1
|
Rational Metabolic Engineering Combined with Biosensor-Mediated Adaptive Laboratory Evolution for l-Cysteine Overproduction from Glycerol in Escherichia coli. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8070299] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
l-Cysteine is an important sulfur-containing amino acid with numerous applications in the pharmaceutical and cosmetic industries. The microbial production of l-cysteine has received substantial attention, and the supply of the precursor l-serine is important in l-cysteine biosynthesis. In this study, to achieve l-cysteine overproduction, we first increased l-serine production by deleting genes involved in the pathway of l-serine degradation to glycine (serine hydroxymethyl transferase, SHMT, encoded by glyA genes) in strain 4W (with l-serine titer of 1.1 g/L), thus resulting in strain 4WG with l-serine titer of 2.01 g/L. Second, the serine-biosensor based on the transcriptional regulator NCgl0581 of C. glutamicum was constructed in E. coli, and the validity and sensitivity of the biosensor were demonstrated in E. coli. Then 4WG was further evolved through adaptive laboratory evolution (ALE) combined with serine-biosensor, thus yielding the strain 4WGX with 4.13 g/L l-serine production. Moreover, the whole genome of the evolved strain 4WGX was sequenced, and ten non-synonymous mutations were found in the genome of strain 4WGX compared with strain 4W. Finally, 4WGX was used as the starting strain, and deletion of the l-cysteine desulfhydrases (encoded by tnaA), overexpression of serine acetyltransferase (encoded by cysE) and the key enzyme of transport pathway (encoded by ydeD) were performed in strain 4WGX. The recombinant strain 4WGX-∆tnaA-cysE-ydeD can produce 313.4 mg/L of l-cysteine using glycerol as the carbon source. This work provides an efficient method for the biosynthesis of value-added commodity products associated with glycerol conversion.
Collapse
|
2
|
Zhang L, Kent JE, Whitaker M, Young DC, Herrmann D, Aleshin AE, Ko YH, Cingolani G, Saad JS, Moody DB, Marassi FM, Ehrt S, Niederweis M. A periplasmic cinched protein is required for siderophore secretion and virulence of Mycobacterium tuberculosis. Nat Commun 2022; 13:2255. [PMID: 35474308 PMCID: PMC9042941 DOI: 10.1038/s41467-022-29873-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 03/31/2022] [Indexed: 11/16/2022] Open
Abstract
Iron is essential for growth of Mycobacterium tuberculosis, the causative agent of tuberculosis. To acquire iron from the host, M. tuberculosis uses the siderophores called mycobactins and carboxymycobactins. Here, we show that the rv0455c gene is essential for M. tuberculosis to grow in low-iron medium and that secretion of both mycobactins and carboxymycobactins is drastically reduced in the rv0455c deletion mutant. Both water-soluble and membrane-anchored Rv0455c are functional in siderophore secretion, supporting an intracellular role. Lack of Rv0455c results in siderophore toxicity, a phenotype observed for other siderophore secretion mutants, and severely impairs replication of M. tuberculosis in mice, demonstrating the importance of Rv0455c and siderophore secretion during disease. The crystal structure of a Rv0455c homolog reveals a novel protein fold consisting of a helical bundle with a 'cinch' formed by an essential intramolecular disulfide bond. These findings advance our understanding of the distinct M. tuberculosis siderophore secretion system.
Collapse
Affiliation(s)
- Lei Zhang
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - James E Kent
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Meredith Whitaker
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - David C Young
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Dominik Herrmann
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Alexander E Aleshin
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Ying-Hui Ko
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Jamil S Saad
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - D Branch Moody
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Francesca M Marassi
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Sabine Ehrt
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
| |
Collapse
|
3
|
Hisatomi A, Shiwa Y, Fujita N, Koshino H, Tanaka N. Identification and structural characterisation of a catecholate-type siderophore produced by Stenotrophomonas maltophilia K279a. MICROBIOLOGY (READING, ENGLAND) 2021; 167. [PMID: 34280083 DOI: 10.1099/mic.0.001071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Siderophores are produced by several bacteria that utilise iron in various environments. Elucidating the structure of a specific siderophore may have valuable applications in drug development. Stenotrophomonas maltophilia, a Gram-negative bacterium that inhabits a wide range of environments and can cause pneumonia, produces siderophores. However, the structure was unknown, and therefore, in this study, we aimed to elucidate it. We purified siderophores from cultures of S. maltophilia K279a using preparative reversed-phase HPLC. The structure was analysed through LC-MS and 1H and 13C NMR. The results demonstrated that S. maltophilia K279a produces 2,3-dihydroxybenzoylserine (DHBS), a monomer unit of enterobactin. We suggested the uptake of Iron(III) by the DHBS complex. DHBS production by S. maltophilia K279a could be attributed to an incomplete enterobactin pathway. Drugs targeting DHBS synthesis could prevent S. maltophilia infection.
Collapse
Affiliation(s)
- Atsushi Hisatomi
- Department of Ecological Symbiotic Science, Graduate school of Agriculture, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Yuh Shiwa
- Department of Molecular Microbiology, Faculty of Life Sciences, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Nobuyuki Fujita
- Department of Molecular Microbiology, Faculty of Life Sciences, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Hiroyuki Koshino
- Molecular Structure Characterization Unit, RIKEN Centre for Sustainable Resource Science, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - Naoto Tanaka
- Department of Ecological Symbiotic Science, Graduate school of Agriculture, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan.,Department of Molecular Microbiology, Faculty of Life Sciences, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| |
Collapse
|
4
|
Klebba PE, Newton SMC, Six DA, Kumar A, Yang T, Nairn BL, Munger C, Chakravorty S. Iron Acquisition Systems of Gram-negative Bacterial Pathogens Define TonB-Dependent Pathways to Novel Antibiotics. Chem Rev 2021; 121:5193-5239. [PMID: 33724814 PMCID: PMC8687107 DOI: 10.1021/acs.chemrev.0c01005] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Iron is an indispensable metabolic cofactor in both pro- and eukaryotes, which engenders a natural competition for the metal between bacterial pathogens and their human or animal hosts. Bacteria secrete siderophores that extract Fe3+ from tissues, fluids, cells, and proteins; the ligand gated porins of the Gram-negative bacterial outer membrane actively acquire the resulting ferric siderophores, as well as other iron-containing molecules like heme. Conversely, eukaryotic hosts combat bacterial iron scavenging by sequestering Fe3+ in binding proteins and ferritin. The variety of iron uptake systems in Gram-negative bacterial pathogens illustrates a range of chemical and biochemical mechanisms that facilitate microbial pathogenesis. This document attempts to summarize and understand these processes, to guide discovery of immunological or chemical interventions that may thwart infectious disease.
