Transfer of palmitate from phospholipids to lipid A in outer membranes of Gram‐negative bacteria

Regulated covalent modifications of lipid A are implicated in virulence of pathogenic Gram‐negative bacteria. The Salmonella typhimurium PhoP/PhoQ‐activated gene pagP is required both for biosynthesis of hepta‐acylated lipid A species containing palmitate and for resistance to cationic anti‐microbial peptides. Palmitoylated lipid A can also function as an endotoxin antagonist. We now show that pagP and its Escherichia coli homolog (crcA) encode …