title: Biological functions of UDP-glucose synthesis in Streptococcus mutans.
abstract: A gene encoding glucose-1-phosphate uridylyltransferase (EC 2.7.7.9) was isolated from Streptococcus mutans. A cell extract of Escherichia coli expressing the cloned gene exhibited glucose-1-phosphate uridylyltransferase activity. The enzyme catalyses the conversion of D-glucose 1-phosphate and UTP into UDP-D-glucose. Rabbit antiserum against the serotype-c-specific antigen did not react with autoclaved extracts from mutant cells in which the cloned gene was insertionally inactivated. The glucose content of the cell-wall preparation purified from the mutant was very much lowered, whereas there was no observable decrease in the content of rhamnose. When the mutant strain was grown in an acidic environment, its cell viability was much lower than that of the wild-type. These results suggest that UDP-D-glucose functions not only as an immediate precursor of the serotype-c-specific antigen of S. mutans (as a glucose donor for side-chain formation), but is also important for the organism's viability in environmental conditions of low pH.
authors.affiliation: Department of Preventive Dentistry, Kyushu University Faculty of Dentistry, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Yamashita
authors.affiliation: Department of Preventive Dentistry, Kyushu University Faculty of Dentistry, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tsukioka
authors.affiliation: Department of Preventive Dentistry, Kyushu University Faculty of Dentistry, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Nakano
authors.affiliation: Department of Preventive Dentistry, Kyushu University Faculty of Dentistry, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Tomihisa
authors.affiliation: Department of Preventive Dentistry, Kyushu University Faculty of Dentistry, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Oho
authors.affiliation: Department of Preventive Dentistry, Kyushu University Faculty of Dentistry, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Koga
mesh_terms: D001483:Base Sequence; D015139:Blotting, Southern; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration; D005779:Immunodiffusion; D008969:Molecular Sequence Data; D011135:Polysaccharides, Bacterial / Q000032:analysis; D011995:Recombination, Genetic; D015183:Restriction Mapping; D012965:Sodium Chloride; D013295:Streptococcus mutans / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013696:Temperature; D005957:UTP-Glucose-1-Phosphate Uridylyltransferase / Q000235:genetics / Q000378:metabolism*; D014532:Uridine Diphosphate Glucose / Q000096:biosynthesis* / Q000502:physiology*
chemical_list: D011135:Polysaccharides, Bacterial; D012965:Sodium Chloride; D005957:UTP-Glucose-1-Phosphate Uridylyltransferase; D014532:Uridine Diphosphate Glucose