FIG. 1.
PypA, PypB, and PypC control HreP expression in Y. enterocolitica. (A) Y. enterocolitica GHY19 (hreP-lacZYA) carrying the indicated plasmids was 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. (B) Y. enterocolitica GHY19 (hreP-lacZYA) carrying the indicated plasmids was grown in the presence (+) or absence (−) of 0.2% arabinose to induce gene expression from the PBAD promoter for 4 h at 26°C. Bacterial lysates were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the HreP proprotein was detected by Western blotting using a proprotein-specific antiserum.