Transfers a palmitate residue from the sn-1 position of a phospholipid to the N-linked hydroxymyristate on the proximal unit of lipid A or its precursors (By similarity). Confers resistance to cationic antimicrobial peptides (CAMPs). Promotes the ability of L.pneumophila to replicate and/or survive in macrophages. Important for ability to kill macrophages and to promote the virulence (PubMed:11401964). 1-hexadecanoyl-2-acyl-sn-glycero-3-phosphocholine + lipid A (E. coli) = a 2-acyl-sn-glycero-3-phosphocholine + hepta-acyl lipid A 1-hexadecanoyl-2-acyl-sn-glycero-3-phosphocholine + lipid IIA = a 2-acyl-sn-glycero-3-phosphocholine + lipid IIB 1-hexadecanoyl-2-acyl-sn-glycero-3-phosphocholine + lipid IVA (E. coli) = a 2-acyl-sn-glycero-3-phosphocholine + lipid IVB Homodimer. Mutant is impaired in stationary-phase survival in low-Mg(2+) medium and shows decreased resistance to different structural classes of CAMPs compared to the wild type. Mutations reduce both the numbers of bacteria recovered during intracellular infection and their cytopathic capacity for U937 macrophages. The mutant is also more defective for lung colonization of A/J mice. Belongs to the lipid A palmitoyltransferase family.