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Chan JM, Ramos-Sevillano E, Betts M, Wilson HU, Weight CM, Houhou-Ousalah A, Pollara G, Brown JS, Heyderman RS. Bacterial surface lipoproteins mediate epithelial microinvasion by Streptococcus pneumoniae. Infect Immun 2024; 92:e0044723. [PMID: 38629841 DOI: 10.1128/iai.00447-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 03/27/2024] [Indexed: 05/08/2024] Open
Abstract
Streptococcus pneumoniae, a common colonizer of the upper respiratory tract, invades nasopharyngeal epithelial cells without causing disease in healthy participants of controlled human infection studies. We hypothesized that surface expression of pneumococcal lipoproteins, recognized by the innate immune receptor TLR2, mediates epithelial microinvasion. Mutation of lgt in serotype 4 (TIGR4) and serotype 6B (BHN418) pneumococcal strains abolishes the ability of the mutants to activate TLR2 signaling. Loss of lgt also led to the concomitant decrease in interferon signaling triggered by the bacterium. However, only BHN418 lgt::cm but not TIGR4 lgt::cm was significantly attenuated in epithelial adherence and microinvasion compared to their respective wild-type strains. To test the hypothesis that differential lipoprotein repertoires in TIGR4 and BHN418 lead to the intraspecies variation in epithelial microinvasion, we employed a motif-based genome analysis and identified an additional 525 a.a. lipoprotein (pneumococcal accessory lipoprotein A; palA) encoded by BHN418 that is absent in TIGR4. The gene encoding palA sits within a putative genetic island present in ~10% of global pneumococcal isolates. While palA was enriched in the carriage and otitis media pneumococcal strains, neither mutation nor overexpression of the gene encoding this lipoprotein significantly changed microinvasion patterns. In conclusion, mutation of lgt attenuates epithelial inflammatory responses during pneumococcal-epithelial interactions, with intraspecies variation in the effect on microinvasion. Differential lipoprotein repertoires encoded by the different strains do not explain these differences in microinvasion. Rather, we postulate that post-translational modifications of lipoproteins may account for the differences in microinvasion.IMPORTANCEStreptococcus pneumoniae (pneumococcus) is an important mucosal pathogen, estimated to cause over 500,000 deaths annually. Nasopharyngeal colonization is considered a necessary prerequisite for disease, yet many people are transiently and asymptomatically colonized by pneumococci without becoming unwell. It is therefore important to better understand how the colonization process is controlled at the epithelial surface. Controlled human infection studies revealed the presence of pneumococci within the epithelium of healthy volunteers (microinvasion). In this study, we focused on the regulation of epithelial microinvasion by pneumococcal lipoproteins. We found that pneumococcal lipoproteins induce epithelial inflammation but that differing lipoprotein repertoires do not significantly impact the magnitude of microinvasion. Targeting mucosal innate immunity and epithelial microinvasion alongside the induction of an adaptive immune response may be effective in preventing pneumococcal colonization and disease.
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Affiliation(s)
- Jia Mun Chan
- Research Department of Infection, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Elisa Ramos-Sevillano
- UCL Respiratory, Division of Medicine, University College London, London, United Kingdom
| | - Modupeh Betts
- Research Department of Infection, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Holly U Wilson
- Research Department of Infection, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Caroline M Weight
- Research Department of Infection, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Ambrine Houhou-Ousalah
- Research Department of Infection, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Gabriele Pollara
- Research Department of Infection, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Jeremy S Brown
- UCL Respiratory, Division of Medicine, University College London, London, United Kingdom
| | - Robert S Heyderman
- Research Department of Infection, Division of Infection and Immunity, University College London, London, United Kingdom
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2
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Ganio K, Nasreen M, Yang Z, Maunders EA, Luo Z, Hossain SI, Ngu DHY, Ellis D, Gu J, Neville SL, Wilksch J, Gunn AP, Whittall JJ, Kobe B, Deplazes E, Kappler U, McDevitt CA. Hfe Permease and Haemophilus influenzae Manganese Homeostasis. ACS Infect Dis 2024; 10:436-452. [PMID: 38240689 PMCID: PMC10863617 DOI: 10.1021/acsinfecdis.3c00407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 01/07/2024] [Accepted: 01/08/2024] [Indexed: 02/10/2024]
Abstract
Haemophilus influenzae is a commensal of the human upper respiratory tract that can infect diverse host niches due, at least in part, to its ability to withstand both endogenous and host-mediated oxidative stresses. Here, we show that hfeA, a gene previously linked to iron import, is essential for H. influenzae manganese recruitment via the HfeBCD transporter. Structural analyses show that metal binding in HfeA uses a unique mechanism that involves substantial rotation of the C-terminal lobe of the protein. Disruption of hfeA reduced H. influenzae manganese acquisition and was associated with decreased growth under aerobic conditions, impaired manganese-superoxide dismutase activity, reduced survival in macrophages, and changes in biofilm production in the presence of superoxide. Collectively, this work shows that HfeA contributes to H. influenzae manganese acquisition and virulence attributes. High conservation of the hfeABCD permease in Haemophilus species suggests that it may serve similar roles in other pathogenic Pasteurellaceae.
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Affiliation(s)
- Katherine Ganio
- Department
of Microbiology and Immunology, the Peter Doherty Institute for Infection
and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia
| | - Marufa Nasreen
- School
of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland 4072, Australia
- Australian
Infectious Diseases Research Centre, The
University of Queensland, St Lucia, Queensland 4072, Australia
| | - Zihao Yang
- School
of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland 4072, Australia
- Australian
Infectious Diseases Research Centre, The
University of Queensland, St Lucia, Queensland 4072, Australia
| | - Eve A. Maunders
- Department
of Microbiology and Immunology, the Peter Doherty Institute for Infection
and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia
| | - Zhenyao Luo
- School
of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland 4072, Australia
- Australian
Infectious Diseases Research Centre, The
University of Queensland, St Lucia, Queensland 4072, Australia
- Institute
for Molecular Bioscience, The University
of Queensland, St Lucia, Queensland 4072, Australia
| | - Sheikh Imamul Hossain
- School
of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland 4072, Australia
- School
of Life Sciences, University of Technology
Sydney, Ultimo, New South Wales 2007, Australia
| | - Dalton H. Y. Ngu
- School
of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland 4072, Australia
- Australian
Infectious Diseases Research Centre, The
University of Queensland, St Lucia, Queensland 4072, Australia
- Institute
for Molecular Bioscience, The University
of Queensland, St Lucia, Queensland 4072, Australia
| | - Daniel Ellis
- School
of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland 4072, Australia
- Australian
Infectious Diseases Research Centre, The
University of Queensland, St Lucia, Queensland 4072, Australia
| | - Jin Gu
- School
of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland 4072, Australia
- Australian
Infectious Diseases Research Centre, The
University of Queensland, St Lucia, Queensland 4072, Australia
| | - Stephanie L. Neville
- Department
of Microbiology and Immunology, the Peter Doherty Institute for Infection
and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia
| | - Jonathan Wilksch
- Department
of Microbiology and Immunology, the Peter Doherty Institute for Infection
and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia
| | - Adam P. Gunn
- Department
of Microbiology and Immunology, the Peter Doherty Institute for Infection
and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia
| | - Jonathan J. Whittall
- School of
Biological Sciences, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Boštjan Kobe
- School
of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland 4072, Australia
- Australian
Infectious Diseases Research Centre, The
University of Queensland, St Lucia, Queensland 4072, Australia
- Institute
for Molecular Bioscience, The University
of Queensland, St Lucia, Queensland 4072, Australia
| | - Evelyne Deplazes
- School
of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland 4072, Australia
- School
of Life Sciences, University of Technology
Sydney, Ultimo, New South Wales 2007, Australia
| | - Ulrike Kappler
- School
of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland 4072, Australia
- Australian
Infectious Diseases Research Centre, The
University of Queensland, St Lucia, Queensland 4072, Australia
| | - Christopher A. McDevitt
- Department
of Microbiology and Immunology, the Peter Doherty Institute for Infection
and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia
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3
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Garstka K, Bellotti D, Wątły J, Kozłowski H, Remelli M, Rowińska-Żyrek M. Metal coordination to solute binding proteins - exciting chemistry with potential biological meaning. Dalton Trans 2023; 52:16140-16150. [PMID: 37814857 DOI: 10.1039/d3dt02417b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
Zn(II) is essential for bacterial survival and virulence. In host cells, its abundance is extremely limited, thus, bacteria have evolved transport mechanisms that enable them to take up this essential metal nutrient. Paracoccus denitrificans encodes two solute binding proteins (SBPs) - ZnuA and AztC, which are responsible for zinc acquisition from the host cells. We focus on understanding the interactions of Zn(II) and Ni(II) (zinc's potential competitor, which is a biologically relevant metal ion essential for various bacterial enzymes) with the extracellular ZnuA and AztC's loops from P. denitrificans that are expected to be possible Zn(II) binding sites. In the case of Zn(II) complexes with ZnuA outercellular loop regions, the numerous histidines act as anchoring donors, forming complexes with up to four coordinated His residues, while in the AztC region, three imidazole nitrogens and one water molecule are involved in Zn(II) binding. In Zn(II) complexes with ZnuA His-rich loop regions, so-called polymorphic binding sites are observed. The large number of available imidazoles and carboxylic side chains also strongly affects the structure of Ni(II) complexes; the more histidines in the studied peptide, the higher the affinity to bind Ni(II) and the higher the pH value at which amide nitrogens start to participate in Ni(II) binding. Additionally, for Ni(II)-ZnuA complexes, a more rare octahedral geometry is observed and such complexes are more stable than the corresponding Zn(II) ones, in contrast to what was observed in the AztC region, suggesting that the numerous histidyl and glutamic acid side chains are more tempting for Ni(II) than for Zn(II).The general strong affinity of Zn(II)-zincophore complexes is also discussed.
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Affiliation(s)
- Kinga Garstka
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland.
| | - Denise Bellotti
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland.
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Joanna Wątły
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland.
| | - Henryk Kozłowski
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland.