Collapse
Affiliation(s)
- Phillip E Klebba
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Salete M C Newton
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - David A Six
- Venatorx Pharmaceuticals, Inc., 30 Spring Mill Drive, Malvern, Pennsylvania 19355, United States
| | - Ashish Kumar
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Taihao Yang
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Brittany L Nairn
- Department of Biological Sciences, Bethel University, 3900 Bethel Drive, St. Paul, Minnesota 55112, United States
| | - Colton Munger
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Somnath Chakravorty
- Jacobs School of Medicine and Biomedical Sciences, SUNY Buffalo, Buffalo, New York 14203, United States
| |
Collapse
|
5
|
Edmonds KA, Zhang Y, Raines DJ, Duhme-Klair AK, Giedroc DP. 1H, 13C, 15N backbone resonance assignments of the apo and holo forms of the ABC transporter solute binding protein PiuA from Streptococcus pneumoniae. BIOMOLECULAR NMR ASSIGNMENTS 2020; 14:233-238. [PMID: 32495035 PMCID: PMC7668159 DOI: 10.1007/s12104-020-09952-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 05/29/2020] [Indexed: 05/06/2023]
Abstract
Streptococcus pneumoniae is a Gram-positive human pathogen that causes millions of infections worldwide with an increasing occurrence of antibiotic resistance. Iron acquisition is essential for its survival and virulence, especially under host-imposed nutritional immunity. S. pneumoniae expresses several ATP-binding cassette (ABC) transporters to facilitate acquisition under iron limitation, including PitABCD, PiaABCD, and PiuBCDA. The substrate specificity of PiuBCDA is not fully established. Herein, we report the backbone 1H, 13C and 15N resonance assignments of the 31 kDa soluble, extracellular domain of the substrate binding protein PiuA in the apo form and in complex with Ga(III) and the catechol siderophore-mimic 4-LICAM. These studies provide valuable information for further functional studies of interactions with other proteins, metals, and small molecules.
Collapse
Affiliation(s)
| | - Yifan Zhang
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
- Graduate Program in Biochemistry, Indiana University, Bloomington, Indiana, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA
| | - Daniel J Raines
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Anne-K Duhme-Klair
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA.
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA.
| |
Collapse
|
6
|
Mehmood A, Naseer S, Ali A, Fatimah H, Rehman S, Kiani AK. Identification of novel vaccine candidates against carbapenem resistant Klebsiella pneumoniae: A systematic reverse proteomic approach. Comput Biol Chem 2020; 89:107380. [PMID: 32992120 DOI: 10.1016/j.compbiolchem.2020.107380] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 08/09/2020] [Accepted: 09/18/2020] [Indexed: 11/18/2022]
Abstract
Klebsiella pneumoniae is declared as antibiotic resistant by WHO, with the critical urgency of developing novel antimicrobial therapeutics as drug resistance is the second most dangerous threat after terrorism. Besides many attempts still, there is no effective vaccine available against K. pneumoniae. By utilizing all the available proteomic data we prioritized the novel proteins ideal for vaccine development using bioinformatics tools and techniques. Among the huge data, eight proteins passed all the barriers and were considered ideal candidates for vaccine development. These include: copper silver efflux system outer membrane protein (CusC), outer membrane porin protein (OmpN), Fe++ enterobactin transporter substrate binding protein (fepB), zinc transporter substrate binding protein (ZnuA), ribonuclease HI, tellurite resistant methyltransferase (the B), and two uncharacterized hypothetical proteins (WP_002918223 and WP_002892366). These proteins were also subjected to epitope analysis and were found best for developing subunit vaccine against K. pneumoniae. The study shows that the potential vaccine targets are sufficiently efficient being virulent, of outer membranous origin and can be proposed for the DNA third-generation vaccines development that would help to cope up infections caused by multidrug-resistant K. pneumoniae.
Collapse
Affiliation(s)
- Asim Mehmood
- Department of Biology and Environmental Science, Faculty of Sciences, Allama Iqbal Open University, Islamabad, Pakistan
| | - Samar Naseer
- Department of Biology and Environmental Science, Faculty of Sciences, Allama Iqbal Open University, Islamabad, Pakistan.
| | - Amjad Ali
- Department of Industrial Biotechnology, Atta Ur Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad, Pakistan
| | - Hina Fatimah
- Department of Biology and Environmental Science, Faculty of Sciences, Allama Iqbal Open University, Islamabad, Pakistan
| | - Shazia Rehman
- Department of Botany, Rawalpindi Women University, Rawalpindi, Pakistan
| | - Aysha Karim Kiani
- Department of Biology and Environmental Science, Faculty of Sciences, Allama Iqbal Open University, Islamabad, Pakistan
| |
Collapse
|
7
|
Zhang Y, Edmonds KA, Raines DJ, Murphy BA, Wu H, Guo C, Nolan EM, VanNieuwenhze MS, Duhme-Klair AK, Giedroc DP. The Pneumococcal Iron Uptake Protein A (PiuA) Specifically Recognizes Tetradentate Fe IIIbis- and Mono-Catechol Complexes. J Mol Biol 2020; 432:5390-5410. [PMID: 32795535 DOI: 10.1016/j.jmb.2020.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/02/2020] [Accepted: 08/05/2020] [Indexed: 12/15/2022]
Abstract
Streptococcus pneumoniae (Spn) is an important Gram-positive human pathogen that causes millions of infections worldwide with an increasing occurrence of antibiotic resistance. Fe acquisition is a crucial virulence determinant in Spn; further, Spn relies on exogenous FeIII-siderophore scavenging to meet nutritional Fe needs. Recent studies suggest that the human catecholamine stress hormone, norepinephrine (NE), facilitates Fe acquisition in Spn under conditions of transferrin-mediated Fe starvation. Here we show that the solute binding lipoprotein PiuA from the piu Fe acquisition ABC transporter PiuBCDA, previously described as an Fe-hemin binding protein, binds tetradentate catechol FeIII complexes, including NE and the hydrolysis products of enterobactin. Two protein-derived ligands (H238, Y300) create a coordinately saturated FeIII complex, which parallel recent studies in the Gram-negative intestinal pathogen Campylobacter jejuni. Our in vitro studies using NMR spectroscopy and 54Fe LC-ICP-MS confirm the FeIII can move from transferrin to apo-PiuA in an NE-dependent manner. Structural analysis of PiuA FeIII-bis-catechol and GaIII-bis-catechol and GaIII-(NE)2 complexes by NMR spectroscopy reveals only localized structural perturbations in PiuA upon ligand binding, largely consistent with recent descriptions of other solute binding proteins of type II ABC transporters. We speculate that tetradentate FeIII complexes formed by mono- and bis-catechol species are important Fe sources in Gram-positive human pathogens, since PiuA functions in the same way as SstD from Staphylococcus aureus.
