Yersiniabactin

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Jürgen Heesemann - One of the best experts on this subject based on the ideXlab platform.

  • the rna chaperone hfq impacts growth metabolism and production of virulence factors in yersinia enterocolitica
    PLOS ONE, 2014
    Co-Authors: Tamara Katharina Kakoschke, Jürgen Heesemann, Giuseppe Magistro, Sara Carina Kakoschke, S Schubert, Marc Borath, Ombeline Rossier
    Abstract:

    To adapt to changes in environmental conditions, bacteria regulate their gene expression at the transcriptional but also at the post-transcriptional level, e.g. by small RNAs (sRNAs) which modulate mRNA stability and translation. The conserved RNA chaperone Hfq mediates the interaction of many sRNAs with their target mRNAs, thereby playing a global role in fine-tuning protein production. In this study, we investigated the significance of Hfq for the enteropathogen Yersina enterocolitica serotype O:8. Hfq facilitated optimal growth in complex and minimal media. Our comparative protein analysis of parental and hfq-negative strains suggested that Hfq promotes lipid metabolism and transport, cell redox homeostasis, mRNA translation and ATP synthesis, and negatively affects carbon and nitrogen metabolism, transport of siderophore and peptides and tRNA synthesis. Accordingly, biochemical tests indicated that Hfq represses ornithine decarboxylase activity, indole production and utilization of glucose, mannitol, inositol and 1,2-propanediol. Moreover, Hfq repressed production of the siderophore Yersiniabactin and its outer membrane receptor FyuA. In contrast, hfq mutants exhibited reduced urease production. Finally, strains lacking hfq were more susceptible to acidic pH and oxidative stress. Unlike previous reports in other Gram-negative bacteria, Hfq was dispensable for type III secretion encoded by the virulence plasmid. Using a chromosomally encoded FLAG-tagged Hfq, we observed increased production of Hfq-FLAG in late exponential and stationary phases. Overall, Hfq has a profound effect on metabolism, resistance to stress and modulates the production of two virulence factors in Y. enterocolitica, namely urease and Yersiniabactin.

  • Horizontal transfer of Yersinia high-pathogenicity island by the conjugative RP4 attB target-presenting shuttle plasmid.
    Molecular microbiology, 2005
    Co-Authors: Uladzimir Antonenka, Jürgen Heesemann, Christina Nölting, Alexander Rakin
    Abstract:

    Summary The high-pathogenicity island (HPI) encodes a highly efficient Yersiniabactin system of iron acquisition responsible for mouse lethality in Yersinia. Although the HPI is widely disseminated among Enterobacteriaceae it lacks functions necessary for its replication and transmission. Therefore, the mechanism of its horizontal transfer and circulation is completely obscure. On the other hand, the HPI is a genetically active island in the bacterial cell. It encodes a functional recombinase and is able to transpose to new targets on the chromosome. Here we report on a possible mechanism of the HPI dissemination based on site-specific recombination of the excised HPI with the attB-presenting (asn tRNA gene) RP4 promiscuous conjugative shuttle plasmid. The resulting cointegrate can be transferred by conjugation to a new host, where it dissociates, and the released HPI integrates into any unoccupied asn tRNA gene target in the genome. This mechanism has been proven both with the ‘mini’ island carrying only the attP recognition site and genes coding for recombination enzymes and with the complete HPI labelled with an antibiotic resistance marker. After acquisition of the mobilized complete form of the HPI, the ability of the HPI-cured Yersinia enterocolitica WA-TH– strain to produce Yersiniabactin has been restored. Such ‘trapping’ of pathogenicity islands and subsequent shuffling to new hosts by a conjugative replicon carrying a suitable attB site could be applied to other functional integrative elements and explain wide dissemination of PAIs.

  • Transcriptional regulation of high pathogenicity island iron uptake genes by YbtA
    International journal of medical microbiology : IJMM, 2005
    Co-Authors: Roman Anisimov, Jürgen Heesemann, Daniela Brem, Alexander Rakin
    Abstract:

    A large group of Enterobacteriaceae, including members of the genus Yersinia, produce the extracellular siderophore Yersiniabactin enabling them to multiply under iron-depleted conditions. Genes, involved in Yersiniabactin synthesis, transport and regulation are clustered in the high pathogenicity island (HPI). YbtA, an AraC-like transcriptional regulator, is presumed to be the central regulator of Yersiniabactin production together with the ferric uptake regulator Fur. In this work, we identified the transcriptional start points of YbtA-regulated promoters of the HPI by primer extension, purified homogeneous YbtA and defined the YbtA-binding sites by DNaseI footprint analysis in ybtA, fyuA, irp6, and irp2 promoters. Besides of the anticipated pair repeats RS1 and RS2 in each promoter, we identified an additional YbtA-binding site designated RS3 in the divergently transcribed ybtA/irp6 promoter. Also, comparing ybtA/irp6 promoters of Y. enterocolitica and Y. pestis, we found that a 125-bp ERIC element insertion in the RS2 sequence of the Y. enterocolitica ybtA/irp6 promoter might increase YbtA expression, but did not affect expression of Irp6.

