title: A gene cluster for 6-deoxy-L-talan synthesis in Actinobacillus actinomycetemcomitans.
abstract: The serotype c antigen of Actinobacillus actinomycetemcomitans consists of 6-deoxy-l-talose. A gene cluster involved in the synthesis of serotype-specific polysaccharide antigen was cloned from the chromosomal DNA of A. actinomycetemcomitans NCTC 9710 (serotype c). This cluster consisted of 17 open reading frames. Escherichia coli produced the polysaccharide that reacts with the serotype c-specific antibody when transformed with a plasmid containing the cluster. Comparing the structure of the gene cluster with a similar cluster from A. actinomycetemcomitans Y4 (serotype b), which produces a polysaccharide consisting of l-rhamnose and d-fucose, revealed that a 5.7 kb region containing seven genes in the cluster from strain Y4 was replaced by a 3.8 kb region containing three genes in strain NCTC 9710. The results suggest that these region, as well as dTDP-6-deoxy-l-talose-forming dTDP-4-keto-l-rhamnose reductase, is essential to the production of extracellular polysaccharide specific to serotype c.
authors.affiliation: Department of Preventive Dentistry, Kyushu University Faculty of Dentistry, Fukuoka 812-8582, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nakano
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Y
authors.initials: Y
authors.lastname: Yamashita
authors.forename: T
authors.initials: T
authors.lastname: Koga
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000145:classification / Q000235:genetics*; D000942:Antigens, Bacterial / Q000096:biosynthesis* / Q000235:genetics; D001483:Base Sequence; D017931:DNA Primers; D005643:Fucose / Q000378:metabolism; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D005810:Multigene Family; D016133:Polymerase Chain Reaction; D011134:Polysaccharides / Q000096:biosynthesis* / Q000235:genetics; D015183:Restriction Mapping; D012210:Rhamnose / Q000378:metabolism; D012703:Serotyping
chemical_list: C070694:6-deoxytalan; D000942:Antigens, Bacterial; D017931:DNA Primers; D011134:Polysaccharides; D005643:Fucose; D012210:Rhamnose