A) Structure of LPS from Escherichia coli K-12. B) ATP utilization by LptB2FGC drives the transport of newly synthesized LPS (yellow) across the periplasmic compartment. LptB2FGC is depicted both as a crystal structure (PDB ID: 6MJP) derived from Vibrio cholerae (left) and as a cartoon (right). The crystal structure carries the catalytically inactive LptB/E163Q variant. LPS, lipopolysaccharide. PL, phospholipid. PG, peptidoglycan. OM, outer membrane. IM, inner membrane. Peri, periplasm. Kdo, keto-deoxyoctulosonate. Hep, heptose. Glu, glucose. Gal, galactose.