Purification, characterization, and structure of pseudobactin 589 A, a siderophore from a plant growth promoting Pseudomonas.
Under conditions of low-iron stress the plant growth promoting bacterium Pseudomonas putida 589 (DSM 50202) produced a yellow-green fluorescent iron-binding peptide siderophore, which was designated pseudobactin 589 A and had an affinity constant toward Fe3+ of 10(25) at pH 7. Protonated pseudobactin 589 A had the molecular formula C54H78O26N15 and a nominal mass spectral molecular mass of 1353 g/mol. Its structure was determined by a combination of nuclear magnetic resonance, fast atom bombardment mass spectrometry, and Edman degradation. Pseudobactin 589 A consisted of a nonapeptide with the amino acid sequence L-Asp-L-Lys-(D)-beta-OH-Asp-D(L)-Ser-L-Thr-D-Ala-D-Glu-L(D)-Ser-L-N delta-OH- Orn, in which lysine was amide bonded via the carboxy and the N epsilon-amino groups. A quinoline-derived chromophore was connected via an amide bond to the alpha-amino nitrogen of aspartic acid and an L-malamide residue was attached to the chromophore. The three bidentate Fe3+ binding ligands consisted of an o-dihydroxy aromatic group from the quinoline derivative, beta-hydroxyaspartic acid, and an internally cyclized N delta-hydroxyornithine. The structure of pseudobactin 589 A is unique but strikingly similar to that of other pseudobactin-type siderophores from other plant growth promoting and plant deleterious pseudomonads.
Persmark
M
M
Department of Biotechnology, University of Lund, Sweden.
Frejd
T
T
Mattiasson
B
B
D000595:Amino Acid Sequence; D007501:Iron / Q000378:metabolism; D007502:Iron Chelating Agents / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010456:Peptides, Cyclic; D010944:Plants / Q000382:microbiology; D011485:Protein Binding; D011549:Pseudomonas / Q000032:analysis* / Q000502:physiology; D017262:Siderophores
D007502:Iron Chelating Agents; D010456:Peptides, Cyclic; D017262:Siderophores; C066052:pseudobactin 589 A; D007501:Iron