E. coli IscR-C92A cannot activate transcription from the intergenic promoter between hmuR and hmuS . In vitro transcription reactions contain plasmids harboring the intergenic promoter between hmuR and hmuS , Eσ 70 RNA polymerase, and increasing concentrations of IscR-C92A protein. Transcripts from the intergenic promoter are marked with an arrow and transcripts from the control RNA-1 promoter are indicated.
{}