Figure 4

Structures and molecular masses of lipid IV_A molecules identified by ESI FT-ICR mass spectrometry in BL21 (DE3)-derived KPM mutants. The ESI FT-ICR mass spectra are shown in Figure 3. Modifications of lipid IV_A with palmitate (green) and P-EtN (magenta) are catalyzed by PagP and EptA, respectively.