FIGURE 6.

GC/MS of the EL206 (rgtD⁻) mutant lipid A. A, parent strain 3841. B, mutant strain EL206 (rgtD⁻) is shown. Trimethylsilyl methylglycosides and fatty acid methyl esters were derived from partitioned lipid A and analyzed by GC/MS. The lipid A from the rgtA⁻, B⁻, and C⁻ mutants gave profiles similar to that of the parent strain, whereas the lipid A from the rgtE⁻ mutant gave a GC/MS profile similar to that of the rgtD⁻ mutant; i.e. it was devoid of GalA residues. GlcNAc is derived from the lipid A GlcN residues.