Curation Information

Effector-stimulated single molecule protein-DNA interactions of a quorum-sensing system in Sinorhizobium meliloti.;Bartels FW, McIntosh M, Fuhrmann A, Metzendorf C, Plattner P, Sewald N, Anselmetti D, Ros R, Becker A;Biophysical journal 2007 Jun 15; 92(12):4391-400 [17384071]
ExpR [Q92L12, view regulon]
Reported TF sp.
Sinorhizobium meliloti 1021
Reported site sp.
Sinorhizobium meliloti 1021
Created by
Dinara Sagitova
Curation notes

Experimental Process

A comparison of sinI mRNA levels in the expR- and expR+ strains showed a 4.3-fold increase, indicating ExpR-mediated activation of sinI by ExpR. EMSA confirmed that ExpR binds specifically to the sinR-sinI intergenic region in the presence of AHL. Footprinting assays showed that ExpR protected a 26-bp region on the sinI promoter. EMSA with subfragments of the sinI-sinR intergenic region confirmed the results obtained from footprinting experiment. Site-directed mutagenesis of the ExpR binding site resulted in the complete absence of binding by ExpR in the presence of oxo-C14-HL.

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
... ... SMc00168
Experimental technique details EMSA (ECO:0001807) - Experimental technique details Hydroxyl-radical footprinting (ECO:0005643) - Experimental technique details qRT-PCR [RNA] (ECO:0001808) - Experimental technique details Site directed mutagenesis (ECO:0005667) - activator not specified