title: A gene cluster for the synthesis of serotype d-specific polysaccharide antigen in Actinobacillus actinomycetemcomitans.
abstract: The serotype d antigen of Actinobacillus actinomycetemcomitans consists of D-glucose, D-mannose, and L-rhamnose in a molar ratio of 1:2:1. A gene cluster involved in the synthesis of serotype-specific polysaccharide antigen was cloned from the chromosomal DNA of A. actinomycetemcomitans IDH 781 (serotype d). This cluster consisted of 12 open reading frames. Insertional inactivation of six genes in this cluster resulted in loss of ability of A. actinomycetemcomitans IDH 781 cells to produce the polysaccharide. Comparing the structure of the gene cluster with similar clusters from other serotypes of A. actinomycetemcomitans, showed that eight genes are unique to serotype d; the other four genes are involved in the biosynthesis of dTDP-L-rhamnose. These results suggest that the synthesis and structure of serotype d-specific polysaccharide of A. actinomycetemcomitans is quite different from those of other serotype strains.
authors.affiliation: Department of Preventive Dentistry, Kyushu University Faculty of Dentistry, 3-1-1 Maidashi, Higashi-ku, 812-8582, Fukuoka, Japan. yosh@dent.kyushu-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Nakano
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshida
authors.forename: N
authors.initials: N
authors.lastname: Suzuki
authors.forename: Y
authors.initials: Y
authors.lastname: Yamashita
authors.forename: T
authors.initials: T
authors.lastname: Koga
mesh_terms: D000188:Actinobacillus / Q000145:classification / Q000235:genetics* / Q000276:immunology; D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000235:genetics*; D015139:Blotting, Southern; D015153:Blotting, Western; D002240:Carbohydrate Sequence; D004926:Escherichia coli / Q000378:metabolism; D005798:Genes, Bacterial; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009702:Nucleoside Diphosphate Sugars / Q000737:chemistry* / Q000235:genetics; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis / Q000235:genetics*; D015183:Restriction Mapping; D013942:Thymine Nucleotides / Q000737:chemistry* / Q000235:genetics
chemical_list: D000942:Antigens, Bacterial; D009702:Nucleoside Diphosphate Sugars; D011135:Polysaccharides, Bacterial; D013942:Thymine Nucleotides; C073293:thymidine diphosphate rhamnose