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Tanabe T, Mitome H, Miyamoto K, Akira K, Tsujibo H, Tomoo K, Nagaoka K, Funahashi T. Analysis of the vibrioferrin biosynthetic pathway of Vibrio parahaemolyticus. Biometals 2024; 37:507-517. [PMID: 38133869 DOI: 10.1007/s10534-023-00566-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 09/01/2023] [Accepted: 11/19/2023] [Indexed: 12/23/2023]
Abstract
Siderophores are small-molecule iron chelators produced by many microorganisms that capture and uptake iron from the natural environment and host. Their biosynthesis in microorganisms is generally performed using non-ribosomal peptide synthetase (NRPS) or NRPS-independent siderophore (NIS) enzymes. Vibrio parahaemolyticus secretes its cognate siderophore vibrioferrin under iron-starvation conditions. Vibrioferrin is a dehydrated condensate composed of α-ketoglutarate, L-alanine, aminoethanol, and citrate, and pvsA (the gene encoding the ATP-grasp enzyme), pvsB (the gene encoding the NIS enzyme), pvsD (the gene encoding the NIS enzyme), and pvsE (the gene encoding decarboxylase) are engaged in its biosynthesis. Here, we elucidated the biosynthetic pathway of vibrioferrin through in vitro enzymatic reactions using recombinant PvsA, PvsB, PvsD, and PvsE proteins. We also found that PvsD condenses L-serine and citrate to generate O-citrylserine, and that PvsE decarboxylates O-citrylserine to form O-citrylaminoethanol. In addition, we showed that O-citrylaminoethanol is converted to alanyl-O-citrylaminoethanol by amidification with L-Ala by PvsA and that alanyl-O-citrylaminoethanol is then converted to vibrioferrin by amidification with α-ketoglutarate by PvsB.
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Affiliation(s)
- Tomotaka Tanabe
- Laboratory of Hygienic Chemistry, College of Pharmaceutical Sciences, Matsuyama University, 4-2 Bunkyo-cho, Matsuyama, Ehime, 790-8578, Japan.
| | - Hidemichi Mitome
- Laboratory of Pharmaceutical Analytical Chemistry, College of Pharmaceutical Sciences, Matsuyama University, 4-2 Bunkyo-cho, Matsuyama, Ehime, 790-8578, Japan
| | - Katsushiro Miyamoto
- Department of Microbiology and Infection Control, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, 4-20-1 Nasahara, Takatsuki, Osaka, 569-1094, Japan
| | - Kazuki Akira
- Laboratory of Pharmaceutical Analytical Chemistry, College of Pharmaceutical Sciences, Matsuyama University, 4-2 Bunkyo-cho, Matsuyama, Ehime, 790-8578, Japan
| | - Hiroshi Tsujibo
- Department of Microbiology and Infection Control, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, 4-20-1 Nasahara, Takatsuki, Osaka, 569-1094, Japan
| | - Koji Tomoo
- Department of Physical Chemistry, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, 4-20-1 Nasahara, Takatsuki, Osaka, 569-1094, Japan
| | - Kenjiro Nagaoka
- Laboratory of Hygienic Chemistry, College of Pharmaceutical Sciences, Matsuyama University, 4-2 Bunkyo-cho, Matsuyama, Ehime, 790-8578, Japan
| | - Tatsuya Funahashi
- Laboratory of Hygienic Chemistry, College of Pharmaceutical Sciences, Matsuyama University, 4-2 Bunkyo-cho, Matsuyama, Ehime, 790-8578, Japan
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2
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Patil RH, Luptáková D, Havlíček V. Infection metallomics for critical care in the post-COVID era. Mass Spectrom Rev 2023; 42:1221-1243. [PMID: 34854486 DOI: 10.1002/mas.21755] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 07/15/2021] [Accepted: 07/15/2021] [Indexed: 06/07/2023]
Abstract
Infection metallomics is a mass spectrometry (MS) platform we established based on the central concept that microbial metallophores are specific, sensitive, noninvasive, and promising biomarkers of invasive infectious diseases. Here we review the in vitro, in vivo, and clinical applications of metallophores from historical and functional perspectives, and identify under-studied and emerging application areas with high diagnostic potential for the post-COVID era. MS with isotope data filtering is fundamental to infection metallomics; it has been used to study the interplay between "frenemies" in hosts and to monitor the dynamic response of the microbiome to antibiotic and antimycotic therapies. During infection in critically ill patients, the hostile environment of the host's body activates secondary bacterial, mycobacterial, and fungal metabolism, leading to the production of metallophores that increase the pathogen's chance of survival in the host. MS can reveal the structures, stability, and threshold concentrations of these metal-containing microbial biomarkers of infection in humans and model organisms, and can discriminate invasive disease from benign colonization based on well-defined thresholds distinguishing proliferation from the colonization steady state.
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Affiliation(s)
- Rutuja H Patil
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
- Department of Analytical Chemistry, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Dominika Luptáková
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Vladimír Havlíček
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
- Department of Analytical Chemistry, Faculty of Science, Palacký University, Olomouc, Czechia
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3
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Abstract
Staphylococcus aureus is one of the most common opportunistic human pathogens causing several infectious diseases. Ever since the emergence of the first methicillin-resistant Staphylococcus aureus (MRSA) strain decades back, the organism has been a major cause of hospital-acquired infections (HA-MRSA). The spread of this pathogen across the community led to the emergence of a more virulent subtype of the strain, i.e., Community acquired Methicillin resistant Staphylococcus aureus (CA-MRSA). Hence, WHO has declared Staphylococcus aureus as a high-priority pathogen. MRSA pathogenesis is remarkable because of the ability of this "superbug" to form robust biofilm both in vivo and in vitro by the formation of polysaccharide intercellular adhesin (PIA), extracellular DNA (eDNA), wall teichoic acids (WTAs), and capsule (CP), which are major components that impart stability to a biofilm. On the other hand, secretion of a diverse array of virulence factors such as hemolysins, leukotoxins, enterotoxins, and Protein A regulated by agr and sae two-component systems (TCS) aids in combating host immune response. The up- and downregulation of adhesion genes involved in biofilm formation and genes responsible for synthesizing virulence factors during different stages of infection act as a genetic regulatory see-saw in the pathogenesis of MRSA. This review provides insight into the evolution and pathogenesis of MRSA infections with a focus on genetic regulation of biofilm formation and virulence factors secretion.
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Affiliation(s)
| | - Seema Rawat
- Microbiology Laboratory, School of Life Sciences, Central University of Gujarat, Gandhinagar, Gujarat, India
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4
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Dzyhovskyi V, Stokowa-Sołtys K. Divalent metal ion binding to Staphylococcus aureus FeoB transporter regions. J Inorg Biochem 2023; 244:112203. [PMID: 37018851 DOI: 10.1016/j.jinorgbio.2023.112203] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/21/2023] [Accepted: 03/27/2023] [Indexed: 03/31/2023]
Abstract
Transition metal ions such as iron, copper, zinc, manganese or, nickel are essential in many biological processes. Bacteria have developed a number of mechanisms for their acquisition and transport, in which numerous of proteins and smaller molecules are involved. One of the representatives of these proteins is FeoB, which belongs to the Feo (ferrous ion transporter) family. Although ferrous iron transport system is widespread among microorganisms, it is still poorly described in Gram-positive pathogens, such as Staphylococcus aureus. In this work, combined potentiometric and spectroscopic studies (UV-Vis, CD and EPR) were carried out to determine Cu(II), Fe(II) and Zn(II) binding modes to FeoB fragments (Ac-IDYHKLMK-NH2, Ac-ETSHDKY-NH2, and Ac-SFLHMVGS-NH2). For the first time iron(II) complexes with peptides were characterized by potentiometry. All studied ligands are able to form a variety of thermodynamically stable complexes with transition metal ions. It was concluded that among the studied systems, the most effective metal ion binding is observed for the Ac-ETSHDKY-NH2 peptide. Moreover, comparing preferences of all ligands towards different metal ions, copper(II) complexes are the most stable ones at physiological pH.