  • Irp9, Encoded by the High-Pathogenicity Island of Yersinia enterocolitica, Is Able To Convert Chorismate into Salicylate, the Precursor of the Siderophore Yersiniabactin
    Journal of bacteriology, 2003
    Co-Authors: Cosima Pelludat, Daniela Brem, Jürgen Heesemann
    Abstract:

    The Irp9 protein of Yersinia enterocolitica participates in the synthesis of salicylate, the precursor of the siderophore Yersiniabactin. In Pseudomonas species, salicylate synthesis is mediated by two enzymes: isochorismate synthase and isochorismate pyruvate-lyase. Both enzymes are required for complementation of a Yersinia irp9 mutant. However, irp9 is not able to complement Escherichia coli entC for the production of enterobactin, which requires isochorismate as a precursor. These results suggest that Irp9 directly converts chorismate into salicylate.

  • Functional analysis of Yersiniabactin transport genes of Yersinia enterocolitica.
    Microbiology, 2001
    Co-Authors: Daniela Brem, Cosima Pelludat, Alexander Rakin, Christoph A. Jacobi, Jürgen Heesemann
    Abstract:

    Yersinia enterocolitica O:8, biogroup (BG) IB, strain WA-C carries a high-pathogenicity island (HPI) including iron-repressible genes (irp1–9, fyuA) for biosynthesis and uptake of the siderophore Yersiniabactin (Ybt). The authors report the functional analysis of irp6,7,8, which show 98–99% similarity to the corresponding genes ybtP,Q,X on the HPI of Yersinia pestis. It was demonstrated that irp6,7 are involved in ferric (Fe)-Ybt utilization and mouse virulence of Y. enterocolitica, thus confirming corresponding results for Y. pestis. Additionally it was shown that inactivation of the ampG-like gene irp8 did not affect either Fe-Ybt utilization or mouse virulence. To determine whether irp6, irp7 and fyuA (encoding the outer-membrane Fe-Ybt/pesticin receptor FyuA) are sufficient to mediate Fe-Ybt transport/utilization, these genes were transferred into Escherichia coli entD,F and into non-pathogenic Y. enterocolitica, BG IA, strain NF-O. Surprisingly, E. coli entD,F but not Y. enterocolitica NF-O gained the capability to utilize exogenous Fe-Ybt as a result of this gene transfer, although both strains expressed functional FyuA (pesticin sensitivity). These results suggest that besides irp6, irp7 and fyuA, additional genes are required for sufficient Fe-Ybt transport/utilization. Finally, it was shown that irp6, irp7 and fyuA but not irp8 are involved in controlling Ybt biosynthesis and fyuA gene expression: irp6 and/or irp7 mutation leads to upregulation whereas fyuA mutation leads to downregulation. However, fyuA-dependent control of Ybt biosynthesis could be bypassed in a fyuA mutant by ingredients of chrome azurol S (CAS) siderophore indicator agar.

Christopher T Walsh - One of the best experts on this subject based on the ideXlab platform.

  • epimerization of an l cysteinyl to a d cysteinyl residue during thiazoline ring formation in siderophore chain elongation by pyochelin synthetase from pseudomonas aeruginosa
    Biochemistry, 2003
    Co-Authors: Hiten M Patel, Junhua Tao, Christopher T Walsh
    Abstract:

    The thiazoline-containing siderophores pyochelin, Yersiniabactin, and Micacocidin A all have d-thiazoline rings, participating in high-affinity chelation of ferric iron. However, studies with pyochelin (Pch) synthetase and Yersiniabactin (Ybt) synthetase reconstituted from pure protein components have shown that only l-cysteine is activated and tethered as a covalent aminoacyl−S−enzyme intermediate. Nor are any of the canonical epimerase domains of nonribosomal peptide synthetase (NRPS) assembly lines found in the Ybt or Pch synthetase modules. Here, we report that the PchE subunit of the Pch synthetase exchanges solvent deuterium into the C2 center of the thiazoline moieties during siderophore chain elongation. Both PchE and HMWP2, from Ybt synthetase, subunits have a 310−360-residue insert in their amino acid activation domains that look like defective methyltransferase (MT) domains. We suggest these inserts are noncanonical epimerase domains, reversibly deprotonating and reprotonating acyl−S−enzyme int...

