Figure 2.

pilE mRNA (a) and PilE protein (b) in Nel 29315 wt, Δnps and Δnpa. (a) Log phase cells were incubated with varying concentrations of IPTG for 4 hr, at 37°C, and pilE or nps mRNA from the lysates was measured by RT‐PCR in the presence (+RT) or absence (−RT) of reverse transcriptase, using nps‐specific primers (see Table S2). The 16S rRNA reaction was used as a loading control and control for mRNA stability. Nel ΔpilE was included as negative control. Lane labeled “C” denotes control for PCR reactions, performed in the presence of DNA (+RT) or H₂O (−RT). (b) PilE levels were detected by western blot using polyclonal antibodies raised to Nel PilE. Arrow points to PilE. Nel ΔpilE was included as negative control. Δnps+inps, complemented strain expressing an IPTG‐inducible wt nps; Δnps+pML2, control strain containing a plasmid with the lacZ promoter