HdhR-mediated repression of hdhA was confirmed by lacZ promoter fusion and RT-PCR assays which showed that hdhA expression increased significantly in the hdhR mutant compared to the wild-type S. meliloti 1021 strain. EMSA verified that HdhR binds to the hdhA promoter fragment from +80 to -118 bp relative to the hdhA translation start. DNase I footprinting analyses determined that HdhR protected two regions from approximately -12 to -37 and from -42 to -67 bps upstream of the hdhA start codon.
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|