FIG 8.
Hypothetical model of PlarA regulation by LarR. In the presence of l-Lac, activated LarR binds to the Lar box motif and multimerizes on the half-Lar boxes. This will promote direct interaction of one LarR dimer with the RNA polymerase, resulting in transcriptional activation of the PlarA (productive binding). In the presence of d-Lac, d-Lac could block LarR activation, for instance, by impairing l-Lac recognition as illustrated here, which will result in limited LarR binding and multimerization and absence of transcriptional activation (unproductive binding).