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Abstract
Despite the abundance of iron in nature, iron acquisition is a challenge for life in general because the element mostly exists in the extremely insoluble ferric (Fe3+) form in oxic environments. To overcome this, microbes have evolved multiple iron uptake strategies, a common one of which is through the secretion of siderophores, which are iron-chelating metabolites generated endogenously. Siderophore-mediated iron transport, a standby when default iron transport routes are abolished under iron rich conditions, is essential under iron starvation conditions. While there has been a wealth of knowledge about the molecular basis of siderophore synthesis, uptake and regulation in model bacteria, we still know surprisingly little about siderophore biology in diverse environmental microbes. Shewanella represent a group of γ-proteobacteria capable of respiring a variety of organic and inorganic substrates, including iron ores. This respiratory process relies on a large number of iron proteins, c-type cytochromes in particular. Thus, iron plays an essential and special role in physiology of Shewanella. In addition, these bacteria use a single siderophore biosynthetic system to produce an array of macrocyclic dihydroxamate siderophores, some of which show particular biological activities. In this review, we first outline current understanding of siderophore synthesis, uptake and regulation in model bacteria, and subsequently discuss the siderophore biology in Shewanella.
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Affiliation(s)
- Lulu Liu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Wei Wang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Shihua Wu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Haichun Gao
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
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6
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M VNUM, Faidh MA, Chadha A. The ornithine cyclodeaminase/µ-crystallin superfamily of proteins: A novel family of oxidoreductases for the biocatalytic synthesis of chiral amines. Current Research in Biotechnology 2022. [DOI: 10.1016/j.crbiot.2022.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
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7
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Mular A, Shanzer A, Kozłowski H, Hubmann I, Misslinger M, Krzywik J, Decristoforo C, Gumienna-Kontecka E. Cyclic Analogs of Desferrioxamine E Siderophore for 68Ga Nuclear Imaging: Coordination Chemistry and Biological Activity in Staphylococcus aureus. Inorg Chem 2021; 60:17846-17857. [PMID: 34783539 PMCID: PMC8653149 DOI: 10.1021/acs.inorgchem.1c02453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
As multidrug-resistant
bacteria are an emerging problem and threat
to humanity, novel strategies for treatment and diagnostics are actively
sought. We aim to utilize siderophores, iron-specific strong chelating
agents produced by microbes, as gallium ion carriers for diagnosis,
applying that Fe(III) can be successfully replaced by Ga(III) without
losing biological properties of the investigated complex, which allows
molecular imaging by positron emission tomography (PET). Here, we
report synthesis, full solution chemistry, thermodynamic characterization,
and the preliminary biological evaluation of biomimetic derivatives
(FOX) of desferrioxamine E (FOXE) siderophore, radiolabeled with 68Ga for possible applications in PET imaging of S.
aureus. From a series of six biomimetic analogs, which differ
from FOXE with cycle length and position of hydroxamic and amide groups,
the highest Fe(III) and Ga(III) stability was determined for the most
FOXE alike compounds–FOX 2-4 and FOX 2-5; we have also established
the stability constant of the Ga-FOXE complex. For this purpose, spectroscopic
and potentiometric titrations, together with the Fe(III)–Ga(III)
competition method, were used. [68Ga]Ga-FOXE derivatives
uptake and microbial growth promotion studies conducted on S. aureus were efficient for compounds with a larger cavity,
i.e., FOX 2-5, 2-6, and 3-5. Even though showing low uptake values,
Fe-FOX 2-4 seems to be also a good Fe-source to support the growth
of S. aureus. Overall, proposed derivatives may hold
potential as inert and stable carrier agents for radioactive Ga(III)
ions for diagnostic medical applications or interesting starting compounds
for further modifications. In this work,
the authors have investigated a set of novel
ferrioxamine E analogs as potential Ga-68 chelators and tools for
infection imaging.
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Affiliation(s)
- Andrzej Mular
- Faculty of Chemistry, University of Wrocław, 50-383 Wrocław, Poland
| | - Abraham Shanzer
- Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Henryk Kozłowski
- Faculty of Chemistry, University of Wrocław, 50-383 Wrocław, Poland.,Department of Health Sciences, University of Opole, 45-060 Opole, Poland
| | - Isabella Hubmann
- Department of Nuclear Medicine, Medical University Innsbruck, A-6020 Innsbruck, Austria
| | - Matthias Misslinger
- Institute of Molecular Biology, Medical University Innsbruck, A-6020 Innsbruck, Austria
| | - Julia Krzywik
- TriMen Chemicals, Piłsudskiego 141, 92-318 Łódź, Poland
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, A-6020 Innsbruck, Austria
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8
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Monteith AJ, Skaar EP. The impact of metal availability on immune function during infection. Trends Endocrinol Metab 2021; 32:916-928. [PMID: 34483037 PMCID: PMC8516721 DOI: 10.1016/j.tem.2021.08.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 12/16/2022]
Abstract
Nutrient transition metals are required cofactors for many proteins to perform functions necessary for life. As such, the concentration of nutrient metals is carefully maintained to retain critical biological processes while limiting toxicity. During infection, invading bacterial pathogens must acquire essential metals, such as zinc, manganese, iron, and copper, from the host to colonize and cause disease. To combat this, the host exploits the essentiality and toxicity of nutrient metals by producing factors that limit metal availability, thereby starving pathogens or accumulating metals in excess to intoxicate the pathogen in a process termed 'nutritional immunity'. As a result of inflammation, a heterogeneous environment containing both metal-replete and -deplete niches is created, in which nutrient metal availability may have an underappreciated role in regulating immune cell function during infection. How the host manipulates nutrient metal availability during infection, and the downstream effects that nutrient metals and metal-sequestering proteins have on immune cell function, are discussed in this review.
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Affiliation(s)
- Andrew J Monteith
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Institute for Infection, Immunology, & Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA.
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9
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Torres Salazar BO, Heilbronner S, Peschel A, Krismer B. Secondary Metabolites Governing Microbiome Interaction of Staphylococcal Pathogens and Commensals. Microb Physiol 2021; 31:198-216. [PMID: 34325424 DOI: 10.1159/000517082] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/03/2021] [Indexed: 11/19/2022]
Abstract
Various Staphylococcus species colonize skin and upper airways of warm-blooded animals. They compete successfully with many other microorganisms under the hostile and nutrient-poor conditions of these habitats using mechanisms that we are only beginning to appreciate. Small-molecule mediators, whose biosynthesis requires complex enzymatic cascades, so-called secondary metabolites, have emerged as crucial components of staphylococcal microbiome interactions. Such mediators belong to a large variety of compound classes and several of them have attractive properties for future drug development. They include, for instance, bacteriocins such as lanthipeptides, thiopeptides, and fibupeptides that inhibit bacterial competitor species; signaling molecules such as thiolactone peptides that induce or inhibit sensory cascades in other bacteria; or metallophores such as staphyloferrins and staphylopine that scavenge scant transition metal ions. For some secondary metabolites such as the aureusimines, the exact function remains to be elucidated. How secondary metabolites shape the fitness of Staphylococcus species in the complex context of other microbial and host defense factors remains a challenging field of future research. A detailed understanding will help to harness staphylococcal secondary metabolites for excluding the pathogenic species Staphylococcus aureus from the nasal microbiomes of at-risk patients, and it will be instrumental for the development of advanced anti-infective interventions.
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Affiliation(s)
- Benjamin O Torres Salazar
- Department of Infection Biology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany.,Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, Tübingen, Germany.,German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Simon Heilbronner
- Department of Infection Biology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany.,Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, Tübingen, Germany.,German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Andreas Peschel
- Department of Infection Biology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany.,Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, Tübingen, Germany.,German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Bernhard Krismer
- Department of Infection Biology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany.,Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, Tübingen, Germany.,German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
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10
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Abstract
Small molecule natural products are a chemically diverse class of biomolecules that fulfill myriad biological functions, including autoregulation, communication with microbial neighbors and the host, interference competition, nutrient acquisition, and resistance to oxidative stress. Human commensal bacteria are increasingly recognized as a potential source of new natural products, which may provide insight into the molecular ecology of many different human body sites as well as novel scaffolds for therapeutic development. Here, we review the scientific literature on natural products derived from residents of the human nasal/oral cavity, discuss their discovery, biosynthesis, and ecological roles, and identify key questions in the study of these compounds.
