Mapping of 5′ ends of rpoE mRNA identified five new transcriptional initiation sites (P1 to P5) located distal to Eσ E-regulated promoter. Transcription of the rpoE gene is positively autoregulated by Eσ E and by unknown mechanisms that control the expression of its distally located promoter(s). RpoE regulates extracytoplasmic functions including lipopolysaccharide (LPS) translocation and some of its non-stoichiometric modifications. The RpoE σ factor is essential for the viability of Escherichia coli.