  • Biosynthesis of Yersiniabactin, a Complex Polyketide-Nonribosomal Peptide, Using Escherichia coli as a Heterologous Host
    Applied and Environmental Microbiology, 2003
    Co-Authors: Blaine A. Pfeifer, Christopher T Walsh, Clay C. C. Wang, Chaitan Khosla
    Abstract:

    The medicinal value associated with complex polyketide and nonribosomal peptide natural products has prompted biosynthetic schemes dependent upon heterologous microbial hosts. Here we report the successful biosynthesis of Yersiniabactin (Ybt), a model polyketide-nonribosomal peptide hybrid natural product, using Escherichia coli as a heterologous host. After introducing the biochemical pathway for Ybt into E. coli, biosynthesis was initially monitored qualitatively by mass spectrometry. Next, production of Ybt was quantified in a high-cell-density fermentation environment with titers reaching 67 ± 21 (mean ± standard deviation) mg/liter and a volumetric productivity of 1.1 ± 0.3 mg/liter-h. This success has implications for basic and applied studies on Ybt biosynthesis and also, more generally, for future production of polyketide, nonribosomal peptide, and mixed polyketide-nonribosomal peptide natural products using E. coli.

  • Yersiniabactin synthetase a four protein assembly line producing the nonribosomal peptide polyketide hybrid siderophore of yersinia pestis
    Chemistry & Biology, 2002
    Co-Authors: Deborah Ann Miller, Lusong Luo, Nathan J Hillson, Thomas A Keating, Christopher T Walsh
    Abstract:

    Abstract Yersiniabactin synthetase comprises four proteins, YbtE, HMWP1, HMWP2, and YbtU, encompassing seventeen functional domains, twelve catalytic and five carrier, to select, activate, and incorporate salicylate, three cysteines, and one malonyl moiety into the iron chelator Yersiniabactin (Ybt). In the present study, Yersiniabactin has been reconstituted in vitro from the 4 protein assembly line by the use of eight biosynthetic precursors. The rate of one turnover, comprising 22 chemical operations performed by the assembly line to release the completed Ybt molecule, was determined at 1.4 min −1 . During the course of Ybt production, the elongating acyl-S-enzyme chain was shown to transfer across a nonribosomal peptide synthetase/polyketide synthase (NRPS/PKS) interprotein interface and then a PKS/NRPS intraprotein interface. This study on the Ybt synthetase assembly line represents the first complete in vitro reconstitution of a nonribosomal peptide/polyketide hybrid system.

  • Yersiniabactin synthetase: a four-protein assembly line producing the nonribosomal peptide/polyketide hybrid siderophore of Yersinia pestis.
    Chemistry & biology, 2002
    Co-Authors: Deborah Ann Miller, Lusong Luo, Nathan J Hillson, Thomas A Keating, Christopher T Walsh
    Abstract:

    Abstract Yersiniabactin synthetase comprises four proteins, YbtE, HMWP1, HMWP2, and YbtU, encompassing seventeen functional domains, twelve catalytic and five carrier, to select, activate, and incorporate salicylate, three cysteines, and one malonyl moiety into the iron chelator Yersiniabactin (Ybt). In the present study, Yersiniabactin has been reconstituted in vitro from the 4 protein assembly line by the use of eight biosynthetic precursors. The rate of one turnover, comprising 22 chemical operations performed by the assembly line to release the completed Ybt molecule, was determined at 1.4 min −1 . During the course of Ybt production, the elongating acyl-S-enzyme chain was shown to transfer across a nonribosomal peptide synthetase/polyketide synthase (NRPS/PKS) interprotein interface and then a PKS/NRPS intraprotein interface. This study on the Ybt synthetase assembly line represents the first complete in vitro reconstitution of a nonribosomal peptide/polyketide hybrid system.

  • Purification, priming, and catalytic acylation of carrier protein domains in the polyketide synthase and nonribosomal peptidyl synthetase modules of the HMWP1 subunit of Yersiniabactin synthetase
    Proceedings of the National Academy of Sciences of the United States of America, 2000
    Co-Authors: Zucai Suo, Claire C. Tseng, Christopher T Walsh
    Abstract:

