1989 Fiscal Year Final Research Report Summary
Cloning of the gene encoding glucosyltransferase from Streptococcus sobrinus
| Project/Area Number |
63570871
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Functional basic dentistry
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| Research Institution | Okayama University |
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Principal Investigator |
FUKUI Kazuhiro Okayama University Dental School, Associate Professor, 歯学部, 助教授 (70034171)
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| Co-Investigator(Kenkyū-buntansha) |
KOKEGUCHI Susumu Okayama University Dental School, Assistant, 歯学部, 助手 (10144776)
OHTA Hiroyuki Okayama University Dental School, Assistant, 歯学部, 助手 (80168947)
KODAMA Takao Okayama University Dental School, Associate Professor, 歯学部, 助教授 (30034200)
KATO Keijiro Okayama University Dental School, Professor, 歯学部, 教授 (50028718)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Streptococcus sobrinus / glucosyltransferase gene / cloning / water-insoluble glucan / dextran binding domain |
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| Research Abstract |
The gene encoding glucosyltransferase responsible for water-insoluble glucansynthesis (GTF-I) of streptococcus sobrinus(formerly Streptococcus mutans 6715) was cloned, expressed, and sequenced. A gene bank from S.sobrinus 6715 DNA was contructed in vector pUC18 and screened with anti-GTF-I antibody to detect clones producing GTF-I peptide. Five immunopositive clones were isolated, all of which produced peptides that bound alpha-1,6 glucan.
GTF-I activity was found in only two large peptides : one stretching over the full length of the GTF-I peptide and composed of about 1,600 amino acid residues (AB1 clone) and the other lacking about 80 N-terminal residues and about 260 C-terminal residues (AB2 clone). A deletion study of the AB2 clone indicated that specific glucan binding, which is essential for water-insoluble glucan synthesis, was lost prior to sucrase activity with an increase in deletion from the 3'end of the GTF-I gene.
These results suggest that the GTF-I peptide consists of three segments : that for sucrose splitting (-1,100 residues), that for glucan binding (-240 residues), and that unknown function (-260 residues), in order from the N terminus. The primary structure of GTF-I peptide, deduced by DNA sequencing of the AB1 clone, was found to be very similar to that of the homologus protein from another strain of S.sobrinus.
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Research Products
(2 results)
