bacterial outer membrane biogenesis Lipooligosaccharide metabolism lipooligosaccharide biosynthesis PMID:11521077 LOS biosynthesis pathway Biosynthesis of lipooligosaccharide (LOS), an important amphiphilic molecule integrated in and extending outward from the outer membrane of some bacterial cell wall (Neisseria and Haemophilus sp). LOS is similar to lipopolysaccharide (LPS) but lacking the O-antigen polysaccharide side chain repeats. LOS comprises two parts: i) core oligosaccharide and ii) lipid A. UPa:UPA00501 membrane lipid biosynthesis