- Institute of Health Sciences, University of Opole, Katowicka 68 St, 45-060 Opole, Poland
| | - Maurizio Remelli
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
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Peng M, Xu Y, Dou B, Yang F, He Q, Liu Z, Gao T, Liu W, Yang K, Guo R, Li C, Tian Y, Zhou D, Bei W, Yuan F. The adcA and lmb Genes Play an Important Role in Drug Resistance and Full Virulence of Streptococcus suis. Microbiol Spectr 2023; 11:e0433722. [PMID: 37212676 PMCID: PMC10269787 DOI: 10.1128/spectrum.04337-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/25/2023] [Indexed: 05/23/2023] Open
Abstract
Streptococcus suis is an recognized zoonotic pathogen of swine and severely threatens human health. Zinc is the second most abundant transition metal in biological systems. Here, we investigated the contribution of zinc to the drug resistance and pathogenesis of S. suis. We knocked out the genes of AdcACB and Lmb, two Zn-binding lipoproteins. Compared to the wild-type strain, we found that the survival rate of this double-mutant strain (ΔadcAΔlmb) was reduced in Zinc-limited medium, but not in Zinc-supplemented medium. Additionally, phenotypic experiments showed that the ΔadcAΔlmb strain displayed impaired adhesion to and invasion of cells, biofilm formation, and tolerance of cell envelope-targeting antibiotics. In a murine infection model, deletion of the adcA and lmb genes in S. suis resulted in a significant decrease in strain virulence, including survival rate, tissue bacterial load, inflammatory cytokine levels, and histopathological damage. These findings show that AdcA and Lmb are important for biofilm formation, drug resistance, and virulence in S. suis. IMPORTANCE Transition metals are important micronutrients for bacterial growth. Zn is necessary for the catalytic activity and structural integrity of various metalloproteins involved in bacterial pathogenic processes. However, how these invaders adapt to host-imposed metal starvation and overcome nutritional immunity remains unknown. Thus, pathogenic bacteria must acquire Zn during infection in order to successfully survive and multiply. The host uses nutritional immunity to limit the uptake of Zn by the invading bacteria. The bacterium uses a set of high-affinity Zn uptake systems to overcome this host metal restriction. Here, we identified two Zn uptake transporters in S. suis, AdcA and Lmb, by bioinformatics analysis and found that an adcA and lmb double-mutant strain could not grow in Zn-deficient medium and was more sensitive to cell envelope-targeting antibiotics. It is worth noting that the Zn uptake system is essential for biofilm formation, drug resistance, and virulence in S. suis. The Zn uptake system is expected to be a target for the development of novel antimicrobial therapies.
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Affiliation(s)
- Mingzheng Peng
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Yuanyuan Xu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Beibei Dou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Fengming Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Qiyun He
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Zewen Liu
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Ting Gao
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Wei Liu
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Keli Yang
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Rui Guo
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Chang Li
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Yongxiang Tian
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Danna Zhou
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Weicheng Bei
- Hubei Hongshan Laboratory, Wuhan, China
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- Guangxi Yangxiang Co. Ltd., Guangxi, China
| | - Fangyan Yuan
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
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5
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Binuclear Cu(II), Ni(II) and Zn(II) Complexes of Hydrazone Schiff Bases: Synthesis, Spectroscopy, DFT Calculations, and SOD Mimetic Activity. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2023.134926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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6
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Payen S, Rrodriguez JA, Segura M, Gottschalk M. Laminin-binding protein of Streptococcus suis serotype 2 influences zinc acquisition and cytokine responses. Vet Res 2023; 54:1. [PMID: 36604750 PMCID: PMC9817373 DOI: 10.1186/s13567-022-01128-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 11/08/2022] [Indexed: 01/07/2023] Open
Abstract
Streptococcus suis serotype 2 is an important bacterial pathogen of swine, responsible for substantial economic losses to the swine industry worldwide. The knowledge on the pathogenesis of the infection caused by S. suis is still poorly known. It has been previously described that S. suis possesses at least one lipoprotein with double laminin and zinc (Zn)-binding properties, which was described in the literature as either laminin-binding protein (Lmb, as in the current study), lipoprotein 103, CDS 0330 or AdcAII. In the present study, the role of the Lmb in the pathogenesis of the infection caused by S. suis serotype 2 was dissected. Using isogenic mutants, results showed that Lmb does not play an important role in the laminin-binding activity of S. suis, even when clearly exposed at the bacterial surface. In addition, the presence of this lipoprotein does not influence bacterial adhesion to and invasion of porcine respiratory epithelial and brain endothelial cells and it does not increase the susceptibility of S. suis to phagocytosis. On the other hand, the Lmb was shown to play an important role as cytokine activator when tested in vitro with dendritic cells. Finally, this lipoprotein plays a critical role in Zn acquisition from the host environment allowing bacteria to grow in vivo. The significant lower virulence of the Lmb defective mutant may be related to a combination of a lower bacterial survival due to the incapacity to acquire Zn from their surrounding milieu and a reduced cytokine activation.
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Affiliation(s)
- Servane Payen
- grid.14848.310000 0001 2292 3357Research Group On Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC J2S 2M2 Canada
| | - Jesús Aranda Rrodriguez
- grid.7080.f0000 0001 2296 0625Department de Genètica I Microbiologia, Universitat Autónoma de Barcelona (UAB), Bellaterra (Cerdanyola del Vallès), 08193 Barcelona, Spain
| | - Mariela Segura
- grid.14848.310000 0001 2292 3357Research Group On Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC J2S 2M2 Canada
| | - Marcelo Gottschalk
- grid.14848.310000 0001 2292 3357Research Group On Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC J2S 2M2 Canada
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7
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Zheng C, Qiu J, Zhao X, Yu S, Wang H, Wan M, Wei M, Jiao X. The AdcR-regulated AdcA and AdcAII contribute additively to zinc acquisition and virulence in Streptococcus suis. Vet Microbiol 2022; 269:109418. [PMID: 35430524 DOI: 10.1016/j.vetmic.2022.109418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 02/10/2022] [Accepted: 04/01/2022] [Indexed: 12/25/2022]
Abstract
Metals are necessary elements for bacteria. Typically, vertebrate hosts restrict invading bacterial pathogens from accessing metals. Therefore, bacteria have evolved high-affinity metal importers to acquire metals. Streptococcus suis is a major swine pathogen and an emerging zoonotic agent that endangers the swine industry and human health worldwide. Herein, we aimed to identify the zinc acquisition systems in S. suis and evaluate their roles in bacterial virulence. Bioinformatic analyses revealed that S. suis encodes homologues of AdcA and AdcAII, two well-characterised Zn-binding lipoproteins in certain streptococci. Quantitative reverse transcription PCR (qRT-PCR) analysis revealed that the expressions of adcA and adcAII were significantly upregulated in response to Zn limitation, with a higher expression level of adcAII than adcA. Gene deletion mutants and complementation strains were constructed; their growth characteristics under Zn-deficient and Zn-replete conditions indicated that AdcA and AdcAII have overlapping functionality in Zn acquisition. A mouse infection model was used to evaluate the roles of AdcA and AdcAII in S. suis virulence. Mice infected with the double mutant ΔadcAΔadcAII exhibited a significantly higher survival rate, decreased bacterial burden, and lower production of inflammatory cytokines compared to those infected with the wild type (WT) strain. Furthermore, ΔadcAΔadcAII showed reduced competitiveness in infection establishment compared with the WT strain. RNA sequencing, qRT-PCR, and electrophoretic mobility shift assays revealed that AdcR negatively regulates the expressions of adcA and adcAII. Collectively, our results demonstrated that AdcA and AdcAII, which are negatively regulated by AdcR, contribute additively to zinc acquisition and virulence in S. suis.
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Affiliation(s)
- Chengkun Zheng
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Jun Qiu
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Xiaoxian Zhao
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Sijia Yu
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Hong Wang
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Mengyan Wan
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Man Wei
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Xinan Jiao
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China.
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8
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Goel A, Tomer N, Bhalla P, Malhotra R. Pyranone based probe for the selective and specific recognition of zinc ions. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2022.120828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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9
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Yekwa EL, Serrano FA, Yukl E. Conformational flexibility in the zinc solute-binding protein ZnuA. Acta Crystallogr F Struct Biol Commun 2022; 78:128-134. [PMID: 35234138 PMCID: PMC8900738 DOI: 10.1107/s2053230x22001662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/10/2022] [Indexed: 11/10/2022] Open
Abstract
Zinc is an essential metal for all kingdoms of life, making its transport across the cell membrane a critical function. In bacteria, high-affinity zinc import is accomplished by ATP-binding cassette (ABC) transporters, which rely on extracellular solute-binding proteins (SBPs) of cluster A-I to acquire the metal and deliver it to the membrane permease. These systems are important for survival and virulence, making them attractive targets for the development of novel antibiotics. Citrobacter koseri is an emerging pathogen with extensive antibiotic resistance. High-affinity zinc binding to the C. koseri cluster A-I SBP ZnuA has been characterized and the structure of the zinc-bound (holo) form has been determined by X-ray crystallography. Remarkably, despite 95% sequence identity to the ZnuA homologue from Salmonella enterica, C. koseri ZnuA exhibits a different zinc-coordination environment and a closed rather than an open conformation. Comparison with structures of another close ZnuA homologue from Escherichia coli suggests a surprisingly flexible conformational landscape that may be important for efficient zinc binding and/or delivery to the membrane permease.
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10
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Structural and biochemical characterization of Acinetobacter baumannii ZnuA. J Inorg Biochem 2022; 231:111787. [DOI: 10.1016/j.jinorgbio.2022.111787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/27/2022] [Accepted: 03/06/2022] [Indexed: 11/19/2022]
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11
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He L, Wang L, Zhao L, Zhuang Z, Wang X, Huang H, Fu Q, Huang L, Qin Y, Wang P, Yan Q. Integration of RNA-seq and RNAi reveals the contribution of znuA gene to the pathogenicity of Pseudomonas plecoglossicida and to the immune response of Epinephelus coioides. JOURNAL OF FISH DISEASES 2021; 44:1831-1841. [PMID: 34339054 DOI: 10.1111/jfd.13502] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/21/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
Pseudomonas plecoglossicida is an important pathogen in aquaculture and causes serious economic losses. Our previous study indicated that znuA gene might play an important role in the pathogenicity of P. plecoglossicida. Five shRNAs were designed and synthesized to silence the znuA gene of P. plecoglossicida. Two of the five mutants of P. plecoglossicida exhibited significant reduction in the expression level of znuA mRNA with different efficiencies. The mutant with the highest silencing efficiency of 89.2% was chosen for further studies. Intrapleural injection of the znuA-RNAi strain at a dose of 105 cfu/fish did not cause the death of Epinephelus coioides, and no significant signs were observed at the spleen surface of infected E. coioides, while the counterpart E. coioides infected by the same dose of wild-type strain of P. plecoglossicida all died in 5 days post-infection (dpi). The expression of znuA gene of znuA-RNAi strain in E. coioides was always lower than that in wild-type strain of P. plecoglossicida. The pathogen load in the early stage of infection was higher than that in the later stage of infection. Although the infection of the znuA-RNAi strain of P. plecoglossicida could induce the production of antibodies in E. coioides, it failed to produce a good immune protection against the infection of wild-type strain of P. plecoglossicida. Compared with the transcriptome data of E. coioides infected by the wild-type strain of P. plecoglossicida, the transcriptome data of E. coioides infected by the znuA-RNAi strain of P. plecoglossicida have altered significantly. Among them, KEGG enrichment analysis showed that the focal adhesion pathway was significantly enriched and exhibited the largest number of 302 DEMs (differentially expressed mRNAs). These results showed that the immune response of E. coioides to P. plecoglossicida infection was significantly affected by the RNAi of znuA gene.