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Affiliation(s)
- Colin Charles Barber
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley 94720, USA
| | - Wenjun Zhang
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley 94720, USA.,Chan-Zuckerberg Biohub, San Francisco 94158, USA
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11
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Le Masters T, Johnson S, Jeraldo PR, Greenwood-Quaintance KE, Cunningham SA, Abdel MP, Chia N, Patel R. Comparative Transcriptomic Analysis of Staphylococcus aureus Associated with Periprosthetic Joint Infection under in Vivo and in Vitro Conditions. J Mol Diagn 2021; 23:986-999. [PMID: 34098085 DOI: 10.1016/j.jmoldx.2021.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 02/25/2021] [Accepted: 05/06/2021] [Indexed: 11/15/2022] Open
Abstract
Transcriptomic analysis can provide insight as to how Staphylococcus aureus adapts to the environmental niche of periprosthetic joint infection (PJI), a challenging clinical infection. Here, in vivo RNA expression of eight S. aureus PJIs was compared with expression of the corresponding isolates in planktonic culture using a total RNA-sequencing approach. Expression varied among isolates, with a common trend showing increased expression of several ica-independent biofilm formation genes, including sdr, fnb, ebpS, and aaa; genes encoding enzymes and toxins, including coa, nuc, hlb, and hlgA/B/C; and genes facilitating acquisition of iron via the iron-binding molecule siderophore B (snb) and heme consumption protein (isd) pathways in PJI. Several antimicrobial resistance determinants were detected; although their presence correlated with phenotypic susceptibility of the associated isolates, no difference in expression between in vivo and in vitro conditions was identified.
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Affiliation(s)
- Thao Le Masters
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Stephen Johnson
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota
| | - Patricio R Jeraldo
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota; Department of Surgery, Mayo Clinic, Rochester, Minnesota
| | - Kerryl E Greenwood-Quaintance
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Scott A Cunningham
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Matthew P Abdel
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota
| | - Nicholas Chia
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota; Department of Surgery, Mayo Clinic, Rochester, Minnesota
| | - Robin Patel
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota; Division of Infectious Diseases, Department of Medicine, Mayo Clinic, Rochester, Minnesota.
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12
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Carlson SK, Erickson DL, Wilson E. Staphylococcus aureus metal acquisition in the mastitic mammary gland. Microb Pathog 2020; 144:104179. [DOI: 10.1016/j.micpath.2020.104179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/23/2020] [Accepted: 03/27/2020] [Indexed: 12/28/2022]
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13
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Price EE, Boyd JM. Genetic Regulation of Metal Ion Homeostasis in Staphylococcus aureus. Trends Microbiol 2020; 28:821-31. [PMID: 32381454 DOI: 10.1016/j.tim.2020.04.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 12/16/2022]
Abstract
The acquisition of metal ions and the proper maturation of holo-metalloproteins are essential processes for all organisms. However, metal ion homeostasis is a double-edged sword. A cytosolic accumulation of metal ions can lead to mismetallation of proteins and cell death. Therefore, maintenance of proper concentrations of intracellular metals is essential for cell fitness and pathogenesis. Staphylococcus aureus, like all bacterial pathogens, uses transcriptional metalloregulatory proteins to aid in the detection and the genetic response to changes in metal ion concentrations. Herein, we review the mechanisms by which S. aureus senses and responds to alterations in the levels of cellular zinc, iron, heme, and copper. The interplay between metal ion sensing and metal-dependent expression of virulence factors is also discussed.
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14
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Endicott N, Rivera GSM, Yang J, Wencewicz TA. Emergence of Ferrichelatase Activity in a Siderophore-Binding Protein Supports an Iron Shuttle in Bacteria. ACS Cent Sci 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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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15
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Tang J, Ju Y, Gu Q, Xu J, Zhou H. Structural Insights into Substrate Recognition and Activity Regulation of the Key Decarboxylase SbnH in Staphyloferrin B Biosynthesis. J Mol Biol 2019; 431:4868-4881. [PMID: 31634470 DOI: 10.1016/j.jmb.2019.10.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/08/2019] [Accepted: 10/10/2019] [Indexed: 12/21/2022]
Abstract
Staphyloferrin B is a hydroxycarboxylate siderophore that is crucial for the invasion and virulence of Staphylococcus aureus in mammalian hosts where free iron ions are scarce. The assembly of staphyloferrin B involves four enzymatic steps, in which SbnH, a pyridoxal 5'-phosphate (PLP)-dependent decarboxylase, catalyzes the second step. Here, we report the X-ray crystal structures of S. aureus SbnH (SaSbnH) in complex with PLP, citrate, and the decarboxylation product citryl-diaminoethane (citryl-Dae). The overall structure of SaSbnH resembles those of the previously reported PLP-dependent amino acid decarboxylases, but the active site of SaSbnH showed unique structural features. Structural and mutagenesis analysis revealed that the citryl moiety of the substrate citryl-l-2,3-diaminopropionic acid (citryl-l-Dap) inserts into a narrow groove at the dimer interface of SaSbnH and forms hydrogen bonding interactions with both subunits. In the active site, a conserved lysine residue forms an aldimine linkage with the cofactor PLP, and a phenylalanine residue is essential for accommodating the l-configuration Dap of the substrate. Interestingly, the freestanding citrate molecule was found to bind to SaSbnH in a conformation inverse to that of the citryl group of citryl-Dae and efficiently inhibit SaSbnH. As an intermediate in the tricarboxylic acid (TCA) cycle, citrate is highly abundant in bacterial cells until iron depletion; thus, its inhibition of SaSbnH may serve as an iron-dependent regulatory mechanism in staphyloferrin B biosynthesis.
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Affiliation(s)
- Jieyu Tang
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China; Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Yingchen Ju
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China; Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Qiong Gu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jun Xu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Huihao Zhou
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China; Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China.
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16
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Souza BSVD, Silva KCS, Parente AFA, Borges CL, Paccez JD, Pereira M, Soares CMDA, Giambiagi-deMarval M, Silva-Bailão MG, Parente-Rocha JA. The influence of pH on Staphylococcus saprophyticus iron metabolism and the production of siderophores. Microbes Infect 2019; 21:456-463. [PMID: 31075417 DOI: 10.1016/j.micinf.2019.04.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 04/29/2019] [Accepted: 04/30/2019] [Indexed: 01/11/2023]
Abstract
Staphylococcus saprophyticus is a gram-positive coagulase negative bacteria which shows clinical importance due to its capability of causing urinary tract infections (UTI), as well as its ability to persist in this environment. Little is known about how S. saprophyticus adapts to the pH shift that occurs during infection. Thus, in this study we aim to use a proteomic approach to analyze the metabolic adaptations which occur as a response by S. saprophyticus when exposed to acid (5.5) and alkaline (9.0) pH environments. Proteins related to iron storage are overexpressed in acid pH, whilst iron acquisition proteins are overexpressed in alkaline pH. It likely occurs because iron is soluble at acid pH and insoluble at alkaline pH. To evaluate if S. saprophyticus synthesizes siderophores, CAS assays were performed, and the results confirmed their production. The chemical characterization of siderophores demonstrates that S. saprophyticus produces carboxylates derived from citrate. Of special note is the fact that citrate synthase (CS) is down-regulated during incubation at acid pH, corroborating this result. This data was also confirmed by enzymatic assay. Our results demonstrate that iron metabolism regulation is influenced by different pH levels, and show, for the first time, the production of siderophores by S. saprophyticus. Enzymatic assays suggest that citrate from the tricarboxylic acid cycle (TCA) is used as substrate for siderophore production.
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Affiliation(s)
- Bianca Silva Vieira de Souza
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Av. Esperança, ICB2, 74690-900, Goiânia - Goiás, Brazil.
| | - Karla Christina Sousa Silva
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Av. Esperança, ICB2, 74690-900, Goiânia - Goiás, Brazil.
| | - Ana Flávia Alves Parente
- Instituto de Biologia, Campus Universitário Darcy Ribeiro, Universidade de Brasília, 70297-400, Brasília - Distrito Federal, Brazil.
| | - Clayton Luiz Borges
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Av. Esperança, ICB2, 74690-900, Goiânia - Goiás, Brazil.
| | - Juliano Domiraci Paccez
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Av. Esperança, ICB2, 74690-900, Goiânia - Goiás, Brazil.
| | - Maristela Pereira
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Av. Esperança, ICB2, 74690-900, Goiânia - Goiás, Brazil.
| | - Célia Maria de Almeida Soares
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Av. Esperança, ICB2, 74690-900, Goiânia - Goiás, Brazil.
| | - Marcia Giambiagi-deMarval
- Laboratório de Microbiologia Molecular, Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21941-970, Rio de Janeiro - Rio de Janeiro, Brazil.
| | - Mirelle Garcia Silva-Bailão
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Av. Esperança, ICB2, 74690-900, Goiânia - Goiás, Brazil.
| | - Juliana Alves Parente-Rocha
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Av. Esperança, ICB2, 74690-900, Goiânia - Goiás, Brazil.
