Fig. 5.
NaxD is required for the galactosamine modification of F. novicida free lipid A.
A–D. Total lipids were extracted from (A, C) wild-type F. novicida (WT) and (B, D) naxD mutant (ΔnaxD) strains in mid-log phase and (A, B) free lipid A, (C, D) undecaprenyl phosphate-N-acetylgalactosamine (GalNAc), and undecaprenyl phosphate-galactosamine (GalN) were analysed by ESI/MS in negative ion mode via direct infusion.
E. A schematic for the deacetylation of undecaprenyl phosphate-GalNAc (expected m/z = 1048.74) to undecaprenyl phosphate-GalN (expected m/z = 1006.73) is shown.
(A, E) Galactosamine is highlighted in green and (E) the acetyl group is highlighted in red.