Curation Information

Publication
In vitro analysis of protein-operator interactions of the NikR and fur metal-responsive regulators of coregulated genes in Helicobacter pylori.;Delany I, Ieva R, Soragni A, Hilleringmann M, Rappuoli R, Scarlato V;Journal of bacteriology 2005 Nov; 187(22):7703-15 [16267295]
TF
NikR [B5Z8Y5, view regulon]
Reported TF sp.
Helicobacter pylori G27
Reported site sp.
Helicobacter pylori G27
Created by
Matthew Coveyou
Curation notes
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Experimental Process

DNAse I footprinting identified two putative NikR binding sites in the nikR-exbB intergenic region, one associated with each gene promoter; confirmed previous studies of binding to the ureA promoter; and identified two putative sites on the fur promoter, denoted OpI and OpII. The ureA promoter was aligned with those of four other H. pylori strains, which demonstrated high conservation. Scanning mutagenesis of the ureA site identified key nucleotides, which were then aligned with the putative nikR and exbB sites. Western blot assays were performed on nikR and fur mutants to determine the regulatory effect, if any, of nikR on fur expression. NikR was shown to repress fur expression (though not as dramatically as fur autorepression), and these results were confirmed by primer extension assay. This was judged sufficient to warrant alignment of fur-OpI and OpII with the ureA, nikR, and exbB putative sites.

Transcription Factor Binding Sites


TCTCATTTTAATGTAACTTATAAGA
CATTATTATTGTATAATAATATTC
TAACACTAATTCATTTTAAATAATA
TAAAATTAACAATTATAATACAAAA
TGATTGTATTGTTTTAATAATAACA
TCGCATTTTAATGTAACTTATAAGA
CATTATTATTGTATAATAATATTC
TAACACTAATTCATTTTAAATAATA
TAAAATTAACAATTATAATACAAAC
TGATTGTATTGTTTTAATAATAACA

Gene Regulation

Regulated genes for each binding site are displayed below. Gene regulation diagrams show binding sites, positively-regulated genes, negatively-regulated genes, both positively and negatively regulated genes, genes with unspecified type of regulation. For each indvidual site, experimental techniques used to determine the site are also given.

Site sequence Regulated genes Gene diagram Experimental techniques TF function TF type
TCGCATTTTAATGTAACTTATAAGA HPG27_401
... ... HPG27_401
Experimental technique details DNAse footprinting (ECO:0005631) - Experimental technique details Multiple sequence alignment (MSA) (ECO:0005556) - Experimental technique details Primer Extension assay (ECO:0005657) - Experimental technique details Western blot (quantitative) expression analysis (ECO:0000279) - repressor tetramer
CATTATTATTGTATAATAATATTC HPG27_401
... ... HPG27_401
Experimental technique details DNAse footprinting (ECO:0005631) - Experimental technique details Multiple sequence alignment (MSA) (ECO:0005556) - Experimental technique details Primer Extension assay (ECO:0005657) - Experimental technique details Western blot (quantitative) expression analysis (ECO:0000279) - repressor tetramer
TAACACTAATTCATTTTAAATAATA
... ... ureB ureA
Experimental technique details DNAse footprinting (ECO:0005631) - Experimental technique details Multiple sequence alignment (MSA) (ECO:0005556) - Experimental technique details Site directed mutagenesis (ECO:0005667) - not specified tetramer
TAAAATTAACAATTATAATACAAAC
... ... HPG27_1288 HPG27_1287 HPG27_1285 HPG27_1286 HPG27_1289
Experimental technique details DNAse footprinting (ECO:0005631) - Experimental technique details Multiple sequence alignment (MSA) (ECO:0005556) - not specified tetramer
TGATTGTATTGTTTTAATAATAACA
... ... HPG27_1289 HPG27_1288 HPG27_1287 HPG27_1285 HPG27_1286
Experimental technique details DNAse footprinting (ECO:0005631) - Experimental technique details Multiple sequence alignment (MSA) (ECO:0005556) - not specified tetramer