FIGURE 2.

Depletion of YidC affects Hbp biogenesis in vivo. A, analysis of expression and secretion of Hbp in YidC depletion strain JS7131. Cells harboring pEH3-Hbp were grown in the presence or absence of l-arabinose to allow expression or depletion of YidC, respectively. After 5.5 h of growth, expression of Hbp was induced by addition of IPTG (1 mm), and growth was continued. Samples were collected 2 h after induction, separated in cells (C) and spent medium (M) and analyzed by SDS-PAGE and Coomassie staining. Cells were resuspended in SDS sample buffer directly, whereas medium samples were first TCA-precipitated. Cells loaded in lane 1 were collected after 5.5 h of growth, prior to addition of IPTG. The relevant areas of the same gel are shown. Molecular mass markers (kDa) are shown at the left side of the panels. The Hbp passenger (pass), proform (pro), and β-domain are indicated at the right side of the panels. B, immunoblot analysis of the OmpA content in 0.03 OD₆₆₀ units of cells collected under A. The precursor (pre) and mature (mat) forms of OmpA are indicated at the right side of the panel. C, immunoblot analysis of the YidC and PspA content in 0.03 OD₆₆₀ units of cells collected under A.