title: Isolation of a mutant of Salmonella typhimurium dependent on D-arabinose-5-phosphate for growth and synthesis of 3-deoxy-D-mannoctulosonate (ketodeoxyoctonate).
abstract: A new type of auxotrophic mutant of Salmonella typhimurium has been isolated that is defective in the synthesis of the 3-deoxy-D-mannooctulosonate (ketodeoxyoctonate) region of the lipopolysaccharide and requires D-arabinose-5-phosphate for growth. Genetic and biochemical evidence indicated that the mutant defect was due to an altered ketodeoxyoctonate-8-phosphate synthetase with an apparent K(m) for D-arabinose-5-phosphate 35-fold higher than that of the parental enzyme. As a result of this enzymatic lesion, the mutant strain was dependent on exogenous D-arabinose-5-phosphate both for growth and for synthesis of a complete lipopolysaccharide.
mesh_terms: D001089:Arabinose / Q000378:metabolism*; D002247:Carbon Isotopes; D005690:Galactose / Q000378:metabolism; D008025:Ligases / Q000378:metabolism; D008070:Lipopolysaccharides / Q000096:biosynthesis*; D009154:Mutation; D010428:Pentosephosphates; D010710:Phosphates / Q000378:metabolism; D010728:Phosphoenolpyruvate; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis; D012486:Salmonella typhimurium / Q000201:enzymology / Q000302:isolation & purification / Q000378:metabolism*; D013400:Sugar Acids / Q000096:biosynthesis*
chemical_list: D002247:Carbon Isotopes; D008070:Lipopolysaccharides; D010428:Pentosephosphates; D010710:Phosphates; D011135:Polysaccharides, Bacterial; D013400:Sugar Acids; C002532:2-keto-3-deoxyoctonate; D010728:Phosphoenolpyruvate; D001089:Arabinose; D008025:Ligases; D005690:Galactose