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Ing NL, Nusca TD, Hochbaum AI. Correction: Geobacter sulfurreducens pili support ohmic electronic conduction in aqueous solution. Phys Chem Chem Phys 2018; 20:1294. [DOI: 10.1039/c7cp90275a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Correction for ‘Geobacter sulfurreducens pili support ohmic electronic conduction in aqueous solution’ by Nicole L. Ing et al., Phys. Chem. Chem. Phys., 2017, 19, 21791–21799.
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Affiliation(s)
- Nicole L. Ing
- Department of Chemical Engineering and Materials Science
- University of California, Irvine
- Irvine
- USA
| | - Tyler D. Nusca
- Department of Chemical Engineering and Materials Science
- University of California, Irvine
- Irvine
- USA
| | - Allon I. Hochbaum
- Department of Chemical Engineering and Materials Science
- University of California, Irvine
- Irvine
- USA
- Department of Chemistry
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Abstract
Solid-state and electrochemical observations of ohmic conductivity in purifiedGeobacter sulfurreducenspili.
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Affiliation(s)
- Nicole L. Ing
- Department of Chemical Engineering and Materials Science
- University of California
- Irvine
- Irvine
- USA
| | - Tyler D. Nusca
- Department of Chemical Engineering and Materials Science
- University of California
- Irvine
- Irvine
- USA
| | - Allon I. Hochbaum
- Department of Chemical Engineering and Materials Science
- University of California
- Irvine
- Irvine
- USA
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Abstract
Bacterial biofilms are problematic in natural and anthropogenic environments, and they confer protective properties on their constituent cells, making them difficult to treat with conventional antibiotics. Antibiofilm strategies, therefore, represent a promising direction of research for treating biofilm infections. Natural autodispersal and interspecies dispersal signaling pathways provide insight into cell-cell communication mechanisms, species dynamics in mixed communities, and potential targets for infection therapies. Here, we describe a novel interspecies dispersal signaling pathway between Pseudomonas aeruginosa and Escherichia coli. E. coli biofilms disperse in response to compounds in P. aeruginosa culture supernatant. Two components of the P. aeruginosa Las and Rhl quorum sensing systems, N-(3-oxo-dodecanoyl) homoserine lactone (3oxoC12HSL) and rhamnolipids, are found to act cooperatively to disperse E. coli biofilms. Our results indicate that rhamnolipids do not affect growth, biofilm development, or dispersal in E. coli but instead complement 3oxoC12HSL signaling by inducing selective permeability of the E. coli membrane. The increased target cell permeability is consistent with rhamnolipid-mediated removal of lipopolysaccharide from E. coli membranes and appears to selectively increase the permeability of lipophilic acyl homoserine lactones. This work suggests that rhamnolipids play a critical role in P. aeruginosa-E. coli interspecies signaling. Rhamnolipids and other biosurfactants may have similar effects in other intra- and interspecies chemical signaling pathways.
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Affiliation(s)
- Arunima Bhattacharjee
- Department
of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, United States
| | - Tyler D. Nusca
- Department
of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, United States
| | - Allon I. Hochbaum
- Department
of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, United States
- Department
of Chemistry, University of California, Irvine, Irvine, California 92697, United States
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Tripathi A, Schofield MM, Chlipala GE, Schultz PJ, Yim I, Newmister SA, Nusca TD, Scaglione JB, Hanna PC, Tamayo-Castillo G, Sherman DH. Correction to “Baulamycins A and B, Broad-Spectrum Antibiotics Identified as Inhibitors of Siderophore Biosynthesis in Staphylococcus aureus and Bacillus anthracis”. J Am Chem Soc 2014. [PMCID: PMC4353028 DOI: 10.1021/ja505297x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Tripathi A, Schofield MM, Chlipala GE, Schultz PJ, Yim I, Newmister SA, Nusca TD, Scaglione JB, Hanna PC, Tamayo-Castillo G, Sherman DH. Baulamycins A and B, broad-spectrum antibiotics identified as inhibitors of siderophore biosynthesis in Staphylococcus aureus and Bacillus anthracis. J Am Chem Soc 2014; 136:1579-86. [PMID: 24401083 PMCID: PMC4028973 DOI: 10.1021/ja4115924] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Siderophores are high-affinity iron chelators produced by microorganisms and frequently contribute to the virulence of human pathogens. Targeted inhibition of the biosynthesis of siderophores staphyloferrin B of Staphylococcus aureus and petrobactin of Bacillus anthracis hold considerable potential as a single or combined treatment for methicillin-resistant S. aureus (MRSA) and anthrax