title: Expression of lipopolysaccharide O antigen in Escherichia coli K-12 hybrids containing plasmid and chromosomal genes from Shigella dysenteriae 1.
abstract: The requirement for both plasmid and chromosomal genes in the biosynthesis of Shigella dysenteriae 1 lipopolysaccharide O antigen was demonstrated in Escherichia coli-Shigella hybrids. A 6-megadalton S. dysenteriae 1 plasmid, designated pWR23, was phenotypically tagged with the Tn3 ampicillin-resistance transposon. The tagged plasmid, designated pWR24, was transferred by transformation or conjugal mobilization to a rough E. coli K-12 recipient. Although the resultant hybrids were agglutinated in S. dysenteriae 1 antiserum, they did not remove all of the anti-Shiga agglutinins in absorption experiments. Modified lipid A core structure was detected in these hybrids, but Shiga O antigen was not expressed. When the his+ locus of the S. dysenteriae 1 chromosome was transferred by transduction to E. coli K-12 containing pWR24, complete Shiga O antigen was expressed. Lipopolysaccharide extracted from these hybrids was indistinguishable chemically, electrophoretically, and serologically from native S. dysenteriae 1 lipopolysaccharide.
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics*; D002876:Chromosomes, Bacterial; D004926:Escherichia coli / Q000235:genetics; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D008070:Lipopolysaccharides / Q000235:genetics*; D010957:Plasmids; D011135:Polysaccharides, Bacterial / Q000235:genetics*; D012762:Shigella dysenteriae / Q000235:genetics*
chemical_list: D000942:Antigens, Bacterial; D008070:Lipopolysaccharides; D011135:Polysaccharides, Bacterial