Figure 5.

The LptD OM protein is essential in both P. aeruginosa (PA) and E. coli (EC), and the sequences share significant homology. The folded proteins lack the signal peptide (residues 1–33 in PA or residues 1–24 in EC), both contain a periplasmic domain and a C-terminal β-barrel domain. However, differences in sequence, length, and the number of disulfide bonds (proven in EC, full lines [59]; likely in PA, dotted lines) are seen between LptD in these organisms. These sequence differences may account for the selective action of the antibiotic L27-11 for Pseudomonas sp.