| Structural highlights
1id0 is a 1 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , |
| Activity: | Transferase, with EC number 2.7.11.8, 2.7.11.9, 2.7.11.10, 2.7.11.11, 2.7.11.12, 2.7.11.13, 2.7.11.21, 2.7.11.22, 2.7.11.24, 2.7.11.25, 2.7.11.30 and 2.7.12.1 2.7.11.1, 2.7.11.8, 2.7.11.9, 2.7.11.10, 2.7.11.11, 2.7.11.12, 2.7.11.13, 2.7.11.21, 2.7.11.22, 2.7.11.24, 2.7.11.25, 2.7.11.30 and 2.7.12.1 |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[PHOQ_ECOLI] Member of the two-component regulatory system PhoP/PhoQ involved in adaptation to low Mg(2+) environments and the control of acid resistance genes. In low periplasmic Mg(2+), PhoQ functions as a membrane-associated protein kinase that undergoes autophosphorylation and subsequently transfers the phosphate to PhoP, resulting in the expression of PhoP-activated genes (PAG) and repression of PhoP-repressed genes (PRG). In high periplasmic Mg(2+), acts as a protein phosphatase that dephosphorylates phospho-PhoP, resulting in the repression of PAG and may lead to expression of some PRG (By similarity). PhoP-regulated transcription is redox-sensitive, being activated when the periplasm becomes more reducing (deletion of dsbA/dsbB, or treatment with dithiothreitol). MgrB acts between DsbA/DsbB and PhoP/PhoQ in this pathway; the 2 periplasmic Cys residues of MgrB are required for its action on PhoQ, which then acts on PhoP. Mediates magnesium influx to the cytosol by activation of mgtA. Promotes expression of the two-component regulatory system rstA/rstB and transcription of the hemL, mgrB, nagA, slyB, vboR and yrbL genes.[1]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
PhoQ is a transmembrane histidine kinase belonging to the family of two-component signal transducing systems common in prokaryotes and lower eukaryotes. In response to changes in environmental Mg(2+) concentration, PhoQ regulates the level of phosphorylated PhoP, its cognate transcriptional response-regulator. The PhoQ cytoplasmic region comprises two independently folding domains: the histidine-containing phosphotransfer domain and the ATP-binding kinase domain. We have determined the structure of the kinase domain of Escherichia coli PhoQ complexed with the non-hydrolyzable ATP analog adenosine 5'-(beta,gamma-imino)triphosphate and Mg(2+). Nucleotide binding appears to be accompanied by conformational changes in the loop that surrounds the ATP analog (ATP-lid) and has implications for interactions with the substrate phosphotransfer domain. The high resolution (1.6 A) structure reveals a detailed view of the nucleotide-binding site, allowing us to identify potential catalytic residues. Mutagenic analyses of these residues provide new insights into the catalytic mechanism of histidine phosphorylation in the histidine kinase family. Comparison with the active site of the related GHL ATPase family reveals differences that are proposed to account for the distinct functions of these proteins.
Structural and mutational analysis of the PhoQ histidine kinase catalytic domain. Insight into the reaction mechanism.,Marina A, Mott C, Auyzenberg A, Hendrickson WA, Waldburger CD J Biol Chem. 2001 Nov 2;276(44):41182-90. Epub 2001 Aug 7. PMID:11493605[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Kato A, Tanabe H, Utsumi R. Molecular characterization of the PhoP-PhoQ two-component system in Escherichia coli K-12: identification of extracellular Mg2+-responsive promoters. J Bacteriol. 1999 Sep;181(17):5516-20. PMID:10464230
- ↑ Marina A, Mott C, Auyzenberg A, Hendrickson WA, Waldburger CD. Structural and mutational analysis of the PhoQ histidine kinase catalytic domain. Insight into the reaction mechanism. J Biol Chem. 2001 Nov 2;276(44):41182-90. Epub 2001 Aug 7. PMID:11493605 doi:10.1074/jbc.M106080200
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