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Affiliation(s)
- Le He
- Fisheries College, Jimei University, Xiamen, China
| | - Luying Wang
- Fisheries College, Jimei University, Xiamen, China
| | - Lingmin Zhao
- Fisheries College, Jimei University, Xiamen, China
| | - Zhixia Zhuang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, China
| | - Xiaoru Wang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, China
| | - Huabin Huang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, China
| | - Qi Fu
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, China
| | - Lixing Huang
- Fisheries College, Jimei University, Xiamen, China
| | - Yingxue Qin
- Fisheries College, Jimei University, Xiamen, China
| | - Pan Wang
- Key Laboratory of Aquatic Functional Feed and Environmental Regulation of Fujian Province, Fujian Dabeinong Aquatic Sci. & Tech. Co., Ltd., Zhangzhou, China
| | - Qingpi Yan
- Fisheries College, Jimei University, Xiamen, China
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12
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Župan ML, Luo Z, Ganio K, Pederick VG, Neville SL, Deplazes E, Kobe B, McDevitt CA. Conformation of the Solute-Binding Protein AdcAII Influences Zinc Uptake in Streptococcus pneumoniae. Front Cell Infect Microbiol 2021; 11:729981. [PMID: 34490149 PMCID: PMC8416893 DOI: 10.3389/fcimb.2021.729981] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 07/27/2021] [Indexed: 01/13/2023] Open
Abstract
Streptococcus pneumoniae scavenges essential zinc ions from the host during colonization and infection. This is achieved by the ATP-binding cassette transporter, AdcCB, and two solute-binding proteins (SBPs), AdcA and AdcAII. It has been established that AdcAII serves a greater role during initial infection, but the molecular details of how the protein selectively acquires Zn(II) remain poorly understood. This can be attributed to the refractory nature of metal-free AdcAII to high-resolution structural determination techniques. Here, we overcome this issue by separately mutating the Zn(II)-coordinating residues and performing a combination of structural and biochemical analyses on the variant proteins. Structural analyses of Zn(II)-bound AdcAII variants revealed that specific regions within the protein underwent conformational changes via direct coupling to each of the metal-binding residues. Quantitative in vitro metal-binding assays combined with affinity determination and phenotypic growth assays revealed that each of the four Zn(II)-coordinating residues contributes to metal binding by AdcAII. Intriguingly, the phenotypic growth impact of the mutant adcAII alleles was, in general, independent of affinity, suggesting that the Zn(II)-bound conformation of the SBP is crucial for efficacious metal uptake. Collectively, these data highlight the intimate coupling of ligand affinity with protein conformational change in ligand-receptor proteins and provide a putative mechanism for AdcAII. These findings provide further mechanistic insight into the structural and functional diversity of SBPs that is broadly applicable to other prokaryotes.
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Affiliation(s)
- Marina L Župan
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| | - Zhenyao Luo
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia.,Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Katherine Ganio
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| | - Victoria G Pederick
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - Stephanie L Neville
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| | - Evelyne Deplazes
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW, Australia.,School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, WA, Australia
| | - Boštjan Kobe
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia.,Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Christopher A McDevitt
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
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13
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Selective and Sensitive Discrimination of Zinc and Cadmium Based on a Novel Fluorescent Porous Organic Polymer. JOURNAL OF ANALYSIS AND TESTING 2021. [DOI: 10.1007/s41664-021-00193-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Pan Y, Chen Y, Chen J, Ma Q, Gong T, Yu S, Zhang Q, Zou J, Li Y. The Adc regulon mediates zinc homeostasis in Streptococcus mutans. Mol Oral Microbiol 2021; 36:278-290. [PMID: 34351080 DOI: 10.1111/omi.12350] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/22/2021] [Accepted: 07/28/2021] [Indexed: 02/05/2023]
Abstract
Zinc (Zn2+ ) is an essential divalent trace metal for living cells. Intracellular zinc homeostasis is critical to the survival and virulence of bacteria. Thus, the frequent fluctuations of salivary zinc, caused by the low physiological level and the frequent exogenous zinc introduction, present a serious challenge for bacteria colonizing the oral cavity. However, the regulation strategies to keep intracellular Zn2+ homeostasis in Streptococcus mutans, an important causative pathogen of dental caries, are unknown. Because zinc uptake is primarily mediated by an ATP-binding ABC transporter AdcABC in Streptococcus strains, we examined the function of AdcABC and transcription factor AdcR in S. mutans in this study. The results demonstrated that deletion of either adcA or adcCB gene impaired the growth but enhanced the extracellular polymeric matrix production in S. mutans, both of which could be relieved after excessive Zn2+ supplementation. Using RNA sequencing analysis, quantitative reverse transcription polymerase chain reaction examination, LacZ-reporter studies, and electrophoretic mobility shift assay, we showed that a MarR (multiple antibiotic resistance regulator) family transcription factor, AdcR, negatively regulates the expression of the genes adcR, adcC, adcB, and adcA by acting on the adcRCB and adcA promoters in response to Zn2+ concentration in their environmental niches. The deletion of adcR increases the sensitivity of S. mutans to excessive Zn2+ supply. Taken together, our findings suggest that Adc regulon, which consists of a Zn2+ uptake transporter AdcCBA and a Zn2+ -responsive repressor AdcR, plays a prominent role in the maintenance of intracellular zinc homeostasis of S. mutans.
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Affiliation(s)
- Yangyang Pan
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Pediatric Dentistry, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, China
| | - Yang Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jiamin Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Qizhao Ma
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Tao Gong
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Shuxing Yu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Qiong Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jing Zou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yuqing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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15
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Potential factors involved in the early pathogenesis of Streptococcus uberis mastitis: a review. Folia Microbiol (Praha) 2021; 66:509-523. [PMID: 34085166 DOI: 10.1007/s12223-021-00879-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 05/24/2021] [Indexed: 10/21/2022]
Abstract
Bovine mastitis is an inflammation of the mammary gland, which could be the result of allergy, physical trauma, or invasion by pathogens as Streptococcus uberis. This pathogen is an environmental pathogen associated with subclinical and clinical intramammary infection (IMI) in both lactating and non-lactating cows, which can persist in the udder and cause a chronic infection in the mammary gland. In spite of the important economic losses and increased prevalence caused by S. uberis mastitis, virulence factors involved in bacterial colonization of mammary glands and the pathogenic mechanisms are not yet clear. In the last 30 years, several studies have defined adherence and internalization of S. uberis as the early stages in IMI. S. uberis adheres to and invades into mammary gland cells, and this ability has been observed in in vitro assays. Until now, these abilities have not been determined in vivo challenges since they have been difficult to study. Bacterial surface proteins are able to bind to extracellular matrix protein components such as fibronectin, collagen and laminin, as well as proteins in milk. These proteins play a role in adhesion to host cells and have been denominated microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). This article aims to summarize our current knowledge on the most relevant properties of the potential factors involved in the early pathogenesis of S. uberis mastitis.
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16
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Ganguly T, Peterson AM, Kajfasz JK, Abranches J, Lemos JA. Zinc import mediated by AdcABC is critical for colonization of the dental biofilm by Streptococcus mutans in an animal model. Mol Oral Microbiol 2021; 36:214-224. [PMID: 33819383 PMCID: PMC9178666 DOI: 10.1111/omi.12337] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/29/2021] [Accepted: 04/01/2021] [Indexed: 12/18/2022]
Abstract
Trace metals are essential to all domains of life but toxic when found at high concentrations. Although the importance of iron in host-pathogen interactions is firmly established, contemporary studies indicate that other trace metals, including manganese and zinc, are also critical to the infectious process. In this study, we sought to identify and characterize the zinc uptake system(s) of Streptococcus mutans, a keystone pathogen in dental caries and a causative agent of bacterial endocarditis. Different than other pathogenic bacteria, including several streptococci, that encode multiple zinc import systems, bioinformatic analysis indicated that the S. mutans core genome encodes a single, highly conserved, zinc importer commonly known as AdcABC. Inactivation of the genes coding for the metal-binding AdcA (ΔadcA) or both AdcC ATPase and AdcB permease (ΔadcCB) severely impaired the ability of S. mutans to grow under zinc-depleted conditions. Intracellular metal quantifications revealed that both mutants accumulated less zinc when grown in the presence of a subinhibitory concentration of a zinc-specific chelator. Notably, the ΔadcCB strain displayed a severe colonization defect in a rat oral infection model. Both Δadc strains were hypersensitive to high concentrations of manganese, showed reduced peroxide tolerance, and formed less biofilm in sucrose-containing media when cultivated in the presence of the lowest amount of zinc that support their growth, but not when zinc was supplied in excess. Collectively, this study identifies AdcABC as the major high affinity zinc importer of S. mutans and provides preliminary evidence that zinc is a growth-limiting factor within the dental biofilm.
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Affiliation(s)
- Tridib Ganguly
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Alexandra M. Peterson
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Jessica K. Kajfasz
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Jacqueline Abranches
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - José A. Lemos
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
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17
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Abstract
Zinc is an essential nutrient for the virulence of bacterial pathogens such as Streptococcus pneumoniae. Many Gram-positive bacteria use a two-domain lipoprotein for zinc acquisition, but how this class of metal-recruiting proteins acquire zinc and interact with the uptake machinery has remained poorly defined. Zinc is an essential element in all domains of life. Nonetheless, how prokaryotes achieve selective acquisition of zinc from the extracellular environment remains poorly understood. Here, we elucidate a novel mechanism for zinc-binding in AdcA, a solute-binding protein of Streptococcus pneumoniae. Crystal structure analyses reveal the two-domain organization of the protein and show that only the N-terminal domain (AdcAN) is necessary for zinc import. Zinc binding induces only minor changes in the global protein conformation of AdcA and stabilizes a highly mobile loop within the AdcAN domain. This loop region, which is conserved in zinc-specific solute-binding proteins, facilitates closure of the AdcAN binding site and is crucial for zinc acquisition. Collectively, these findings elucidate the structural and functional basis of selective zinc uptake in prokaryotes.
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18
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Specificity of Interactions between Components of Two Zinc ABC Transporters in Paracoccus denitrificans. Int J Mol Sci 2020; 21:ijms21239098. [PMID: 33265916 PMCID: PMC7731109 DOI: 10.3390/ijms21239098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 11/24/2022] Open
Abstract
Bacterial ATP binding cassette (ABC) transporters mediate the influx of numerous substrates. The cluster A-I ABC transporters are responsible for the specific uptake of the essential metals zinc, manganese or iron, making them necessary for survival in metal-limited environments, which for pathogens include the animal host. In Paracoccus denitrificans, there are two zinc ABC transporter systems: ZnuABC and AztABCD with apparently redundant functions under zinc-limited conditions. The unusual presence of two zinc ABC transporter systems in the same organism allowed for the investigation of specificity in the interaction between the solute binding protein (SBP) and its cognate permease. We also assessed the role of flexible loop features in the SBP in permease binding and zinc transport. The results indicate that the SBP–permease interaction is highly specific and does not require the flexible loop features of the SBP. We also present an expanded table of the properties of characterized cluster A-I SBPs and a multiple sequence alignment highlighting the conserved features. Through this analysis, an apparently new family of binding proteins associated with ABC transporters was identified. The presence of homologues in several human pathogens raises the possibility of using it as a target for the development of new antimicrobial therapies.
