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. 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. Belongs to the lipid A palmitoyltransferase family.