Purification and characterization of rhodobactin: a mixed ligand siderophore from Rhodococcus rhodochrous strain OFS

Dhungana, Suraj; Michalczyk, Ryszard; Boukhalfa, Hakim; Lack, Joseph G.; Koppisch, Andrew T.; Fairlee, Jason M.; Johnson, Mark D.; Ruggiero, Christy E.; John, Seth G.; Cox, Matthew M.; Browder, Cindy C.; Forsythe, Jennifer H.; Vanderberg, Laura A.; Neu, Mary P.; Hersman, Larry E.

doi:10.1007/s10534-006-9079-y

Cited by 27 publications

(27 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, the putative catecholate siderophore was not produced during growth of R. equi on medium containing 3.6 M FeSO 4 , resembling the production of rhodobactin, which is completely repressed in the presence of 3 M iron (10). The genome of R. equi harbors two iron repressors, Fur and IdeR (http://www.sanger.ac.uk/Projects/R_equi/); the latter has been shown to be functional in R. equi (4).…”

Section: Discussionmentioning

confidence: 92%

“…Both siderophores are mixed-ligand siderophores containing hydroxamate and catecholate moieties (6,10). Spectroscopic analysis of the culture supernatant suggested that the chromophore produced by R. equi contains a catecholate moiety.…”

Section: Discussionmentioning

confidence: 99%

“…However, a mutant unable to grow at low iron concentrations contained an insertion in the iupABC operon encoding an ABC transport system similar to siderophore transporters, suggesting that R. equi produces at least one siderophore (29). The only rhodococcal siderophores characterized to date are heterobactins and rhodobactin from the nonpathogenic Rhodococcus erythropolis and Rhodococcus rhodochrous, respectively, containing catecholate and hydroxamate functionalities as iron-coordinating groups (6,10). However, the genes encoding the enzymatic machinery for their biosynthesis remain unknown.…”

mentioning

confidence: 99%

See 2 more Smart Citations

The Intracellular Pathogen Rhodococcus equi Produces a Catecholate Siderophore Required for Saprophytic Growth

et al. 2008

View full text Add to dashboard Cite

Little is known about the iron acquisition systems of the soilborne facultative intracellular pathogen Rhodococcus equi. We previously reported that expression of iupABC, encoding a putative siderophore ABC transporter system, is iron regulated and required for growth at low iron concentrations. Here we show that disruption of iupA leads to the concomitant accumulation of catecholates and a chromophore with absorption maxima at 341 and 528 nm during growth under iron-replete conditions. In contrast, the wild-type strain produces these compounds only in iron-depleted medium. Disruption of iupU and iupS, encoding nonribosomal peptide synthetases, prevented growth of the corresponding R. equi SID1 and SID3 mutants at low iron concentrations. However, only R. equi SID3 did not produce the chromophore produced by the wild-type strain during growth at low iron concentrations. The phenotype of R. equi SID3, but not that of R. equi SID1, could be rescued by coculture with the wild type, allowing growth at low iron concentrations. This strongly suggests that the product of the iupS gene is responsible for the synthesis of a diffusible compound required for growth at low iron concentrations. Transcription of iupU was constitutive, but that of iupS was iron regulated, with an induction of 3 orders of magnitude during growth in iron-depleted compared to iron-replete medium. Neither mutant was attenuated in vivo in a mouse infection model, indicating that the iupU-and iupS-encoded iron acquisition systems are primarily involved in iron uptake during saprophytic life.

show abstract

Section: Discussionmentioning

confidence: 92%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

The Intracellular Pathogen Rhodococcus equi Produces a Catecholate Siderophore Required for Saprophytic Growth

et al. 2008

View full text Add to dashboard Cite

show abstract

“…The rhodococcal siderophores characterized to date (heterobactin A, rhodobactin, and rhodochelin) all contain ornithine or modified ornithine residues (4,7,14). The remaining genes in this gene cluster are predicted to encode proteins required for the modification of ornithine by formylation and hydroxylation (RhbA and RhbD), amino acid activation (RhbE), and release of the tetrapeptide from the NRPS (RhbB).…”

