FIG. 2.
PypB activates transcription of flp and pypB. Y. enterocolitica cultures containing the indicated flp-lacZ or pypB-lacZ reporter plasmids and either pBAD18Kan (−) as a control or pBAD-pypB (+) to induce PypB overproduction (PypBOP) from the PBAD promoter were grown in the presence of 0.2% arabinose for 3 h at 26°C before determinations of β-galactosidase activity (in arbitrary Miller units). Data are means and standard deviations of data from at least three experiments, each performed in triplicate. One hundred fifty nucleotides upstream of the flp ATG start codon are sufficient for flp activation by PypB, while nt 245 to 500 upstream of the ATG start codon of pypB are necessary for pypB activation by PypB.