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3ezh

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Crystal Structure of the E. coli Histidine Kinase NarX Sensor Domain in Complex with Nitrate

Structural highlights

3ezh is a 2 chain structure with sequence from Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.7Å
Ligands:	,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

NARX_ECOLI Acts as a sensor for nitrate/nitrite and transduces signal of nitrate availability to the NarL protein and of both nitrate/nitrite to the NarP protein. NarX probably activates NarL and NarP by phosphorylation in the presence of nitrate. NarX also plays a negative role in controlling NarL activity, probably through dephosphorylation in the absence of nitrate.

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

Histidine kinase receptors are a large family of membrane-spanning proteins found in many prokaryotes and some eukaryotes. They are a part of two-component signal transduction systems, which each comprise a sensor kinase and a response regulator and are involved with the regulation of many cellular processes. NarX is a histidine kinase receptor that responds to nitrate and nitrite to effect regulation of anaerobic respiration in various bacteria. We present high-resolution X-ray crystal structures of the periplasmic sensor domain from Escherichia coli NarX in a complex with nitrate and in the apo state. Our analysis reveals that nitrate-binding induces conformation changes that result in a piston-type displacement between the N- and C-terminal helices of the periplasmic domain. Such conformational changes might represent a conserved mechanism of signaling in histidine kinases by which ligand binding is communicated across the lipid bilayer.

Structural Analysis of Ligand Stimulation of the Histidine Kinase NarX.,Cheung J, Hendrickson WA Structure. 2009 Feb 13;17(2):190-201. PMID:19217390^[1]

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

References

↑ Cheung J, Hendrickson WA. Structural Analysis of Ligand Stimulation of the Histidine Kinase NarX. Structure. 2009 Feb 13;17(2):190-201. PMID:19217390 doi:S0969-2126(09)00030-6