Immunoblotting with CmeABC-specific antibodies showed that expression of cmeB was about fivefold higher in cmeR mutant strain than in the wild-type strain. Additionally, cmeABC-lacZ reporter assay showed that expression of cmeB was approximately 6.2fold higher in cmeB mutant than in the wild-type indicating that CmeR represses the transcription of cmeABC. EMSA confirmed that CmeR regulates the cmeABC operon via direct interaction with the promoter of cmeABC. EMSAs performed with a series of PCR products whose sequences span different portions of the IT region between cmeR and cmeABC confirmed specific CmeR binding. Single nucleotide deletion in conjunction with cmeABC-lacZ reporter assay further confirmed specific binding of CmeR to its target promoter.
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|