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19
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Meni A, Yukl ET. Structural Features Mediating Zinc Binding and Transfer in the AztABCD Zinc Transporter System. Biomolecules 2020; 10:biom10081156. [PMID: 32781785 PMCID: PMC7463823 DOI: 10.3390/biom10081156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 12/27/2022] Open
Abstract
Many bacteria require ATP binding cassette (ABC) transporters for the import of the essential metal zinc from limited environments. These systems rely on a periplasmic or cell-surface solute binding protein (SBP) to bind zinc with high affinity and specificity. AztABCD is one such zinc transport system recently identified in a large group of diverse bacterial species. In addition to a classical SBP (AztC), the operon also includes a periplasmic metallochaperone (AztD) shown to transfer zinc directly to AztC. Crystal structures of both proteins from Paracoccus denitrificans have been solved and suggest several structural features on each that may be important for zinc binding and transfer. Here we determine zinc binding affinity, dissociation kinetics, and transfer kinetics for several deletion mutants as well as a crystal structure for one of them. The results indicate specific roles for loop structures on AztC and an N-terminal motif on AztD in zinc binding and transfer. These data are consistent with a structural transfer model proposed previously and provide further mechanistic insight into the processes of zinc binding and transfer.
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20
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Durmort C, Ercoli G, Ramos-Sevillano E, Chimalapati S, Haigh RD, De Ste Croix M, Gould K, Hinds J, Guerardel Y, Vernet T, Oggioni M, Brown JS. Deletion of the Zinc Transporter Lipoprotein AdcAII Causes Hyperencapsulation of Streptococcus pneumoniae Associated with Distinct Alleles of the Type I Restriction-Modification System. mBio 2020; 11:e00445-20. [PMID: 32234814 PMCID: PMC7157770 DOI: 10.1128/mbio.00445-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 03/03/2020] [Indexed: 12/18/2022] Open
Abstract
The capsule is the dominant Streptococcus pneumoniae virulence factor, yet how variation in capsule thickness is regulated is poorly understood. Here, we describe an unexpected relationship between mutation of adcAII, which encodes a zinc uptake lipoprotein, and capsule thickness. Partial deletion of adcAII in three of five capsular serotypes frequently resulted in a mucoid phenotype that biochemical analysis and electron microscopy of the D39 adcAII mutants confirmed was caused by markedly increased capsule thickness. Compared to D39, the hyperencapsulated ΔadcAII mutant strain was more resistant to complement-mediated neutrophil killing and was hypervirulent in mouse models of invasive infection. Transcriptome analysis of D39 and the ΔadcAII mutant identified major differences in transcription of the Sp_0505-0508 locus, which encodes an SpnD39III (ST5556II) type I restriction-modification system and allelic variation of which correlates with capsule thickness. A PCR assay demonstrated close linkage of the SpnD39IIIC and F alleles with the hyperencapsulated ΔadcAII strains. However, transformation of ΔadcAII with fixed SpnD39III alleles associated with normal capsule thickness did not revert the hyperencapsulated phenotype. Half of hyperencapsulated ΔadcAII strains contained the same single nucleotide polymorphism in the capsule locus gene cps2E, which is required for the initiation of capsule synthesis. These results provide further evidence for the importance of the SpnD39III (ST5556II) type I restriction-modification system for modulating capsule thickness and identified an unexpected linkage between capsule thickness and mutation of ΔadcAII Further investigation will be needed to characterize how mutation of adcAII affects SpnD39III (ST5556II) allele dominance and results in the hyperencapsulated phenotype.IMPORTANCE The Streptococcus pneumoniae capsule affects multiple interactions with the host including contributing to colonization and immune evasion. During infection, the capsule thickness varies, but the mechanisms regulating this are poorly understood. We have identified an unsuspected relationship between mutation of adcAII, a gene that encodes a zinc uptake lipoprotein, and capsule thickness. Mutation of adcAII resulted in a striking hyperencapsulated phenotype, increased resistance to complement-mediated neutrophil killing, and increased S. pneumoniae virulence in mouse models of infection. Transcriptome and PCR analysis linked the hyperencapsulated phenotype of the ΔadcAII strain to specific alleles of the SpnD39III (ST5556II) type I restriction-modification system, a system which has previously been shown to affect capsule thickness. Our data provide further evidence for the importance of the SpnD39III (ST5556II) type I restriction-modification system for modulating capsule thickness and identify an unexpected link between capsule thickness and ΔadcAII, further investigation of which could further characterize mechanisms of capsule regulation.
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Affiliation(s)
- Claire Durmort
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Giuseppe Ercoli
- Centre for Inflammation and Tissue Repair, Department of Medicine, Royal Free and University College Medical School, Rayne Institute, London, United Kingdom
| | - Elisa Ramos-Sevillano
- Centre for Inflammation and Tissue Repair, Department of Medicine, Royal Free and University College Medical School, Rayne Institute, London, United Kingdom
| | - Suneeta Chimalapati
- Centre for Inflammation and Tissue Repair, Department of Medicine, Royal Free and University College Medical School, Rayne Institute, London, United Kingdom
| | - Richard D Haigh
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Megan De Ste Croix
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Katherine Gould
- Institute for Infection and Immunity, St. George's University of London, London, United Kingdom
| | - Jason Hinds
- Institute for Infection and Immunity, St. George's University of London, London, United Kingdom
| | - Yann Guerardel
- Univ. Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Thierry Vernet
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Marco Oggioni
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Jeremy S Brown
- Centre for Inflammation and Tissue Repair, Department of Medicine, Royal Free and University College Medical School, Rayne Institute, London, United Kingdom
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21
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Structure and Metal Binding Properties of Chlamydia trachomatis YtgA. J Bacteriol 2019; 202:JB.00580-19. [PMID: 31611288 DOI: 10.1128/jb.00580-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 10/08/2019] [Indexed: 12/17/2022] Open
Abstract
The obligate intracellular pathogen Chlamydia trachomatis is a globally significant cause of sexually transmitted bacterial infections and the leading etiological agent of preventable blindness. The first-row transition metal iron (Fe) plays critical roles in chlamydial cell biology, and acquisition of this nutrient is essential for the survival and virulence of the pathogen. Nevertheless, how C. trachomatis acquires Fe from host cells is not well understood, since it lacks genes encoding known siderophore biosynthetic pathways, receptors for host Fe storage proteins, and the Fe acquisition machinery common to many bacteria. Recent studies have suggested that C. trachomatis directly acquires host Fe via the ATP-binding cassette permease YtgABCD. Here, we characterized YtgA, the periplasmic solute binding protein component of the transport pathway, which has been implicated in scavenging Fe(III) ions. The structure of Fe(III)-bound YtgA was determined at 2.0-Å resolution with the bound ion coordinated via a novel geometry (3 Ns, 2 Os [3N2O]). This unusual coordination suggested a highly plastic metal binding site in YtgA capable of interacting with other cations. Biochemical analyses showed that the metal binding site of YtgA was not restricted to interaction with only Fe(III) ions but could bind all transition metal ions examined. However, only Mn(II), Fe(II), and Ni(II) ions bound reversibly to YtgA, with Fe being the most abundant cellular transition metal in C. trachomatis Collectively, these findings show that YtgA is the metal-recruiting component of the YtgABCD permease and is most likely involved in the acquisition of Fe(II) and Mn(II) from host cells.IMPORTANCE Chlamydia trachomatis is the most common bacterial sexually transmitted infection in developed countries, with an estimated global prevalence of 4.2% in the 15- to 49-year age group. Although infection is asymptomatic in more than 80% of infected women, about 10% of cases result in serious disease. Infection by C. trachomatis is dependent on the ability to acquire essential nutrients, such as the transition metal iron, from host cells. In this study, we show that iron is the most abundant transition metal in C. trachomatis and report the structural and biochemical properties of the iron-recruiting protein YtgA. Knowledge of the high-resolution structure of YtgA will provide a platform for future structure-based antimicrobial design approaches.
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22
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Eijkelkamp BA, Morey JR, Neville SL, Tan A, Pederick VG, Cole N, Singh PP, Ong CLY, Gonzalez de Vega R, Clases D, Cunningham BA, Hughes CE, Comerford I, Brazel EB, Whittall JJ, Plumptre CD, McColl SR, Paton JC, McEwan AG, Doble PA, McDevitt CA. Dietary zinc and the control of Streptococcus pneumoniae infection. PLoS Pathog 2019; 15:e1007957. [PMID: 31437249 PMCID: PMC6705770 DOI: 10.1371/journal.ppat.1007957] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 07/03/2019] [Indexed: 12/21/2022] Open
Abstract
Human zinc deficiency increases susceptibility to bacterial infection. Although zinc supplementation therapies can reduce the impact of disease, the molecular basis for protection remains unclear. Streptococcus pneumoniae is a major cause of bacterial pneumonia, which is prevalent in regions of zinc deficiency. We report that dietary zinc levels dictate the outcome of S. pneumoniae infection in a murine model. Dietary zinc restriction impacts murine tissue zinc levels with distribution post-infection altered, and S. pneumoniae virulence and infection enhanced. Although the activation and infiltration of murine phagocytic cells was not affected by zinc restriction, their efficacy of bacterial control was compromised. S. pneumoniae was shown to be highly sensitive to zinc intoxication, with this process impaired in zinc restricted mice and isolated phagocytic cells. Collectively, these data show how dietary zinc deficiency increases sensitivity to S. pneumoniae infection while revealing a role for zinc as a component of host antimicrobial defences. Zinc deficiency affects one-third of the world’s population and is associated with an increased susceptibility to bacterial infection. Despite this, the molecular basis for how zinc deficiency compromises host control of infection remains to be understood. We show that dietary zinc deficiency impacts host tissue zinc abundances and its mobilization during infection by the major respiratory pathogen Streptococcus pneumoniae. Zinc acts as a direct antimicrobial against the pathogen, mobilized by phagocytic cells as a component of the innate immune response. Although immune activation and infiltration of phagocytic cells is unaffected by host zinc status, the lack of antimicrobial zinc compromises bacterial control in zinc deficient hosts. These findings highlight the importance of zinc sufficiency in resisting bacterial infection.
