This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Plamondon, P.
Right arrow Articles by Vadeboncoeur, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Plamondon, P.
Right arrow Articles by Vadeboncoeur, C.

 Previous Article  |  Next Article 

Journal of Bacteriology, November 1999, p. 6914-6921, Vol. 181, No. 22
0021-9193/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

Phenotypic Consequences Resulting from a Methionine-to-Valine Substitution at Position 48 in the HPr Protein of Streptococcus salivarius

Pascale Plamondon, Denis Brochu, Suzanne Thomas, Julie Fradette, Lucie Gauthier, Katy Vaillancourt, Nicole Buckley, Michel Frenette, and Christian Vadeboncoeur*

Groupe de Recherche en Écologie Buccale, Département de Biochimie, Faculté des Sciences et de Génie and Faculté de Médecine Dentaire, Université Laval, Cité Universitaire, Québec, Québec, Canada G1K 7P4

Received 1 October 1998/Accepted 13 September 1999

In gram-positive bacteria, the HPr protein of the phosphoenolpyruvate:sugar phosphotransferase system (PTS) can be phosphorylated on a histidine residue at position 15 (His15) by enzyme I (EI) of the PTS and on a serine residue at position 46 (Ser46) by an ATP-dependent protein kinase (His~P and Ser-P, respectively). We have isolated from Streptococcus salivarius ATCC 25975, by independent selection from separate cultures, two spontaneous mutants (Ga3.78 and Ga3.14) that possess a missense mutation in ptsH (the gene encoding HPr) replacing the methionine at position 48 by a valine. The mutation did not prevent the phosphorylation of HPr at His15 by EI nor the phosphorylation at Ser46 by the ATP-dependent HPr kinase. The levels of HPr(Ser-P) in glucose-grown cells of the parental and mutant Ga3.78 were virtually the same. However, mutant cells growing on glucose produced two- to threefold less HPr(Ser-P)(His~P) than the wild-type strain, while the levels of free HPr and HPr(His~P) were increased 18- and 3-fold, respectively. The mutants grew as well as the wild-type strain on PTS sugars (glucose, fructose, and mannose) and on the non-PTS sugars lactose and melibiose. However, the growth rate of both mutants on galactose, also a non-PTS sugar, decreased rapidly with time. The M48V substitution had only a minor effect on the repression of alpha -galactosidase, beta -galactosidase, and galactokinase by glucose, but this mutation abolished diauxie by rendering cells unable to prevent the catabolism of a non-PTS sugar (lactose, galactose, and melibiose) when glucose was available. The results suggested that the capacity of the wild-type cells to preferentially metabolize glucose over non-PTS sugars resulted mainly from inhibition of the catabolism of these secondary energy sources via a HPr-dependent mechanism. This mechanism was activated following glucose but not lactose metabolism, and it did not involve HPr(Ser-P) as the only regulatory molecule.

* Corresponding author. Mailing address: GREB, Université Laval, Cité Universitaire, Québec, Québec, Canada G1K 7P4. Phone: 418-656-2319. Fax: 418-656-2861. E-mail: Christian.Vadeboncoeur{at}bcm.ulaval.ca.

Journal of Bacteriology, November 1999, p. 6914-6921, Vol. 181, No. 22
0021-9193/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Poncet, S., Soret, M., Mervelet, P., Deutscher, J., Noirot, P. (2009). Transcriptional Activator YesS Is Stimulated by Histidine-phosphorylated HPr of the Bacillus subtilis Phosphotransferase System. J. Biol. Chem. 284: 28188-28197 [Abstract] [Full Text]  
  • Pinedo, C. A., Bringhurst, R. M., Gage, D. J. (2008). Sinorhizobium meliloti Mutants Lacking Phosphotransferase System Enzyme HPr or EIIA Are Altered in Diverse Processes, Including Carbon Metabolism, Cobalt Requirements, and Succinoglycan Production. J. Bacteriol. 190: 2947-2956 [Abstract] [Full Text]  
  • Deutscher, J., Francke, C., Postma, P. W. (2006). How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria. Microbiol. Mol. Biol. Rev. 70: 939-1031 [Abstract] [Full Text]  
  • Cochu, A., Roy, D., Vaillancourt, K., LeMay, J.-D., Casabon, I., Frenette, M., Moineau, S., Vadeboncoeur, C. (2005). The Doubly Phosphorylated Form of HPr, HPr(Ser-P)(His~P), Is Abundant in Exponentially Growing Cells of Streptococcus thermophilus and Phosphorylates the Lactose Transporter LacS as Efficiently as HPr(His~P). Appl. Environ. Microbiol. 71: 1364-1372 [Abstract] [Full Text]  
  • Lessard, C., Cochu, A., Lemay, J.-D., Roy, D., Vaillancourt, K., Frenette, M., Moineau, S., Vadeboncoeur, C. (2003). Phosphorylation of Streptococcus salivarius Lactose Permease (LacS) by HPr(His~P) and HPr(Ser-P)(His~P) and Effects on Growth. J. Bacteriol. 185: 6764-6772 [Abstract] [Full Text]  
  • Thomas, S., Brochu, D., Vadeboncoeur, C. (2001). Diversity of Streptococcus salivarius ptsH Mutants That Can Be Isolated in the Presence of 2-Deoxyglucose and Galactose and Characterization of Two Mutants Synthesizing Reduced Levels of HPr, a Phosphocarrier of the Phosphoenolpyruvate:Sugar Phosphotransferase System. J. Bacteriol. 183: 5145-5154 [Abstract] [Full Text]  
  • Djordjevic, G. M., Tchieu, J. H., Saier, M. H. Jr. (2001). Genes Involved in Control of Galactose Uptake in Lactobacillus brevis and Reconstitution of the Regulatory System in Bacillus subtilis. J. Bacteriol. 183: 3224-3236 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»