title: Evolution of cariogenic character in Streptococcus mutans: horizontal transmission of glycosyl hydrolase family 70 genes.
abstract: Acquisition of the ability to produce polysaccharides from sucrose, i.e. the gtf gene encoding glucosyltransferase (GTF), is the key evolutionary event enabling dental biofilm formation by streptococci. To clarify the ancestry of streptococcal GTFs, time of its occurrence, and order of specific events, we investigated the distribution of GTFs among bacteria by phylogenetic analysis of the glycosyl hydrolase family 70 enzymes. We found that streptococcal GTFs were derived from other lactic acid bacteria such as Lactobacillus and Leuconostoc, and propose the following evolutionary model: horizontal gene transfer via transposons occurred when streptococci encountered lactic acid bacteria contained in fermented food. Intra-genomic gene duplication occurred by a secondary selection pressure such as consumption of refined sugar. Our findings concerning this evolution in Streptococcus mutans provide an important background for studies of the relationship between the historical spread of dental caries and anthropological factors.
authors: Department of Pediatric Dentistry, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan.
authors: Tomonori
authors: T
authors: Hoshino
authors: Taku
authors: T
authors: Fujiwara
authors: Shigetada
authors: S
authors: Kawabata
mesh_terms: D001483:Base Sequence; D020134:Catalytic Domain / Q000235:genetics; D002874:Chromosome Mapping; D019143:Evolution, Molecular; D023061:Gene Order; D022761:Gene Transfer, Horizontal; D016680:Genome, Bacterial; D005936:Glucans / Q000378:metabolism; D005964:Glucosyltransferases / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D008954:Models, Biological; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs / Q000235:genetics; D013295:Streptococcus mutans / Q000201:enzymology / Q000235:genetics*
chemical_list: D005936:Glucans; D005964:Glucosyltransferases