title: P22-mediated transduction analysis of the rough A (rfa) region of the chromosome of Salmonella typhimurium.
abstract: Seven temperature-sensitive rough mutants of Salmonella typhimurium were found to be sensitive to smooth-specific phages at low temperature (25 C, 30 C) and resistant or partially resistant to rough-specific phages, whereas at high temperatures (37 C, 45 C) they were resistant or partially resistant to smooth-specific phages but sensitive to rough-specific phages. These data indicate that at low temperature each strain makes lipopolysaccharide which is relatively normal, but at high temperatures O-specific side chains are not added to the lipopolysaccharide. At 45 C, these strains have the R-res-1 or R-res-2 phage sensitivity phenotype, and their genetic lesions map by P22-mediated transduction in the rfa gene cluster between cysE-pyrE, suggesting a mutation in genes with transferase functions. P22-mediated joint transduction with temperature-sensitive rfa mutants, leaky rfa mutants, and rfa P22 lysogens have shown the following order of genes in the S. typhimurium linkage map: xyl-mtlA-mtlB-cysE-rfaF-rfaG-pyrE. An rfaE allele was not jointly transduced in the cysE-pyrE segment.
mesh_terms: D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D003433:Crosses, Genetic; D005796:Genes; D008070:Lipopolysaccharides / Q000096:biosynthesis*; D008242:Lysogeny; D009154:Mutation; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D012483:Salmonella Phages / Q000254:growth & development; D012486:Salmonella typhimurium / Q000166:cytology / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D013696:Temperature; D014161:Transduction, Genetic
chemical_list: D008070:Lipopolysaccharides; D011135:Polysaccharides, Bacterial