Increased ler expression overcomes repression of LEE in an sspA mutant. The expressions of virulence genes in wild type EHEC EDL933 (lane 1), the sspA mutant harboring the empty vector pACYC184 (pVector) (lane 2) and pACYCler (pler) expressing ler from its native promoters (lane 3) were determined by primer extension analyses using labeled DNA oligos specific to LEE1/ler (A), LEE2/espZ (B), LEE4/sepL (C), grlRA (D) and stcE (E) along with the ompA-specific oligo as a control. Samples were prepared and analyzed as described in the legend of Figure 1. The relative transcript levels of target genes normalized to that of ompA are indicated by the numbers in parenthesis.
Hansen and Jin BMC Microbiology 2012 12:231 doi:10.1186/1471-2180-12-231