期刊
FEMS MICROBIOLOGY LETTERS
卷 205, 期 2, 页码 337-342出版社
ELSEVIER SCIENCE BV
DOI: 10.1111/j.1574-6968.2001.tb10969.x
关键词
streptococci; fructose-phosphotransferase system; xylitol toxicity; dental caries
类别
资金
- NIDCR NIH HHS [R01 DE012236, DE12236] Funding Source: Medline
Three genes, designated as fruC,fruD and fruI, were predicted to encode polypeptides homologous to fructose-specific enzyme II (IIFru) of the phosphoenolpyruvate-dependent sugar: phosphotransferase system, and were cloned from Streptococcus mutans, the primary etiological agent of human dental caries. The fruC and fruD genes encoded domains BC and domain A of IIFru, respectively. The fruI gene encoded IICBA(Fru). Northern hybridization and slot blot analysis showed that expression of fruI was inducible by sucrose and fructose, while fruCD were expressed constitutively and at much lower levels. Inactivation of either fruI or fruCD alone, or of both fruCD and fruI, had no major impact on growth on fructose at a concentration of 0.5% (w/v). However, when the strains were grown with 0.2% fructose as the sole carbohydrate source, a significant decrease in the growth rate was seen with the fruCD/fruI double mutants. Assays of sugar:phosphotransferase activity showed that the fruCD/fruI double mutants had roughly 30% of the capacity of the wild-type strain to transport fructose via the phosphoenolpyruvate-dependent sugar: phosphotransferase system. Xylitol toxicity assays indicated that the inducible fructose permease was responsible for xylitol transport. (C) 2001 Published by Elsevier Science B.V. on behalf of the Federation of European Microbiological Societies.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据