infection, respectively. The biosynthetic pathways for both siderophores involve a nonribosomal peptide synthetase independent siderophore (NIS) synthetase, including SbnE in staphyloferrin B and AsbA in petrobactin. In this study, we developed a biochemical assay specific for NIS synthetases to screen for inhibitors of SbnE and AsbA against a library of marine microbial-derived natural product extracts (NPEs). Analysis of the NPE derived from Streptomyces tempisquensis led to the isolation of the novel antibiotics baulamycins A (BmcA, 6) and B (BmcB, 7). BmcA and BmcB displayed in vitro activity with IC50 values of 4.8 μM and 19 μM against SbnE and 180 μM and 200 μM against AsbA, respectively. Kinetic analysis showed that the compounds function as reversible competitive enzyme inhibitors. Liquid culture studies with S. aureus , B. anthracis , E. coli , and several other bacterial pathogens demonstrated the capacity of these natural products to penetrate bacterial barriers and inhibit growth of both Gram-positive and Gram-negative species. These studies provide proof-of-concept that natural product inhibitors targeting siderophore virulence factors can provide access to novel broad-spectrum antibiotics, which may serve as important leads for the development of potent anti-infective agents.
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Affiliation(s)
- Ashootosh Tripathi
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109
| | - Michael M. Schofield
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109
- Department of Microbiology & Immunology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - George E. Chlipala
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109
| | - Pamela J. Schultz
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109
| | - Isaiah Yim
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109
| | - Sean A. Newmister
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109
| | - Tyler D. Nusca
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109
- Department of Microbiology & Immunology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Jamie B. Scaglione
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109
| | - Philip C. Hanna
- Department of Microbiology & Immunology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Giselle Tamayo-Castillo
- Unidad Estrategica de Bioprospección, Instituto Nacional de Biodiversidad (INBio), Santo Domingo de Heredia, Costa Rica & CIPRONA, Escuela de Química, Universidad de Costa Rica, 2060 San Pedro, Costa Rica
| | - David H. Sherman
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109
- Department of Microbiology & Immunology, University of Michigan Medical School, Ann Arbor, MI 48109
- Departments of Medicinal Chemistry and Chemistry, University of Michigan, Ann Arbor, MI 48109
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Nusca TD, Kim Y, Maltseva N, Lee JY, Eschenfeldt W, Stols L, Schofield MM, Scaglione JB, Dixon SD, Oves-Costales D, Challis GL, Hanna PC, Pfleger BF, Joachimiak A, Sherman DH. Functional and structural analysis of the siderophore synthetase AsbB through reconstitution of the petrobactin biosynthetic pathway from Bacillus anthracis. J Biol Chem 2012; 287:16058-72. [PMID: 22408253 PMCID: PMC3346087 DOI: 10.1074/jbc.m112.359349] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Indexed: 01/03/2023] Open
Abstract
Petrobactin, a mixed catechol-carboxylate siderophore, is required for full virulence of Bacillus anthracis, the causative agent of anthrax. The asbABCDEF operon encodes the biosynthetic machinery for this secondary metabolite. Here, we show that the function of five gene products encoded by the asb operon is necessary and sufficient for conversion of endogenous precursors to petrobactin using an in vitro system. In this pathway, the siderophore synthetase AsbB catalyzes formation of amide bonds crucial for petrobactin assembly through use of biosynthetic intermediates, as opposed to primary metabolites, as carboxylate donors. In solving the crystal structure of the B. anthracis siderophore biosynthesis protein B (AsbB), we disclose a three-dimensional model of a nonribosomal peptide synthetase-independent siderophore (NIS) synthetase. Structural characteristics provide new insight into how this bifunctional condensing enzyme can bind and adenylate multiple citrate-containing substrates followed by incorporation of both natural and unnatural polyamine nucleophiles. This activity enables formation of multiple end-stage products leading to final assembly of petrobactin. Subsequent enzymatic assays with the nonribosomal peptide synthetase-like AsbC, AsbD, and AsbE polypeptides show that the alternative products of AsbB are further converted to petrobactin, verifying previously proposed convergent routes to formation of this siderophore. These studies identify potential therapeutic targets to halt deadly infections caused by B. anthracis and other pathogenic bacteria and suggest new avenues for the chemoenzymatic synthesis of novel compounds.