Collapse
Affiliation(s)
- Yifan Zhang
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA; Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Katherine A Edmonds
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Daniel J Raines
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Brennan A Murphy
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Hongwei Wu
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Chuchu Guo
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Elizabeth M Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Anne-K Duhme-Klair
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA; Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA.
| |
Collapse
|
8
|
Endicott N, Rivera GSM, Yang J, Wencewicz TA. Emergence of Ferrichelatase Activity in a Siderophore-Binding Protein Supports an Iron Shuttle in Bacteria. ACS CENTRAL SCIENCE 2020; 6:493-506. [PMID: 32341999 PMCID: PMC7181320 DOI: 10.1021/acscentsci.9b01257] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Indexed: 05/08/2023]
Abstract
Siderophores are small-molecule high-affinity multidentate chelators selective for ferric iron that are produced by pathogenic microbes to aid in nutrient sequestration and enhance virulence. In Gram-positive bacteria, the currently accepted paradigm in siderophore-mediated iron acquisition is that effluxed metal-free siderophores extract ferric iron from biological sources and the resulting ferric siderophore complex undergoes diffusion-controlled association with a surface-displayed siderophore-binding protein (SBP) followed by ABC permease-mediated translocation across the cell envelope powered by ATP hydrolysis. Here we show that a more efficient paradigm is possible in Gram-positive bacteria where extracellular metal-free siderophores associate directly with apo-SBPs on the cell surface and serve as non-covalent cofactors that enable the holo-SBPs to non-reductively extract ferric iron directly from host metalloproteins with so-called "ferrichelatase" activity. The resulting SBP-bound ferric siderophore complex is ready for import through an associated membrane permease and enzymatic turnover is achieved through cofactor replacement from the readily available pool of extracellular siderophores. This new "iron shuttle" model closes a major knowledge gap in microbial iron acquisition and defines new roles of the siderophore and SBP as cofactor and enzyme, respectively, in addition to the classically accepted roles as a transport substrate and receptor pair. We propose the formal name "siderophore-dependent ferrichelatases" for this new class of catalytic SBPs.
Collapse
|
9
|
Otero-Asman JR, Quesada JM, Jim KK, Ocampo-Sosa A, Civantos C, Bitter W, Llamas MA. The extracytoplasmic function sigma factor σ VreI is active during infection and contributes to phosphate starvation-induced virulence of Pseudomonas aeruginosa. Sci Rep 2020; 10:3139. [PMID: 32081993 PMCID: PMC7035377 DOI: 10.1038/s41598-020-60197-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 02/07/2020] [Indexed: 12/27/2022] Open
Abstract
The extracytoplasmic function sigma factor σVreI of the human pathogen Pseudomonas aeruginosa promotes transcription of potential virulence determinants, including secretion systems and secreted proteins. Its activity is modulated by the VreR anti-σ factor that inhibits the binding of σVreI to the RNA polymerase in the absence of a (still unknown) inducing signal. The vreI-vreR genes are expressed under inorganic phosphate (Pi) starvation, a physiological condition often encountered in the host that increases P. aeruginosa pathogenicity. However, whether or not σVreI is active in vivo during infection and contributes to the Pi starvation-induced virulence of this pathogen has not been analyzed yet. Using zebrafish embryos and a human alveolar basal epithelial cell line as P. aeruginosa hosts, we demonstrate in this work that σVreI is active during infection and that lack of σVreI considerably reduces the Pi starvation-induced virulence of this pathogen. Surprisingly, lack of the σVreI inhibitor, the VreR anti-σ factor, also diminishes the virulence of P. aeruginosa. By transcriptomic analyses we show that VreR modulates gene expression not only in a σVreI-dependent but also in a σVreI-independent manner. This includes potential virulence determinants and transcriptional regulators that could be responsible for the reduced virulence of the ΔvreR mutant.
Collapse
Affiliation(s)
- Joaquín R Otero-Asman
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - José M Quesada
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Kin K Jim
- Department of Medical Microbiology and Infection Control, Amsterdam University medical centers, location VU University, Amsterdam, The Netherlands
| | - Alain Ocampo-Sosa
- Service of Microbiology, Hospital Universitario Marqués de Valdecilla-Instituto de Investigación Sanitaria Valdecilla, Santander, Spain
| | - Cristina Civantos
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Wilbert Bitter
- Department of Medical Microbiology and Infection Control, Amsterdam University medical centers, location VU University, Amsterdam, The Netherlands
| | - María A Llamas
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain.
| |
Collapse
|
10
|
Wang Z, Hu W, Zheng H. Pathogenic siderophore ABC importer YbtPQ adopts a surprising fold of exporter. SCIENCE ADVANCES 2020; 6:eaay7997. [PMID: 32076651 PMCID: PMC7002159 DOI: 10.1126/sciadv.aay7997] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/22/2019] [Indexed: 05/05/2023]
Abstract
To fight for essential metal ions, human pathogens secrete virulence-associated siderophores and retake the metal-chelated siderophores through a subfamily of adenosine triphosphate (ATP)-binding cassette (ABC) importer, whose molecular mechanisms are completely unknown. We have determined multiple structures of the yersiniabactin importer YbtPQ from uropathogenic Escherichia coli (UPEC) at inward-open conformation in both apo and substrate-bound states by cryo-electron microscopy. YbtPQ does not adopt any known fold of ABC importers but surprisingly adopts the fold of type IV ABC exporters. To our knowledge, it is the first time an exporter fold of ABC importer has been reported. We have also observed two unique features in YbtPQ: unwinding of a transmembrane helix in YbtP upon substrate release and tightly associated nucleotide-binding domains without bound nucleotides. Together, our study suggests that siderophore ABC importers have a distinct transport mechanism and should be classified as a separate subfamily of ABC importers.
