Synthesis of a fructosyltransferase by Streptococcus sanguis

Keevil, C. W.; West, Aileen A.; Bourne, Nigel; Marsh, Philip

doi:10.1111/j.1574-6968.1983.tb00107.x

Cited by 15 publications

(7 citation statements)

References 11 publications

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“…In particular, a high K+/Na+ ratio was essential for the production of FTF by S . sanguis NCTC 7865 with high Na+ concentrations almost completely abolishing its synthesis and secretion (Keevil et al, 1983. Significantly, these cations have also been shown to modulate the generation of protonmotive force (pmf) in oral streptococci.…”

Section: A a West And Othersmentioning

confidence: 98%

The Relationship between Glycosyltransferase Production and Membrane Fatty Acid Composition of Streptococcus sanguis NCTC 7865 Grown in the Presence of Protonmotive Force Inhibitors

West

Whiley²,

Marsh

et al. 1987

Microbiology

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The fatty acid composition of Streptococcus sanguis NCTC 7865 was not altered by changing the cation composition (Na+/K+) of the growth medium; glucosyltransferase (GTF; EC 2.4.1.5) also remained constant. In contrast, fructosyltransferase (FTF-S; EC 2.4.1.10) production was reduced by at least 50% in medium with a high Na+ concentration. Growth in the presence of ionophores (gramicidin, nigericin or valinomycin) resulted in an increased proportion of saturated fatty acids, principally octadecanoic acid (C18:0), while the proportion of unsaturated fatty acids, predominantly octadecenoic (C18:1) and hexadecenoic (C16:1) acids, decreased. GTF-S production was reduced in the presence of ionophores whereas FTF-S production was completely abolished. Tween 80 significantly increased both GTF-S production and the proportion of unsaturated fatty acids in the cytoplasmic membrane; FTF-S production was unaltered by Tween 80. The production of GTF-S was inversely proportional to the C18:0:C18:1 fatty acid ratio of the cytoplasmic membrane. It was concluded that FTF-S production is directly influenced by protonmotive force (pmf), whereas GTF-S production is affected more by the physical properties of the cytoplasmic membrane, in particular its fatty acid composition. However, as perturbations in pmf generation can lead to variations in membrane fatty acid composition it can be argued that pmf indirectly influences GTF production by changing the saturated:unsaturated or C18:0:C18:1 fatty acid ratio of the cytoplasmic membrane.

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Section: A a West And Othersmentioning

confidence: 98%

The Relationship between Glycosyltransferase Production and Membrane Fatty Acid Composition of Streptococcus sanguis NCTC 7865 Grown in the Presence of Protonmotive Force Inhibitors

West

Whiley²,

Marsh

et al. 1987

Microbiology

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“…The K + concentration of the defined M3 medium was increased to 100 mM to maximise glycosyltransferase activity [17,18] and to simulate the high K + concentration found in dental plaque [21].…”

Section: Effect Of Gramicidin On Continuous Culturesmentioning

confidence: 99%

“…sanguis was originally believed to synthesise a constitutive glycosyltransferase (a-(1-6) glucan: D-fructose-2-glucosyltransferase) which catalyses the formation of a soluble dextran-like glucan [1,4]. Moreover, the organism was also believed to be incapable of FTF synthesis but this has been disproved recently by work showing that the enzyme is pro-duced during chemostat perturbations [17], and in media with a high K+/Na + ratio [17,18]. Moreover, the organism was also believed to be incapable of FTF synthesis but this has been disproved recently by work showing that the enzyme is pro-duced during chemostat perturbations [17], and in media with a high K+/Na + ratio [17,18].…”

Section: Introductionmentioning

confidence: 99%

“…However, little or no GTF activity was detectable when S. sanguis was grown in continuous culture in a defined medium, suggesting that synthesis of the enzyme is regulated [17]. It was suggested that chemostat perturbations enhanced FTF synthesis by boosting streptococcal metabolism [6,8] whilst a high Na + concentration reduced protonmotive force (alp) [16] which might be involved in the secretion of the enzyme [17,18]. It was suggested that chemostat perturbations enhanced FTF synthesis by boosting streptococcal metabolism [6,8] whilst a high Na + concentration reduced protonmotive force (alp) [16] which might be involved in the secretion of the enzyme [17,18].…”

Section: Introductionmentioning

confidence: 99%

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The effect of ionophores on growth and glycosyltransferase production of Streptococcus sanguis

West¹

1984

FEMS Microbiology Letters

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Batch cultures of Streptococcus sanguis NCTC7865 were grown in complex medium in the presence and absence of the ionophores gramicidin, valinomycin and nigericin, to study their effects on growth and glycosyltransferase production. Growth of S. sanguis was markedly inhibited by nigericin or gramicidin, whereas valinomycin had no significant effect. The presence of ionophores caused only slight decreases in glucosyltransferase activity. Fructosyltransferase activity was however reduced by at least 90%. The results indicate that ΔpH rather than ΔΨ is essential for maintaining normal growth in S. sanguis. However, both ΔpH and ΔΨ are necessary for fructosyltransferase synthesis and secretion, but are not apparently involved in the synthesis and secretion of glucosyltransferase.