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17
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Conroy BS, Grigg JC, Kolesnikov M, Morales LD, Murphy MEP. Staphylococcus aureus heme and siderophore-iron acquisition pathways. Biometals 2019; 32:409-424. [PMID: 30911924 DOI: 10.1007/s10534-019-00188-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/18/2019] [Indexed: 11/24/2022]
Abstract
Staphylococcus aureus is a versatile opportunistic human pathogen. Infection by this bacterium requires uptake of iron from the human host, but iron is highly restricted in this environment. Staphylococcus aureus iron sufficiency is achieved primarily through uptake of heme and high-affinity iron chelators, known as siderophores. Two siderophores (staphyloferrins) are produced and secreted by S. aureus into the extracellular environment to capture iron. Staphylococcus aureus expresses specific uptake systems for staphyloferrins and more general uptake systems for siderophores produced by other microorganisms. The S. aureus heme uptake system uses highly-specific cell surface receptors to extract heme from hemoglobin and hemoglobin-haptoglobin complexes for transport into the cytoplasm where it is degraded to liberate iron. Initially thought to be independent systems, recent findings indicate that these iron uptake pathways intersect. IruO is a reductase that releases iron from heme and some ferric-siderophores. Moreover, multifunctional SbnI produces a precursor for staphyloferrin B biosynthesis, and also binds heme to regulate expression of the staphyloferrin B biosynthesis pathway. Intersection of the S. aureus iron uptake pathways is hypothesized to be important for rapid adaptation to available iron sources. Components of the heme and siderophore uptake systems are currently being targeted in the development of therapeutics against S. aureus.
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Affiliation(s)
- Brigid S Conroy
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, V6T 1Z3, Canada
| | - Jason C Grigg
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, V6T 1Z3, Canada
| | - Maxim Kolesnikov
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, V6T 1Z3, Canada
| | - L Daniela Morales
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, V6T 1Z3, Canada
| | - Michael E P Murphy
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, V6T 1Z3, Canada.
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18
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Liu L, Li S, Wang S, Dong Z, Gao H. Complex Iron Uptake by the Putrebactin-Mediated and Feo Systems in Shewanella oneidensis. Appl Environ Microbiol 2018; 84:e01752-18. [PMID: 30097446 DOI: 10.1128/AEM.01752-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 08/07/2018] [Indexed: 01/15/2023] Open
Abstract
Shewanella oneidensis is an extensively studied bacterium capable of respiring minerals, including a variety of iron ores, as terminal electron acceptors (EAs). Although iron plays an essential and special role in iron respiration of S. oneidensis, little has been done to date to investigate the characteristics of iron transport in this bacterium. In this study, we found that all proteins encoded by the pub-putA-putB cluster for putrebactin (S. oneidensis native siderophore) synthesis (PubABC), recognition-transport of Fe3+-putrebactin across the outer membrane (PutA), and reduction of ferric putrebactin (PutB) are essential to putrebactin-mediated iron uptake. Although homologs of PutA are many, none can function as its replacement, but some are able to work with other bacterial siderophores. We then showed that Fe2+-specific Feo is the other primary iron uptake system, based on the synthetical lethal phenotype resulting from the loss of both iron uptake routes. The role of the Feo system in iron uptake appears to be more critical, as growth is significantly impaired by the absence of the system but not of putrebactin. Furthermore, we demonstrate that hydroxyl acids, especially α-types such as lactate, promote iron uptake in a Feo-dependent manner. Overall, our findings underscore the importance of the ferrous iron uptake system in metal-reducing bacteria, providing an insight into iron homeostasis by linking these two biological processes.IMPORTANCE S. oneidensis is among the first- and the best-studied metal-reducing bacteria, with great potential in bioremediation and biotechnology. However, many questions regarding mechanisms closely associated with those applications, such as iron homeostasis, including iron uptake, export, and regulation, remain to be addressed. Here we show that Feo is a primary player in iron uptake in addition to the siderophore-dependent route. The investigation also resolved a few puzzles regarding the unexpected phenotypes of the putA mutant and lactate-dependent iron uptake. By elucidating the physiological roles of these two important iron uptake systems, this work revealed the breadth of the impacts of iron uptake systems on the biological processes.
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19
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Carroll CS, Moore MM. Ironing out siderophore biosynthesis: a review of non-ribosomal peptide synthetase (NRPS)-independent siderophore synthetases. Crit Rev Biochem Mol Biol 2018; 53:356-381. [DOI: 10.1080/10409238.2018.1476449] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
| | - Margo M. Moore
- Department of Biological Sciences, Simon Fraser University, Burnaby, Canada
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20
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Spohn M, Edenhart S, Alanjary M, Ziemert N, Wibberg D, Kalinowski J, Niedermeyer THJ, Stegmann E, Wohlleben W. Identification of a novel aminopolycarboxylic acid siderophore gene cluster encoding the biosynthesis of ethylenediaminesuccinic acid hydroxyarginine (EDHA). Metallomics 2018; 10:722-734. [PMID: 29667664 DOI: 10.1039/c8mt00009c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The mechanism of siderophore-mediated iron supply enhances fitness and survivability of microorganisms under iron limited growth conditions. One class of naturally occurring ionophores is the small aminopolycarboxylic acids (APCAs). Although they are structurally related to the most famous anthropogenic chelating agent, ethylenediaminetetraacetate (EDTA), they have been largely neglected by the scientific community. Here, we demonstrate the detection of APCA gene clusters by a computational screening of a nucleotide database. This genome mining approach enabled the discovery of a yet unknown APCA gene cluster in well-described actinobacterial strains, either known for their potential to produce valuable secondary metabolites (Streptomyces avermitilis) or for their pathogenic lifestyle (Streptomyces scabies, Corynebacterium pseudotuberculosis, Corynebacterium ulcerans and Nocardia brasiliensis). The herein identified gene cluster was shown to encode the biosynthesis of APCA, ethylenediaminesuccinic acid hydroxyarginine (EDHA). Detailed and comparatively performed production and transcriptional profiling of EDHA and its biosynthesis genes showed strict iron-responsive biosynthesis.
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Affiliation(s)
- Marius Spohn
- Interfaculty Institute of Microbiology and Infection Medicine Tuebingen, Microbiology/Biotechnology, University of Tuebingen, Tuebingen, Germany.
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21
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Nunn PB, Codd GA. Metabolic solutions to the biosynthesis of some diaminomonocarboxylic acids in nature: Formation in cyanobacteria of the neurotoxins 3-N-methyl-2,3-diaminopropanoic acid (BMAA) and 2,4-diaminobutanoic acid (2,4-DAB). Phytochemistry 2017; 144:253-270. [PMID: 29059579 DOI: 10.1016/j.phytochem.2017.09.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 09/18/2017] [Accepted: 09/20/2017] [Indexed: 06/07/2023]
Abstract
The non-encoded diaminomonocarboxylic acids, 3-N-methyl-2,3-diaminopropanoic acid (syn: α-amino-β-methylaminopropionic acid, MeDAP; β-N-methylaminoalanine, BMAA) and 2,4-diaminobutanoic acid (2,4-DAB), are distributed widely in cyanobacterial species in free and bound forms. Both amino acids are neurotoxic in whole animal and cell-based bioassays. The biosynthetic pathway to 2,4-DAB is well documented in bacteria and in one higher plant species, but has not been confirmed in cyanobacteria. The biosynthetic pathway to BMAA is unknown. This review considers possible metabolic routes, by analogy with reactions used in other species, by which these amino acids might be biosynthesised by cyanobacteria, which are a widespread potential environmental source of these neurotoxins. Where possible, the gene expression that might be implicated in these biosyntheses is discussed.
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Affiliation(s)
- Peter B Nunn
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, PO1 2DT, UK.
| | - Geoffrey A Codd
- School of Life Sciences, University of Dundee, DD1 5EH, UK; School of Natural Sciences, University of Stirling, FK9 4LA, UK.
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22
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Abstract
Staphylococcus aureus produces a cocktail of metallophores (staphylopine, staphyloferrin A, and staphyloferrin B) to scavenge transition metals during infection of a host. In addition, S. aureus displays the extracellular surface lipoproteins FhuD1 and FhuD2 along with the ABC transporter complex FhuCBG to facilitate the use of hydroxamate xenosiderophores such as desferrioxamine B (DFOB) for iron acquisition. DFOB is used as a chelation therapy to treat human iron overload diseases and has been linked to an increased risk of S. aureus infections. We used a panel of synthetic DFOB analogs and a FhuD2-selective trihydroxamate sideromycin to probe xenosiderophore utilization in S. aureus and establish structure-activity relationships for Fe(III) binding, FhuD2 binding, S. aureus growth promotion, and competition for S. aureus cell entry. Fe(III) binding assays and FhuD2 intrinsic fluorescence quenching experiments revealed that diverse chemical modifications of the terminal ends of linear ferrioxamine siderophores influences Fe(III) affinity but not FhuD2 binding. Siderophore-sideromycin competition assays and xenosiderophore growth promotion assays revealed that S. aureus SG511 and ATCC 11632 can distinguish between competing siderophores based exclusively on net charge of the siderophore-Fe(III) complex. Our work provides a roadmap for tuning hydroxamate xenosiderophore scaffolds to suppress (net negative charge) or enhance (net positive or neutral charge) uptake by S. aureus for applications in metal chelation therapy and siderophore-mediated antibiotic delivery, respectively.
