3bqa

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Revision as of 08:09, 25 October 2017

Crystal Structure of an E.coli PhoQ Sensor Domain Mutant

Structural highlights

3bqa is a 2 chain structure with sequence from "bacillus_coli"_migula_1895 "bacillus coli" migula 1895. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
Related:	3bq8
Gene:	phoQ ("Bacillus coli" Migula 1895)
Activity:	Histidine kinase, with EC number 2.7.13.3
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

The PhoP-PhoQ two-component system is a well studied bacterial signaling system that regulates virulence and stress response. Catalytic activity of the histidine kinase sensor protein PhoQ is activated by low extracellular concentrations of divalent cations such as Mg2+, and subsequently the response regulator PhoP is activated in turn through a classic phosphotransfer pathway that is typical in such systems. The PhoQ sensor domains of enteric bacteria contain an acidic cluster of residues (EDDDDAE) that has been implicated in direct binding to divalent cations. We have determined crystal structures of the wild-type Escherichia coli PhoQ periplasmic sensor domain and of a mutant variant in which the acidic cluster was neutralized to conservative uncharged residues (QNNNNAQ). The PhoQ domain structure is similar to that of DcuS and CitA sensor domains, and this PhoQ-DcuS-CitA (PDC) sensor fold is seen to be distinct from the superficially similar PAS domain fold. Analysis of the wild-type structure reveals a dimer that allows for the formation of a salt bridge across the dimer interface between Arg-50' and Asp-179 and with nickel ions bound to aspartate residues in the acidic cluster. The physiological importance of the salt bridge to in vivo PhoQ function has been confirmed by mutagenesis. The mutant structure has an alternative, non-physiological dimeric association.

Crystal structure of a functional dimer of the PhoQ sensor domain.,Cheung J, Bingman CA, Reyngold M, Hendrickson WA, Waldburger CD J Biol Chem. 2008 May 16;283(20):13762-70. Epub 2008 Mar 18. PMID:18348979^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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
↑ Cheung J, Bingman CA, Reyngold M, Hendrickson WA, Waldburger CD. Crystal structure of a functional dimer of the PhoQ sensor domain. J Biol Chem. 2008 May 16;283(20):13762-70. Epub 2008 Mar 18. PMID:18348979 doi:10.1074/jbc.M710592200

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/3bqa"

@@ Line 1: / Line 1: @@
 ==Crystal Structure of an E.coli PhoQ Sensor Domain Mutant==
 <StructureSection load='3bqa' size='340' side='right' caption='[[3bqa]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
@@ Line 7: / Line 8: @@
 <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">phoQ ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</td></tr>
 <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Histidine_kinase Histidine kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.13.3 2.7.13.3] </span></td></tr>
-<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3bqa FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3bqa OCA], [http://pdbe.org/3bqa PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3bqa RCSB], [http://www.ebi.ac.uk/pdbsum/3bqa PDBsum]</span></td></tr>
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3bqa FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3bqa OCA], [http://pdbe.org/3bqa PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3bqa RCSB], [http://www.ebi.ac.uk/pdbsum/3bqa PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3bqa ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 30: / Line 31: @@
 </div>
 <div class="pdbe-citations 3bqa" style="background-color:#fffaf0;"></div>
-==See Also==
-*[[PhoP-PhoQ|PhoP-PhoQ]]
 == References ==
 <references/>

3bqa

From Proteopedia

Revision as of 08:09, 25 October 2017

Crystal Structure of an E.coli PhoQ Sensor Domain Mutant

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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