Extended Data Figure 1: LPS and its cross-membrane transport in Gram-negative bacteria.
From: Structural basis of MsbA-mediated lipopolysaccharide transport
a, b, Chemical structure (a) and cartoon representation (b) of E. coli rough LPS (lipid A with inner and outer core oligosaccharides). The carbon atoms of the glucosamines are numbered, and the lipid acyl chains attached to the glucosamines are labelled as R2 to R3″. Kdo, 3-deoxy-d-manno-oct-2-ulosonic acid; Hep, l-glycero-d-manno-heptose; Glc, glucose; Gal, galactose. c, The LPS-transport pathway in E. coli consists of four steps: (1) MsbA-driven flipping of rough LPS from the cytoplasmic to the periplasmic leaflet of the inner membrane; (2) WaaL-mediated ligation of O-antigen onto rough LPS to form mature, smooth LPS; (3) cross-periplasm transport of LPS, mediated by proteins LptF, LptG, LptB, LptC and LptA; and (4) LPS insertion into the outer leaflet of the outer membrane, mediated by proteins LptD and LptE.
