometimes the genes of the two operons are transcribed in only one transcript |CITS:[1532387]|. In some species the arrangement of these genes in the genome is different than in Escherichia coli |CITS:[17536175]|.
KdpD exhibits both kinase and phosphatase activities towards KdpE |CITS:[9099740][11123681][9651326]|. Under K+-limiting conditions or under osmotic stress imposed by a salt, autophosphorylation of KdpD at His-673 is stimulated |CITS:[17536175][11016946][8223625]|. Subsequently, the phosphate group is transferred from KdpD to Asp-52 of KdpE |CITS:[8437514][1630317][9099740]|, leading to the dimerization and activation of KdpE |CITS:[16322582]|. At high concentrations of K+, the kinase activity of KdpD is inhibited |CITS:[11016946]|.
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:[19101563]|.
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Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
KdpE Non-Functional   Apo [BPP], [IEP], [IPI] [1], [2]
KdpE-Phosphorylated Functional Covalent Holo [BPP], [IEP], [IPI] [1], [2]
Evolutionary Family: OmpR
Sensing class: External-Two-component systems
Connectivity class: Local Regulator
Gene name: kdpE
  Genome position: 721056-721733
  Length: 678 bp / 225 aa
Operon name: kdpDE
TU(s) encoding the TF:
Transcription unit        Promoter

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)
membrane (3)
Regulated operon(s) kdpFABC
First gene in the operon(s) kdpF
Simple and complex regulons KdpE
Simple and complex regulatory phrases Regulatory phrase (List of promoters regulated by the phrase)

Transcription factor binding sites (TFBSs) arrangements       

  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] [3], [4]

Evolutionary conservation of regulatory elements    
     Note: Evolutionary conservation of regulatory interactions and promoters is limited to gammaproteobacteria.
Promoter-target gene evolutionary conservation


 [BPP] Binding of purified proteins

 [IEP] Inferred from expression pattern

 [IPI] Inferred from physical interaction

 [GEA] Gene expression analysis

 [HIBSCS] Human inference based on similarity to consensus sequences

 [SM] Site mutation


 [1] 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

 [2] 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

 [3] 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

 [4] Sugiura A., Nakashima K., Tanaka K., Mizuno T., 1992, Clarification of the structural and functional features of the osmoregulated kdp operon of Escherichia coli., Mol Microbiol. 6(13):1769-76