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Affiliation(s)
- Bart A Eijkelkamp
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Jacqueline R Morey
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Stephanie L Neville
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, Australia.,Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Aimee Tan
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Victoria G Pederick
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Nerida Cole
- The Atomic Medicine Initiative, University of Technology, Broadway, Sydney, New South Wales, Australia.,ARC Training Centre in Biodevices, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Victoria, Australia
| | - Prashina P Singh
- The Atomic Medicine Initiative, University of Technology, Broadway, Sydney, New South Wales, Australia
| | - Cheryl-Lynn Y Ong
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Raquel Gonzalez de Vega
- The Atomic Medicine Initiative, University of Technology, Broadway, Sydney, New South Wales, Australia
| | - David Clases
- The Atomic Medicine Initiative, University of Technology, Broadway, Sydney, New South Wales, Australia
| | - Bliss A Cunningham
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Catherine E Hughes
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Iain Comerford
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Erin B Brazel
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Jonathan J Whittall
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Charles D Plumptre
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Shaun R McColl
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - James C Paton
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Alastair G McEwan
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Philip A Doble
- The Atomic Medicine Initiative, University of Technology, Broadway, Sydney, New South Wales, Australia
| | - Christopher A McDevitt
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, Australia.,Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
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23
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Kandari D, Gopalani M, Gupta M, Joshi H, Bhatnagar S, Bhatnagar R. Identification, Functional Characterization, and Regulon Prediction of the Zinc Uptake Regulator ( zur) of Bacillus anthracis - An Insight Into the Zinc Homeostasis of the Pathogen. Front Microbiol 2019; 9:3314. [PMID: 30687290 PMCID: PMC6336718 DOI: 10.3389/fmicb.2018.03314] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 12/19/2018] [Indexed: 11/29/2022] Open
Abstract
Zinc has an abounding occurrence in the prokaryotes and plays paramount roles including catalytic, structural, and regulatory. Zinc uptake regulator (Zur), a Fur family transcriptional regulator, is connoted in maintaining zinc homeostasis in the pathogenic bacteria by binding to zinc and regulating the genes involved in zinc uptake and mobilization. Zinc homeostasis has been marginally scrutinized in Bacillus anthracis, the top-rated bio-terror agent, with no decipherment of the role of Zur. Of the three Fur family regulators in B. anthracis, BAS4181 is annotated as a zinc-specific transcriptional regulator. This annotation was further substantiated by our stringent computational and experimental analyses. The residues critical for zinc and DNA binding were delineated by homology modeling and sequence/structure analysis. ba zur existed as a part of a three-gene operon. Purified BaZur prodigiously existed in the dimeric form, indicated by size exclusion chromatography and blue native-polyacrylamide gel electrophoresis (PAGE). Computational and manual strategies were employed to decipher the putative regulon of ba zur, comprising of 11 genes, controlled by six promoters, each harboring at least one Zur box. The DNA binding capability of the purified BaZur to the upstream regions of the ba zur operon, yciC, rpmG, znuA, and genes encoding a GTPase cobalamine synthesis protein and a permease was ascertained by electrophoretic mobility shift assays. The regulon genes, implicated in zinc uptake and mobilization, were mostly negatively regulated by BaZur. The ba zur expression was downregulated upon exposure of cells to an excess of zinc. Conversely, it exhibited a marked upregulation under N, N, N', N'-Tetrakis (2-pyridylmethyl) ethylenediamine (TPEN) mediated zinc-depleted environment, adding credence to its negative autoregulation. Moreover, an increase in the transcript levels of the regulon genes znuA, rpmG, and yciC upon exposure of cells to TPEN connoted their role in combating hypo-zincemic conditions by bringing about zinc uptake and mobilization. Thus, this study functionally characterizes Zur of B. anthracis and elucidates its role in maintaining zinc homeostasis.
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Affiliation(s)
- Divya Kandari
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Monisha Gopalani
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Manish Gupta
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Hemant Joshi
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Sonika Bhatnagar
- Computational and Structural Biology Laboratory, Division of Biotechnology, Netaji Subhas Institute of Technology, University of Delhi, New Delhi, India
| | - Rakesh Bhatnagar
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
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24
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Gharami S, Aich K, Sarkar D, Ghosh P, Murmu N, Mondal TK. An ESIPT based chromogenic and fluorescent ratiometric probe for Zn2+ with imaging in live cells and tissues. NEW J CHEM 2019. [DOI: 10.1039/c8nj04695f] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A benzothiazole based fluorescent probe for selective and efficient detection of Zn2+ showing potential application in human breast cancer cells.
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Affiliation(s)
- Saswati Gharami
- Department of Chemistry
- Jadavpur University
- Kolkata-70003
- India
| | - Krishnendu Aich
- Department of Chemistry
- Jadavpur University
- Kolkata-70003
- India
| | - Deblina Sarkar
- Department of Signal Transduction and Biogenic Amines (STBA)
- Chittaranjan National Cancer Institute
- Kolkata-700026
- India
| | - Paramita Ghosh
- Department of Signal Transduction and Biogenic Amines (STBA)
- Chittaranjan National Cancer Institute
- Kolkata-700026
- India
| | - Nabendu Murmu
- Department of Signal Transduction and Biogenic Amines (STBA)
- Chittaranjan National Cancer Institute
- Kolkata-700026
- India
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25
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Neupane DP, Kumar S, Yukl ET. Two ABC Transporters and a Periplasmic Metallochaperone Participate in Zinc Acquisition in Paracoccus denitrificans. Biochemistry 2018; 58:126-136. [PMID: 30353723 PMCID: PMC6824839 DOI: 10.1021/acs.biochem.8b00854] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
![]()
Bacteria must acquire the essential
element zinc from extremely
limited environments, and this function is performed largely by ATP
binding cassette (ABC) transporters. These systems rely on a periplasmic
or extracellular solute binding protein (SBP) to bind zinc specifically
with a high affinity and deliver it to the membrane permease for import
into the cytoplasm. However, zinc acquisition systems in bacteria
may be more complex, involving multiple transporters and other periplasmic
or extracellular zinc binding proteins. Here we describe the zinc
acquisition functions of two zinc SBPs (ZnuA and AztC) and a novel
periplasmic metallochaperone (AztD) in Paracoccus denitrificans. ZnuA was characterized in vitro and demonstrated
to bind as many as 5 zinc ions with a high affinity. It does not interact
with AztD, in contrast to what has been demonstrated for AztC, which
is able to acquire a single zinc ion through associative transfer
from AztD. Deletions of the corresponding genes singly and in combination
show that either AztC or ZnuA is sufficient and essential for robust
growth in zinc-limited media. Although AztD cannot support transport
of zinc into the cytoplasm, it likely functions to store zinc in the
periplasm for transfer through the AztABCD system.
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Affiliation(s)
- Durga P Neupane
- Department of Chemistry and Biochemistry , New Mexico State University , Las Cruces , New Mexico 88003 , United States
| | - Santosh Kumar
- Department of Biological Sciences , University of Texas at Dallas , Richardson , Texas 75080 , United States
| | - Erik T Yukl
- Department of Chemistry and Biochemistry , New Mexico State University , Las Cruces , New Mexico 88003 , United States
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26
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Bartual SG, Alcorlo M, Martínez-Caballero S, Molina R, Hermoso JA. Three-dimensional structures of Lipoproteins from Streptococcus pneumoniae and Staphylococcus aureus. Int J Med Microbiol 2018; 308:692-704. [DOI: 10.1016/j.ijmm.2017.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/21/2017] [Indexed: 01/01/2023] Open
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27
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Iron and Zinc Regulate Expression of a Putative ABC Metal Transporter in Corynebacterium diphtheriae. J Bacteriol 2018; 200:JB.00051-18. [PMID: 29507090 DOI: 10.1128/jb.00051-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 02/28/2018] [Indexed: 11/20/2022] Open
Abstract
Corynebacterium diphtheriae, a Gram-positive, aerobic bacterium, is the causative agent of diphtheria and cutaneous infections. While mechanisms required for heme iron acquisition are well known in C. diphtheriae, systems involved in the acquisition of other metals such as zinc and manganese remain poorly characterized. In this study, we identified a genetic region that encodes an ABC-type transporter (iutBCD) and that is flanked by two genes (iutA and iutE) encoding putative substrate binding proteins of the cluster 9 family, a related group of transporters associated primarily with the import of Mn and Zn. We showed that IutA and IutE are both membrane proteins with comparable Mn and Zn binding abilities. We demonstrated that the iutABCD genes are cotranscribed and repressed in response to iron by the iron-responsive repressor DtxR. Transcription of iutE was positively regulated in response to iron availability in a DtxR-dependent manner and was repressed in response to Zn by the Zn-dependent repressor Zur. Electrophoretic mobility shift assays showed that DtxR does not bind to the iutE upstream region, which indicates that DtxR regulation of iutE is indirect and that other regulatory factors controlled by DtxR are likely responsible for the iron-responsive regulation. Analysis of the iutE promoter region identified a 50-bp sequence at the 3' end of the iutD gene that is required for the DtxR-dependent and iron-responsive activation of the iutE gene. These findings indicate that transcription of iutE is controlled by a complex mechanism that involves multiple regulatory factors whose activity is impacted by both Zn and Fe.IMPORTANCE Vaccination against diphtheria prevents toxin-related symptoms but does not inhibit bacterial colonization of the human host by the bacterium. Thus, Corynebacterium diphtheriae remains an important human pathogen that poses a significant health risk to unvaccinated individuals. The ability to acquire iron, zinc, and manganese is critical to the pathogenesis of many disease-causing organisms. Here, we describe a gene cluster in C. diphtheriae that encodes a metal importer that is homologous to broadly distributed metal transport systems, some with important roles in virulence in other bacterial pathogens. Two metal binding components of the gene cluster encode surface exposed proteins, and studies of such proteins may guide the development of second-generation vaccines for C. diphtheriae.
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28
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Cao K, Li N, Wang H, Cao X, He J, Zhang B, He QY, Zhang G, Sun X. Two zinc-binding domains in the transporter AdcA from Streptococcus pyogenes facilitate high-affinity binding and fast transport of zinc. J Biol Chem 2018; 293:6075-6089. [PMID: 29491141 DOI: 10.1074/jbc.m117.818997] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 02/25/2018] [Indexed: 11/06/2022] Open
Abstract
Zinc is an essential metal in bacteria. One important bacterial zinc transporter is AdcA, and most bacteria possess AdcA homologs that are single-domain small proteins due to better efficiency of protein biogenesis. However, a double-domain AdcA with two zinc-binding sites is significantly overrepresented in Streptococcus species, many of which are major human pathogens. Using molecular simulation and experimental validations of AdcA from Streptococcus pyogenes, we found here that the two AdcA domains sequentially stabilize the structure upon zinc binding, indicating an organization required for both increased zinc affinity and transfer speed. This structural organization appears to endow Streptococcus species with distinct advantages in zinc-depleted environments, which would not be achieved by each single AdcA domain alone. This enhanced zinc transport mechanism sheds light on the significance of the evolution of the AdcA domain fusion, provides new insights into double-domain transporter proteins with two binding sites for the same ion, and indicates a potential target of antimicrobial drugs against pathogenic Streptococcus species.
