PchR-box recognition by the AraC-type regulator PchR of Pseudomonas aeruginosa requires the siderophore pyochelin as an effector.

Détails

ID Serval
serval:BIB_BDFC95C57ACD
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
PchR-box recognition by the AraC-type regulator PchR of Pseudomonas aeruginosa requires the siderophore pyochelin as an effector.
Périodique
Molecular Microbiology
Auteur(s)
Michel L., González N., Jagdeep S., Nguyen-Ngoc T., Reimmann C.
ISSN
0950-382X[print], 0950-382X[linking]
Statut éditorial
Publié
Date de publication
2005
Volume
58
Numéro
2
Pages
495-509
Langue
anglais
Résumé
Under iron limitation, the opportunistic human pathogen Pseudomonas aeruginosa produces the siderophore pyochelin. When secreted into the extracellular environment, pyochelin complexes ferric ions and delivers them, via the outer membrane receptor FptA, to the bacterial cytoplasm. Extracellular pyochelin also acts as a signalling molecule, inducing the expression of pyochelin biosynthesis and uptake genes by a mechanism involving the AraC-type regulator PchR. We have identified a 32 bp conserved sequence element (PchR-box) in promoter regions of pyochelin-controlled genes and we show that the PchR-box in the pchR-pchDCBA intergenic region is essential for the induction of the pyochelin biosynthetic operon pchDCBA and the repression of the divergently transcribed pchR gene. PchR was purified as a fusion with maltose-binding protein (MBP). Mobility shift assays demonstrated specific binding of MBP-PchR to the PchR-box in the presence, but not in the absence of pyochelin and iron. PchR-box mutations that interfered with pyochelin-dependent regulation in vivo, also affected pyochelin-dependent PchR-box recognition in vitro. We conclude that pyochelin, probably in its iron-loaded state, is the intracellular effector required for PchR-mediated regulation. The fact that extracellular pyochelin triggers this regulation suggests that the siderophore can enter the cytoplasm.
Mots-clé
Bacterial Proteins/genetics, Bacterial Proteins/metabolism, Base Sequence, DNA-Binding Proteins/genetics, DNA-Binding Proteins/metabolism, Gene Expression Regulation, Bacterial, Genes, araC, Humans, Iron/metabolism, Molecular Sequence Data, Phenols/metabolism, Promoter Regions, Genetic, Pseudomonas aeruginosa/genetics, Pseudomonas aeruginosa/metabolism, Recombinant Fusion Proteins/genetics, Recombinant Fusion Proteins/metabolism, Sequence Alignment, Siderophores/metabolism, Thiazoles/metabolism, Transcription Factors/genetics, Transcription Factors/metabolism
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 15:00
Dernière modification de la notice
09/05/2019 0:34
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