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Affiliation(s)
- Tyler D. Nusca
- From the Life Sciences Institute and
- the Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Youngchang Kim
- the Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Natalia Maltseva
- the Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | | | - William Eschenfeldt
- the Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Lucy Stols
- the Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | | | | | - Shandee D. Dixon
- the Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Daniel Oves-Costales
- the Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Gregory L. Challis
- the Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Philip C. Hanna
- the Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Brian F. Pfleger
- From the Life Sciences Institute and
- the Department of Chemical and Biological Engineering, University of Wisconsin, Madison, Wisconsin 53706-1691
| | - Andrzej Joachimiak
- the Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
- the Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637, and
| | - David H. Sherman
- From the Life Sciences Institute and
- the Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109
- the Departments of Medicinal Chemistry and Chemistry, University of Michigan, Arbor, Michigan 48109
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Himpsl SD, Pearson MM, Arewång CJ, Nusca TD, Sherman DH, Mobley HLT. Proteobactin and a yersiniabactin-related siderophore mediate iron acquisition in Proteus mirabilis. Mol Microbiol 2011; 78:138-57. [PMID: 20923418 DOI: 10.1111/j.1365-2958.2010.07317.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Proteus mirabilis causes complicated urinary tract infections (UTIs). While the urinary tract is an iron-limiting environment, iron acquisition remains poorly characterized for this uropathogen. Microarray analysis of P. mirabilis HI4320 cultured under iron limitation identified 45 significantly upregulated genes (P ≤ 0.05) that represent 21 putative iron-regulated systems. Two gene clusters, PMI0229-0239 and PMI2596-2605, encode putative siderophore systems. PMI0229-0239 encodes a non-ribosomal peptide synthetase-independent siderophore system for producing a novel siderophore, proteobactin. PMI2596-2605 are contained within the high-pathogenicity island, originally described in Yersinia pestis, and encodes proteins with apparent homology and organization to those involved in yersiniabactin production and uptake. Cross-feeding and biochemical analysis shows that P. mirabilis is unable to utilize or produce yersiniabactin, suggesting that this yersiniabactin-related locus is functionally distinct. Only disruption of both systems resulted in an in vitro iron-chelating defect; demonstrating production and iron-chelating activity for both siderophores. These findings clearly show that proteobactin and the yersiniabactin-related siderophore function as iron acquisition systems. Despite the activity of both siderophores, only mutants lacking the yersiniabactin-related siderophore have reduced fitness in vivo. The fitness requirement for the yersiniabactin-related siderophore during UTI shows, for the first time, the importance of siderophore production in vivo for P. mirabilis.
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Affiliation(s)
- Stephanie D Himpsl
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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Carlson PE, Dixon SD, Janes BK, Carr KA, Nusca TD, Anderson EC, Keene SE, Sherman DH, Hanna PC. Genetic analysis of petrobactin transport in Bacillus anthracis. Mol Microbiol 2010; 75:900-9. [PMID: 20487286 DOI: 10.1111/j.1365-2958.2009.07025.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Iron acquisition mechanisms play an important role in the pathogenesis of many infectious microbes. In Bacillus anthracis, the siderophore petrobactin is required for both growth in iron-depleted conditions and for full virulence of the bacterium. Here we demonstrate the roles of two putative petrobactin binding proteins FatB and FpuA (encoded by GBAA5330 and GBAA4766 respectively) in B. anthracis iron acquisition and pathogenesis. Markerless deletion mutants were created using allelic exchange. The Delta fatB strain was capable of wild-type levels of growth in iron-depleted conditions, indicating that FatB does not play an essential role in petrobactin uptake. In contrast, Delta fpuA bacteria exhibited a significant decrease in growth under low-iron conditions when compared with wild-type bacteria. This mutant could not be rescued by the addition of exogenous purified petrobactin. Further examination of this strain demonstrated increased levels of petrobactin accumulation in the culture supernatants, suggesting no defect in siderophore synthesis or export but, instead, an inability of Delta fpuA to import this siderophore. Delta fpuA spores were also significantly attenuated in a murine model of inhalational anthrax. These results provide the first genetic evidence demonstrating the role of FpuA in petrobactin uptake.
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Affiliation(s)
- Paul E Carlson
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48104, USA
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