Collapse
|
11
|
Kooshapur H, Ma J, Tjandra N, Bermejo GA. NMR Analysis of Apo Glutamine‐Binding Protein Exposes Challenges in the Study of Interdomain Dynamics. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201911015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Hamed Kooshapur
- Laboratory of Structural BiophysicsBiochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of Health Bethesda MD 20892 USA
| | - Junhe Ma
- Laboratory of Structural BiophysicsBiochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of Health Bethesda MD 20892 USA
- Present address: Ashland Specialty Ingredients 500 Hercules Rd. Wilmington DE 19808 USA
| | - Nico Tjandra
- Laboratory of Structural BiophysicsBiochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of Health Bethesda MD 20892 USA
| | - Guillermo A. Bermejo
- Office of Intramural ResearchCenter for Information TechnologyNational Institutes of Health Bethesda MD 20892 USA
| |
Collapse
|
12
|
Bacterial ABC transporters of iron containing compounds. Res Microbiol 2019; 170:345-357. [DOI: 10.1016/j.resmic.2019.10.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/15/2019] [Accepted: 10/15/2019] [Indexed: 11/20/2022]
|
13
|
Kooshapur H, Ma J, Tjandra N, Bermejo GA. NMR Analysis of Apo Glutamine-Binding Protein Exposes Challenges in the Study of Interdomain Dynamics. Angew Chem Int Ed Engl 2019; 58:16899-16902. [PMID: 31515908 DOI: 10.1002/anie.201911015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Indexed: 02/06/2023]
Abstract
Glutamine-binding protein (GlnBP) displays an apo, "open" and a holo, "closed" crystal form, mutually related by a rigid-body reorientation of its domains. A fundamental question about such large-scale conformational transitions, whether the closed state exists in the absence of ligand, is controversial in the case of GlnBP. NMR observations have indicated no evidence of the closed form, whereas experimentally validated computations have suggested a remarkable ca. 40 % population. Herein, a paramagnetic NMR strategy designed to detect the putative apo-closed species shows that a major population of the latter is highly improbable. Further, NMR residual dipolar couplings collected under three anisotropic conditions do not reveal differential domain alignment and establish that the average solution conformation is satisfied by the apo-open crystal structure. Our results indicate that the computational prediction of large-scale interdomain motions is not trivial and may lead to erroneous conclusions without proper experimental validation.
Collapse
Affiliation(s)
- Hamed Kooshapur
- Laboratory of Structural Biophysics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Junhe Ma
- Laboratory of Structural Biophysics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.,Present address: Ashland Specialty Ingredients, 500 Hercules Rd., Wilmington, DE, 19808, USA
| | - Nico Tjandra
- Laboratory of Structural Biophysics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Guillermo A Bermejo
- Office of Intramural Research, Center for Information Technology, National Institutes of Health, Bethesda, MD, 20892, USA
| |
Collapse
|
14
|
Soleja N, Jairajpuri MA, Queen A, Mohsin M. Genetically encoded FRET-based optical sensor for Hg 2+ detection and intracellular imaging in living cells. J Ind Microbiol Biotechnol 2019; 46:1669-1683. [PMID: 31531745 DOI: 10.1007/s10295-019-02235-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 09/05/2019] [Indexed: 12/31/2022]
Abstract
Due to the potential toxicity of mercury, there is an immediate need to understand its uptake, transport and flux within living cells. Conventional techniques used to analyze Hg2+ are invasive, involve high cost and are less sensitive. In the present study, a highly efficient genetically encoded mercury FRET sensor (MerFS) was developed to measure the cellular dynamics of Hg2+ at trace level in real time. To construct MerFS, the periplasmic mercury-binding protein MerP was sandwiched between enhanced cyan fluorescent protein (ECFP) and venus. MerFS is pH stable, offers a measurable fluorescent signal and binds to Hg2+ with high sensitivity and selectivity. Mutant MerFS-51 binds with an apparent affinity (Kd) of 5.09 × 10-7 M, thus providing a detection range for Hg2+ quantification between 0.210 µM and 1.196 µM. Furthermore, MerFS-51 was targeted to Escherichia coli (E. coli), yeast and human embryonic kidney (HEK)-293T cells that allowed dynamic measurement of intracellular Hg2+ concentration with a highly responsive saturation curve, proving its potential application in cellular systems.
Collapse
Affiliation(s)
- Neha Soleja
- Department of Biosciences, Jamia Millia Islamia, New Delhi, 110025, India
| | | | - Aarfa Queen
- Department of Chemistry, Jamia Millia Islamia, New Delhi, 110025, India
| | - Mohd Mohsin
- Department of Biosciences, Jamia Millia Islamia, New Delhi, 110025, India.
| |
Collapse
|
15
|
Parsing the functional specificity of Siderocalin/Lipocalin 2/NGAL for siderophores and related small-molecule ligands. JOURNAL OF STRUCTURAL BIOLOGY-X 2019; 2:100008. [PMID: 32647813 PMCID: PMC7337064 DOI: 10.1016/j.yjsbx.2019.100008] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/03/2019] [Accepted: 05/06/2019] [Indexed: 12/12/2022]
Abstract
Ligand recognition by antibacterial Siderocalin controls the competition for iron during infection. We determined nine crystal structures of Siderocalin mutants with ligands. We determined three candidate ligands did not bind. We determined the crystal structure of SBP YfiY. Multiplexed specificity of Siderocalin was determined.
Siderocalin/Lipocalin 2/Neutrophil Gelatinase Associated Lipocalin/24p3 is an innate immune system protein with bacteriostatic activity, acting by tightly binding and sequestering diverse catecholate and mixed-type ferric siderophores from enteric bacteria and mycobacteria. Bacterial virulence achieved through siderophore modifications, or utilization of alternate siderophores, can be explained by evasion of Siderocalin binding. Siderocalin has also been implicated in a wide variety of disease processes, though often in seemingly contradictory ways, and has been proposed to bind to a broader array of ligands beyond siderophores. Using structural, directed mutational, and binding studies, we have sought to rigorously test, and fully elucidate, the Siderocalin recognition mechanism. Several proposed ligands fail to meet rigorous binding criteria, including the bacterial siderophore pyochelin, the iron-chelating catecholamine hormone norepinephrine, and the bacterial second messenger cyclic diguanylate monophosphate. While possessing a remarkably rigid structure, in principle simplifying analyses of ligand recognition, understanding Scn recognition is complicated by the observed conformational and stoichiometric plasticity, and instability, of its bona fide siderophore ligands. Since the role of Siderocalin at the early host/pathogen interface is to compete for bacterial ferric siderophores, we also analyzed how bacterial siderophore binding proteins and enzymes alternately recognize siderophores that efficiently bind to, or evade, Siderocalin sequestration – including determining the crystal structure of Bacillus cereus YfiY bound to schizokinen. These studies combine to refine the potential physiological functions of Siderocalin by defining its multiplexed recognition mechanism.
