Structural modification of Escherichia coli lipid A by myristoyltransferase gene from Klebsiella pneumoniae.

Lipid A in lipopolysaccharide (LPS) of Escherichia coli mutant strains was modified by the introduction of myristoyltransferase gene cloned from Klebsiella pneumoniae. When the gene was introduced into the mutant having lipid A containing only 3-hydroxymyristic acids, it produced lipid A with two additional myristic acids (C ). When the same gene was introduced into the mutant with pentaacylated lipid A containing one lauric acid (C ), C was replaced by C .

Modification of lipid A structure and activity by the introduction of palmitoyltransferase gene to the acyltransferase-knockout mutant of Escherichia coli.

Lauroyltransferase gene (lpxL), Myristoyltransferase gene (lpxM) and palmitoyltransferase gene (crcA) of Escherichia coli BL21 were independently disrupted by the insertional mutations. The knockout mutant of two transferase genes (lpxL and crcA) produced lipid A with no lauric or palmitic acids and only a little amount of myristic acid. The mutant was susceptible to polymyxin B, but showed comparable growth with the wild-type strain at 30°C.