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Characterization of glucose-specific catabolite repression-resistant mutants of Bacillus subtilis: identification of a novel hexose:H+ symporter.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Paulsen, Ian T. Chauvaux, S. Choi, Pan Gyu Saier, Milton H. |
| Copyright Year | 1998 |
| Abstract | Insertional mutagenesis was conducted on Bacillus subtilis cells to screen for mutants resistant to catabolite repression. Three classes of mutants that were resistant to glucose-promoted but not mannitol-promoted catabolite repression were identified. Cloning and sequencing of the mutated genes revealed that the mutations occurred in the structural genes for (i) enzyme II of the phosphoenolpyruvate-glucose phosphotransferase (PtsG), (ii) antiterminator GlcT, which controls PtsG synthesis, and (iii) a previously uncharacterized carrier of the major facilitator superfamily, which we have designated GlcP. The last protein exhibits greatest sequence similarity to the fucose:H+ symporter of Escherichia coli and the glucose/galactose:H+ symporter of Brucella abortus. In a wild-type B. subtilis genetic background, the glcP::Tn10 mutation (i) partially but specifically relieved glucose- and sucrose-promoted catabolite repression, (ii) reduced the growth rate in minimal glucose medium, and (iii) reduced rates of [14C]glucose and [14C]methyl alpha-glucoside uptake. In a delta pts genetic background no phenotype was observed, suggesting that expression of the glcP gene required a functional phosphotransferase system. When overproduced in a delta pts mutant of E. coli, GlcP could be shown to specifically transport glucose, mannose, 2-deoxyglucose and methyl alpha-glucoside with low micromolar affinities. Accumulation of the nonmetabolizable glucose analogs was demonstrated, and inhibitor studies suggested a dependency on the proton motive force. We conclude that B. subtilis possesses at least two distinct routes of glucose entry, both of which contribute to the phenomenon of catabolite repression. |
| Starting Page | 498 |
| Ending Page | 504 |
| Page Count | 7 |
| File Format | PDF HTM / HTML |
| DOI | 10.1128/jb.180.3.498-504.1998 |
| PubMed reference number | 9457850 |
| Journal | Medline |
| Volume Number | 180 |
| Issue Number | 3 |
| Alternate Webpage(s) | http://jb.asm.org/content/180/3/498.full.pdf |
| Alternate Webpage(s) | https://doi.org/10.1128/jb.180.3.498-504.1998 |
| Journal | Journal of bacteriology |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
