5ku5

Crystal Structure of CusS Sensor Domain with Silver Bound

spinqualitylabelsall models 5ku5, resolution 2.15Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5ku5 is a 4 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 2.15Å Ligands: ACT, AG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CUSS_ECOLI Member of the two-component regulatory system CusS/CusR. Copper ion sensor. Could also be a silver ion sensor. Activates CusR by phosphorylation. Publication Abstract from PubMed In bacteria, two-component systems act as signaling systems to respond to environmental stimuli. Two-component systems generally consist of a sensor histidine kinase and a response regulator, which work together through histidyl-aspartyl phosphorelay to result in gene regulation. One of the two-component systems in Escherichia coli, CusS-CusR, is known to induce expression of cusCFBA genes at increased periplasmic Cu(I) and Ag(I) concentrations to help maintain metal ion homeostasis. CusS is a membrane-associated histidine kinase with a periplasmic sensor domain connected to the cytoplasmic ATP binding and catalytic domains through two transmembrane helices. The mechanism of how CusS senses increasing metal ion concentrations and activates CusR is not yet known. Here, we present the crystal structure of the Ag(I)-bound periplasmic sensor domain of CusS at a resolution of 2.15 A. The structure reveals that CusS forms a homodimer with four Ag(I) binding sites per dimeric complex. Two symmetric metal binding sites are found at the dimeric interface, which are each formed by two histidines and one phenylalanine with an unusual cation-pi interaction. The other metal ion binding sites are in a nonconserved region within each monomer. Functional analyses of CusS variants with mutations in the metal sites suggest that the metal ion binding site at the dimer interface is more important for function. The structural and functional data provide support for a model in which metal-induced dimerization results in increases in kinase activity in the cytoplasmic domains of CusS. The Structure of the Periplasmic Sensor Domain of the Histidine Kinase CusS Shows Unusual Metal Ion Coordination at the Dimeric Interface.,Affandi T, Issaian AV, McEvoy MM Biochemistry. 2016 Sep 12. PMID:27583660 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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