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Affiliation(s)
- Kun Cao
- From the Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, 601 Huang-Pu Avenue West, Guangzhou 510632, China
| | - Nan Li
- From the Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, 601 Huang-Pu Avenue West, Guangzhou 510632, China
| | - Hongcui Wang
- From the Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, 601 Huang-Pu Avenue West, Guangzhou 510632, China
| | - Xin Cao
- From the Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, 601 Huang-Pu Avenue West, Guangzhou 510632, China
| | - Jiaojiao He
- From the Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, 601 Huang-Pu Avenue West, Guangzhou 510632, China
| | - Bing Zhang
- From the Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, 601 Huang-Pu Avenue West, Guangzhou 510632, China
| | - Qing-Yu He
- From the Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, 601 Huang-Pu Avenue West, Guangzhou 510632, China
| | - Gong Zhang
- From the Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, 601 Huang-Pu Avenue West, Guangzhou 510632, China
| | - Xuesong Sun
- From the Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, 601 Huang-Pu Avenue West, Guangzhou 510632, China
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29
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Sridharan U, Ragunathan P, Spellerberg B, Ponnuraj K. Molecular dynamics simulation of metal free structure of Lmb, a laminin-binding adhesin of Streptococcus agalactiae: metal removal and its structural implications. J Biomol Struct Dyn 2018; 37:714-725. [PMID: 29421962 DOI: 10.1080/07391102.2018.1438923] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Metal-binding receptors are one of the extracellular components of ATP-binding cassette transporters that are essential for regulation of metal homeostasis in bacteria. Laminin-binding adhesin (Lmb) of Streptococcus agalactiae falls under this class of solute binding proteins. It binds to zinc with a high affinity. Crystal structure of Lmb solved previously by our group reveals that the zinc is tetrahedrally coordinated by three histidines and a glutamate at the interdomain cleft. Lmb contains a long disordered loop close to the metal-binding site whose precise function is unknown. Several experimental attempts to produce apo-Lmb failed and this prompted us to carry out in silico studies to analyse the structural importance of the metal in Lmb. Here, we present the results of the molecular dynamics (MD) simulation studies of native, apo-(metal removed) and the long loop truncated Lmb models along with a homologous protein, TroA from Treponema pallidum that was taken up for validating the MD results of Lmb. Absence of a metal results in significant structural changes in Lmb, particularly at the metal-binding pocket and with the long loop, although the overall fold is retained. This study thus revealed that the Lmb can exist in different conformational states with subtle differences in the overall fold based on the presence or absence of the metal. This could be functionally important for a putative metal uptake and release and also for the adhesive function of Lmb in recognizing laminin, which contains a high number of zinc finger motifs.
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Affiliation(s)
- Upasana Sridharan
- a Centre of Advanced Study in Crystallography and Biophysics , University of Madras, Guindy Campus , Chennai , India
| | - Preethi Ragunathan
- a Centre of Advanced Study in Crystallography and Biophysics , University of Madras, Guindy Campus , Chennai , India
| | - Barbara Spellerberg
- b Institute for Medical Microbiology and Hygiene , University of Ulm , Ulm , Germany
| | - Karthe Ponnuraj
- a Centre of Advanced Study in Crystallography and Biophysics , University of Madras, Guindy Campus , Chennai , India
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30
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Allosteric histidine switch for regulation of intracellular zinc(II) fluctuation. Proc Natl Acad Sci U S A 2017; 114:13661-13666. [PMID: 29229866 DOI: 10.1073/pnas.1708563115] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Metalloregulators allosterically control transcriptional activity through metal binding-induced reorganization of ligand residues and/or hydrogen bonding networks, while the coordination atoms on the same ligand residues remain seldom changed. Here we show that the MarR-type zinc transcriptional regulator ZitR switches one of its histidine nitrogen atoms for zinc coordination during the allosteric control of DNA binding. The Zn(II)-coordination nitrogen on histidine 42 within ZitR's high-affinity zinc site (site 1) switches from Nε2 to Nδ1 upon Zn(II) binding to its low-affinity zinc site (site 2), which facilitates ZitR's conversion from the nonoptimal to the optimal DNA-binding conformation. This histidine switch-mediated cooperation between site 1 and site 2 enables ZitR to adjust its DNA-binding affinity in response to a broad range of zinc fluctuation, which may allow the fine tuning of transcriptional regulation.
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31
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Neupane DP, Avalos D, Fullam S, Roychowdhury H, Yukl ET. Mechanisms of zinc binding to the solute-binding protein AztC and transfer from the metallochaperone AztD. J Biol Chem 2017; 292:17496-17505. [PMID: 28887302 DOI: 10.1074/jbc.m117.804799] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/16/2017] [Indexed: 01/22/2023] Open
Abstract
Bacteria can acquire the essential metal zinc from extremely zinc-limited environments by using ATP-binding cassette (ABC) transporters. These transporters are critical virulence factors, relying on specific and high-affinity binding of zinc by a periplasmic solute-binding protein (SBP). As such, the mechanisms of zinc binding and release among bacterial SBPs are of considerable interest as antibacterial drug targets. Zinc SBPs are characterized by a flexible loop near the high-affinity zinc-binding site. The function of this structure is not always clear, and its flexibility has thus far prevented structural characterization by X-ray crystallography. Here, we present intact structures for the zinc-specific SBP AztC from the bacterium Paracoccus denitrificans in the zinc-bound and apo-states. A comparison of these structures revealed that zinc loss prompts significant structural rearrangements, mediated by the formation of a sodium-binding site in the apo-structure. We further show that the AztC flexible loop has no impact on zinc-binding affinity, stoichiometry, or protein structure, yet is essential for zinc transfer from the metallochaperone AztD. We also found that 3 His residues in the loop appear to temporarily coordinate zinc and then convey it to the high-affinity binding site. Thus, mutation of any of these residues to Ala abrogated zinc transfer from AztD. Our structural and mechanistic findings conclusively identify a role for the AztC flexible loop in zinc acquisition from the metallochaperone AztD, yielding critical insights into metal binding by AztC from both solution and AztD. These proteins are highly conserved in human pathogens, making this work potentially useful for the development of novel antibiotics.
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Affiliation(s)
- Durga P Neupane
- From the Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
| | - Dante Avalos
- From the Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
| | - Stephanie Fullam
- From the Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
| | - Hridindu Roychowdhury
- From the Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
| | - Erik T Yukl
- From the Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
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32
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Lin L, Wang D, Chen SH, Wang DJ, Yin GD. A highly sensitive fluorescent chemosensor for selective detection of zinc (II) ion based on the oxadiazole derivative. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 174:272-278. [PMID: 27960140 DOI: 10.1016/j.saa.2016.11.053] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/25/2016] [Accepted: 11/30/2016] [Indexed: 06/06/2023]
Abstract
A novel fluorescent chemosensor based on the oxadiazole, 2-(2-hydroxyphenyl)-5-(4-methoxyphenyl)-1,3,4-oxadiazole, was designed and synthesized. The interaction of the oxadiazole with different metal ions had been investigated through UV-vis absorption and fluorescence spectra in 9:1 (v/v) ethanol-water (pH=7.0) solution. The oxadiazole showed a pronounced fluorescence enhancement at 430nm upon addition of Zn2+ in aqueous solution, whereas it had no apparent interference from other metal ions. The results indicated that the oxadiazole possessed high selectivity and sensitivity to Zn2+ ion. The stoichiometric ratio between the oxadiazole and Zn2+ ion was calculated to be 2:1 by Job plot experiment, meanwhile their binding modes was confirmed by 1H NMR and mass spectrometry. Their association constant was determined to be 1.95×105M-1 and the detection limit for Zn2+ ion was 6.14×10-7mol/L.
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Affiliation(s)
- Lu Lin
- College of Chemistry and Chemical Engineering, Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Hubei Normal University, Huangshi 435002, China
| | - Dan Wang
- College of Chemistry and Chemical Engineering, Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Hubei Normal University, Huangshi 435002, China
| | - Si-Hong Chen
- College of Chemistry and Chemical Engineering, Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Hubei Normal University, Huangshi 435002, China
| | - Dun-Jia Wang
- College of Chemistry and Chemical Engineering, Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Hubei Normal University, Huangshi 435002, China.
| | - Guo-Dong Yin
- College of Chemistry and Chemical Engineering, Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Hubei Normal University, Huangshi 435002, China
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33
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Mandal SK, Chandravanshi M, Gogoi P, Kanaujia SP. In silico characterization of TTHA0596: A potential Zn 2+ binding protein of ATP-binding cassette transporter. GENE REPORTS 2017. [DOI: 10.1016/j.genrep.2017.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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34
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Turner AG, Ong CLY, Walker MJ, Djoko KY, McEwan AG. Transition Metal Homeostasis in Streptococcus pyogenes and Streptococcus pneumoniae. Adv Microb Physiol 2017; 70:123-191. [PMID: 28528647 DOI: 10.1016/bs.ampbs.2017.01.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Trace metals such as Fe, Mn, Zn and Cu are essential for various biological functions including proper innate immune function. The host immune system has complicated and coordinated mechanisms in place to either starve and/or overload invading pathogens with various metals to combat the infection. Here, we discuss the roles of Fe, Mn and Zn in terms of nutritional immunity, and also the roles of Cu and Zn in metal overload in relation to the physiology and pathogenesis of two human streptococcal species, Streptococcus pneumoniae and Streptococcus pyogenes. S. pneumoniae is a major human pathogen that is carried asymptomatically in the nasopharynx by up to 70% of the population; however, transition to internal sites can cause a range of diseases such as pneumonia, otitis media, meningitis and bacteraemia. S. pyogenes is a human pathogen responsible for diseases ranging from pharyngitis and impetigo, to severe invasive infections. Both species have overlapping capacity with respect to metal acquisition, export and regulation and how metal homeostasis relates to their virulence and ability to invade and survive within the host. It is becoming more apparent that metals have an important role to play in the control of infection, and with further investigations, it could lead to the potential use of metals in novel antimicrobial therapies.
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Affiliation(s)
- Andrew G Turner
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Cheryl-Lynn Y Ong
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Mark J Walker
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Karrera Y Djoko
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Alastair G McEwan
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia.
