Role of siderophore in iron uptake in cowpea Rhizobium GN1 (peanut isolate): Possible involvement of iron repressible outer membrane proteins

Jadhav, R. S.

doi:10.1016/0378-1097(94)90011-6

Cited by 4 publications

(4 citation statements)

References 15 publications

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“…Siderophores produced by root nodule bacteria include carboxylates such as rhizobactin (Smith et al, 1985), citrate (Guerinot et al, 1990) and anthranilate (Rioux et al, 1986a, b), catechols (Modi et al, 1985; Nambiar & Sivaramakrishnan, 1987; Patel et al, 1988; Jadhav & Desai, 1994; Roy etal., 1994) and hydroxamates (Carson et al, 1992, 1994; Lesueur et al, 1993; Persmark et al, 1993). Rhizobactin 1021 from Rhizobium meliloti (recently renamed Sinorhizobium meliloti; de Lajudie et al, 1994) 1021, the only root nodule bacterial hydroxamate siderophore whose structure is known, is a dihydroxamate containing a central citrate moiety, substituted on one terminal carboxyl group by 1- amino-3-(N-acetyJ-N-hydroxyamino)-propane and by Tamino-3-(N-hydroxy-N-(E)-2-decenylamino)propane on the other (Persmark et al, 1993).…”

Section: Introductionmentioning

confidence: 99%

Rhizobium leguminosarum bv. viciae produces a novel cyclic trihydroxamate siderophore, vicibactin

et al. 1998

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Trihydroxamate siderophores were isolated from iron-def icient cultures of three strains of Rhilobiurn legurninorarum biovar wiciae, two from Japan (WSM709, WSM710) and one from the Mediterranean (WU235), and from a Tn5-induced mutant of WSM710 (MNF7101). The first three all produced the same compound (vicibactin), which was uncharged and could be purified by solvent extraction into benzyl alcohol. The gallium and ferric complexes of vicibactin were extractable into benzyl alcohol at pH 59, while metal-free vicibactin could be extracted with good yield at pH 89. The trihydroxamate from MNF7101 (vicibactin 7101) could not be extracted into benzyl alcohol, but its cationic nature permitted purification by chromatography on Sephadex CM-25 (NHt form). Relative molecular masses and empirical formulae were obtained from fast-atom-bombardment MS. The structures were derived from one-and two-dimensional IH and I3C NMR spectroscopy, using DQF-COSY, NOESY, HMQC and HMBC techniques on the compounds dissolved in methanol-d, and DMSOd6. Vicibactin proves to be a cyclic molecule containing three residues each of (R)-2,5-diamino-N2-acetyl-N5-hydroxypentanoic acid (W-acetyl-M-hydroxy-Dornithine) and (R)-3-hydroxybutanoic acid, arranged alternately, with alternating ester and peptide bonds. Vicibactin 7101 differed only in lacking the acetyl substitution on the N2 of the W-hydroxyornithine, resulting in net positive charge; it was still functional as a siderophore and promoted 55Fe uptake by iron-starved cells of WSM710 in the presence of an excess of phosphate. The rate of vicibactin biosynthesis by iron-def icient cells of WSM710 was essentially constant between pH 5.5 and 79, but much decreased at pH 59. When iron-starved cultures were supplemented with potential precursors for vicibactin, the rates of i t s synthesis were consistent with both fi hydroxybutyrate and ornithine being precursors. At least three genes seem likely to be involved in synthesis of vicibactin from ornithine and fi hydroxybutyrate : a hydroxylase adding the -OH group to the N5 of ornithine, an acetylase adding the acetyl group to the N2 of ornithine, and a peptide synthetase system.

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Section: Introductionmentioning

confidence: 99%

Rhizobium leguminosarum bv. viciae produces a novel cyclic trihydroxamate siderophore, vicibactin

et al. 1998

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“…In Escherichia coli, cell surface-exposed protein loops of the outer membrane receptors have been demonstrated to bind specific Fe(III)-siderophore complexes, which are subsequently internalized via a nonspecific channel region of the receptor (43,70). Although there have been a number of reports of iron-regulated outer membrane proteins (OMPs) in rhizobia (14,23,28,41,61,68,69), most simply state that such proteins were observed and that they may serve as Fe(III)-siderophore receptors.…”

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confidence: 99%

The Bradyrhizobium japonicum fegA gene encodes an iron-regulated outer membrane protein with similarity to hydroxamate-type siderophore receptors

LeVier

Guerinot

1996

J Bacteriol

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“…To test whether the citrate-dependent strains had become deficient in their ability to secrete siderophores, we grew the three citrate-dependent evolved isolates in media without citrate that had been conditioned by the growth of the ancestral REL606 and then re-supplemented with glucose. Unlike what has been observed previously for siderophore-defective strains [ 32 , 33 ], none of the citrate-dependent strains grew faster or to a higher final yield on the spent media than on DM without citrate (at an 0.05 level, Welch’s 1-tail T test) (Figure 4 ). This argues against defects in siderophore production as the sole cause of citrate dependency, but does not rule out the possibility that it is related to the ability to transport iron-siderophore complexes.…”

Section: Resultsmentioning

confidence: 46%

Multiple long-term, experimentally-evolved populations of Escherichia coliacquire dependence upon citrate as an iron chelator for optimal growth on glucose

2012

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BackgroundSpecialization for ecological niches is a balance of evolutionary adaptation and its accompanying tradeoffs. Here we focus on the Lenski Long-Term Evolution Experiment, which has maintained cultures of Escherichia coli in the same defined seasonal environment for 50,000 generations. Over this time, much adaptation and specialization to the environment has occurred. The presence of citrate in the growth media selected one lineage to gain the novel ability to utilize citrate as a carbon source after 31,000 generations. Here we test whether other strains have specialized to rely on citrate after 50,000 generations.ResultsWe show that in addition to the citrate-catabolizing strain, three other lineages evolving in parallel have acquired a dependence on citrate for optimal growth on glucose. None of these strains were stimulated indirectly by the sodium present in disodium citrate, nor exhibited even partial utilization of citrate as a carbon source. Instead, all three of these citrate-stimulated populations appear to rely on it as a chelator of iron.ConclusionsThe strains we examine here have evolved specialization to their environment through apparent loss of function. Our results are most consistent with the accumulation of mutations in iron transport genes that were obviated by abundant citrate. The results present another example where a subtle decision in the design of an evolution experiment led to unexpected evolutionary outcomes.

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Role of siderophore in iron uptake in cowpea Rhizobium GN1 (peanut isolate): Possible involvement of iron repressible outer membrane proteins

Cited by 4 publications

References 15 publications

Rhizobium leguminosarum bv. viciae produces a novel cyclic trihydroxamate siderophore, vicibactin

Rhizobium leguminosarum bv. viciae produces a novel cyclic trihydroxamate siderophore, vicibactin

The Bradyrhizobium japonicum fegA gene encodes an iron-regulated outer membrane protein with similarity to hydroxamate-type siderophore receptors

Multiple long-term, experimentally-evolved populations of Escherichia coliacquire dependence upon citrate as an iron chelator for optimal growth on glucose

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