Collapse
Key Words
- ABC, ATP‐binding cassette
- AEB, aerobactin
- AU, crystallographic asymmetric unit
- Antimicrobial responses
- BOCT, brain-type organic cation receptor
- Bacterial substrate binding proteins
- CAM, catechol
- CMB, carboxymycobactin
- DHBA, dihydroxybenzoic acid
- ENT, enterobactin or enterochelin
- FQ, fluorescence quenching
- Ferric enterobactin/enterochelin
- HOPO, hydroxypyridinone
- NE, norepinephrine
- NGAL, Neutrophil Gelatinase Associated Lipocalin
- PBP, bacterial periplasmic binding protein
- PCH, pyochelin
- PDB, Research Collaboratory for Structural Biology Protein Databank
- PVD, pyoverdine
- SBP, bacterial membrane-associated, substrate-binding protein
- SCH, schizokinen
- Scn, Siderocalin
- X-ray crystallography
- c-di-GMP, cyclic diguanylate monophosphate
Collapse
|
16
|
Wang D, Weng J, Wang W. An unconventional ligand‐binding mechanism of substrate‐binding proteins: MD simulation and Markov state model analysis of BtuF. J Comput Chem 2019; 40:1440-1448. [DOI: 10.1002/jcc.25798] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/22/2018] [Accepted: 01/28/2019] [Indexed: 01/01/2023]
Affiliation(s)
- Dongdong Wang
- Department of Chemistry, Institutes of Biomedical Sciences and Multiscale Research Institute of Complex System Fudan University Shanghai 200438 People's Republic of China
| | - Jingwei Weng
- Department of Chemistry, Institutes of Biomedical Sciences and Multiscale Research Institute of Complex System Fudan University Shanghai 200438 People's Republic of China
| | - Wenning Wang
- Department of Chemistry, Institutes of Biomedical Sciences and Multiscale Research Institute of Complex System Fudan University Shanghai 200438 People's Republic of China
| |
Collapse
|
17
|
Chao A, Sieminski PJ, Owens CP, Goulding CW. Iron Acquisition in Mycobacterium tuberculosis. Chem Rev 2018; 119:1193-1220. [PMID: 30474981 DOI: 10.1021/acs.chemrev.8b00285] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The highly contagious disease tuberculosis (TB) is caused by the bacterium Mycobacterium tuberculosis (Mtb), which has been evolving drug resistance at an alarming rate. Like all human pathogens, Mtb requires iron for growth and virulence. Consequently, Mtb iron transport is an emerging drug target. However, the development of anti-TB drugs aimed at these metabolic pathways has been restricted by the dearth of information on Mtb iron acquisition. In this Review, we describe the multiple strategies utilized by Mtb to acquire ferric iron and heme iron. Mtb iron uptake is a complex process, requiring biosynthesis and subsequent export of Mtb siderophores, followed by ferric iron scavenging and ferric-siderophore import into Mtb. Additionally, Mtb possesses two possible heme uptake pathways and an Mtb-specific mechanism of heme degradation that yields iron and novel heme-degradation products. We conclude with perspectives for potential therapeutics that could directly target Mtb heme and iron uptake machineries. We also highlight how hijacking Mtb heme and iron acquisition pathways for drug import may facilitate drug transport through the notoriously impregnable Mtb cell wall.
Collapse
Affiliation(s)
| | | | - Cedric P Owens
- Schmid College of Science and Technology , Chapman University , Orange , California 92866 , United States
| | | |
Collapse
|
18
|
Perraud Q, Moynié L, Gasser V, Munier M, Godet J, Hoegy F, Mély Y, Mislin GLA, Naismith JH, Schalk IJ. A Key Role for the Periplasmic PfeE Esterase in Iron Acquisition via the Siderophore Enterobactin in Pseudomonas aeruginosa. ACS Chem Biol 2018; 13:2603-2614. [PMID: 30086222 DOI: 10.1021/acschembio.8b00543] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Enterobactin (ENT) is a siderophore (iron-chelating compound) produced by Escherichia coli to gain access to iron, an indispensable nutrient for bacterial growth. ENT is used as an exosiderophore by Pseudomonas aeruginosa with transport of ferri-ENT across the outer membrane by the PfeA transporter. Next to the pfeA gene on the chromosome is localized a gene encoding for an esterase, PfeE, whose transcription is regulated, as for pfeA, by the presence of ENT in bacterial environment. Purified PfeE hydrolyzed ferri-ENT into three molecules of 2,3-DHBS (2,3-dihydroxybenzoylserine) still complexed with ferric iron, and complete dissociation of iron from ENT chelating groups was only possible in the presence of both PfeE and an iron reducer, such as DTT. The crystal structure of PfeE and an inactive PfeE mutant complexed with ferri-ENT or a nonhydrolyzable ferri-catechol complex allowed identification of the enzyme binding site and the catalytic triad. Finally, cell fractionation and fluorescence microscopy showed periplasmic localization of PfeE in P. aeruginosa cells. Thus, the molecular mechanism of iron dissociation from ENT in P. aeruginosa differs from that previously described in E. coli. In P. aeruginosa, siderophore hydrolysis occurs in the periplasm, with ENT never reaching the bacterial cytoplasm. In E. coli, ferri-ENT crosses the inner membrane via the ABC transporter FepBCD and ferri-ENT is hydrolyzed by the esterase Fes only once it is in the cytoplasm.
