Title |
Sequence and Phylogenetic Analyses of Novel Glucosyltransferase Genes of Mutans Streptococci Isolated from Pig Oral Cavity |
Author |
Noriko Shinozaki-Kuwahara, Kazuko Takada, and Masatomo Hirasawa* |
Address |
Department of Microbiology and Immunology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba 271-8587, Japan |
Bibliography |
Journal of Microbiology, 46(2),202-208, 2008,
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DOI |
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Key Words |
glucosyltransferase, Strptococcus orisuis, Streptococcus criceti, phylogenetic tree |
Abstract |
Nucleotide sequences of water-insoluble glucan-producing glucosyltransferase (gtf) genes of new mutans streptococci isolated from pig oral cavity, Streptococcus orisuis JCM14035, and of Streptococcus criceti HS-6 were determined. The gtf gene of S. orisuis JCM14035 consisted of a 4,401 bp ORF encoding for a 1,466 amino acids, and was revealed to belong to the gtfI group. The percent homology of amino acid sequence of the GTF-I from S. orisuis and S. criceti are 95.0%, however, this score ranges from 77.0% to 78.0% when compared to Streptococcus sobrinus 6715. The deduced N-terminal amino acid sequence was considered responsible for the secretion of GTF-I in S. orisuis JCM14035 and S. criceti HS-6 with high similarity
to known GTF proteins from other streptococci. In addition, two other conserved regions, i.e., N-terminal putative catalytic-site and C-terminal glucan binding domain, were also found in GTF-Is of S. orisuis JCM14035 and S. criceti HS-6. Phylogenetic analysis suggested that S. orisuis JCM14035 and S. criceti HS-6, closely related to each other, resemble S. sobrinus and S. downei based on the amino acid sequences of the GTFs. |