FIG. 2.
pypB and pypC are autoregulated and regulate each other. Y. enterocolitica GHY306 (pypA-lacZYA), GHY307 (pypB-lacZYA), GHY334 (pypC-lacZYA), and GHY366 (ΔpypB pypC-lacZYA) carrying the indicated plasmids were grown in the presence of 0.2% arabinose to induce gene expression from the PBAD promoter for 3 h at 26°C before determination of β-galactosidase activity (in arbitrary Miller units). Data are means and standard deviations from at least three experiments, each performed in triplicate. While pypA activity is only marginally influenced by either Pyp protein, pypB and pypC are autoregulated and regulate each other.