Collapse
Affiliation(s)
- Quentin Perraud
- Université de Strasbourg, UMR7242, ESBS, 300 Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France
- CNRS, UMR7242, ESBS, 300 Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France
| | - Lucile Moynié
- Biomedical Sciences Research Complex, University of St. Andrews, North Haugh, St. Andrews KY16 9ST, United Kingdom
- Research Complex at Harwell, Didcot OX11 0FA, United Kingdom
- Division of Structural Biology, University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7BN, United Kingdom
| | - Véronique Gasser
- Université de Strasbourg, UMR7242, ESBS, 300 Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France
- CNRS, UMR7242, ESBS, 300 Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France
| | - Mathilde Munier
- Université de Strasbourg, UMR7242, ESBS, 300 Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France
- CNRS, UMR7242, ESBS, 300 Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France
| | - Julien Godet
- Université de Strasbourg, Laboratoire de BioImagerie et Pathologies, UMR CNRS 7021, F-67413 Illkirch, Strasbourg, France
| | - Françoise Hoegy
- Université de Strasbourg, UMR7242, ESBS, 300 Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France
- CNRS, UMR7242, ESBS, 300 Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France
| | - Yves Mély
- Université de Strasbourg, Laboratoire de BioImagerie et Pathologies, UMR CNRS 7021, F-67413 Illkirch, Strasbourg, France
| | - Gaëtan. L. A. Mislin
- Université de Strasbourg, UMR7242, ESBS, 300 Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France
- CNRS, UMR7242, ESBS, 300 Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France
| | - James H. Naismith
- Biomedical Sciences Research Complex, University of St. Andrews, North Haugh, St. Andrews KY16 9ST, United Kingdom
- Research Complex at Harwell, Didcot OX11 0FA, United Kingdom
- Division of Structural Biology, University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7BN, United Kingdom
| | - Isabelle J. Schalk
- Université de Strasbourg, UMR7242, ESBS, 300 Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France
- CNRS, UMR7242, ESBS, 300 Bld Sébastien Brant, F-67413 Illkirch, Strasbourg, France
| |
Collapse
|
19
|
Radka CD, Chen D, DeLucas LJ, Aller SG. The crystal structure of the Yersinia pestis iron chaperone YiuA reveals a basic triad binding motif for the chelated metal. Acta Crystallogr D Struct Biol 2017; 73:921-939. [PMID: 29095164 PMCID: PMC5683015 DOI: 10.1107/s2059798317015236] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 10/18/2017] [Indexed: 12/25/2022] Open
Abstract
Biological chelating molecules called siderophores are used to sequester iron and maintain its ferric state. Bacterial substrate-binding proteins (SBPs) bind iron-siderophore complexes and deliver these complexes to ATP-binding cassette (ABC) transporters for import into the cytoplasm, where the iron can be transferred from the siderophore to catalytic enzymes. In Yersinia pestis, the causative agent of plague, the Yersinia iron-uptake (Yiu) ABC transporter has been shown to improve iron acquisition under iron-chelated conditions. The Yiu transporter has been proposed to be an iron-siderophore transporter; however, the precise siderophore substrate is unknown. Therefore, the precise role of the Yiu transporter in Y. pestis survival remains uncharacterized. To better understand the function of the Yiu transporter, the crystal structure of YiuA (YPO1310/y2875), an SBP which functions to present the iron-siderophore substrate to the transporter for import into the cytoplasm, was determined. The 2.20 and 1.77 Å resolution X-ray crystal structures reveal a basic triad binding motif at the YiuA canonical substrate-binding site, indicative of a metal-chelate binding site. Structural alignment and computational docking studies support the function of YiuA in binding chelated metal. Additionally, YiuA contains two mobile helices, helix 5 and helix 10, that undergo 2-3 Å shifts across crystal forms and demonstrate structural breathing of the c-clamp architecture. The flexibility in both c-clamp lobes suggest that YiuA substrate transfer resembles the Venus flytrap mechanism that has been proposed for other SBPs.
Collapse
Affiliation(s)
- Christopher D. Radka
- Graduate Biomedical Sciences Microbiology Theme, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Dongquan Chen
- Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Lawrence J. DeLucas
- Office of the Provost, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Stephen G. Aller
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| |
Collapse
|
20
|
Nas MY, Cianciotto NP. Stenotrophomonas maltophilia produces an EntC-dependent catecholate siderophore that is distinct from enterobactin. MICROBIOLOGY-SGM 2017; 163:1590-1603. [PMID: 28984234 DOI: 10.1099/mic.0.000545] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Stenotrophomonas maltophilia, a Gram-negative, multi-drug-resistant bacterium, is increasingly recognized as a key opportunistic pathogen. Thus, we embarked upon an investigation of S. maltophilia iron acquisition. To begin, we determined that the genome of strain K279a is predicted to encode a complete siderophore system, including a biosynthesis pathway, an outer-membrane receptor for ferrisiderophore, and other import and export machinery. Compatible with these data, K279a and other clinical isolates of S. maltophilia secreted a siderophore-like activity when grown at 25-37 °C in low-iron media, as demonstrated by a chrome azurol S assay, which detects iron chelation, and Arnow and Rioux assays, which detect catecholate structures. Importantly, these supernatants rescued the growth of iron-starved S. maltophilia, documenting the presence of a biologically active siderophore. A mutation in one of the predicted biosynthesis genes (entC) abolished production of the siderophore and impaired bacterial growth in low-iron conditions. Inactivation of the putative receptor gene (fepA) prevented the utilization of siderophore-containing supernatants for growth in low-iron conditions. Although the biosynthesis and import loci showed some similarity to those of enterobactin, a well-known catecholate made by enteric bacteria, the siderophore of K279a was unable to rescue the growth of an enterobactin-utilizing indicator strain, and conversely iron-starved S. maltophilia could not use purified enterobactin. Furthermore, the S. maltophilia siderophore displayed patterns of solubility in organic compounds and mobility upon thin-layer chromatography that were distinct from those of enterobactin and its derivative, salmochelin. Together, these data demonstrate that S. maltophilia secretes a novel catecholate siderophore.
Collapse
Affiliation(s)
- Megan Y Nas
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, IL 60611, USA
| | - Nicholas P Cianciotto
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, IL 60611, USA
| |
Collapse
|
21
|
Agarwal S, Dey S, Ghosh B, Biswas M, Dasgupta J. Structure and dynamics of Type III periplasmic proteins VcFhuD and VcHutB reveal molecular basis of their distinctive ligand binding properties. Sci Rep 2017; 7:42812. [PMID: 28216648 PMCID: PMC5316997 DOI: 10.1038/srep42812] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 01/13/2017] [Indexed: 12/20/2022] Open
Abstract
Molecular mechanisms of xenosiderophore and heme acquisitions using periplasmic binding protein (PBP) dependent ATP-binding cassette transporters to scavenge the essential nutrient iron are elusive yet in Vibrio cholerae. Our current study delineates the structures, dynamics and ligand binding properties of two Type III PBPs of V. cholerae, VcFhuD and VcHutB. Through crystal structures and fluorescence quenching studies we demonstrate unique features of VcFhuD to bind both hydroxamate and catecholate type xenosiderophores. Like E. coli FhuD, VcFhuD binds ferrichrome and ferri-desferal using conserved Tryptophans and R102. However, unlike EcFhuD, slightly basic ligand binding pocket of VcFhuD could favour ferri-enterobactin binding with plausible participation of R203, along with R102, like it happens in catecholate binding PBPs. Structural studies coupled with spectrophotometric and native PAGE analysis indicated parallel binding of two heme molecules to VcHutB in a pH dependent manner, while mutational analysis established the relative importance of Y65 and H164 in heme binding. MD simulation studies exhibited an unforeseen inter-lobe swinging motion in Type III PBPs, magnitude of which is inversely related to the packing of the linker helix with its neighboring helices. Small inter-lobe movement in VcFhuD or dramatic twisting in VcHutB is found to influence ligand binding.
