Autoregulation of iclR, the gene encoding the repressor of the glyoxylate bypass operon

The aceBAK operon was partially induced by a multicopy plasmid which carried the promoter region of the gene which encodes its repressor, iclR. Gel shift and DNase I analyses demonstrated that iclR binds to its own promoter. Disruption of iclR increased the expression of an iclR::lacZ operon fusion. Although aceBAK and iclR are both regulated by IclR, aceBAK expression responds to the carbon source, while expression of iclR does not.