Identification of C(4)-dicarboxylate transport systems in Pseudomonas aeruginosa PAO1.

Détails

ID Serval
serval:BIB_7AE6709D7CDD
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Identification of C(4)-dicarboxylate transport systems in Pseudomonas aeruginosa PAO1.
Périodique
Journal of Bacteriology
Auteur(s)
Valentini M., Storelli N., Lapouge K.
ISSN
1098-5530 (Electronic)
ISSN-L
0021-9193
Statut éditorial
Publié
Date de publication
2011
Peer-reviewed
Oui
Volume
193
Numéro
17
Pages
4307-4316
Langue
anglais
Résumé
Pseudomonas aeruginosa utilizes preferentially C(4)-dicarboxylates such as malate, fumarate, and succinate as carbon and energy sources. We have identified and characterized two C(4)-dicarboxylate transport (Dct) systems in P. aeruginosa PAO1. Inactivation of the dctA(PA1183) gene caused a growth defect of the strain in minimal media supplemented with succinate, fumarate or malate, indicating that DctA has a major role in Dct. However, residual growth of the dctA mutant in these media suggested the presence of additional C(4)-dicarboxylate transporter(s). Tn5 insertion mutagenesis of the ΔdctA mutant led to the identification of a second Dct system, i.e., the DctPQM transporter belonging to the tripartite ATP-independent periplasmic (TRAP) family of carriers. The ΔdctA ΔdctPQM double mutant showed no growth on malate and fumarate and residual growth on succinate, suggesting that DctA and DctPQM are the only malate and fumarate transporters, whereas additional transporters for succinate are present. Using lacZ reporter fusions, we showed that the expression of the dctA gene and the dctPQM operon was enhanced in early exponential growth phase and induced by C(4)-dicarboxylates. Competition experiments demonstrated that the DctPQM carrier was more efficient than the DctA carrier for the utilization of succinate at micromolar concentrations, whereas DctA was the major transporter at millimolar concentrations. To conclude, this is the first time that the high- and low-affinity uptake systems for succinate DctA and DctPQM have been reported to function coordinately to transport C(4)-dicarboxylates and that the alternative sigma factor RpoN and a DctB/DctD two-component system regulates simultaneously the dctA gene and the dctPQM operon.
Mots-clé
Bacterial Proteins/genetics, Bacterial Proteins/metabolism, Biological Transport, Dicarboxylic Acid Transporters/genetics, Dicarboxylic Acid Transporters/metabolism, Fumarates/metabolism, Gene Expression Regulation, Bacterial, Genes, Regulator, Genes, Reporter, Lac Operon, Malates/metabolism, Mutagenesis, Insertional, Plasmids, Pseudomonas aeruginosa/genetics, Pseudomonas aeruginosa/metabolism, RNA Polymerase Sigma 54/genetics, RNA Polymerase Sigma 54/metabolism, Sigma Factor/genetics, Sigma Factor/metabolism, Succinic Acid/metabolism
Pubmed
Web of science
Open Access
Oui
Création de la notice
21/10/2011 9:34
Dernière modification de la notice
20/08/2019 15:36
Données d'usage