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Affiliation(s)
- Nathaniel P. Endicott
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, United States
| | - Eries Lee
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, United States
| | - Timothy A. Wencewicz
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, United States
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23
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Neumann W, Gulati A, Nolan EM. Metal homeostasis in infectious disease: recent advances in bacterial metallophores and the human metal-withholding response. Curr Opin Chem Biol 2016; 37:10-18. [PMID: 27992799 DOI: 10.1016/j.cbpa.2016.09.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 09/14/2016] [Indexed: 10/20/2022]
Abstract
A tug-of-war between the mammalian host and bacterial pathogen for nutrients, including first-row transition metals (e.g. Mn, Fe, Zn), occurs during infection. Here we present recent advances about three metal-chelating metabolites that bacterial pathogens deploy when invading the host: staphylopine, staphyloferrin B, and enterobactin. These highlights provide new insights into the mechanisms of bacterial metal acquisition and regulation, as well as the contributions of host-defense proteins during the human innate immune response. The studies also underscore that the chemical composition of the microenvironment at an infection site can influence bacterial pathogenesis and the innate immune system.
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Affiliation(s)
- Wilma Neumann
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Anmol Gulati
- 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.
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24
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Kobylarz MJ, Grigg JC, Liu Y, Lee MSF, Heinrichs DE, Murphy MEP. Deciphering the Substrate Specificity of SbnA, the Enzyme Catalyzing the First Step in Staphyloferrin B Biosynthesis. Biochemistry 2016; 55:927-39. [PMID: 26794841 PMCID: PMC5084695 DOI: 10.1021/acs.biochem.5b01045] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Staphylococcus aureus assembles the siderophore,
staphyloferrin B, from l-2,3-diaminopropionic acid (l-Dap), α-ketoglutarate, and citrate. Recently, SbnA and SbnB
were shown to produce l-Dap and α-ketoglutarate from O-phospho-l-serine (OPS) and l-glutamate.
SbnA is a pyridoxal 5′-phosphate (PLP)-dependent enzyme with
homology to O-acetyl-l-serine sulfhydrylases;
however, SbnA utilizes OPS instead of O-acetyl-l-serine (OAS), and l-glutamate serves as a nitrogen
donor instead of a sulfide. In this work, we examined how SbnA dictates
substrate specificity for OPS and l-glutamate using a combination
of X-ray crystallography, enzyme kinetics, and site-directed mutagenesis.
Analysis of SbnA crystals incubated with OPS revealed the structure
of the PLP-α-aminoacrylate intermediate. Formation of the intermediate
induced closure of the active site pocket by narrowing the channel
leading to the active site and forming a second substrate binding
pocket that likely binds l-glutamate. Three active site residues
were identified: Arg132, Tyr152, Ser185 that were essential for OPS
recognition and turnover. The Y152F/S185G SbnA double mutant was completely
inactive, and its crystal structure revealed that the mutations induced
a closed form of the enzyme in the absence of the α-aminoacrylate
intermediate. Lastly, l-cysteine was shown to be a competitive
inhibitor of SbnA by forming a nonproductive external aldimine with
the PLP cofactor. These results suggest a regulatory link between
siderophore and l-cysteine biosynthesis, revealing a potential
mechanism to reduce iron uptake under oxidative stress.
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Affiliation(s)
- Marek J Kobylarz
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia , Vancouver, British Columbia, Canada V6T 1Z3
| | - Jason C Grigg
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia , Vancouver, British Columbia, Canada V6T 1Z3
| | - Yunan Liu
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia , Vancouver, British Columbia, Canada V6T 1Z3
| | - Mathew S F Lee
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia , Vancouver, British Columbia, Canada V6T 1Z3
| | | | - Michael E P Murphy
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia , Vancouver, British Columbia, Canada V6T 1Z3
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25
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Madsen JLH, Johnstone TC, Nolan EM. Chemical Synthesis of Staphyloferrin B Affords Insight into the Molecular Structure, Iron Chelation, and Biological Activity of a Polycarboxylate Siderophore Deployed by the Human Pathogen Staphylococcus aureus. J Am Chem Soc 2015; 137:9117-27. [DOI: 10.1021/jacs.5b04557] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Julie L. H. Madsen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Timothy C. Johnstone
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Elizabeth M. Nolan
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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26
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Abstract
Bacteria secrete small molecules known as siderophores to acquire iron from their surroundings. For over 60 years, investigations into the bioinorganic chemistry of these molecules, including fundamental coordination chemistry studies, have provided insight into the crucial role that siderophores play in bacterial iron homeostasis. The importance of understanding the fundamental chemistry underlying bacterial life has been highlighted evermore in recent years because of the emergence of antibiotic-resistant bacteria and the need to prevent the global rise of these superbugs. Increasing reports of siderophores functioning in capacities other than iron transport have appeared recently, but reports of "non-classical" siderophore functions have long paralleled those of iron transport. One particular non-classical function of these iron chelators, namely antibiotic activity, was documented before the role of siderophores in iron transport was established. In this Perspective, we present an exposition of past and current work into non-classical functions of siderophores and highlight the directions in which we anticipate that this research is headed. Examples include the ability of siderophores to function as zincophores, chalkophores, and metallophores for a variety of other metals, sequester heavy metal toxins, transport boron, act as signalling molecules, regulate oxidative stress, and provide antibacterial activity.
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Affiliation(s)
- Timothy C Johnstone
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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27
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Hannauer M, Arifin AJ, Heinrichs DE. Involvement of reductases IruO and NtrA in iron acquisition byStaphylococcus aureus. Mol Microbiol 2015; 96:1192-210. [DOI: 10.1111/mmi.13000] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2015] [Indexed: 12/20/2022]
Affiliation(s)
- Mélissa Hannauer
- Department of Microbiology and Immunology; University of Western Ontario; London ON Canada N6A 5C1
| | - Andrew J. Arifin
- Department of Microbiology and Immunology; University of Western Ontario; London ON Canada N6A 5C1
| | - David E. Heinrichs
- Department of Microbiology and Immunology; University of Western Ontario; London ON Canada N6A 5C1
- Centre for Human Immunology; University of Western Ontario; London ON Canada N6A 5C1
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28
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Hannauer M, Sheldon JR, Heinrichs DE. Involvement of major facilitator superfamily proteins SfaA and SbnD in staphyloferrin secretion in Staphylococcus aureus. FEBS Lett 2015; 589:730-7. [PMID: 25680529 DOI: 10.1016/j.febslet.2015.02.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 01/31/2015] [Accepted: 02/02/2015] [Indexed: 12/11/2022]
Abstract
A paucity of information exists concerning the mechanism(s) by which bacteria secrete siderophores into the extracellular compartment. We investigated the role of SfaA and SbnD, two major facilitator superfamily (MFS)-type efflux proteins, in the secretion of the Staphylococcus aureus siderophores staphyloferrin A (SA) and staphyloferrin B (SB), respectively. Deletion of sfaA resulted in a drastic reduction of SA secreted into the supernatant with a corresponding accumulation of SA in the cytoplasm and a significant growth defect in cells devoid of SB synthesis. In contrast, sbnD mutants showed transiently lowered levels of secreted SB, suggesting the involvement of additional efflux mechanisms.
