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. 2012 May;78(9):3068–3078. doi: 10.1128/AEM.07871-11

Fig 4.

Fig 4

Characterization of gene expression from the complementation constructs. (A) Alkaline phosphatase activity and immunoblot analysis of TraWSS::′PhoA expression in gonococcal strain MS11 (WT) and in gonococcal strains transformed with the complementation constructs. Expression of TraWSS::′PhoA from the lctP-aspC site was driven by the lac promoter (lacPO) in strain MR547. Expression of TraWSS::′PhoA from the iga-trpB site was driven by one of three promoters: lacPO in strain MR544, the constitutive opaB promoter (PopaB) in strain MR546, or the tetracycline-inducible promoter (Ptet) in strain MR557. Production of TraWSS::′PhoA was induced with either 0.5 mM IPTG or 2 ng/ml ATc. Alkaline phosphatase activity was normalized to mg of protein. The amount of TraWSS::′PhoA fusion protein was detected by immunoblotting with anti-PhoA (α-PhoA) antibodies. The mean ± standard deviation of at least three independent experiments is shown. *, alkaline phosphatase activity from the strain with lacPO at the lctP-aspC site in the presence of inducer was significantly different from that of the uninduced control (P < 0.005) and also different from the activities of strains with lacPO, PopaB, and Ptet at the iga-trpB site (P ≤ 0.01) by Student's two-tailed t test; **, alkaline phosphatase activity from the strains with lacPO or Ptet at the iga-trpB site in the presence of inducer was significantly different from that of the respective uninduced controls (P ≤ 0.001) but was not significantly different between strains (P > 0.05) by Student's two-tailed t test; §, alkaline phosphatase activity from the strain with PopaB at the iga-trpB site was significantly different from the activities of all other inducible strains (P < 0.001) by Student's two-tailed t test. (B) Use of the iga-trpB complementation constructs in N. meningitidis. Strains MR1004 (producing TraWSS::′PhoA under the control of lacPO) and MR1005 (producing TraWSS::′PhoA under the control of Ptet) were grown on GCB-Tris-XP agar plates containing either the XP substrate alone, XP with 1 mM IPTG, or XP with 20 ng/ml ATc.