Journal article
Ligand-Binding Properties of the Carboxyl-Terminal Repeat Domain of Streptococcus mutans Glucan-Binding Protein A
Journal of bacteriology, Vol.182(3), pp.728-733
02/2000
DOI: 10.1128/JB.182.3.728-733.2000
PMCID: PMC94336
PMID: 10633107
Abstract
Streptococcus mutans
glucan-binding protein A (GbpA) has sequence similarity in its carboxyl-terminal domain with glucosyltransferases (GTFs), the enzymes responsible for catalyzing the synthesis of the glucans to which GbpA and GTFs can bind and which promote
S. mutans
attachment to and accumulation on the tooth surface. It was predicted that this C-terminal region, comprised of what have been termed YG repeats, represents the GbpA glucan-binding domain (GBD). In an effort to test this hypothesis and to quantitate the ligand-binding specificities of the GbpA GBD, several fusion proteins were generated and tested by affinity electrophoresis or by precipitation of protein-ligand complexes, allowing the determination of binding constants. It was determined that the 16 YG repeats in GbpA comprise its GBD and that GbpA has a greater affinity for dextran (a water-soluble form of glucan) than for mutan (a water-insoluble form of glucan). Placement of the GBD at the carboxyl terminus was necessary for maximum glucan binding, and deletion of as few as two YG repeats from either end of the GBD reduced the affinity for dextran by over 10-fold. Interestingly, the binding constant of GbpA for dextran was 34-fold higher than that calculated for the GBDs of two
S. mutans
GTFs, one of which catalyzes the synthesis of water-soluble glucan and the other of which catalyzes the synthesis of water-insoluble glucan.
Details
- Title: Subtitle
- Ligand-Binding Properties of the Carboxyl-Terminal Repeat Domain of Streptococcus mutans Glucan-Binding Protein A
- Creators
- Wolfgang Haas - Department of Microbiology, Immunology, and Molecular Genetics, Albany Medical College, Albany, New York 12208Jeffrey A Banas - Department of Microbiology, Immunology, and Molecular Genetics, Albany Medical College, Albany, New York 12208
- Resource Type
- Journal article
- Publication Details
- Journal of bacteriology, Vol.182(3), pp.728-733
- DOI
- 10.1128/JB.182.3.728-733.2000
- PMID
- 10633107
- PMCID
- PMC94336
- NLM abbreviation
- J Bacteriol
- ISSN
- 0021-9193
- eISSN
- 1098-5530
- Publisher
- American Society for Microbiology
- Language
- English
- Date published
- 02/2000
- Academic Unit
- Pediatric Dentistry; Dental Research
- Record Identifier
- 9984066087502771
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