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35
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The Adc/Lmb System Mediates Zinc Acquisition in Streptococcus agalactiae and Contributes to Bacterial Growth and Survival. J Bacteriol 2016; 198:3265-3277. [PMID: 27672194 DOI: 10.1128/jb.00614-16] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 09/16/2016] [Indexed: 12/14/2022] Open
Abstract
The Lmb protein of Streptococcus agalactiae is described as an adhesin that binds laminin, a component of the human extracellular matrix. In this study, we revealed a new role for this protein in zinc uptake. We also identified two Lmb homologs, AdcA and AdcAII, redundant binding proteins that combine with the AdcCB translocon to form a zinc-ABC transporter. Expression of this transporter is controlled by the zinc concentration in the medium through the zinc-dependent regulator AdcR. Triple deletion of lmb, adcA, and adcAII, or that of the adcCB genes, impaired growth and cell separation in a zinc-restricted environment. Moreover, we found that this Adc zinc-ABC transporter promotes S. agalactiae growth and survival in some human biological fluids, suggesting that it contributes to the infection process. These results indicated that zinc has biologically vital functions in S. agalactiae and that, under the conditions tested, the Adc/Lmb transporter constitutes the main zinc acquisition system of the bacterium. IMPORTANCE A zinc transporter, composed of three redundant binding proteins (Lmb, AdcA, and AdcAII), was characterized in Streptococcus agalactiae This system was shown to be essential for bacterial growth and morphology in zinc-restricted environments, including human biological fluids.
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Wątły J, Potocki S, Rowińska-Żyrek M. Zinc Homeostasis at the Bacteria/Host Interface-From Coordination Chemistry to Nutritional Immunity. Chemistry 2016; 22:15992-16010. [DOI: 10.1002/chem.201602376] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Joanna Wątły
- Faculty of Chemistry; University of Wroclaw; F. Joliot-Curie 14 50-383 Wroclaw Poland
| | - Sławomir Potocki
- Faculty of Chemistry; University of Wroclaw; F. Joliot-Curie 14 50-383 Wroclaw Poland
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Kohler S, Voß F, Gómez Mejia A, Brown JS, Hammerschmidt S. Pneumococcal lipoproteins involved in bacterial fitness, virulence, and immune evasion. FEBS Lett 2016; 590:3820-3839. [DOI: 10.1002/1873-3468.12352] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 08/01/2016] [Accepted: 08/05/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Sylvia Kohler
- Department Genetics of Microorganisms; Interfaculty Institute for Genetics and Functional Genomics; University of Greifswald; Germany
| | - Franziska Voß
- Department Genetics of Microorganisms; Interfaculty Institute for Genetics and Functional Genomics; University of Greifswald; Germany
| | - Alejandro Gómez Mejia
- Department Genetics of Microorganisms; Interfaculty Institute for Genetics and Functional Genomics; University of Greifswald; Germany
| | - Jeremy S. Brown
- Department of Medicine; Centre for Inflammation and Tissue Repair; University College Medical School; London UK
| | - Sven Hammerschmidt
- Department Genetics of Microorganisms; Interfaculty Institute for Genetics and Functional Genomics; University of Greifswald; Germany
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Tedde V, Rosini R, Galeotti CL. Zn2+ Uptake in Streptococcus pyogenes: Characterization of adcA and lmb Null Mutants. PLoS One 2016; 11:e0152835. [PMID: 27031880 PMCID: PMC4816340 DOI: 10.1371/journal.pone.0152835] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Accepted: 02/29/2016] [Indexed: 01/29/2023] Open
Abstract
An effective regulation of metal ion homeostasis is essential for the growth of microorganisms in any environment and in pathogenic bacteria is strongly associated with their ability to invade and colonise their hosts. To gain a better insight into zinc acquisition in Group A Streptococcus (GAS) we characterized null deletion mutants of the adcA and lmb genes of Streptococcus pyogenes strain MGAS5005 encoding the orthologues of AdcA and AdcAII, the two surface lipoproteins with partly redundant roles in zinc homeostasis in Streptococcus pneumoniae. Null adcA and lmb mutants were analysed for their capability to grow in zinc-depleted conditions and were found to be more susceptible to zinc starvation, a phenotype that could be rescued by the addition of Zn2+ ions to the growth medium. Expression of AdcA, Lmb and HtpA, the polyhistidine triad protein encoded by the gene adjacent to lmb, during growth under conditions of limited zinc availability was examined by Western blot analysis in wild type and null mutant strains. In the wild type strain, AdcA was always present with little variation in expression levels between conditions of excess or limited zinc availability. In contrast, Lmb and HtpA were expressed at detectable levels only during growth in the presence of low zinc concentrations or in the null adcA mutant, when expression of lmb is required to compensate for the lack of adcA expression. In the latter case, Lmb and HtpA were overexpressed by several fold, thus indicating that also in GAS AdcA is a zinc-specific importer and, although it shares this function with Lmb, the two substrate-binding proteins do not show fully overlapping roles in zinc homeostasis.
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Affiliation(s)
- Vittorio Tedde
- Research Centre, GlaxoSmithKline Vaccines S.r.l., Siena, Italy
| | - Roberto Rosini
- Research Centre, GlaxoSmithKline Vaccines S.r.l., Siena, Italy
| | - Cesira L. Galeotti
- Research Centre, GlaxoSmithKline Vaccines S.r.l., Siena, Italy
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
- * E-mail:
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Brown LR, Gunnell SM, Cassella AN, Keller LE, Scherkenbach LA, Mann B, Brown MW, Hill R, Fitzkee NC, Rosch JW, Tuomanen EI, Thornton JA. AdcAII of Streptococcus pneumoniae Affects Pneumococcal Invasiveness. PLoS One 2016; 11:e0146785. [PMID: 26752283 PMCID: PMC4709005 DOI: 10.1371/journal.pone.0146785] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 12/22/2015] [Indexed: 11/18/2022] Open
Abstract
Across bacterial species, metal binding proteins can serve functions in pathogenesis in addition to regulating metal homeostasis. We have compared and contrasted the activities of zinc (Zn2+)-binding lipoproteins AdcA and AdcAII in the Streptococcus pneumoniae TIGR4 background. Exposure to Zn2+-limiting conditions resulted in delayed growth in a strain lacking AdcAII (ΔAdcAII) when compared to wild type bacteria or a mutant lacking AdcA (ΔAdcA). AdcAII failed to interact with the extracellular matrix protein laminin despite homology to laminin-binding proteins of related streptococci. Deletion of AdcA or AdcAII led to significantly increased invasion of A549 human lung epithelial cells and a trend toward increased invasion in vivo. Loss of AdcAII, but not AdcA, was shown to negatively impact early colonization of the nasopharynx. Our findings suggest that expression of AdcAII affects invasiveness of S. pneumoniae in response to available Zn2+ concentrations.
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Affiliation(s)
- Lindsey R. Brown
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS, 39762, United States of America
| | - Steven M. Gunnell
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS, 39762, United States of America
| | - Adam N. Cassella
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS, 39762, United States of America
| | - Lance E. Keller
- Department of Microbiology, University of Mississippi Medical Center, Jackson, MS, 39216, United States of America
| | - Lisa A. Scherkenbach
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN, 38105, United States of America
| | - Beth Mann
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN, 38105, United States of America
| | - Matthew W. Brown
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS, 39762, United States of America
| | - Rebecca Hill
- Department of Chemistry, Mississippi State University, Mississippi State, MS, 39762, United States of America
| | - Nicholas C. Fitzkee
- Department of Chemistry, Mississippi State University, Mississippi State, MS, 39762, United States of America
| | - Jason W. Rosch
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN, 38105, United States of America
| | - Elaine I. Tuomanen
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN, 38105, United States of America
| | - Justin A. Thornton
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS, 39762, United States of America
- * E-mail:
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Luo Z, Morey JR, McDevitt CA, Kobe B. Heterogeneous nucleation is required for crystallization of the ZnuA domain of pneumococcal AdcA. Acta Crystallogr F Struct Biol Commun 2015; 71:1459-64. [PMID: 26625286 PMCID: PMC4666472 DOI: 10.1107/s2053230x15021330] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 11/10/2015] [Indexed: 01/17/2023] Open
Abstract
Zn(2+) is an essential nutrient for all known forms of life. In the major human pathogen Streptococcus pneumoniae, the acquisition of Zn(2+) is facilitated by two Zn(2+)-specific solute-binding proteins: AdcA and AdcAII. To date, there has been a paucity of structural information on AdcA, which has hindered a deeper understanding of the mechanism underlying pneumococcal Zn(2+) acquisition. Native AdcA consists of two domains: an N-terminal ZnuA domain and a C-terminal ZinT domain. In this study, the ZnuA domain of AdcA was crystallized. The initial crystals of the ZnuA-domain protein were obtained using dried seaweed as a heterogeneous nucleating agent. No crystals were obtained in the absence of the heterogeneous nucleating agent. These initial crystals were subsequently used as seeds to produce diffraction-quality crystals. The crystals diffracted to 2.03 Å resolution and had the symmetry of space group P1. This study demonstrates the utility of heterogeneous nucleation. The solution of the crystal structures will lead to further understanding of Zn(2+) acquisition by S. pneumoniae.
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Affiliation(s)
- Zhenyao Luo
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Jacqueline R. Morey
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Christopher A. McDevitt
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Boštjan Kobe
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
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41
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Li K, Bruner SD. Structure and functional analysis of the siderophore periplasmic binding protein from the fuscachelin gene cluster of T
hermobifida fusca. Proteins 2015; 84:118-28. [DOI: 10.1002/prot.24959] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/19/2015] [Accepted: 10/23/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Kunhua Li
- Department of Chemistry; University of Florida; Gainesville Florida 32611
| | - Steven D. Bruner
- Department of Chemistry; University of Florida; Gainesville Florida 32611
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Morey JR, McDevitt CA, Kehl-Fie TE. Host-imposed manganese starvation of invading pathogens: two routes to the same destination. Biometals 2015; 28:509-19. [PMID: 25836716 PMCID: PMC4430393 DOI: 10.1007/s10534-015-9850-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 03/24/2015] [Indexed: 01/07/2023]
Abstract
During infection invading pathogens must acquire all essential nutrients, including first row transition metals, from the host. To combat invaders, the host exploits this fact and restricts the availability of these nutrients using a defense mechanism known as nutritional immunity. While iron sequestration is the most well-known aspect of this defense, recent work has revealed that the host restricts the availability of other essential elements, notably manganese (Mn), during infection. Furthermore, these studies have revealed that the host utilizes multiple strategies that extend beyond metal sequestration to prevent bacteria from obtaining these metals. This review will discuss the mechanisms by which bacteria attempt to obtain the essential first row transition metal ion Mn during infection, and the approaches utilized by the host to prevent this occurrence. In addition, this review will discuss the impact of host-imposed Mn starvation on invading bacteria.
