Curation Information

The hdhA gene encodes a haloacid dehalogenase that is regulated by the LysR-type regulator, HdhR, in Sinorhizobium meliloti.;Sallabhan R, Kerdwong J, Dubbs JM, Somsongkul K, Whangsuk W, Piewtongon P, Mongkolsuk S, Loprasert S;Molecular biotechnology 2013 Jun; 54(2):148-57 [22638965]
HdhR [Q92Y01, view regulon]
Reported TF sp.
Sinorhizobium meliloti 1021
Reported site sp.
Sinorhizobium meliloti 1021
Created by
Dinara Sagitova
Curation notes
The authors report that the HdhR protected region contains four LysR-type consensus sites (5'T–N11–A 3'). Individual sites were not listed.

Experimental Process

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.

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