This Article Full Text Full Text (PDF) 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 den Hengst, C. D. Articles by Kok, J. Search for Related Content PubMed PubMed Citation Articles by den Hengst, C. D. Articles by Kok, J.

Identification and Functional Characterization of the Lactococcus lactis CodY-Regulated Branched-Chain Amino Acid Permease BcaP (CtrA)

Chris D. den Hengst, Maarten Groeneveld, Oscar P. Kuipers,^* and Jan Kok

Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands

Received 21 December 2005/ Accepted 14 February 2006

Transcriptome analyses have previously revealed that a gene encoding the putative amino acid transporter CtrA (YhdG) is one of the major targets of the pleiotropic regulator CodY in Lactococcus lactis and Bacillus subtilis. The role of ctrA in L. lactis was further investigated with respect to both transport activity as well as CodY-mediated regulation. CtrA is required for optimal growth in media containing free amino acids as the only amino acid source. Amino acid transport studies showed that ctrA encodes a secondary amino acid transport system that is specific for branched-chain amino acids (BCAAs) (isoleucine, leucine, and valine) and methionine, which is in disagreement with its previously proposed function (a cationic amino acid transporter), which was assigned based on homology. We propose to rename CtrA BcaP, for branched-chain amino acid permease. BcaP is a member of a group of conserved transport systems, as homologs are widely distributed among gram-positive bacteria. Deletion of bcaP resulted in the loss of most of the BCAA uptake activity of L. lactis, indicating that BcaP is the major BCAA carrier of this organism. Deletion of bcaP together with a second (putative) BCAA permease, encoded by brnQ, further reduced the viability of the strain. DNA microarray analysis showed that deletion of bcaP predominantly affects genes belonging to the regulons of the transcriptional regulator CodY, which is involved in global nitrogen metabolism and needs BCAAs for its activation, and of CmbR, which is involved in sulfur amino acid metabolism.

Present address: Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.

This article has been cited by other articles:

• Braun, P. R., Al-Younes, H., Gussmann, J., Klein, J., Schneider, E., Meyer, T. F. (2008). Competitive Inhibition of Amino Acid Uptake Suppresses Chlamydial Growth: Involvement of the Chlamydial Amino Acid Transporter BrnQ. J. Bacteriol. 190: 1822-1830 [Abstract] [Full Text]  
• Sperandio, B., Gautier, C., McGovern, S., Ehrlich, D. S., Renault, P., Martin-Verstraete, I., Guedon, E. (2007). Control of Methionine Synthesis and Uptake by MetR and Homocysteine in Streptococcus mutans. J. Bacteriol. 189: 7032-7044 [Abstract] [Full Text]