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29
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Kobylarz MJ, Grigg JC, Sheldon JR, Heinrichs DE, Murphy MEP. SbnG, a citrate synthase in Staphylococcus aureus: a new fold on an old enzyme. J Biol Chem 2014; 289:33797-807. [PMID: 25336653 DOI: 10.1074/jbc.m114.603175] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In response to iron deprivation, Staphylococcus aureus produces staphyloferrin B, a citrate-containing siderophore that delivers iron back to the cell. This bacterium also possesses a second citrate synthase, SbnG, that is necessary for supplying citrate to the staphyloferrin B biosynthetic pathway. We present the structure of SbnG bound to the inhibitor calcium and an active site variant in complex with oxaloacetate. The overall fold of SbnG is structurally distinct from TCA cycle citrate synthases yet similar to metal-dependent class II aldolases. Phylogenetic analyses revealed that SbnG forms a separate clade with homologs from other siderophore biosynthetic gene clusters and is representative of a metal-independent subgroup in the phosphoenolpyruvate/pyruvate domain superfamily. A structural superposition of the SbnG active site to TCA cycle citrate synthases and site-directed mutagenesis suggests a case for convergent evolution toward a conserved catalytic mechanism for citrate production.
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Affiliation(s)
- Marek J Kobylarz
- From the Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada and
| | - Jason C Grigg
- From the Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada and
| | | | - David E Heinrichs
- the Department of Microbiology and Immunology and the Centre for Human Immunology University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Michael E P Murphy
- From the Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada and
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30
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Sheldon JR, Marolda CL, Heinrichs DE. TCA cycle activity in Staphylococcus aureus is essential for iron-regulated synthesis of staphyloferrin A, but not staphyloferrin B: the benefit of a second citrate synthase. Mol Microbiol 2014; 92:824-39. [PMID: 24666349 DOI: 10.1111/mmi.12593] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2014] [Indexed: 02/06/2023]
Abstract
Staphylococcus aureus elaborates two citrate-containing siderophores, staphyloferrin A (SA) and staphyloferrin B (SB), that enhance growth under iron-restriction, yet, paradoxically, expression of the TCA cycle citrate synthase, CitZ, is downregulated during iron starvation. Iron starvation does, however, result in expression of SbnG, recently identified as a novel citrate synthase that is encoded from within the iron-regulated SB biosynthetic locus, suggesting an important role for SbnG in staphyloferrin production. We demonstrate that during growth of S. aureus in iron-restricted media containing glucose, SB is produced but, in contrast, SA production is severely repressed; accordingly, SB-deficient mutants grow poorly in these media. Hypothesizing that reduced TCA cycle activity hinders SA production, we show that a citZ mutant is capable of SB synthesis, but not SA synthesis, providing evidence that SbnG does not generate citrate for incorporation into SA. A citZ sbnG mutant synthesizes neither staphyloferrin, is severely compromised for growth in iron-restricted media, and is significantly more impaired for virulence than either of the single-deletion mutants. We propose that SB is the more important of the two siderophores for S. aureus insofar as it is synthesized, and supports iron-restricted growth, without need of TCA cycle activity.
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Affiliation(s)
- Jessica R Sheldon
- Department of Microbiology and Immunology, University of Western Ontario, London, ON, Canada
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Nobre LS, Saraiva LM. Role of the siderophore transporter SirABC in the Staphylococcus aureus resistance to oxidative stress. Curr Microbiol 2014; 69:164-8. [PMID: 24682218 DOI: 10.1007/s00284-014-0567-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 01/30/2014] [Indexed: 10/25/2022]
Abstract
In Staphylococcus aureus, the intracellular siderophore staphyloferrin B, which has been shown to chelate iron-bound to serum transferrin, is transported into cells by the SirABC system. In this work, we have analysed the role of the Sir transporter under stress conditions that resemble those imposed by the mammalian innate immune system. We show that exposure of S. aureus to oxidative and nitrosative stress generated by hydrogen peroxide and S-nitrosoglutathione, respectively, induced the expression of the sirA gene. The disruption of the sir operon led to a strain with lower viability and decreased resistance to oxidative stress. S. aureus sir null mutant was also analysed during infection of murine macrophages and shown to contribute to S. aureus survival inside macrophages. Altogether, our results indicate that the Sir transport system confers protection against reactive oxygen species, therefore, contributing to the virulence of S. aureus.
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Kobylarz MJ, Grigg JC, Takayama SIJ, Rai DK, Heinrichs DE, Murphy MEP. Synthesis of L-2,3-diaminopropionic acid, a siderophore and antibiotic precursor. ACTA ACUST UNITED AC 2014; 21:379-88. [PMID: 24485762 DOI: 10.1016/j.chembiol.2013.12.011] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 12/03/2013] [Accepted: 12/07/2013] [Indexed: 11/29/2022]
Abstract
L-2,3-diaminopropionic acid (L-Dap) is an amino acid that is a precursor of antibiotics and staphyloferrin B a siderophore produced by Staphylococcus aureus. SbnA and SbnB are encoded by the staphyloferrin B biosynthetic gene cluster and are implicated in L-Dap biosynthesis. We demonstrate here that SbnA uses PLP and substrates O-phospho-L-serine and L-glutamate to produce a metabolite N-(1-amino-1-carboxyl-2-ethyl)-glutamic acid (ACEGA). SbnB is shown to use NAD(+) to oxidatively hydrolyze ACEGA to yield α-ketoglutarate and L-Dap. Also, we describe crystal structures of SbnB in complex with NADH and ACEGA as well as with NAD(+) and α-ketoglutarate to reveal the residues required for substrate binding, oxidation, and hydrolysis. SbnA and SbnB contribute to the iron sparing response of S. aureus that enables staphyloferrin B biosynthesis in the absence of an active tricarboxylic acid cycle.
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Affiliation(s)
- Marek J Kobylarz
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Jason C Grigg
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Shin-ichi J Takayama
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Dushyant K Rai
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - David E Heinrichs
- Department of Microbiology and Immunology, The Centre for Human Immunology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Michael E P Murphy
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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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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Luo G, Spellberg B, Gebremariam T, Lee H, Xiong YQ, French SW, Bayer A, Ibrahim AS. Combination therapy with iron chelation and vancomycin in treating murine staphylococcemia. Eur J Clin Microbiol Infect Dis 2014; 33:845-51. [PMID: 24292099 DOI: 10.1007/s10096-013-2023-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 11/15/2013] [Indexed: 02/07/2023]
Abstract
Iron acquisition is a virulence factor for Staphylococcus aureus. We assessed the efficacy of the iron chelator, deferasirox (Def), alone or in combination with vancomycin (Van) against two methicillin-resistant S. aureus (MRSA) strains in vitro and in a murine bacteremia model. In vitro time-kill assays were carried out against MRSA or vancomycin-intermediate S. aureus (VISA) strains. The impact of Def on Van binding to the surface of S. aureus was measured by flow cytometry. Furthermore, we compared the efficacy of Def, Van, or both drugs in treating S. aureus bacteremia in a murine model. Combination therapy reduced MRSA and VISA viability in vitro versus either drug alone or untreated controls (p < 0.005); this outcome was correlated with enhanced Van surface binding to S. aureus cells. In vivo, Def + Van combination therapy significantly reduced the bacterial burden in mice kidneys (p = 0.005) and spleen (p < 0.001), and reduced the severity of infection with MRSA or VISA strains compared to placebo-treated mice. Our results show that Def enhances the in vitro and in vivo capacity of Van-mediated MRSA killing via a mechanism that appears to involve increased binding of Van to the staphylococcal surface. Iron chelation is a promising, novel adjunctive therapeutic strategy for MRSA and VISA infections.
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Nobre LS, Saraiva LM. Effect of combined oxidative and nitrosative stresses on Staphylococcus aureus transcriptome. Appl Microbiol Biotechnol 2013; 97:2563-73. [PMID: 23389340 DOI: 10.1007/s00253-013-4730-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 01/13/2013] [Accepted: 01/15/2013] [Indexed: 12/28/2022]
Abstract
Staphylococcus aureus is a pathogen responsible for severe community- and nosocomially acquired infections. To fight pathogen intrusion, the innate immune system uses a plethora of weapons, with the generation of oxidative and nitrosative stresses among the most efficient. In this work, the S. aureus genome-wide transcriptional responses to oxidative stress generated by hydrogen peroxide, to nitrosative stress imposed by S-nitrosoglutathione (GSNO), and to the combination of the two were investigated using microarray analysis. The results showed that these stresses have a significant impact on the transcriptome of S. aureus. Hydrogen peroxide modified mainly the mRNA abundance of genes involved in oxidative detoxification and DNA metabolism, which together represent 14 % of the total number of upregulated genes. GSNO caused significant alteration of the expression of gene products with regulatory function. However, the simultaneous addition of GSNO and hydrogen peroxide was found to cause the more significant transcriptomic alteration, affecting ∼10 % of the total transcriptome. In particular, exposure of S. aureus to GSNO plus hydrogen peroxide modified the transcription of genes associated with cell envelope and iron metabolism, including induction of ftnA and dps genes that encode iron-storage and oxidative-protecting proteins. Further studies revealed that when exposed to combined GSNO-hydrogen peroxide stresses, S. aureus has decreased viability, which is enhanced in the presence of iron, and low siderophore activity. Altogether, this study revealed, for the first time, how the combined oxidative and nitrosative stresses inflicted during phagocytosis interfere at the transcriptional level with the S. aureus cellular metabolism.
