FIG 1.

NlpE and Cpx are required for tolerance of LolB depletion. (A) Overview of lipoprotein biogenesis and trafficking. Lipoproteins are secreted via the Sec translocon and are acylated at Cys⁺¹ in the IM. Mature triacylated lipoproteins that are targeted for the OM enter LolCDE for extraction from the IM. LolA and LolB are part of an efficient trafficking pathway that is essential in wild-type cells. An alternate LolAB-independent pathway can also traffic lipoproteins but is insufficient in wild-type cells. Asp residues at +2 and +3 amino acids cause IM retention of lipoproteins. The targets of Glb and Cpd2 inhibitors are shown. (B) Strains tested for tolerance to LolB depletion. Expression of LolB was repressed by culturing in the absence of l-arabinose. Ten-fold serial dilutions of cultures are shown.