This Article Full Text (PDF) Other Versions of this Article: JB.01452-06v1 189/3/880    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hall, J. A. Articles by Pajor, A. M. Search for Related Content PubMed PubMed Citation Articles by Hall, J. A. Articles by Pajor, A. M.

 Previous Article  |  Next Article 

J. Bacteriol. doi:10.1128/JB.01452-06
Copyright (c) 2006, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Functional Reconstitution of SdcS, a Na⁺-coupled Dicarboxylate Carrier Protein from Staphylococcus aureus

From the Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77555

^* To whom correspondence should be addressed. Email: ampajor{at}utmb.edu.

	Abstract

In Staphylococcus aureus, the transport of dicarboxylates is mediated in part by the Na⁺-linked carrier protein, SdcS. This transporter is a member of the divalent anion/Na⁺ symporter (DASS) family, a group that includes the mammalian Na⁺/dicarboxylate cotransporters NaDC1 and NaDC3. In earlier work, we cloned and expressed SdcS in Escherichia coli, and found it to have transport properties similar to its eukaryotic counterparts (Hall, J. A. and A. M. Pajor. 2005. J. Bacteriol. 187:5189-5194.). Here, we report the partial purification and subsequent reconstitution of functional SdcS into liposomes. These proteoliposomes exhibited succinate counterflow activity as well as Na⁺-electrochemical gradient driven transport. Examination of substrate specificity indicated that the minimal requirement necessary for transport was a four-carbon terminal dicarboxylate backbone, and that productive substrate-transporter interaction was sensitive to substitutions at the substrate C-2 and C-3 positions. Further analysis established that SdcS facilitates an electroneutral symport reaction having a 2:1 cation/dicarboxylate ratio. This study represents the first characterization of a reconstituted Na⁺-coupled DASS family member, thus providing an effective method to evaluate functional, as well as structural, aspects of DASS transporters in a system free of the complexities and constraints associated with native membrane environments.

This article has been cited by other articles:

• Youn, J.-W., Jolkver, E., Kramer, R., Marin, K., Wendisch, V. F. (2008). Identification and Characterization of the Dicarboxylate Uptake System DccT in Corynebacterium glutamicum. J. Bacteriol. 190: 6458-6466 [Abstract] [Full Text]  
• Teramoto, H., Shirai, T., Inui, M., Yukawa, H. (2008). Identification of a Gene Encoding a Transporter Essential for Utilization of C4 Dicarboxylates in Corynebacterium glutamicum. Appl. Environ. Microbiol. 74: 5290-5296 [Abstract] [Full Text]