title: Isolation and characterization of a temperature-sensitive lethal mutant of Salmonella typhimurium that is conditionally defective in 3-deoxy-D-manno-octulosonate-8-phosphate synthesis.
abstract: A new mutant of Salmonella typhimurium was isolated which possesses a temperature-sensitive defect in the synthesis of 3-deoxy-D-manno-octulosonic acid. The defect in 3-deoxy-D-manno-octulosonic acid synthesis is due to a temperature-sensitive 3-deoxy-D-manno-octulosonate-8-phosphate synthetase, and the mutant accumulates an incomplete lipid A under nonpermissive conditions. Evidence is presented which indicates that the incomplete lipid A molecule is most likely identical in structure to the lipid A precursor synthesized by previously characterized mutants conditionally defective in 3-deoxy-D-manno-octulosonic acid synthesis. However, unlike related mutants which undergo growth stasis under nonpermissive conditions, the accumulation of lipid A precursor in the new mutant results in cell death at elevated temperatures.
mesh_terms: D000446:Aldehyde-Lyases / Q000378:metabolism; D008050:Lipid A / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000096:biosynthesis*; D009154:Mutation; D012486:Salmonella typhimurium / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013403:Sugar Phosphates / Q000096:biosynthesis*; D013696:Temperature
chemical_list: C012875:3-deoxy-D-manno-octulosonic acid-8-dihydrogen phosphate; D008050:Lipid A; D008070:Lipopolysaccharides; D013403:Sugar Phosphates; C020011:2-dehydro-3-deoxyphosphooctonate aldolase; D000446:Aldehyde-Lyases