The fructosyltransferase of Streptococcus salivarius
نویسندگان
چکیده
منابع مشابه
Inactivation of cell-associated fructosyltransferase in Streptococcus salivarius.
In stationary phase, 95% of the fructosyltransferase (FTase) activity of Streptococcus salivarius ATCC 25975 was found associated with the cells. Within the first 15 min after inoculation into fresh medium, the specific activity of cell-associated FTase decreased by 92% of its initial value. After this period of initial loss, the enzyme was synthesized during exponential growth until a maximum ...
متن کاملRole of C-terminal domains in surface attachment of the fructosyltransferase of Streptococcus salivarius ATCC 25975.
The cell-associated beta-D-fructosyltransferase of Streptococcus salivarius, which is devoid of the cell wall anchoring motif, LPXTG, is released on exposure to its substrate, sucrose. Deletions within the C terminus of the enzyme implicated both the hydrophobic and the proline-glycine-serine-threonine-rich wall-associated domain in stabilizing the enzyme on the cell surface.
متن کاملPurification and enzymic properties of the fructosyltransferase of Streptococcus salivarius ATCC 25975.
The recombinant fructosyltransferase (Ftf) of Streptococcus salivarius was expressed in Escherichia coli and purified to electrophoretic homogeneity after a combination of adsorption, ion-exchange and gel-filtration chromatography. The N-terminal signal sequence of the Ftf was removed by E. coli at the same site as in its natural host. The purified Ftf exhibited maximum activity at pH 6.0 and 3...
متن کاملMutation of aspartic acid residues in the fructosyltransferase of Streptococcus salivarius ATCC 25975.
The site-directed mutated fructosyltransferases (Ftfs) of Streptococcus salivarius ATCC 25975, D312E, D312S, D312N and D312K were all active at 37 degrees C, indicating that Asp-312 present in the 'sucrose box' was not the nucleophilic Asp residue responsible for the formation of a covalent fructosyl-enzyme intermediate required for enzyme activity. Analysis of the kinetic constants of the puri...
متن کاملGenetic regulation of fructosyltransferase in Streptococcus mutans.
Streptococcus mutans possesses several extracellular sucrose-metabolizing enzymes which have been implicated as important virulence factors in dental caries. This study was initiated to investigate the genetic regulation of one of these enzymes, the extracellular fructosyltransferase (Ftf). Fusions were constructed with the region upstream of the S. mutans GS5 Ftf gene (ftf) and a promoterless ...
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ژورنال
عنوان ژورنال: New Phytologist
سال: 1993
ISSN: 0028-646X,1469-8137
DOI: 10.1111/j.1469-8137.1993.tb03754.x