    The 207-kDa polyketide synthase (PKS) module (residues 1-1895) and the 143-kDa nonribosomal peptidyl synthetase (NRPS) module (1896-3163) of the 350-kDa HMWP1 subunit of Yersiniabactin synthetase have been expressed in and purified from Escherichia coli in soluble forms to characterize the acyl carrier protein (ACP) domain of the PKS module and the homologous peptidyl carrier protein (PCP(3)) domain of the NRPS module. The apo-ACP and PCP domains could be selectively posttranslationally primed by the E. coli ACPS and EntD phosphopantetheinyl transferases (PPTases), respectively, whereas the Bacillus subtilis PPTase Sfp primed both carrier protein domains in vitro or during in vivo coexpression. The holo-NRPS module but not the holo-PKS module was then selectively aminoacylated with cysteine by the adenylation domain embedded in the HMWP2 subunit of Yersiniabactin synthetase, acting in trans. When the acyltransferase (AT) domain of HMWP1 was analyzed for its ability to malonylate the holo carrier protein domains, in cis acylation was first detected. Then, in trans malonylation of the excised holo-ACP or holo-PCP(3)-TE fragments by HMWP1 showed both were malonylated with a 3:1 catalytic efficiency ratio, showing a promiscuity to the AT domain.

Alexander Rakin - One of the best experts on this subject based on the ideXlab platform.

  • Horizontal transfer of Yersinia high-pathogenicity island by the conjugative RP4 attB target-presenting shuttle plasmid.
    Molecular microbiology, 2005
    Co-Authors: Uladzimir Antonenka, Jürgen Heesemann, Christina Nölting, Alexander Rakin
    Abstract:

    Summary The high-pathogenicity island (HPI) encodes a highly efficient Yersiniabactin system of iron acquisition responsible for mouse lethality in Yersinia. Although the HPI is widely disseminated among Enterobacteriaceae it lacks functions necessary for its replication and transmission. Therefore, the mechanism of its horizontal transfer and circulation is completely obscure. On the other hand, the HPI is a genetically active island in the bacterial cell. It encodes a functional recombinase and is able to transpose to new targets on the chromosome. Here we report on a possible mechanism of the HPI dissemination based on site-specific recombination of the excised HPI with the attB-presenting (asn tRNA gene) RP4 promiscuous conjugative shuttle plasmid. The resulting cointegrate can be transferred by conjugation to a new host, where it dissociates, and the released HPI integrates into any unoccupied asn tRNA gene target in the genome. This mechanism has been proven both with the ‘mini’ island carrying only the attP recognition site and genes coding for recombination enzymes and with the complete HPI labelled with an antibiotic resistance marker. After acquisition of the mobilized complete form of the HPI, the ability of the HPI-cured Yersinia enterocolitica WA-TH– strain to produce Yersiniabactin has been restored. Such ‘trapping’ of pathogenicity islands and subsequent shuffling to new hosts by a conjugative replicon carrying a suitable attB site could be applied to other functional integrative elements and explain wide dissemination of PAIs.

  • Transcriptional regulation of high pathogenicity island iron uptake genes by YbtA
    International journal of medical microbiology : IJMM, 2005
    Co-Authors: Roman Anisimov, Jürgen Heesemann, Daniela Brem, Alexander Rakin
    Abstract:

    A large group of Enterobacteriaceae, including members of the genus Yersinia, produce the extracellular siderophore Yersiniabactin enabling them to multiply under iron-depleted conditions. Genes, involved in Yersiniabactin synthesis, transport and regulation are clustered in the high pathogenicity island (HPI). YbtA, an AraC-like transcriptional regulator, is presumed to be the central regulator of Yersiniabactin production together with the ferric uptake regulator Fur. In this work, we identified the transcriptional start points of YbtA-regulated promoters of the HPI by primer extension, purified homogeneous YbtA and defined the YbtA-binding sites by DNaseI footprint analysis in ybtA, fyuA, irp6, and irp2 promoters. Besides of the anticipated pair repeats RS1 and RS2 in each promoter, we identified an additional YbtA-binding site designated RS3 in the divergently transcribed ybtA/irp6 promoter. Also, comparing ybtA/irp6 promoters of Y. enterocolitica and Y. pestis, we found that a 125-bp ERIC element insertion in the RS2 sequence of the Y. enterocolitica ybtA/irp6 promoter might increase YbtA expression, but did not affect expression of Irp6.

  • Functional analysis of Yersiniabactin transport genes of Yersinia enterocolitica.
    Microbiology, 2001
    Co-Authors: Daniela Brem, Cosima Pelludat, Alexander Rakin, Christoph A. Jacobi, Jürgen Heesemann
    Abstract:

    Yersinia enterocolitica O:8, biogroup (BG) IB, strain WA-C carries a high-pathogenicity island (HPI) including iron-repressible genes (irp1–9, fyuA) for biosynthesis and uptake of the siderophore Yersiniabactin (Ybt). The authors report the functional analysis of irp6,7,8, which show 98–99% similarity to the corresponding genes ybtP,Q,X on the HPI of Yersinia pestis. It was demonstrated that irp6,7 are involved in ferric (Fe)-Ybt utilization and mouse virulence of Y. enterocolitica, thus confirming corresponding results for Y. pestis. Additionally it was shown that inactivation of the ampG-like gene irp8 did not affect either Fe-Ybt utilization or mouse virulence. To determine whether irp6, irp7 and fyuA (encoding the outer-membrane Fe-Ybt/pesticin receptor FyuA) are sufficient to mediate Fe-Ybt transport/utilization, these genes were transferred into Escherichia coli entD,F and into non-pathogenic Y. enterocolitica, BG IA, strain NF-O. Surprisingly, E. coli entD,F but not Y. enterocolitica NF-O gained the capability to utilize exogenous Fe-Ybt as a result of this gene transfer, although both strains expressed functional FyuA (pesticin sensitivity). These results suggest that besides irp6, irp7 and fyuA, additional genes are required for sufficient Fe-Ybt transport/utilization. Finally, it was shown that irp6, irp7 and fyuA but not irp8 are involved in controlling Ybt biosynthesis and fyuA gene expression: irp6 and/or irp7 mutation leads to upregulation whereas fyuA mutation leads to downregulation. However, fyuA-dependent control of Ybt biosynthesis could be bypassed in a fyuA mutant by ingredients of chrome azurol S (CAS) siderophore indicator agar.

  • Common and Specific Characteristics of the High-Pathogenicity Island of Yersinia enterocolitica
    Infection and immunity, 1999
    Co-Authors: Alexander Rakin, Sören Schubert, C. Noelting, J. Heesemann
    Abstract:

    Yersinia pestis, Y. pseudotuberculosis O:1, and Y. enterocolitica biogroup 1B strains carry a high-pathogenicity island (HPI), which mediates biosynthesis and uptake of the siderophore Yersiniabactin and a mouse-lethal phenotype. The HPI of Y. pestis and Y. pseudotuberculosis (Yps HPI) are highly conserved in sequence and organization, while the HPI of Y. enterocolitica (Yen HPI) differs significantly. The 43,393-bp Yen HPI sequence of Y. enterocolitica WA-C, serotype O:8, was completed and compared to that of the Yps HPI of Y. pseudotuberculosis PB1, serotype O:1A. A common GC-rich region (G+C content, 57.5 mol%) of 30.5 kb is conserved between yersinia strains. This region carries genes for Yersiniabactin biosynthesis, regulation, and uptake and thus can be considered the functional “core” of the HPI. In contrast, the second part of the HPI is AT rich and completely different in two evolutionary lineages of the HPI, being 12.8 kb in the Yen HPI and 5.6 kb in the Yps HPI. The variable part acquired one IS100 element in the Yps HPI and accumulated four insertion elements, IS1328, IS1329, IS1400, and IS1222, in the Yen HPI. The insertion of a 125-bp ERIC sequence modifies the structure of the promoter of the ybtA Yersiniabactin regulator in the Yen HPI. In contrast to the precise excision of the Yps HPI in Y. pseudotuberculosis, the Yen HPI suffers imprecise deletions. The Yen HPI is stably integrated in one of the three asn tRNA copies in Y. enterocolitica biogroup 1B (serotypes O:8, O:13, O:20, and O:21), probably due to inactivation of the putative integrase. The 17-bp duplications of the 3′ end of the asnT RNA are present in both Yersinia spp. The HPI attachment site is unoccupied in nonpathogenic Y. enterocolitica NF-O, biogroup 1A, serotype O:5. The HPI of Yersinia is a composite and widely spread genomic element with a highly conserved Yersiniabactin functional “core” and a divergently evolved variable part.

  • The Yersiniabactin Biosynthetic Gene Cluster of Yersinia enterocolitica: Organization and Siderophore-Dependent Regulation
    Journal of bacteriology, 1998
    Co-Authors: Cosima Pelludat, Alexander Rakin, Christoph A. Jacobi, Sören Schubert, Jürgen Heesemann
    Abstract:

