FIG 6.

IutE iron activation requires a DNA region upstream of the promoter. (A) EMSA with purified DtxR and promoter regions of tox, iutA, and iutE; DtxR was added where indicated (+). (B) Beta-galactosidase units observed from promoter fusion constructs following growth in mPGT with metal supplementation as indicated. The means and standard deviations from three independent experiments are shown. (C) DNA sequence of the iutE promoter region with notable features marked. The boundaries of the promoter fusions and DNA fragments used for EMSA are indicated (key). +1, start site of transcription; −10, putative promoter element.