Regulation of the mgrA, katA, ahpCF and hemA operons was previously identified. EMSA using the mgrA promoter demonstrated PerR binding. Site directed mutagenesis of the mgrA promoter concluded that deletion of a large portion of the box, as well as a ‘T’ insertion in the downstream portion of the box, prevents manganese-dependent PerR binding. These results confirmed that the per box is directly recognized by PerR. Per boxes were previously identified in the katA, ahpCF and hemA operon promoter regions. DNase I footprinting confirmed binding to these promoters and localized the PerR binding sites. A katA:lacZ fusion demonstrated a lack of repression of katA by PerR in the presence of hydrogen peroxide and metal-limited conditions, which confirmed expression levels in a perR deletion experiment.
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|