title: Structure of the 2-keto-3-deoxy-D-manno-octonic-acid-containing capsular polysaccharide (K12 antigen) of the urinary-tract-infective Escherichia coli O4:K12:H-.
abstract: The primary structure of the K12 antigenic capsular polysaccharide (K12 antigen) of Escherichia coli O4:K12:H- was elucidated by composition, nuclear magnetic resonance spectroscopy, methylation, periodate oxidation and oligosaccharide analysis. The polysaccharide consists of repeating trisaccharide alpha-rhamnosyl-1,2-alpha-rhamnosyl-1,5-dOclA units (dOclA = 2-keto-3-deoxy-D-manno-octonic acid) which are joined through beta-2,3-linkages. About 50% of the dOclA units are O-acetylated at C7 or C8. The sequence of acetylated and non-acetylated dOclA residues is not known. As had been reported before, the polysaccharide is linked to a phosphatidic acid at the reducing end (dOclA) via a phosphodiester bridge. The serologically specific part of the K12 antigen is its polysaccharide moiety.
mesh_terms: D000941:Antigens / Q000302:isolation & purification*; D000942:Antigens, Bacterial / Q000302:isolation & purification*; D000954:Antigens, Surface; D002236:Carbohydrate Conformation; D002241:Carbohydrates / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D004926:Escherichia coli / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D011135:Polysaccharides, Bacterial / Q000032:analysis; D013400:Sugar Acids / Q000032:analysis; D014552:Urinary Tract Infections / Q000276:immunology / Q000382:microbiology
chemical_list: D000941:Antigens; D000942:Antigens, Bacterial; D000954:Antigens, Surface; D002241:Carbohydrates; C030659:K antigens; D011135:Polysaccharides, Bacterial; D013400:Sugar Acids; C002532:2-keto-3-deoxyoctonate