1ZH2

Crystal Structure Of The Calcium-Bound Receiver Domain Of Kdp Potassium Transport System Response Regulator KdpE

Summary for 1ZH2

• Entry DOI: 10.2210/pdb1zh2/pdb
• Related: 1zh3 1zh4
• Descriptor: KDP operon transcriptional regulatory protein kdpE, CALCIUM ION (3 entities in total)
• Functional Keywords: two-component system, gene regulation, transcription factor, kdp potassium transport system, doubly wound five-stranded beta-alpha fold, transcription
• Biological source: Escherichia coli
• Cellular location: Cytoplasm (Probable): P21866
• Total number of polymer chains: 2
• Total formula weight: 27056.90

Authors

Toro-Roman, A.,Wu, T.,Stock, A.M. (deposition date: 2005-04-22, release date: 2005-12-13, Last modification date: 2023-08-23)

Primary citation

Toro-Roman, A.,Wu, T.,Stock, A.M.
A common dimerization interface in bacterial response regulators KdpE and TorR.
Protein Sci., 14:3077-3088, 2005

PubMed Abstract: Bacterial response regulators are key regulatory proteins that function as the final elements of so-called two-component signaling systems. The activities of response regulators in vivo are modulated by phosphorylation that results from interactions between the response regulator and its cognate histidine protein kinase. The level of response regulator phosphorylation, which is regulated by intra-or extracellular signals sensed by the histidine protein kinase, ultimately determines the output response that is initiated or carried out by the response regulator. We have recently hypothesized that in the OmpR/PhoB subfamily of response regulator transcription factors, this activation involves a common mechanism of dimerization using a set of highly conserved residues in the alpha4-beta5-alpha5 face. Here we report the X-ray crystal structures of the regulatory domains of response regulators TorR (1.8 A), Ca(2+)-bound KdpE (2.0 A), and Mg(2+)/BeF(3)(-)-bound KdpE (2.2 A), both members of the OmpR/ PhoB subfamily from Escherichia coli. Both regulatory domains form symmetric dimers in the asymmetric unit that involve the alpha4-beta5-alpha5 face. As observed previously in other OmpR/PhoB response regulators, the dimer interfaces are mediated by highly conserved residues within this subfamily. These results provide further evidence that most all response regulators of the OmpR/ PhoB subfamily share a common mechanism of activation by dimerization.

PubMed: 16322582
DOI: 10.1110/ps.051722805

Experimental method

X-RAY DIFFRACTION (2 Å)