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Affiliation(s)
- Lígia S Nobre
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República (EAN), 2780-157 Oeiras, Portugal
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Abstract
All but a few bacterial species have an absolute need for heme, and most are able to synthesize it via a pathway that is highly conserved among all life domains. Because heme is a rich source for iron, many pathogenic bacteria have also evolved processes for sequestering heme from their hosts. The heme biosynthesis pathways are well understood at the genetic and structural biology levels. In comparison, much less is known about the heme acquisition, trafficking, and degradation processes in bacteria. Gram-positive and Gram-negative bacteria have evolved similar strategies but different tactics for importing and degrading heme, likely as a consequence of their different cellular architectures. The differences are manifested in distinct structures for molecules that perform similar functions. Consequently, the aim of this chapter is to provide an overview of the structural biology of proteins and protein-protein interactions that enable Gram-positive and Gram-negative bacteria to sequester heme from the extracellular milieu, import it to the cytosol, and degrade it to mine iron.
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Affiliation(s)
- David R Benson
- Department of Chemistry, University of Kansas, Multidisciplinary Research Building, 2030 Becker Dr., Lawrence, KS, 66047, USA,
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Cheung J, Murphy M, Heinrichs D. Discovery of an Iron-Regulated Citrate Synthase in Staphylococcus aureus. ACTA ACUST UNITED AC 2012; 19:1568-78. [DOI: 10.1016/j.chembiol.2012.10.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 09/06/2012] [Accepted: 10/03/2012] [Indexed: 11/21/2022]
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Tohyama S, Tomura A, Ikeda N, Hatano M, Odanaka J, Kubota Y, Umekita M, Igarashi M, Sawa R, Morino T. Discovery and Characterization of NK13650s, Naturally Occurring p300-Selective Histone Acetyltransferase Inhibitors. J Org Chem 2012; 77:9044-52. [DOI: 10.1021/jo301534b] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Shigehiro Tohyama
- Institute of Microbial Chemistry, Tokyo, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo
141-0021, Japan
| | - Arihiro Tomura
- Pharmaceuticals Research Laboratories, Research & Development Group, Nippon Kayaku, 3-31-12 Shimo, Kita-ku, Tokyo 115-8588, Japan
| | - Noriko Ikeda
- Institute of Microbial Chemistry, Tokyo, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo
141-0021, Japan
| | - Masaki Hatano
- Institute of Microbial Chemistry, Tokyo, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo
141-0021, Japan
| | - Junko Odanaka
- Pharmaceuticals Research Laboratories, Research & Development Group, Nippon Kayaku, 3-31-12 Shimo, Kita-ku, Tokyo 115-8588, Japan
| | - Yumiko Kubota
- Institute of Microbial Chemistry, Tokyo, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo
141-0021, Japan
| | - Maya Umekita
- Institute of Microbial Chemistry, Tokyo, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo
141-0021, Japan
| | - Masayuki Igarashi
- Institute of Microbial Chemistry, Tokyo, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo
141-0021, Japan
| | - Ryuichi Sawa
- Institute of Microbial Chemistry, Tokyo, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo
141-0021, Japan
| | - Tomio Morino
- Pharmaceuticals Research Laboratories, Research & Development Group, Nippon Kayaku, 3-31-12 Shimo, Kita-ku, Tokyo 115-8588, Japan
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Abstract
Lipoproteins fulfill diverse roles in antibiotic resistance, adhesion, protein secretion, signaling and sensing, and many also serve as the substrate binding protein (SBP) partner to ABC transporters for the acquisition of a diverse array of nutrients including peptides, sugars, and scarcely abundant metals. In the staphylococci, the iron-regulated SBPs are significantly upregulated during iron starvation and function to sequester and deliver iron into the bacterial cell, enabling staphylococci to circumvent iron restriction imposed by the host environment. Accordingly, this subset of lipoproteins has been implicated in staphylococcal pathogenesis and virulence. Lipoproteins also activate the host innate immune response, triggered through Toll-like receptor-2 (TLR2) and, notably, the iron-regulated subset of lipoproteins are particularly immunogenic. In this review, we discuss the iron-regulated staphylococcal lipoproteins with regard to their biogenesis, substrate specificity, and impact on the host innate immune response.
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Affiliation(s)
- Jessica R Sheldon
- Department of Microbiology and Immunology, Western University, London ON, Canada
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Abstract
Transition metals are essential nutrients to virtually all forms of life, including bacterial pathogens. In Staphylococcus aureus, metal ions participate in diverse biochemical processes such as metabolism, DNA synthesis, regulation of virulence factors, and defense against oxidative stress. As an innate immune response to bacterial infection, vertebrate hosts sequester transition metals in a process that has been termed "nutritional immunity." To successfully infect vertebrates, S. aureus must overcome host sequestration of these critical nutrients. The objective of this review is to outline the current knowledge of staphylococcal metal ion acquisition systems, as well as to define the host mechanisms of nutritional immunity during staphylococcal infection.
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Affiliation(s)
- James E. Cassat
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Eric P. Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, 1161 21st Ave South, A-5102 MCN, Nashville, TN 37232-2363, USA
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Beasley FC, Cheung J, Heinrichs DE. Mutation of L-2,3-diaminopropionic acid synthase genes blocks staphyloferrin B synthesis in Staphylococcus aureus. BMC Microbiol 2011; 11:199. [PMID: 21906287 PMCID: PMC3179956 DOI: 10.1186/1471-2180-11-199] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 09/09/2011] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Staphylococcus aureus synthesizes two siderophores, staphyloferrin A and staphyloferrin B, that promote iron-restricted growth. Previous work on the biosynthesis of staphyloferrin B has focused on the role of the synthetase enzymes, encoded from within the sbnA-I operon, which build the siderophore from the precursor molecules citrate, alpha-ketoglutarate and L-2,3-diaminopropionic acid. However, no information yet exists on several other enzymes, expressed from the biosynthetic cluster, that are thought to be involved in the synthesis of the precursors (or synthetase substrates) themselves. RESULTS Using mutants carrying insertions in sbnA and sbnB, we show that these two genes are essential for the synthesis of staphyloferrin B, and that supplementation of the growth medium with L-2,3-diaminopropionic acid can bypass the block in staphyloferrin B synthesis displayed by the mutants. Several mechanisms are proposed for how the enzymes SbnA, with similarity to cysteine synthase enzymes, and SbnB, with similarity to amino acid dehydrogenases and ornithine cyclodeaminases, function together in the synthesis of this unusual nonproteinogenic amino acid L-2,3-diaminopropionic acid. CONCLUSIONS Mutation of either sbnA or sbnB result in abrogation of synthesis of staphyloferrin B, a siderophore that contributes to iron-restricted growth of S. aureus. The loss of staphyloferrin B synthesis is due to an inability to synthesize the unusual amino acid L-2,3-diaminopropionic acid which is an important, iron-liganding component of the siderophore structure. It is proposed that SbnA and SbnB function together as an L-Dap synthase in the S. aureus cell.
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Affiliation(s)
- Federico C Beasley
- Department of Microbiology & Immunology, University of Western Ontario, 1151 Richmond Street, London, Ontario, N6A 5C1, Canada
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Kreutzer MF, Kage H, Gebhardt P, Wackler B, Saluz HP, Hoffmeister D, Nett M. Biosynthesis of a complex yersiniabactin-like natural product via the mic locus in phytopathogen Ralstonia solanacearum. Appl Environ Microbiol 2011; 77:6117-24. [PMID: 21724891 DOI: 10.1128/AEM.05198-11] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
A genome mining study in the plant pathogenic bacterium Ralstonia solanacearum GMI1000 unveiled a polyketide synthase/nonribosomal peptide synthetase gene cluster putatively involved in siderophore biosynthesis. Insertional mutagenesis confirmed the respective locus to be operational under iron-deficient conditions and spurred the isolation of the associated natural product. Bioinformatic analyses of the gene cluster facilitated the structural characterization of this compound, which was subsequently identified as the antimycoplasma agent micacocidin. The metal-chelating properties of micacocidin were evaluated in competition experiments, and the cellular uptake of gallium-micacocidin complexes was demonstrated in R. solanacearum GMI1000, indicating a possible siderophore role. Comparative genomics revealed a conservation of the micacocidin gene cluster in defined, but globally dispersed phylotypes of R. solanacearum.