Section: Discussionmentioning

confidence: 99%

“…The synthesis of rhequibactin depends on a six-cistron operon containing two NRPS genes, iupS and iupT, and four genes encoding siderophore biosynthesis and transport proteins. Upstream and transcribed divergently of this operon is a four-cistron operon encoding enzymes required for the production of 2,3-dihydroxybenzoic acid, which is also present in the mixed-type catecholate-hydroxamate siderophores heterobactin A, rhodobactin, and rhodochelin produced by R. erythropolis, R. rhodochrous, and R. jostii, respectively (4,7,14). In addition to rhequibactin, R. equi appears to synthesize a nonsoluble siderophore that is produced by an NRPS protein encoded by iupU (30).…”

mentioning

confidence: 99%

The Hydroxamate Siderophore Rhequichelin Is Required for Virulence of the Pathogenic Actinomycete Rhodococcus equi

et al. 2012

View full text Add to dashboard Cite

We previously showed that the facultative intracellular pathogen Rhodococcus equi produces a nondiffusible and catecholatecontaining siderophore (rhequibactin) involved in iron acquisition during saprophytic growth. Here, we provide evidence that the rhbABCDE cluster directs the biosynthesis of a hydroxamate siderophore, rhequichelin, that plays a key role in virulence. The rhbC gene encodes a nonribosomal peptide synthetase that is predicted to produce a tetrapeptide consisting of N 5 -formyl-N 5 -hydroxyornithine, serine, N 5 -hydroxyornithine, and N 5 -acyl-N 5 -hydroxyornithine. The other rhb genes encode putative tailoring enzymes mediating modification of ornithine residues incorporated into the hydroxamate product of RhbC. Transcription of rhbC was upregulated during growth in iron-depleted medium, suggesting that it plays a role in iron acquisition. This was confirmed by deletion of rhbCD, rendering the resulting strain R. equi SID2 unable to grow in the presence of the iron chelator 2,2-dipyridyl. Supernatant of the wild-type strain rescued the phenotype of R. equi SID2. The importance of rhequichelin in virulence was highlighted by the rapid increase in transcription levels of rhbC following infection and the inability of R. equi SID2 to grow within macrophages. Unlike the wild-type strain, R. equi SID2 was unable to replicate in vivo and was rapidly cleared from the lungs of infected mice. Rhequichelin is thus a key virulence-associated factor, although nonpathogenic Rhodococcus species also appear to produce rhequichelin or a structurally closely related compound. Rhequichelin biosynthesis may therefore be considered an example of cooption of a core actinobacterial trait in the evolution of R. equi virulence.

show abstract

Characterization of microbial siderophores by mass spectrometry

Pluháček

Lemr

Ghosh

et al. 2015

Mass Spectrometry Reviews

View full text Add to dashboard Cite

Siderophores play important roles in microbial iron piracy, and are applied as infectious disease biomarkers and novel pharmaceutical drugs. Inductively coupled plasma and molecular mass spectrometry (ICP-MS) combined with high resolution separations allow characterization of siderophores in complex samples taking advantages of mass defect data filtering, tandem mass spectrometry, and iron-containing compound quantitation. The enrichment approaches used in siderophore analysis and current ICP-MS technologies are reviewed. The recent tools for fast dereplication of secondary metabolites and their databases are reported. This review on siderophores is concluded with their recent medical, biochemical, geochemical, and agricultural applications in mass spectrometry context.

show abstract

Purification and characterization of rhodobactin: a mixed ligand siderophore from Rhodococcus rhodochrous strain OFS

Cited by 27 publications

References 39 publications

The Intracellular Pathogen Rhodococcus equi Produces a Catecholate Siderophore Required for Saprophytic Growth

The Intracellular Pathogen Rhodococcus equi Produces a Catecholate Siderophore Required for Saprophytic Growth

The Hydroxamate Siderophore Rhequichelin Is Required for Virulence of the Pathogenic Actinomycete Rhodococcus equi

Characterization of microbial siderophores by mass spectrometry

Contact Info

Product

Resources

About