Structural and mechanistic insights into Helicobacter pylori NikR functionStructural and mechanistic insights into Helicobacter pylori NikR function

Structural highlights

2wvc is a 2 chain structure with sequence from Helicobacter pylori 26695. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.1Å
Ligands:, ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

NIKR_HELPY Transcriptional regulator (Potential).

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

NikR is a transcriptional metalloregulator central in the mandatory response to acidity of Helicobacter pylori that controls the expression of numerous genes by binding to specific promoter regions. NikR/DNA interactions were proposed to rely on protein activation by Ni(II) binding to high-affinity (HA) and possibly secondary external (X) sites. We describe a biochemical characterization of HpNikR mutants that shows that the HA sites are essential but not sufficient for DNA binding, while the secondary external (X) sites and residues from the HpNikR dimer-dimer interface are important for DNA binding. We show that a second metal is necessary for HpNikR/DNA binding, but only to some promoters. Small-angle X-ray scattering shows that HpNikR adopts a defined conformation in solution, resembling the cis-conformation and suggests that nickel does not trigger large conformational changes in HpNikR. The crystal structures of selected mutants identify the effects of each mutation on HpNikR structure. This study unravels key structural features from which we derive a model for HpNikR activation where: (i) HA sites and an hydrogen bond network are required for DNA binding and (ii) metallation of a unique secondary external site (X) modulates HpNikR DNA binding to low-affinity promoters by disruption of a salt bridge.

Structural and mechanistic insights into Helicobacter pylori NikR activation.,Bahlawane C, Dian C, Muller C, Round A, Fauquant C, Schauer K, de Reuse H, Terradot L, Michaud-Soret I Nucleic Acids Res. 2010 May;38(9):3106-18. Epub 2010 Jan 19. PMID:20089510[1]

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

References

  1. Bahlawane C, Dian C, Muller C, Round A, Fauquant C, Schauer K, de Reuse H, Terradot L, Michaud-Soret I. Structural and mechanistic insights into Helicobacter pylori NikR activation. Nucleic Acids Res. 2010 May;38(9):3106-18. Epub 2010 Jan 19. PMID:20089510 doi:10.1093/nar/gkp1216

2wvc, resolution 2.10Å

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