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. 2009 Jan 7;37(4):1211–1224. doi: 10.1093/nar/gkn1046

Figure 4.

Figure 4.

Binding isotherms of MepR and selected ligands. (A through D) MepR-binding isotherms to various lengths of cognate DNA from the mepA promoter. (A) MepR binding to a 44-bp site encompassing the entire mepA promoter DNase I footprint. (B) MepR binding to a 26-bp site of the mepA promoter that has been truncated from the 3′-end. (C) MepR binding to a 22-bp site of the mepA promoter that has been truncated from the 3′-end. (D) MepR binding to a 31-bp site of the mepA promoter that has been truncated from the 5′-end. (E) MepR-binding isotherms to a 26-bp DNA binding site from the mepR promoter. (F) Nucleotide sequence of the mepA promoter. The –10 and –35 elements of the promoter are shown in bold and labelled and the transcription start site (TSS) is indicated as a bent arrow. The pseudo-inverted repeats of the promoter are shown by horizontal arrows and the signature GTTAG motifs are underlined. The boundaries of the 22, 26 and 31-bp sequences used in the binding studies are indicated by blue, red and purple rectangles, respectively. G–I, MepR-binding isotherms for three ‘drugs’. (G) The MepR-Et-binding isotherm. (H) The MepR-DAPI-binding isotherm. (I) The MepR-R6G-binding isotherm. The change in polarization, shown in red circles and indicated in millipolarization units (mP), was plotted against the MepR dimer concentration indicated inside each plot. The binding constants are shown in each plot. The chemical structure of each drug is shown below the respective binding curve.