FIGURE 4.

The large periplasmic domain of YidC is dispensible for expression and secretion of Hbp. A, analysis of expression and secretion of Hbp in JS7131(pEH3-Hbp) upon complementation of YidC depletion with plasmid encoded YidCΔP1 (lanes 7–12) or wild-type YidC (lanes 1–6) as described in the legend to Fig. 2A. Cultures were supplemented with l-arabinose (Ara) to allow expression of YidC from the genome, or l-rhamnose (Rha) to allow expression of YidC and YidCΔP1 from pWSK/Rha, as indicated. Cells (C) and medium (M) fractions are indicated at the top of the panel. Molecular mass markers (kDa) are shown at the left side of the panel. The Hbp passenger (pass) and proform (pro) are indicated at the right side of the panel. B, immunoblot analysis of YidC and YidCΔP1 expression in 0.03 OD₆₆₀ units of cells collected under A using antiserum against YidC. Molecular mass markers (kDa) are shown at the left side of the panel. YidC and YidCΔP1 are indicated at the right side of the panel. C, immunoblot analysis of the PspA content in 0.03 OD₆₆₀ units of cells collected under A.