Iron acquisition with the natural siderophore enantiomers pyochelin and enantio-pyochelin in Pseudomonas species
| Autor: | Youard, Z.A., Wenner, N., Reimmann, C. |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Amino Acid Sequence
Iron/chemistry Iron/metabolism Molecular Sequence Data Molecular Structure Oxidation-Reduction Phenols/chemistry Phenols/metabolism Pseudomonas/chemistry Pseudomonas/genetics Sequence Alignment Siderophores/chemistry Siderophores/genetics Stereoisomerism Thiazoles/chemistry Thiazoles/metabolism |
| Zdroj: | Biometals, vol. 24, no. 3, pp. 513-522 |
| Popis: | The bacterial siderophore pyochelin is composed of salicylate and two cysteine-derived heterocycles, the second of which is modified by reduction and N-methylation during biosynthesis. In Pseudomonas aeruginosa, the first cysteine residue is converted to its D-isoform during thiazoline ring formation, whereas the second cysteine remains in its L-configuration. Stereochemistry is opposite in the Pseudomonas fluorescens siderophore enantio-pyochelin, in which the first ring originates from L-cysteine and the second ring from D-cysteine. Both siderophores promote growth of the producer organism during iron limitation and induce the expression of their biosynthesis genes by activating the transcriptional AraC-type regulator PchR. However, neither siderophore is functional as an iron carrier or as a transcriptional inducer in the other species, demonstrating that both processes are highly stereospecific. Stereospecificity of pyochelin/enantio-pyochelin-mediated iron uptake is ensured at two levels: (i) by the outer membrane siderophore receptors and (ii) by the cytosolic PchR regulators. |
| Databáze: | OpenAIRE |
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