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Abstract
Many organisms use sophisticated systems to acquire growth-limiting iron. Iron limitation is especially apparent in bacterial pathogens of mammalian hosts where free iron concentrations are physiologically negligible. A common strategy is to secrete low molecular weight iron chelators, termed siderophores, and express high affinity receptors for the siderophore-iron complex. Staphylococcus aureus, a widespread pathogen, produces two siderophores, staphyloferrin A (SA) and staphyloferrin B (SB). We have determined the crystal structure of the staphyloferrin B receptor, SirA, at high resolution in both the apo and Fe(III)-SB (FeSB)-bound forms. SirA, a member of the class III binding protein family of metal receptors, has N- and C-terminal domains, each composed of mainly a β-stranded core and α-helical periphery. The domains are bridged by a single α-helix and together form the FeSB binding site. SB coordinates Fe(III) through five oxygen atoms and one nitrogen atom in distorted octahedral geometry. SirA undergoes conformational change upon siderophore binding, largely securing two loops from the C-terminal domain to enclose FeSB with a low nanomolar dissociation constant. The staphyloferrin A receptor, HtsA, homologous to SirA, also encloses its cognate siderophore (FeSA); however, the largest conformational rearrangements involve a different region of the C-terminal domain. FeSB is uniquely situated in the binding pocket of SirA with few of the contacting residues being conserved with those of HtsA interacting with FeSA. Although both SirA and HtsA bind siderophores from the same α-hydroxycarboxylate class, the unique structural features of each receptor provides an explanation for their distinct specificity.
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Affiliation(s)
- Jason C Grigg
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada and
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Grigg JC, Cooper JD, Cheung J, Heinrichs DE, Murphy MEP. The Staphylococcus aureus siderophore receptor HtsA undergoes localized conformational changes to enclose staphyloferrin A in an arginine-rich binding pocket. J Biol Chem 2010; 285:11162-71. [PMID: 20147287 DOI: 10.1074/jbc.m109.097865] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus uses several efficient iron acquisition strategies to overcome iron limitation. Recently, the genetic locus encoding biosynthetic enzymes for the iron chelating molecule, staphyloferrin A (SA), was determined. S. aureus synthesizes and secretes SA into its environment to scavenge iron. The membrane-anchored ATP binding cassette-binding protein, HtsA, receives the ferric-chelate for import into the cell. Recently, we determined the apoHtsA crystal structure, the first siderophore receptor from gram-positive bacteria to be structurally characterized. Herein we present the x-ray crystal structure of the HtsA-ferric-SA complex. HtsA adopts a class III binding protein fold composed of separate N- and C-terminal domains bridged by a single alpha-helix. Recombinant HtsA can efficiently sequester ferric-SA from S. aureus culture supernatants where it is bound within the pocket formed between distinct N- and C-terminal domains. A basic patch composed mainly of six Arg residues contact the negatively charged siderophore, securing it within the pocket. The x-ray crystal structures from two different ligand-bound crystal forms were determined. The structures represent the first structural characterization of an endogenous alpha-hydroxycarboxylate-type siderophore-receptor complex. One structure is in an open form similar to apoHtsA, whereas the other is in a more closed conformation. The conformational change is highlighted by isolated movement of three loops within the C-terminal domain, a domain movement unique to known class III binding protein structures.
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Affiliation(s)
- Jason C Grigg
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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Abstract
Siderophores are iron-scavenging molecules produced by many microbes. In general, they are synthesized using either non-ribosomal peptide synthetase (NRPS) or NRPS-independent siderophore (NIS) pathways. Staphylococcus aureus produces siderophores, of which the structures of staphyloferrin A and staphyloferrin B are known. Recently, the NIS biosynthetic pathway for staphyloferrin A was characterized. Here we show that, in S. aureus, the previously identified sbn (siderophore biosynthesis) locus encodes enzymes required for the synthesis of staphyloferrin B, an alpha-hydroxycarboxylate siderophore comprised of l-2,3-diaminopropionic acid, citric acid, 1,2-diaminoethane and alpha-ketoglutaric acid. Staphyloferrin B NIS biosynthesis was recapitulated in vitro, using purified recombinant Sbn enzymes and the component substrates. In vitro synthesized staphyloferrin B readily promoted the growth of iron-starved S. aureus, via the ABC transporter SirABC. The SbnCEF synthetases and a decarboxylase, SbnH, were necessary and sufficient to produce staphyloferrin B in reactions containing component substrates l-2,3-diaminopropionic acid, citric acid and alpha-ketoglutaric acid. Since 1,2-diaminoethane was not required, this component of the siderophore arises from the SbnH-dependent decarboxylation of a 2,3-diaminoproprionic acid-containing intermediate. Liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) analyses of a series of enzyme reactions identified mass ions corresponding to biosynthetic intermediates, allowing for the first proposed biosynthetic pathway for staphyloferrin B.
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Affiliation(s)
- Johnson Cheung
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada N6A 5C1
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Oves-Costales D, Kadi N, Challis GL. The long-overlooked enzymology of a nonribosomal peptide synthetase-independent pathway for virulence-conferring siderophore biosynthesis. Chem Commun (Camb) 2009:6530-41. [PMID: 19865642 DOI: 10.1039/b913092f] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Siderophores are high-affinity ferric iron chelators biosynthesised and excreted by most microorganisms that play an important role in iron acquisition. Siderophore-mediated scavenging of ferric iron from hosts contributes significantly to the virulence of pathogenic microbes. As a consequence siderophore biosynthesis is an attractive target for chemotherapeutic intervention. Two main pathways for siderophore biosynthesis exist in microbes. One pathway involves nonribosomal peptide synthetase (NRPS) multienzymes while the other is NRPS-independent. The enzymology of NRPS-mediated siderophore biosynthesis has been extensively studied for more than a decade. In contrast, the enzymology of NRPS-independent siderophore (NIS) biosynthesis was overlooked for almost thirty years since the first genetic characterisation of the NIS biosynthetic pathway to aerobactin. However, the past three years have witnessed an explosion of interest in the enzymology of NIS synthetases, the key enzymes in the assembly of siderophores via the NIS pathway. The biochemical characterisation of ten purified recombinant synthetases has been reported since 2007, along with the first structural characterisation of a synthetase by X-ray crystallography in 2009. In this feature article we summarise the recent progress that has been made in understanding the long-overlooked enzymology of NRPS-independent siderophore biosynthesis, highlight important remaining questions, and suggest likely directions for future research.
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Abstract
Pseudomonas syringae pv. syringae B728a is known to produce the siderophore pyoverdine under iron-limited conditions. It has also been proposed that this pathovar has the ability to produce a second siderophore, achromobactin. Here we present genetic and biochemical evidence supporting the hypothesis that P. syringae pv. syringae B728a produces both of these siderophores. We show that strains unable to synthesize either pyoverdine or achromobactin are unable to grow under iron-limiting conditions, which is consistent with these two molecules being the only siderophores synthesized by P. syringae pv. syringae B728a. Enzymes associated with achromobactin biosynthesis were purified and analyzed for substrate recognition. We showed that AcsD, AcsA, and AcsC together are able to condense citrate, ethanolamine, 2,4-diaminobutyrate, and alpha-ketoglutarate into achromobactin. Replacement of ethanolamine with ethylene diamine or 1,3-diaminopropane in these reactions resulted in the formation of achromobactin analogs that were biologically active. This work provides insights into the biosynthetic steps in the formation of achromobactin and is the first in vitro reconstitution of achromobactin biosynthesis.
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50
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Abstract
S. aureus has evolved a comprehensive strategy to address the challenges posed by the human immune system. The emergence of community-associated methicillin-resistant S. aureus (CA-MRSA) infections in individuals with no predisposing conditions suggests an increased pathogenicity of the bacterium, which may be related to acquisition of novel genetic elements. Remarkably, despite an abundance of research, the underlying cause of the epidemic is not known. Here, the various strategies used by S. aureus to evade obstacles laid out by the human host during colonization and infection were reviewed. The controversies surrounding MRSA research were described, and how acquisition of the novel genes could explain the increased incidence and severity of CA-MRSA diseases was described.
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Affiliation(s)
- George Y. Liu
- Division of Pediatric Infectious Diseases and the Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048; Department of Pediatrics, University of California, Los Angeles, CA 90025
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