HpdR-dependent regulation of hpdA was confirmed by Northern blot and lacZ reporter assays. EMSA showed that HpdR directly binds to the hpdA gene promoter. lacZ promoter fusion assays with different lengths hpdA promoter fragments localized the HpdR target sequence to -70 and -132 bp sequence upstream of the hpdA start codon. Visual sequence inspection of the hpdA promoter revealed two conserved repeat sequences. Further experiments with EMSA showed that HpdR binds to the hdpA gene. DNase I footprinting confirmed the binding to both conserved sequences. Direct repeat sequences similar to the two HpdR binding sites in S. meliloti were found in several other organisms.
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|