Figure 1
SspA positively affects LEE expression in stationary phase cells. Primer extension analyses on total RNA extracted from wild type EHEC EDL933 (lane 1), the sspA mutant (lane 2) and the sspA mutant complemented with wild type sspA (lane 3) or mutant sspA84-86 (lane 4) as indicated, grown in LB at 37°C to stationary phase (OD600 ~ 3.0). The Labeled DNA oligos specific to the transcripts of LEE1/ler (A and I), LEE2/espZ (B), LEE3/mpc (C), LEE4/sepL (D), LEE5/tir (E), map (F), grlRA (G) and stcE (H) were used. The ompA transcripts, detected with a labeled ompA-specific DNA oligo, served as internal control for the primer extension reaction. Wild type and mutant SspA were expressed from pQEsspA and pQEsspA84-86 respectively in the absence of induction at similar levels. The transcripts LEE1-5, map, grlRA, stcE and the control transcript ompA are indicated. The relative transcript levels of target genes normalized to that of ompA are indicated by the numbers in parenthesis.