The cAMP-CRP complex binds the <i>fadL</i>, <i>fadD</i> and <i>fadH</i> promoters.

<p><b><i>A</i></b>. Sequence analyses of the CRP binding sites of <i>fadL</i>, <i>fadD</i> and <i>fadH</i>. White letters shaded in black denote strictly conserved bases, bold letters in grey represent highly similar residues, and dots mean gaps. The newly deduced CRP-binding site (<i>fadL</i>1 of <i>A</i>) binds the cAMP-CRP complex (panel <b><i>B</i></b>) whereas the CRP-binding site predicted earlier <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0046275#pone.0046275-Feng1" target="_blank">[17]</a> (abbreviated <i>fadL</i>2) does not (panel <b><i>C</i></b>). <i>D</i> Binding of the <i>fadD</i> promoter region by the cAMP-CRP complex. <b><i>E</i></b> and <b><i>F</i></b>. The <i>fadH</i> promoter region contains two functional CRP-binding sites, <i>fadH</i>1 and <i>fadH</i>2, respectively. The DIG-labeled probe shifted by the cAMP-CRP complex is indicated by an arrow. All EMSA experiments were carried out using 6.5% native PAGE and representative results are shown. The protein samples were incubated with 0.6 pmol of DIG-labeled probe in a total volume of 20 µl that contained 200 pmol cAMP (when added). The right hand four lanes of each contained (left to right) 10, 5, 10 and 20 pmol of CRP, respectively.