Fig 3.

Skp/FkpA and SurA have distinct roles in LptD assembly. Cultures were grown to an OD₆₀₀ of about 0.7 to 0.8 in LB medium. Whole-cell lysates were analyzed by SDS-PAGE and immunoblotted with the appropriate antibody. “X-Band” is a cross-reacting band of approximately 55 kDa, shown here as a loading control. (A) Medium was supplemented with 0.2% l-arabinose to induce the psurA plasmid. Overexpression of SurA in the Δskp ΔfkpA strain has no effect on LptD levels. (B) The deletion of major OMPs has no effect on LptD levels in the absence of skp and fkpA. (C) Overexpression of Skp or FkpA does not increase LptD levels in the absence of surA. (D) Medium was supplemented with 0.2% l-arabinose to induce the plasmids. DsbA levels were visualized using Coomassie brilliant blue staining after SDS-PAGE analysis. Overexpression of DsbA in the Δskp ΔfkpA strain does not affect LptD levels.