    The ability to synthesize and uptake the Yersinia siderophore Yersiniabactin is a hallmark of the highly pathogenic, mouse-lethal species Yersinia pestis, Y. pseudotuberculosis, and Y. enterocolitica 1B. We have identified four genes, irp1, irp3, irp4, and irp5, on a 13-kb chromosomal DNA fragment of Y. enterocolitica O8, WA-314. These genes constitute the Yersiniabactin biosynthetic gene cluster together with the previously defined irp2. The irp1 gene consists of 9,486 bp capable of encoding a 3,161-amino-acid high-molecular-weight protein 1 (HMWP1) polypeptide with a predicted mass of 384.6 kDa. The first 3,000 bp of irp1 show similarity to the corresponding regions of the polyketide synthase genes of Bacillus subtilis and Streptomyces antibioticus. The remaining part of irp1 is most similar to irp2, encoding HMWP2, which might be the reason for immunological cross-reactivity of the two polypeptides. Irp4 was found to have 41.7% similarity to thioesterase-like protein of the anguibactin biosynthetic genes of Vibrio anguillarum. Irp5 shows 41% similarity to EntE, the 2,3-dihydroxybenzoic acid-activating enzyme utilized in enterobactin synthesis of Escherichia coli. Irp4 and Irp5 are nearly identical to YbtT and YbtE, recently identified in Y. pestis. irp3 has no similarity to any known gene. Inactivation of either irp1 or irp2 abrogates Yersiniabactin synthesis. Mutations in irp1 or fyuA (encoding Yersiniabactin/pesticin receptor) result in downregulation of irp2 that can be upregulated by the addition of Yersiniabactin. A FyuA-green fluorescent protein translational fusion was downregulated in an irp1 mutant. Upregulation was achieved by addition of Yersiniabactin but not desferal, pesticin, or pyochelin, which indicates high specificity of the FyuA receptor and autoregulation of genes involved in synthesis and uptake of Yersiniabactin.

Jeffrey P. Henderson - One of the best experts on this subject based on the ideXlab platform.

  • Uropathogenic enterobacteria use the Yersiniabactin metallophore system to acquire nickel
    The Journal of biological chemistry, 2018
    Co-Authors: Anne E. Robinson, Eun-ik Koh, Jessica E. Lowe, Jeffrey P. Henderson
    Abstract:

    Invasive Gram-negative bacteria often express multiple virulence-associated metal ion chelators to combat host-mediated metal deficiencies. Escherichia coli, Klebsiella, and Yersinia pestis isolates encoding the Yersinia high pathogenicity island (HPI) secrete Yersiniabactin (Ybt), a metallophore originally shown to chelate iron ions during infection. However, our recent demonstration that Ybt also scavenges copper ions during infection led us to question whether it might be capable of retrieving other metals as well. Here, we find that uropathogenic E. coli also use Ybt to bind extracellular nickel ions. Using quantitative MS, we show that the canonical metal-Ybt import pathway internalizes the resulting Ni-Ybt complexes, extracts the nickel, and releases metal-free Ybt back to the extracellular space. We find that E. coli and Klebsiella direct the nickel liberated from this pathway to intracellular nickel enzymes. Thus, Ybt may provide access to nickel that is inaccessible to the conserved NikABCDE permease system. Nickel should be considered alongside iron and copper as a plausible substrate for Ybt-mediated metal import by enterobacteria during human infections.

  • Copper import in Escherichia coli by the Yersiniabactin metallophore system
    Nature chemical biology, 2017
    Co-Authors: Eun-ik Koh, Anne E. Robinson, Nilantha Bandara, Buck E. Rogers, Jeffrey P. Henderson
    Abstract:

    Copper plays a dual role as a nutrient and a toxin during bacterial infections. While uropathogenic Escherichia coli (UPEC) strains can use the copper-binding metallophore Yersiniabactin (Ybt) to resist copper toxicity, Ybt also converts bioavailable copper to Cu(II)-Ybt in low-copper conditions. Although E. coli have long been considered to lack a copper import pathway, we observed Ybt-mediated copper import in UPEC using canonical Fe(III)-Ybt transport proteins. UPEC removed copper from Cu(II)-Ybt with subsequent re-export of metal-free Ybt to the extracellular space. Copper released through this process became available to an E. coli cuproenzyme (the amine oxidase TynA), linking this import pathway to a nutrient acquisition function. Ybt-expressing E. coli thus engage in nutritional passivation, a strategy of minimizing a metal ion's toxicity while preserving its nutritional availability. Copper acquisition through this process may contribute to the marked virulence defect of Ybt-transport-deficient UPEC.

  • Cupric Yersiniabactin Is a Virulence-Associated Superoxide Dismutase Mimic
    2016
    Co-Authors: Mary C. Dinauer, Jeffrey P. Henderson
    Abstract:

    ABSTRACT: Many Gram-negative bacteria interact with extracellular metal ions by expressing one or more siderophore types. Among these, the virulence-associated siderophore Yersiniabactin (Ybt) is an avid copper chelator, forming stable cupric (Cu(II)-Ybt) complexes that are detectable in infected patients. Here we show that Ybt-expressing E. coli are protected from intracellular killing within copper-replete phagocytic cells. This survival advantage is highly dependent upon the phagocyte respiratory burst, during which superoxide is generated by the NADPH oxidase complex. Chemical fractionation links this phenotype to a previously unappreciated superoxide dismutase (SOD)-like activity of Cu(II)-Ybt. Unlike previously described synthetic copper-salicylate (Cu(II)-SA) SOD mimics, the salicylate-based natural product Cu(II)-Ybt retains catalytic activity at physiologically plausible protein concentrations. These results reveal a new virulence-associated adaptation based upon spontaneous assembly of a non-protein catalyst. Pathogenic Gram-negative bacteria secrete chemicallydiverse low molecular weight virulence factors calle

