Inner-membrane transporters for the siderophores pyochelin in Pseudomonas aeruginosa and enantio-pyochelin in Pseudomonas fluorescens display different enantioselectivities.

Détails

ID Serval
serval:BIB_8C971D27A331
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Inner-membrane transporters for the siderophores pyochelin in Pseudomonas aeruginosa and enantio-pyochelin in Pseudomonas fluorescens display different enantioselectivities.
Périodique
Microbiology
Auteur(s)
Reimmann C.
ISSN
1465-2080 (Electronic)
ISSN-L
1350-0872
Statut éditorial
Publié
Date de publication
2012
Volume
158
Numéro
Pt 5
Pages
1317-1324
Langue
anglais
Résumé
Iron uptake and transcriptional regulation by the enantiomeric siderophores pyochelin (Pch) and enantio-pyochelin (EPch) of Pseudomonas aeruginosa and Pseudomonas fluorescens, respectively, are stereospecific processes. The iron-loaded forms of Pch (ferriPch) and of EPch (ferriEPch) are recognized stereospecifically (i) at the outer membrane by the siderophore receptors FptA in P. aeruginosa and FetA in P. fluorescens and (ii) in the cytoplasm by the two AraC-type regulators PchR, which are activated by their cognate siderophore. Here, stereospecific siderophore recognition is shown to occur at the inner membrane also. In P. aeruginosa, translocation of ferriPch across the inner membrane is carried out by the single-subunit siderophore transporter FptX. In contrast, the uptake of ferriEPch into the cytoplasm of P. fluorescens was found to involve a classical periplasmic binding protein-dependent ABC transporter (FetCDE), which is encoded by the fetABCDEF operon. Expression of a translational fetA-gfp fusion was repressed by ferric ions, and activated by the cognate siderophore bound to PchR, thus resembling the analogous regulation of the P. aeruginosa ferriPch transport operon fptABCX. The inner-membrane transporters FetCDE and FptX were expressed in combination with either of the two siderophore receptors FetA and FptA in a siderophore-negative P. aeruginosa mutant deleted for the fptABCX operon. Growth tests conducted under iron limitation with ferriPch or ferriEPch as the iron source revealed that FptX was able to transport ferriPch as well as ferriEPch, whereas FetCDE specifically transported ferriEPch. Thus, stereospecific siderophore recognition occurs at the inner membrane by the FetCDE transporter.
Mots-clé
Bacterial Outer Membrane Proteins/metabolism, Base Sequence, Gene Expression Regulation, Bacterial, Genetic Complementation Test, Iron/metabolism, Mutation, Operon, Phenols/metabolism, Pseudomonas aeruginosa/genetics, Pseudomonas aeruginosa/metabolism, Pseudomonas fluorescens/genetics, Pseudomonas fluorescens/metabolism, Receptors, Cell Surface/metabolism, Siderophores/genetics, Siderophores/metabolism, Thiazoles/metabolism
Pubmed
Web of science
Open Access
Oui
Création de la notice
22/07/2012 22:25
Dernière modification de la notice
08/05/2019 21:46
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