Publication Date:
2013-01-01
Description:
Streptococcus mutansproduces 3 types of glucosyltransferases (GTFs), whose cooperative action is essential for cellular adhesion. The recombinase A (RecA) protein is required for homologous recombination. In our previous study, we isolated several strains with a smooth colony morphology and low GTF activity, characteristics speculated to be derived from the GTF fusions. The purpose of the present study was to investigate the mechanism of those fusions.S. mutansstrain MT8148 was grown in the presence of recombinant RecA (rRecA) protein, after which smooth colonies were isolated. The biological functions and sequences of thegtfBandgtfCgenes of this as well as other clinical strains were determined. The sucrose-dependent adherence rates of those strains were reduced as compared to that of MT8148. Determination of the sequences of thegtfBandgtfCgenes showed that an approximately 3500 bp region was deleted from the area between them. Furthermore, expression of therecAgene was elevated in those strains as compared to MT8148. These results suggest that RecA has an important role in fusions ofgtfBandgtfCgenes, leading to alteration of colony morphology and reduction in sucrose-dependent adhesion.
Print ISSN:
2356-6140
Electronic ISSN:
1537-744X
Topics:
Natural Sciences in General
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