  • The Yersiniabactin-Associated ATP Binding Cassette Proteins YbtP and YbtQ Enhance Escherichia coli Fitness during High-Titer Cystitis.
    Infection and immunity, 2016
    Co-Authors: Eun-ik Koh, Chia S. Hung, Jeffrey P. Henderson
    Abstract:

    The Yersinia high-pathogenicity island (HPI) is common to multiple virulence strategies used by Escherichia coli strains associated with urinary tract infection (UTI). Among the genes in this island are ybtP and ybtQ, encoding distinctive ATP binding cassette (ABC) proteins associated with iron(III)-Yersiniabactin import in Yersinia pestis In this study, we compared the impact of ybtPQ on a model E. coli cystitis strain during in vitro culture and experimental murine infections. A ybtPQ-null mutant exhibited no growth defect under standard culture conditions, consistent with nonessentiality in this background. A growth defect phenotype was observed and genetically complemented in vitro during iron(III)-Yersiniabactin-dependent growth. Following inoculation into the bladders of C3H/HEN and C3H/HeOuJ mice, this strain exhibited a profound, 10(6)-fold competitive infection defect in the subgroup of mice that progressed to high-titer bladder infections. These results identify a virulence role for YbtPQ in the highly inflammatory microenvironment characteristic of high-titer cystitis. The profound competitive defect may relate to the apparent selection of Yersinia HPI-positive E. coli in uncomplicated clinical UTIs.

  • Microbial copper-binding siderophores at the host-pathogen interface
    The Journal of biological chemistry, 2015
    Co-Authors: Eun-ik Koh, Jeffrey P. Henderson
    Abstract:

    Abstract Numerous pathogenic microorganisms secrete small molecule chelators called siderophores defined by their ability to bind extracellular ferric iron, making it bioavailable to microbes. Recently, a siderophore produced by uropathogenic Escherichia coli, Yersiniabactin, was found to also bind copper ions during human infections. The ability of Yersiniabactin to protect E. coli from copper toxicity and redox-based phagocyte defenses distinguishes it from other E. coli siderophores. Here we compare Yersiniabactin to other extracellular copper-binding molecules and review how copper-binding siderophores may confer virulence-associated gains of function during infection pathogenesis.

Robert D. Perry - One of the best experts on this subject based on the ideXlab platform.

  • Yersiniabactin iron uptake: mechanisms and role in Yersinia pestis pathogenesis
    Microbes and infection, 2011
    Co-Authors: Robert D. Perry, Jacqueline D. Fetherston
    Abstract:

    Yersiniabactin (Ybt) is a siderophore-dependent iron uptake system encoded on a pathogenicity island that is widespread among pathogenic bacteria including the Yersiniae. While biosynthesis of the siderophore has been elucidated, the secretion mechanism and a few components of the uptake/utilization pathway are unidentified. ybt genes are transcriptionally repressed by Fur but activated by YbtA, likely in combination with the siderophore itself. The Ybt system is essential for the ability of Yersinia pestis to cause bubonic plague and important in pneumonic plague as well. However, the ability to cause fatal septicemic plague is independent of Ybt.

  • Crystal structure of ferric-Yersiniabactin, a virulence factor of Yersinia pestis.
    Journal of inorganic biochemistry, 2006
    Co-Authors: M Clarke Miller, Robert D. Perry, Jacqueline D. Fetherston, Sean Parkin, Edward Demoll
    Abstract:

    Yersiniabactin (Ybt), the siderophore produced by Yersinia pestis, has been crystallized successfully in the ferric complex form and the crystal structure has been determined. The crystals are orthorhombic with a space group of P212121 and four distinct molecules per unit cell with cell dimensions of a = 11.3271(±0.0003) A ˚ , b = 22.3556(±0.0006) A ˚ , and c = 39.8991(±0.0011) A ˚ . The crystal structure of ferric Ybt shows that the ferric ion is coordinated as a 1:1 complex by three nitrogen electron pairs and three negatively charged oxygen atoms with a distorted octahedral coordination. The molecule displays a D absolute configuration with chiral centers at N2, C9, C10, C12, C13, and C19 in R, R, R, R, S, S configurations, respectively. Few of the crystal structures of siderophores have been solved, and those which have been are of simple hydroxamate and catechol types such as ferrioxamine B and agrobactin. To our knowledge this is the first report of the ferric crystal structure of 5-member heterocycle siderophore. � 2006 Published by Elsevier Inc.

