The acceptor for polar head groups of the lipid A component of Salmonella lipopolysaccharides.
We describe here experiments which determine at which stage in the lipid A biosynthesis the polar head groups 4-aminoarabinose, phosphorylethanolamine and 3-deoxy-D-manno-octulosonic acid are transferred to the diphosphorylated glucosamine backbone of the lipid A structure. Use was made of a conditional lethal mutant of Salmonella typhimurium (Ts1) which is defective in the synthesis of 3-deoxy-D-manno-octulosonic acid 8-phosphate and accumulates under nonpermissive conditions an underacylated lipid A intermediate [Lehmann, Rupprecht and Osborn (1977) Eur. J. Biochem. 76, 41-49]. Pulse-chase experiments, including a detailed analysis of radioactive pulse and chase products, demonstrated that this underacylated compound is a key intermediate in the lipid A synthesis. It can serve as direct acceptor for the incorporation of the polar head groups 4-aminoarabinose, phosphorylethanolamine and 3-deoxy-D-manno-octulosonic acid. On the basis of these findings some steps in the sequence of reactions involved in the lipid A biosynthesis are proposed.
D000117:Acetylglucosamine / Q000378:metabolism; D000606:Amino Sugars / Q000378:metabolism*; D001089:Arabinose / Q000031:analogs & derivatives* / Q000378:metabolism; D004983:Ethanolamines / Q000378:metabolism*; D005944:Glucosamine / Q000378:metabolism; D007661:Ketoses / Q000378:metabolism*; D008050:Lipid A / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000096:biosynthesis* / Q000378:metabolism; D008954:Models, Biological; D008970:Molecular Weight; D009154:Mutation; D009943:Organophosphorus Compounds / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism*; D013400:Sugar Acids / Q000378:metabolism*
D000606:Amino Sugars; D004983:Ethanolamines; D007661:Ketoses; D008050:Lipid A; D008070:Lipopolysaccharides; D009943:Organophosphorus Compounds; D010710:Phosphates; D013400:Sugar Acids; C016982:aminoarabinose; C002532:2-keto-3-deoxyoctonate; C005448:phosphorylethanolamine; D001089:Arabinose; D005944:Glucosamine; D000117:Acetylglucosamine