FIG. 2.

Bacteria grown in BHI medium do not produce InlJ protein unless inlJ is under the control of the constitutive promoter prot. Immunofluorescence microscopy (A) or immunoblotting of cell wall extracts (B) of L. monocytogenes EGDe wild type (wt), EGDe/pTprot-inlJ (wt pTprot-inlJ), or the ΔsrtA mutant expressing pTprot-inlJ (ΔsrtA pTprot-inlJ) grown in BHI medium with anti-InlA- or anti-InlJ-specific antibodies. InlJ is not detected at the surface of wild-type bacteria, while it is anchored at the surface of bacteria expressing pTprot-inlJ. As for InlA, this anchoring depends on SrtA. (C) InlJ is produced and present at the surface of ΔinlJ/pPL2::prot-inlJ bacteria carrying the fused sequence prot-inlJ in the chromosome. As expected, it is absent at the surface of bacteria of the ΔinlJ strain.