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“…Several bacteria which normally inhabit the human mouth, including Streptococcus mutans (2, 3,12,18,38), S. salivarius (3,12,13,33), S. sanguis (24), and Actinomyces viscosus (3,49), can synthesize polymers of D-fructose. The structures of the fructans produced by many of these organisms have been analyzed, and it appears as though S. salivarius (3,12,13,32) and the actinomycetes (3,49) produce a levan-type fructan, consisting predominantly of ,B(2->6)-linked fructosyl units with a significant degree of branching in the 1 position (13,32).…”

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confidence: 99%

Expression, purification, and characterization of an exo-beta-D-fructosidase of Streptococcus mutans

et al. 1987

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A genetic library of Streptococcus mutans GS-5, constructed in an Escherichia coli plasmid vector, was screened for cells which could utilize sucrose as the sole carbon and energy source. The recombinant plasmid pFRU1, containing a 4.2-kilobase pair insert of S. mutans DNA, was shown to confer this phenotype. Further characterization of the gene product encoded by pFRUl revealed that the enzyme was a P-D-fructosidase with the highest specificity for the j(2-*6)-linked fructan polymer levan. The enzyme could also hydrolyze inulin [13(2-+1)-linked fructan], sucrose, and raffinose with 34, 21, and 12%, respectively, of the activity observed for levan. The gene (designated fruA) appeared to be expressed under its own control in E. coli, as judged by the lack of influence on gene product activity of induction or repression of the ,I-galactosidase promoter adjacent to the insertion site on the cloning vector. The protein was purified to homogeneity, as judged by silver staining of purified protein in denaturing and reducing conditions in polyacrylamide gels, from sonic lysate of E. coli, as well as from culture supernatants of S. mutans GS-5 grown in a chemostat at low dilution rate with fructose as the sole carbohydrate source. Both purified proteins had an apparent molecular mass of 140,000 daltons in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, were immunologically related and comigrated in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as determined by Western blotting with antisera raised against the cloned gene product, and were identical in all physical and biochemical properties tested. The pH optimum of the enzyme acting on fructan polymers was 5.5, with a significant amount of activity remaining at pH 4.0. The optimum pH for sucrose degradation was broader and lower, with a peak at approximately 4.5.Enzyme activity was inhibited almost completely by Hg2' and Ag2+, inhibited partially by Cu2+, not inhibited by fluoride ion or Tris, and slightly stimulated by Mn2' and Co2+. Fructan polymers were attacked exohydrolytically by the enzyme, fructose being the only product released. With sufficient time, both levan and inulin were degraded to completion, with no evidence of product inhibition.Several bacteria which normally inhabit the human mouth, including Streptococcus mutans (2,3,12,18,38), S. salivarius (3, 12, 13, 33), S. sanguis (24), and Actinomyces viscosus (3, 49), can synthesize polymers of D-fructose. The structures of the fructans produced by many of these organisms have been analyzed, and it appears as though S. salivarius (3,12,13,32) and the actinomycetes (3, 49) produce a levan-type fructan, consisting predominantly of ,B(2->6)-linked fructosyl units with a significant degree of branching in the 1 position (13, 32). S. mutans, on the other hand, produces an inulin-type fructan which is made up almost exclusively of 1(2-l) linkages with some branching in the 6 position (2, 3, 12, 38). In some cases, the physical properties of the fructan polymers have been examined, and gene...

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Synthesis of a fructosyltransferase by Streptococcus sanguis

Cited by 15 publications

References 11 publications

The Relationship between Glycosyltransferase Production and Membrane Fatty Acid Composition of Streptococcus sanguis NCTC 7865 Grown in the Presence of Protonmotive Force Inhibitors

The Relationship between Glycosyltransferase Production and Membrane Fatty Acid Composition of Streptococcus sanguis NCTC 7865 Grown in the Presence of Protonmotive Force Inhibitors

The effect of ionophores on growth and glycosyltransferase production of Streptococcus sanguis

Expression, purification, and characterization of an exo-beta-D-fructosidase of Streptococcus mutans

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