Collapse
Affiliation(s)
- Shubhangi Agarwal
- Department of Biotechnology, St. Xavier's College, 30 Park Street, Kolkata 700016, India
| | - Sanjay Dey
- Department of Biotechnology, St. Xavier's College, 30 Park Street, Kolkata 700016, India
| | - Biplab Ghosh
- High Pressure &Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Maitree Biswas
- Department of Biotechnology, St. Xavier's College, 30 Park Street, Kolkata 700016, India
| | - Jhimli Dasgupta
- Department of Biotechnology, St. Xavier's College, 30 Park Street, Kolkata 700016, India
| |
Collapse
|
22
|
Banerjee S, Paul S, Nguyen LT, Chu BCH, Vogel HJ. FecB, a periplasmic ferric-citrate transporter from E. coli, can bind different forms of ferric-citrate as well as a wide variety of metal-free and metal-loaded tricarboxylic acids. Metallomics 2016; 8:125-33. [PMID: 26600288 DOI: 10.1039/c5mt00218d] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Escherichia coli Fec system, consisting of an outer membrane receptor (FecA), a periplasmic substrate binding protein (FecB) and an inner membrane permease-ATPase type transporter (FecC/D), plays an important role in the uptake and transport of Fe(3+)-citrate. Although several FecB sequences from various organisms have been reported, there are no biophysical or structural data available for this protein to date. In this work, using isothermal titration calorimetry (ITC), we report for the first time the ability of FecB to bind different species of Fe(3+)-citrate as well as other citrate complexes with trivalent (Ga(3+), Al(3+), Sc(3+) and In(3+)) and a representative divalent metal ion (Mg(2+)) with low μM affinity. Interestingly, ITC experiments with various iron-free di- and tricarboxylic acids show that FecB can bind tricarboxylates with μM affinity but not biologically relevant dicarboxylates. The ability of FecB to bind with metal-free citrate is also observed in (1)H,(15)N HSQC-NMR titration experiments reported here at two different pH values. Further, differential scanning calorimetry (DSC) experiments indicate that the ligand-bound form of FecB has greater thermal stability than ligand-free FecB under all pH and ligand conditions tested, which is consistent with the idea of domain closure subsequent to ligand binding for this type of periplasmic binding proteins.
Collapse
Affiliation(s)
- Sambuddha Banerjee
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, Alberta T2N 1N4, Canada.
| | - Subrata Paul
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, Alberta T2N 1N4, Canada.
| | - Leonard T Nguyen
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, Alberta T2N 1N4, Canada.
| | - Byron C H Chu
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, Alberta T2N 1N4, Canada.
| | - Hans J Vogel
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, Alberta T2N 1N4, Canada.
| |
Collapse
|
23
|
Li B, Li N, Yue Y, Liu X, Huang Y, Gu L, Xu S. An unusual crystal structure of ferric-enterobactin bound FepB suggests novel functions of FepB in microbial iron uptake. Biochem Biophys Res Commun 2016; 478:1049-53. [PMID: 27539322 DOI: 10.1016/j.bbrc.2016.08.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 08/05/2016] [Indexed: 11/16/2022]
Abstract
Iron acquisition by siderophores is critical for the survival of most bacteria. Enterobactin is a kind of catechol siderophore that exhibits the highest affinity to iron atoms secreted by E. coli and several other species of Enterobacteriaceae. The periplasmic binding protein (PBP) FepB can transport ferric-enterobactin (Fe-Ent) from the outer membrane to the membrane-associated ATP-binding cassette transport system in E. coli. To elucidate this process, we solved the crystal structure of FepB in complex with Fe-Ent at a resolution of 1.8 Å. Consistent with previously reported NMR results, our crystal structure shows that, similar to the other type III PBPs, the FepB structure was folded with separated globular N- and C-termini linked by a long α-helix. Additionally, the structure showed that the Fe-Ent bound to the cleft between the N- and C-terminal domains. Exceptionally, FepB differs from the other known siderophore binding PBPs in that it forms a trimer by capturing four Fe-Ents that can each contribute to FepB trimerization. Dynamic light-scattering experiments are consistent with the structural observations and indicate that FepB forms a trimer in a Fe-Ent-dependent manner.
Collapse
Affiliation(s)
- Bingqing Li
- Key Laboratory of Rare and Uncommon Diseases, Department of Microbiology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan 250062, China; State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan 250100, China.
| | - Ning Li
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan 250100, China
| | - Yingying Yue
- Key Laboratory of Rare and Uncommon Diseases, Department of Microbiology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan 250062, China
| | - Xiuhua Liu
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan 250100, China
| | - Yan Huang
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan 250100, China
| | - Lichuan Gu
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan 250100, China
| | - Sujuan Xu
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan 250100, China.
| |
Collapse
|
24
|
Microbial siderophore-based iron assimilation and therapeutic applications. Biometals 2016; 29:377-88. [PMID: 27146331 DOI: 10.1007/s10534-016-9935-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 04/23/2016] [Indexed: 10/21/2022]
Abstract
Siderophores are structurally diverse, complex natural products that bind metals with extraordinary specificity and affinity. The acquisition of iron is critical for the survival and virulence of many pathogenic microbes and diverse strategies have evolved to synthesize, import and utilize iron. There has been a substantial increase of known siderophore scaffolds isolated and characterized in the past decade and the corresponding biosynthetic gene clusters have provided insight into the varied pathways involved in siderophore biosynthesis, delivery and utilization. Additionally, therapeutic applications of siderophores and related compounds are actively being developed. The study of biosynthetic pathways to natural siderophores augments the understanding of the complex mechanisms of bacterial iron acquisition, and enables a complimentary approach to address virulence through the interruption of siderophore biosynthesis or utilization by targeting the key enzymes to the siderophore pathways.