  • Yersinia pestis TonB: role in iron, heme, and hemoprotein utilization.
    Infection and immunity, 2003
    Co-Authors: Robert D. Perry, Scott W Bearden, Jessica Shah, Jan M. Thompson, Jacqueline D. Fetherston
    Abstract:

    In Yersinia pestis, the siderophore-dependent Yersiniabactin (Ybt) iron transport system and heme transport system (Hmu) have putative TonB-dependent outer membrane receptors. Here we demonstrate that hemin uptake and iron utilization from Ybt are TonB dependent. However, the Yfe iron and manganese transport system does not require TonB.

  • the nonribosomal peptide synthetase hmwp2 forms a thiazoline ring during biogenesis of Yersiniabactin an iron chelating virulence factor of yersinia pestis
    Biochemistry, 1998
    Co-Authors: Amy M. Gehring, Ichiro Mori, Robert D. Perry, Christopher T Walsh
    Abstract:

    Pathogenic Yersinia species have been shown to synthesize a siderophore molecule, Yersiniabactin, as a virulence factor during iron starvation. Here we provide the first biochemical evidence for the role of the Yersinia pestis high molecular weight protein 2 (HMWP2), a nonribosomal peptide synthetase homologue, and YbtE in the initiation of Yersiniabactin biosynthesis. YbtE catalyzes the adenylation of salicylate and the transfer of this activated salicyl group to the N-terminal aryl carrier protein domain (ArCP; residues 1-100) of HMWP2. A fragment of HMWP2, residues 1-1491, can adenylate cysteine and with the resulting cysteinyl-AMP autoaminoacylate the peptidyl carrier protein domain (PCP1; residues 1383-1491) either in cis or in trans. Catalytic release of hydroxyphenylthiazoline carboxylic acid (HPT-COOH) and/or N-(hydroxyphenylthiazolinylcarbonyl)cysteine (HPT-cys) is observed upon incubation of YbtE, HMWP2 1-1491, L-cysteine, salicylate, and ATP. These products presumably arise from nucleophilic attack by water or cysteine of a stoichiometric hydroxyphenylthiazolinylcarbonyl-S-PCP1-HMWP2 intermediate. Detection of the heterocyclization capacity of HMWP2 1-1491 implies salicyl-transferring and thiazoline-forming activity for the HMWP2 condensation domain (residues 101-544) and is the first demonstration of such heterocyclization ability in a nonribosomal peptide synthetase enzyme.

  • Iron acquisition in plague: modular logic in enzymatic biogenesis of Yersiniabactin by Yersinia pestis
    Chemistry & biology, 1998
    Co-Authors: Amy M. Gehring, Christopher T Walsh, Edward Demoll, Jacqueline D. Fetherston, Ichiro Mori, George F. Mayhew, Frederick R. Blattner, Robert D. Perry
    Abstract:

    Abstract Background: Virulence in the pathogenic bacterium Yersinia pestis , causative agent of bubonic plague, has been correlated with the biosynthesis and transport of an iron-chelating siderophore, Yersiniabactin, which is induced under iron-starvation conditions. Initial DNA sequencing suggested that this system is highly conserved among the pathogenic Yersinia . Yersiniabactin contains a phenolic group and three five-membered thiazole heterocycles that serve as iron ligands. Results: The entire Y. pestis Yersiniabactin region has been sequenced. Sequence analysis of Yersiniabactin biosynthetic regions ( irp2-ybtE and ybtS ) reveals a strategy for siderophore production using a mixed polyketide synthase/nonribosomal peptide synthetase complex formed between HMWP1 and HMWP2 (encoded by irp1 and irp2 ). The complex contains 16 domains, five of them variants of phosphopantetheine-modified peptidyl carrier protein or acyl carrier protein domains. HMWP1 and HMWP2 also contain methyltransferase and heterocyclization domains. Mutating ybtS revealed that this gene encodes a protein essential for Yersiniabactin synthesis. Conclusions: The HMWP1 and HMWP2 domain organization suggests that the Yersiniabactin siderophore is assembled in a modular fashion, in which a series of covalent intermediates are passed from the amino terminus of HMWP2 to the carboxyl terminus of HMWP1. Biosynthetic labeling studies indicate that the three Yersiniabactin methyl moieties are donated by S -adenosylmethionine and that the linker between the thiazoline and thiazolidine rings is derived from malonyl-CoA. The salicylate moiety is probably synthesized using the aromatic amino-acid biosynthetic pathway, the final step of which converts chorismate to salicylate. YbtS might be necessary for converting chorismate to salicylate.

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