Effect of inactivation of <i>gtf</i> genes on adherence of <i>Streptococcus downei</i>

Colby, Sheila M.; McLaughlin, Robert E.; Ferretti, Joseph J.; Russell, R. R. B.

doi:10.1034/j.1399-302x.1999.140103.x

Cited by 23 publications

(20 citation statements)

References 48 publications

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“…In S. mutans, the tandemly arranged gtfB and gtfC encode GTF-I and GTF-SI enzymes, respectively, and the distally located gtfD encodes a GTF-S. One GTF-I and two tandemly arranged GTF-S enzymes have been isolated and characterized in S. criceti . S. downei and S. sobrinus both have three GTF-S and one GTF-I enzymes (Colby et al, 1999;Hanada et al, 2002). In contrast, members of the oralis group of streptococci (S. sanguis, S. oralis, and S. gordonii) have a single GTF enzyme which appears to make glucans with various proportions of alpha-1,3 and alpha-1,6 linkages (Grahame and Mayer, 1984;Kopec et al, 2001).…”

Section: Distribution Of Gtf Enzymes Among Cariogenic and Commensal Smentioning

confidence: 99%

Glucan-binding Proteins of the Oral Streptococci

Banas

Vickerman

2003

Critical Reviews in Oral Biology & Medicine

296

262

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ABSTRACT:The synthesis of extracellular glucan is an integral component of the sucrose-dependent colonization of tooth surfaces by species of the mutans streptococci. In investigators' attempts to understand the mechanisms of plaque biofilm development, several glucan-binding proteins (GBPs) have been discovered. Some of these, the glucosyltransferases, catalyze the synthesis of glucan, whereas others, designated only as glucan-binding proteins, have affinities for different forms of glucan and contribute to aspects of the biology of their host organisms. The functions of these latter glucan-binding proteins include dextran-dependent aggregation, dextranase inhibition, plaque cohesion, and perhaps cell wall synthesis. In some instances, their glucan-binding domains share common features, whereas in others the mechanism for glucan binding remains unknown. Recent studies indicate that at least some of the glucan-binding proteins modulate virulence and some can act as protective immunogens within animal models. Overall, the multiplicity of GBPs and their aforementioned properties are testimonies to their importance. Future studies will greatly advance the understanding of the distribution, function, and regulation of the GBPs and place into perspective the facets of their contributions to the biology of the oral streptococci.

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Section: Distribution Of Gtf Enzymes Among Cariogenic and Commensal Smentioning

confidence: 99%

Glucan-binding Proteins of the Oral Streptococci

Banas

Vickerman

2003

Critical Reviews in Oral Biology & Medicine

296

262

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“…As a result of variations in linkage type, degree of branching and size, the a-glucans produced by glucansucrases display greatly varying physicochemical properties [4]. For example, the a-glucans produced by Streptococcus mutans glucansucrases in the oral cavity are sticky and are associated with the formation of bacterial plaque on tooth surfaces, which eventually may lead to the development of dental caries [6]. Natural and modified aglucans also hold great potential in biotechnology, as well as in food and health-related applications, particularly because of their potential prebiotic properties [4].…”

Section: Introductionmentioning

confidence: 99%

Flexibility of truncated and full‐length glucansucrase GTF180 enzymes from Lactobacillus reuteri 180

et al. 2014

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Glucansucrase enzymes synthesize high-molecular-mass extracellular aglucan polysaccharides from sucrose. Previously, the crystal structure of truncated glucansucrase glucosyltransferase (GTF)180-DN from Lactobacillus reuteri 180 (lacking the N-terminal domain) revealed an elongated overall structure with two remote domains (IV and V) extending away from the core. By contrast, a new crystal form of the a-1,6/a-1,3 specific glucansucrase GTF180-DN shows an approximate 120 o rotation of domain V about a hinge located between domains IV and V, giving a much more compact structure than before. Positional variability of domain V in solution is confirmed by small angle X-ray scattering experiments and rigid-body ensemble calculations. In addition, small angle Xray scattering measurements of full-length GTF180 also provide the first structural data for a full-length glucansucrase, showing that the enzyme has an almost symmetric boomerang-like molecular shape, with a bend likely located between domains IV and V. The~700-residue N-terminal domain, which is not present in the crystal structures, extends away from domain V and the catalytic core of the enzyme. We conclude that, as a result of the hinge region, in solution, GTF180-DN (and likely also the full-length GTF180) shows conformational flexibility; this may be a general feature of GH70 glucansucrases.

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“…Fermentation of carbohydrates by plaque-forming oral bacteria produces acids, which cause the dissolution of calcium phosphate in the tooth enamel (2). In addition, dietary sucrose serves as a substrate for bacterial glucansucrases, which produce α-glucan polysaccharides that facilitate biofilm formation and significantly enhance the adhesion of bacteria to the tooth enamel (3)(4)(5). Therefore, glucansucrases have been proposed as potential targets for anticaries drugs.…”

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confidence: 99%

Crystal structure of a 117 kDa glucansucrase fragment provides insight into evolution and product specificity of GH70 enzymes

Vujicic-Zagar

Pijning

Kralj

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

151

262

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Glucansucrases are large enzymes belonging to glycoside hydrolase family 70, which catalyze the cleavage of sucrose into fructose and glucose, with the concomitant transfer of the glucose residue to a growing α-glucan polymer. Among others, plaque-forming oral bacteria secrete these enzymes to produce α-glucans, which facilitate the adhesion of the bacteria to the tooth enamel. We determined the crystal structure of a fully active, 1,031-residue fragment encompassing the catalytic and C-terminal domains of GTF180 from Lactobacillus reuteri 180, both in the native state, and in complexes with sucrose and maltose. These structures show that the enzyme has an α-amylase-like ðβ∕αÞ 8 -barrel catalytic domain that is circularly permuted compared to the catalytic domains of members of glycoside hydrolase families 13 and 77, which belong to the same GH-H superfamily. In contrast to previous suggestions, the enzyme has only one active site and one nucleophilic residue. Surprisingly, in GTF180 the peptide chain follows a "U"-path, such that four of the five domains are made up from discontiguous N-and C-terminal stretches of the peptide chain. Finally, the structures give insight into the factors that determine the different linkage types in the polymeric product.crystal structure complexes | exopolysaccharide | Lactobacillus reuteri | dental caries

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Effect of inactivation of gtf genes on adherence of Streptococcus downei

Cited by 23 publications

References 48 publications

Glucan-binding Proteins of the Oral Streptococci

Glucan-binding Proteins of the Oral Streptococci

Flexibility of truncated and full‐length glucansucrase GTF180 enzymes from Lactobacillus reuteri 180

Crystal structure of a 117 kDa glucansucrase fragment provides insight into evolution and product specificity of GH70 enzymes

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