Stereospecificity of the siderophore pyochelin outer membrane transporters in fluorescent pseudomonads.

Details

Serval ID
serval:BIB_83755AB8C4B4
Type
Article: article from journal or magazin.
Collection
Publications
Title
Stereospecificity of the siderophore pyochelin outer membrane transporters in fluorescent pseudomonads.
Journal
Journal of Biological Chemistry
Author(s)
Hoegy F., Lee X., Noel S., Rognan D., Mislin G.L., Reimmann C., Schalk I.J.
ISSN
0021-9258[print], 0021-9258[linking]
Publication state
Published
Issued date
2009
Peer-reviewed
Oui
Volume
284
Number
22
Pages
14949-14957
Language
english
Abstract
Pyochelin (Pch) and enantio-pyochelin (EPch) are enantiomer siderophores that are produced by Pseudomonas aeruginosa and Pseudomonas fluorescens, respectively, under iron limitation. Pch promotes growth of P. aeruginosa when iron is scarce, and EPch carries out the same biological function in P. fluorescens. However, the two siderophores are unable to promote growth in the heterologous species, indicating that siderophore-mediated iron uptake is highly stereospecific. In the present work, using binding and iron uptake assays, we found that FptA, the Fe-Pch outer membrane transporter of P. aeruginosa, recognized (K(d) = 2.5 +/- 1.1 nm) and transported Fe-Pch but did not interact with Fe-EPch. Likewise, FetA, the Fe-EPch receptor of P. fluorescens, was specific for Fe-EPch (K(d) = 3.7 +/- 2.1 nm) but did not bind and transport Fe-Pch. Growth promotion experiments performed under iron-limiting conditions confirmed that FptA and FetA are highly specific for Pch and EPch, respectively. When fptA and fetA along with adjacent transport genes involved in siderophore uptake were swapped between the two bacterial species, P. aeruginosa became able to utilize Fe-EPch as an iron source, and P. fluorescens was able to grow with Fe-Pch. Docking experiments using the FptA structure and binding assays showed that the stereospecificity of Pch recognition by FptA was mostly due to the configuration of the siderophore chiral centers C4'' and C2'' and was only weakly dependent on the configuration of the C4' carbon atom. Together, these findings increase our understanding of the stereospecific interaction between Pch and its outer membrane receptor FptA.
Keywords
Bacterial Outer Membrane Proteins/metabolism, Biological Transport, Cell Membrane/metabolism, Genes, Bacterial, Iron/metabolism, Kinetics, Ligands, Models, Molecular, Molecular Sequence Data, Phenols/chemistry, Pseudomonas aeruginosa/genetics, Pseudomonas aeruginosa/growth & development, Pseudomonas fluorescens/genetics, Pseudomonas fluorescens/growth & development, Receptors, Cell Surface/metabolism, Siderophores/chemistry, Stereoisomerism, Thiazoles/chemistry
Pubmed
Web of science
Open Access
Yes
Create date
02/02/2010 16:34
Last modification date
08/05/2019 21:16
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