A two-component covRS regulatory system regulates expression of fructosyltransferase and a novel extracellular carbohydrate in Streptococcus mutans.

ABSTRACT: The expression of fructosyltransferase (FTF), the enzyme that synthesizes fructan from sucrose, is regulated in the cariogenic bacterium Streptococcus mutans. However, the exact mechanism of FTF regulation is unknown. In this study, the role of a two-component regulatory system (covRS) in FTF expression was investigated. A CovR-defective mutant of S. mutans NG8 was constructed by homologous recombination. By use of immunoblotting, the mutant was shown to overexpress FTF in the absence of sucrose, while the wild type and a covRS-complemented mutant showed sucrose-inducible FTF expression. Reverse transcription-PCR showed that the ftf transcript levels were increased in the covR mutant, suggesting regulation at the transcriptional level. The covR mutant was also found to overproduce extracel

SUBMITTER: Lee SF 

PROVIDER: S-EPMC427443 | biostudies-literature | 2004 Jul

REPOSITORIES: biostudies-literature