Collapse
|
25
|
Abdelkader EH, Yao X, Feintuch A, Adams LA, Aurelio L, Graham B, Goldfarb D, Otting G. Pulse EPR-enabled interpretation of scarce pseudocontact shifts induced by lanthanide binding tags. JOURNAL OF BIOMOLECULAR NMR 2016; 64:39-51. [PMID: 26597990 DOI: 10.1007/s10858-015-0003-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 11/17/2015] [Indexed: 06/05/2023]
Abstract
Pseudocontact shifts (PCS) induced by tags loaded with paramagnetic lanthanide ions provide powerful long-range structure information, provided the location of the metal ion relative to the target protein is known. Usually, the metal position is determined by fitting the magnetic susceptibility anisotropy (Δχ) tensor to the 3D structure of the protein in an 8-parameter fit, which requires a large set of PCSs to be reliable. In an alternative approach, we used multiple Gd(3+)-Gd(3+) distances measured by double electron-electron resonance (DEER) experiments to define the metal position, allowing Δχ-tensor determinations from more robust 5-parameter fits that can be performed with a relatively sparse set of PCSs. Using this approach with the 32 kDa E. coli aspartate/glutamate binding protein (DEBP), we demonstrate a structural transition between substrate-bound and substrate-free DEBP, supported by PCSs generated by C3-Tm(3+) and C3-Tb(3+) tags attached to a genetically encoded p-azidophenylalanine residue. The significance of small PCSs was magnified by considering the difference between the chemical shifts measured with Tb(3+) and Tm(3+) rather than involving a diamagnetic reference. The integrative sparse data approach developed in this work makes poorly soluble proteins of limited stability amenable to structural studies in solution, without having to rely on cysteine mutations for tag attachment.
Collapse
Affiliation(s)
- Elwy H Abdelkader
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Xuejun Yao
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Akiva Feintuch
- Department of Chemical Physics, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Luke A Adams
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Luigi Aurelio
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Bim Graham
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Daniella Goldfarb
- Department of Chemical Physics, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Gottfried Otting
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia.
| |
Collapse
|
26
|
Li K, Bruner SD. Structure and functional analysis of the siderophore periplasmic binding protein from the fuscachelin gene cluster of T
hermobifida fusca. Proteins 2015; 84:118-28. [DOI: 10.1002/prot.24959] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/19/2015] [Accepted: 10/23/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Kunhua Li
- Department of Chemistry; University of Florida; Gainesville Florida 32611
| | - Steven D. Bruner
- Department of Chemistry; University of Florida; Gainesville Florida 32611
| |
Collapse
|
27
|
Li K, Chen WH, Bruner SD. Structure and Mechanism of the Siderophore-Interacting Protein from the Fuscachelin Gene Cluster of Thermobifida fusca. Biochemistry 2015; 54:3989-4000. [PMID: 26043104 DOI: 10.1021/acs.biochem.5b00354] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Microbial iron acquisition is a complex process and frequently a key and necessary step for survival. Among the several paths for iron assimilation, small molecule siderophore-mediated transport is a commonly employed strategy of many microorganisms. The chemistry and biology of the extraordinary tight and specific binding of siderophores to metal is also exploited in therapeutic treatments for microbial virulence and metal toxicity. The intracellular fate of iron acquired via the siderophore pathway is one of the least understood steps in the complex process at the molecular level. A common route to cellular incorporation is the single-electron reduction of ferric to ferrous iron catalyzed by specific and/or nonspecific reducing agents. The biosynthetic gene clusters for siderophores often contain representatives of one or two families of redox-active enzymes: the flavin-containing "siderophore-interacting protein" and iron-sulfur ferric siderophore reductases. Here we present the structure and characterization of the siderophore-interacting protein, FscN, from the fuscachelin siderophore gene cluster of Thermobifida fusca. The structure shows a flavoreductase fold with a noncovalently bound FAD cofactor along with an unexpected metal bound adjacent to the flavin site. We demonstrated that FscN is redox-active and measured the binding and reduction of ferric fuscachelin. This work provides a structural basis for the activity of a siderophore-interacting protein and further insight into the complex and important process of iron acquisition and utilization.
Collapse
Affiliation(s)
- Kunhua Li
- Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Wei-Hung Chen
- Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Steven D Bruner
- Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| |
Collapse
|
28
|
Potgieter M, Bester J, Kell DB, Pretorius E. The dormant blood microbiome in chronic, inflammatory diseases. FEMS Microbiol Rev 2015; 39:567-91. [PMID: 25940667 PMCID: PMC4487407 DOI: 10.1093/femsre/fuv013] [Citation(s) in RCA: 272] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2015] [Indexed: 02/07/2023] Open
Abstract
Blood in healthy organisms is seen as a ‘sterile’ environment: it lacks proliferating microbes. Dormant or not-immediately-culturable forms are not absent, however, as intracellular dormancy is well established. We highlight here that a great many pathogens can survive in blood and inside erythrocytes. ‘Non-culturability’, reflected by discrepancies between plate counts and total counts, is commonplace in environmental microbiology. It is overcome by improved culturing methods, and we asked how common this would be in blood. A number of recent, sequence-based and ultramicroscopic studies have uncovered an authentic blood microbiome in a number of non-communicable diseases. The chief origin of these microbes is the gut microbiome (especially when it shifts composition to a pathogenic state, known as ‘dysbiosis’). Another source is microbes translocated from the oral cavity. ‘Dysbiosis’ is also used to describe translocation of cells into blood or other tissues. To avoid ambiguity, we here use the term ‘atopobiosis’ for microbes that appear in places other than their normal location. Atopobiosis may contribute to the dynamics of a variety of inflammatory diseases. Overall, it seems that many more chronic, non-communicable, inflammatory diseases may have a microbial component than are presently considered, and may be treatable using bactericidal antibiotics or vaccines. Atopobiosis of microbes (the term describing microbes that appear in places other than where they should be), as well as the products of their metabolism, seems to correlate with, and may contribute to, the dynamics of a variety of inflammatory diseases.
Collapse
Affiliation(s)
- Marnie Potgieter
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia 0007, South Africa
| | - Janette Bester
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia 0007, South Africa
| | - Douglas B Kell
- School of Chemistry and The Manchester Institute of Biotechnology, The University of Manchester, 131, Princess St, Manchester M1 7DN, Lancs, UK
| | - Etheresia Pretorius
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia 0007, South Africa
| |
Collapse
|