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 Zhang, Z.
Right arrow Articles by Saier, M. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zhang, Z.
Right arrow Articles by Saier, M. H., Jr.

 Previous Article  |  Next Article 

Journal of Bacteriology, April 2003, p. 2243-2250, Vol. 185, No. 7
0021-9193/03/$08.00+0     DOI: 10.1128/JB.185.7.2243-2250.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

The Ascorbate Transporter of Escherichia coli

Zhongge Zhang,1 Mohammad Aboulwafa,1,2 Meghan H. Smith,1 and Milton H. Saier, Jr.1*

Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093-0116,1 Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Abbassia, Cairo, Egypt2

Received 21 October 2002/ Accepted 16 January 2003

The sgaTBA genes of Escherichia coli encode a putative 12-transmembrane {alpha}-helical segment (12 TMS) transporter, an enzyme IIB-like protein and an enzyme IIA-like protein of the phosphotransferase system (PTS), respectively. We show that all three proteins as well as the energy-coupling PTS proteins, enzyme I and HPr, are required for the anaerobic utilization and uptake of L-ascorbate in vivo and its phosphoenolpyruvate-dependent phosphorylation in vitro. The transporter exhibits an apparent Km for L-ascorbate of 9 µM and is highly specific. The sgaTBA genes are regulated at the transcriptional level by the yjfQ gene product, as well as by Crp and Fnr. The yjfR gene product is essential for L-ascorbate utilization and probably encodes a cytoplasmic L-ascorbate 6-phosphate lactonase. We conclude that SgaT represents a novel prototypical enzyme IIC that functions with SgaA and SgaB to allow phosphoryl transfer from HPr(his-P) to L-ascorbate via the phosphoryl transfer pathway: PEP -> enzyme I-P -> HPr-P -> IIA- -> IIB- L-ascorbate-6-P.

* Corresponding author. Mailing address: Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116. Phone: (858) 534-4084. Fax: (858) 534-7108. E-mail: msaier{at}ucsd.edu.

Journal of Bacteriology, April 2003, p. 2243-2250, Vol. 185, No. 7
0021-9193/03/$08.00+0     DOI: 10.1128/JB.185.7.2243-2250.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Shi, R., Pineda, M., Ajamian, E., Cui, Q., Matte, A., Cygler, M. (2008). Structure of L-Xylulose-5-Phosphate 3-Epimerase (UlaE) from the Anaerobic L-Ascorbate Utilization Pathway of Escherichia coli: Identification of a Novel Phosphate Binding Motif within a TIM Barrel Fold. J. Bacteriol. 190: 8137-8144 [Abstract] [Full Text]  
  • Campos, E., de la Riva, L., Garces, F., Gimenez, R., Aguilar, J., Baldoma, L., Badia, J. (2008). The yiaKLX1X2PQRS and ulaABCDEFG Gene Systems Are Required for the Aerobic Utilization of L-Ascorbate in Klebsiella pneumoniae Strain 13882 with L-Ascorbate-6-Phosphate as the Inducer. J. Bacteriol. 190: 6615-6624 [Abstract] [Full Text]  
  • Campos, E., Montella, C., Garces, F., Baldoma, L., Aguilar, J., Badia, J. (2007). Aerobic L-ascorbate metabolism and associated oxidative stress in Escherichia coli. Microbiology 153: 3399-3408 [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]  
  • Burgess, C. M., Slotboom, D. J., Geertsma, E. R., Duurkens, R. H., Poolman, B., van Sinderen, D. (2006). The Riboflavin Transporter RibU in Lactococcus lactis: Molecular Characterization of Gene Expression and the Transport Mechanism.. J. Bacteriol. 188: 2752-2760 [Abstract] [Full Text]  
  • Goswami, M., Mangoli, S. H., Jawali, N. (2006). Involvement of Reactive Oxygen Species in the Action of Ciprofloxacin against Escherichia coli. Antimicrob. Agents Chemother. 50: 949-954 [Abstract] [Full Text]  
  • Thomas, G. H., Southworth, T., Leon-Kempis, M. R., Leech, A., Kelly, D. J. (2006). Novel ligands for the extracellular solute receptors of two bacterial TRAP transporters. Microbiology 152: 187-198 [Abstract] [Full Text]  
  • De Spiegeleer, P., Sermon, J., Vanoirbeek, K., Aertsen, A., Michiels, C. W. (2005). Role of Porins in Sensitivity of Escherichia coli to Antibacterial Activity of the Lactoperoxidase Enzyme System. Appl. Environ. Microbiol. 71: 3512-3518 [Abstract] [Full Text]  
  • Campos, E., Baldoma, L., Aguilar, J., Badia, J. (2004). Regulation of Expression of the Divergent ulaG and ulaABCDEF Operons Involved in L-Ascorbate Dissimilation in Escherichia coli. J. Bacteriol. 186: 1720-1728 [Abstract] [Full Text]  
  • Gimenez, R., Nunez, M. F., Badia, J., Aguilar, J., Baldoma, L. (2003). The Gene yjcG, Cotranscribed with the Gene acs, Encodes an Acetate Permease in Escherichia coli. J. Bacteriol. 185: 6448-6455 [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»