Curation Information

An anti-repression Fur operator upstream of the promoter is required for iron-mediated transcriptional autoregulation in Helicobacter pylori.;Delany I, Spohn G, Rappuoli R, Scarlato V;Molecular microbiology 2003 Nov; 50(4):1329-38 [14622419]
Fur [B5Z6G7, view regulon]
Reported TF sp.
Helicobacter pylori G27
Reported site sp.
Helicobacter pylori G27
Created by
Matthew Coveyou
Curation notes

Experimental Process

Three putative binding sites, O-I, O-II, and O-III, were identified in previous studies. Primer extension analysis was performed to measure the effects of deletion mutagenesis on O-I, O-III, and O-I/O-III double mutants. O-II overlaps the -10 region of the promoter and so was not a subject for mutagenesis. DNAse I protection was also performed on each site in iron-variable media, and suspicions that O-I acts as an UP element where supported by footprinting with RNAP. Results indicate the spacing between O-II and O-III is key to derepression under iron limitation, and that O-III is involved in derepression in low-iron while O-II binding in high-iron is speculated to result in repression. O-I was bound in both high-iron and low-iron (when O-II and O-III were bound, respectively).

Transcription Factor Binding Sites


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