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Affiliation(s)
- Jacqueline R. Morey
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia
| | - Christopher A. McDevitt
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia
| | - Thomas E. Kehl-Fie
- Department of Microbiology, University of Illinois Urbana-Champaign, Urbana IL, USA
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Thornton JA, Tullos NA, Sanders ME, Ridout G, Wang YD, Taylor SD, McDaniel LS, Marquart ME. Differential bacterial gene expression during experimental pneumococcal endophthalmitis. Ophthalmic Res 2015; 53:149-61. [PMID: 25791614 DOI: 10.1159/000371713] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 12/18/2014] [Indexed: 12/22/2022]
Abstract
Streptococcus pneumoniae (pneumococcus) is a potential cause of bacterial endophthalmitis in humans that can result in ocular morbidity. We sought to identify pneumococcal genes that are differentially expressed during growth in the vitreous humor of the eye in an experimental endophthalmitis model. Microarray analysis was used to identify genes that were differentially expressed when pneumococci replicated in the vitreous of rabbit eyes as compared with bacteria grown in vitro in Todd Hewitt medium. Array results were verified by quantitative real-time PCR analysis of representative genes. Select genes potentially playing a role in virulence during endophthalmitis were deleted, and mutants were tested for reduced eye pathogenesis and altered adhesion to host cells. Array analysis identified 134 genes that were differentially expressed during endophthalmitis; 112 genes demonstrated increased expression during growth in the eye whereas 22 were downregulated. Real-time analysis verified increased expression of neuraminidase A (NanA; SP1693), neuraminidase B (NanB; SP1687) and serine protease (SP1954), and decreased expression of RlrA (SP0461) and choline transporter (SP1861). Mutation of NanA and NanB had no major effect on pathogenesis. Loss of SP1954 led to increased adherence to host cells. S. pneumoniae enhances and represses the expression of a variety of genes during endophthalmitis. While some of these genes reflect changes in metabolic requirements, some appear to play a role in immune evasion and pathogenesis in the eye.
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Affiliation(s)
- Justin A Thornton
- Department of Biological Sciences, Mississippi State University, Starkville, Miss., USA
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Begg SL, Eijkelkamp BA, Luo Z, Couñago RM, Morey JR, Maher MJ, Ong CLY, McEwan AG, Kobe B, O'Mara ML, Paton JC, McDevitt CA. Dysregulation of transition metal ion homeostasis is the molecular basis for cadmium toxicity in Streptococcus pneumoniae. Nat Commun 2015; 6:6418. [PMID: 25731976 PMCID: PMC4366526 DOI: 10.1038/ncomms7418] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 01/27/2015] [Indexed: 11/30/2022] Open
Abstract
Cadmium is a transition metal ion that is highly toxic in biological systems. Although relatively rare in the Earth’s crust, anthropogenic release of cadmium since industrialization has increased biogeochemical cycling and the abundance of the ion in the biosphere. Despite this, the molecular basis of its toxicity remains unclear. Here we combine metal-accumulation assays, high-resolution structural data and biochemical analyses to show that cadmium toxicity, in Streptococcus pneumoniae, occurs via perturbation of first row transition metal ion homeostasis. We show that cadmium uptake reduces the millimolar cellular accumulation of manganese and zinc, and thereby increases sensitivity to oxidative stress. Despite this, high cellular concentrations of cadmium (~17 mM) are tolerated, with negligible impact on growth or sensitivity to oxidative stress, when manganese and glutathione are abundant. Collectively, this work provides insight into the molecular basis of cadmium toxicity in prokaryotes, and the connection between cadmium accumulation and oxidative stress. The molecular basis for the high toxicity of cadmium is unclear. Here, Begg et al. use the bacterium Streptococcus pneumoniae as a model system, and show that cadmium uptake increases sensitivity to oxidative stress by reducing intracellular concentrations of manganese and zinc through different mechanisms.
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Affiliation(s)
- Stephanie L Begg
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 4072, Australia
| | - Bart A Eijkelkamp
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 4072, Australia
| | - Zhenyao Luo
- 1] School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia [2] Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia [3] Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Rafael M Couñago
- 1] School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia [2] Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia [3] Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jacqueline R Morey
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 4072, Australia
| | - Megan J Maher
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Cheryl-Lynn Y Ong
- 1] School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia [2] Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Alastair G McEwan
- 1] School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia [2] Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Bostjan Kobe
- 1] School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia [2] Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia [3] Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Megan L O'Mara
- 1] School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia [2] School of Mathematics and Physics, University of Queensland, Brisbane, Queensland 4072, Australia
| | - James C Paton
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 4072, Australia
| | - Christopher A McDevitt
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 4072, Australia
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Manganese uptake and streptococcal virulence. Biometals 2015; 28:491-508. [PMID: 25652937 DOI: 10.1007/s10534-015-9826-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 01/27/2015] [Indexed: 02/06/2023]
Abstract
Streptococcal solute-binding proteins (SBPs) associated with ATP-binding cassette transporters gained widespread attention first as ostensible adhesins, next as virulence determinants, and finally as metal ion transporters. In this mini-review, we will examine our current understanding of the cellular roles of these proteins, their contribution to metal ion homeostasis, and their crucial involvement in mediating streptococcal virulence. There are now more than 35 studies that have collected structural, biochemical and/or physiological data on the functions of SBPs across a broad range of bacteria. This offers a wealth of data to clarify the formerly puzzling and contentious findings regarding the metal specificity amongst this group of essential bacterial transporters. In particular we will focus on recent findings related to biological roles for manganese in streptococci. These advances will inform efforts aimed at exploiting the importance of manganese and manganese acquisition for the design of new approaches to combat serious streptococcal diseases.
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Blindauer CA. Advances in the molecular understanding of biological zinc transport. Chem Commun (Camb) 2015; 51:4544-63. [DOI: 10.1039/c4cc10174j] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recognition of the importance of zinc homeostasis for health has driven a surge in structural data on major zinc-transporting proteins.
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Overlapping functionality of the Pht proteins in zinc homeostasis of Streptococcus pneumoniae. Infect Immun 2014; 82:4315-24. [PMID: 25069983 DOI: 10.1128/iai.02155-14] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Streptococcus pneumoniae is a globally significant pathogen that causes a range of diseases, including pneumonia, sepsis, meningitis, and otitis media. Its ability to cause disease depends upon the acquisition of nutrients from its environment, including transition metal ions such as zinc. The pneumococcus employs a number of surface proteins to achieve this, among which are four highly similar polyhistidine triad (Pht) proteins. It has previously been established that these proteins collectively aid in the delivery of zinc to the ABC transporter substrate-binding protein AdcAII. Here we have investigated the contribution of each individual Pht protein to pneumococcal zinc homeostasis by analyzing mutant strains expressing only one of the four pht genes. Under conditions of low zinc availability, each of these mutants showed superior growth and zinc accumulation profiles relative to a mutant strain lacking all four genes, indicating that any of the four Pht proteins are able to facilitate delivery of zinc to AdcAII. However, optimal growth and zinc accumulation in vitro and pneumococcal survival and proliferation in vivo required production of all four Pht proteins, indicating that, despite their overlapping functionality, the proteins are not dispensable without incurring a fitness cost. We also show that surface-attached forms of the Pht proteins are required for zinc recruitment and that they do not contribute to defense against extracellular zinc stress.
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Zhang YM, Shao ZQ, Wang J, Wang L, Li X, Wang C, Tang J, Pan X. Prevalent distribution and conservation of Streptococcus suis Lmb protein and its protective capacity against the Chinese highly virulent strain infection. Microbiol Res 2014; 169:395-401. [DOI: 10.1016/j.micres.2013.09.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Revised: 09/06/2013] [Accepted: 09/07/2013] [Indexed: 01/04/2023]
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Abstract
AbstractABC transporters comprise a large, diverse, and ubiquitous superfamily of membrane active transporters. Their core architecture is a dimer of dimers, comprising two transmembrane (TM) domains that bind substrate, and two ATP-binding cassettes, which use the cell's energy currency to couple substrate translocation to ATP hydrolysis. Despite the availability of over a dozen resolved structures and a wealth of biochemical and biophysical data, this field is bedeviled by controversy and long-standing mechanistic questions remain unresolved. The prevailing paradigm for the ABC transport mechanism is the Switch Model, in which the ATP-binding cassettes dimerize upon binding two ATP molecules, and thence dissociate upon sequential ATP hydrolysis. This cycle of nucleotide-binding domain (NBD) dimerization and dissociation is coupled to a switch between inward- or outward facing conformations of a single TM channel; this alternating access enables substrate binding on one face of the membrane and its release at the other. Notwithstanding widespread acceptance of the Switch Model, there is substantial evidence that the NBDs do not separate very much, if at all, and thus physical separation of the ATP cassettes observed in crystallographic structures may be an artefact. An alternative Constant Contact Model has been proposed, in which ATP hydrolysis occurs alternately at the two ATP-binding sites, with one of the sites remaining closed and containing occluded nucleotide at all times. In this model, the cassettes remain in contact and the active sites swing open in an alternately seesawing motion. Whilst the concept of NBD association/dissociation in the Switch Model is naturally compatible with a single alternating-access channel, the asymmetric functioning proposed by the Constant Contact model suggests an alternating or reciprocating function in the TMDs. Here, a new model for the function of ABC transporters is proposed in which the sequence of ATP binding, hydrolysis, and product release in each active site is directly coupled to the analogous sequence of substrate binding, translocation and release in one of two functionally separate substrate translocation pathways. Each translocation pathway functions 180° out of phase. A wide and diverse selection of data for both ABC importers and exporters is examined, and the ability of the Switch and Reciprocating Models to explain the data is compared and contrasted. This analysis shows that not only can the Reciprocating Model readily explain the data; it also suggests straightforward explanations for the function of a number of atypical ABC transporters. This study represents the most coherent and complete attempt at an all-encompassing scheme to explain how these important proteins work, one that is consistent with sound biochemical and biophysical evidence.
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Li N, Yang XY, Guo Z, Zhang J, Cao K, Han J, Zhang G, Liu L, Sun X, He QY. Varied metal-binding properties of lipoprotein PsaA in Streptococcus pneumoniae. J Biol Inorg Chem 2014; 19:829-38. [PMID: 24553956 DOI: 10.1007/s00775-014-1114-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 01/28/2014] [Indexed: 11/29/2022]
Abstract
Streptococcus pneumoniae is a Gram-positive pathogen responsible for pneumonia, otitis media, and meningitis. Manganese and zinc ions are essential for this bacterium, playing regulatory, structural, or catalytic roles as the critical cofactors in the bacterial proteins and metabolic enzymes. Lipoprotein PsaA has been found to mediate Mn(2+) and Zn(2+) transportation in Streptococcus pneumoniae. In the present work, we conducted a systemic study on the contributions from key amino acids in the metal-binding site of PsaA using various spectroscopic and biochemical methods. Our experimental data indicate that four metal-binding residues contribute unequally to the Mn(2+) and Zn(2+) binding, and His139 is most important for both the structural stability and metal binding of the protein. PsaA-Mn(2+) has a lower thermal stability than PsaA-Zn(2+), possibly due to the different coordination preferences of the metals. Kinetics analysis revealed that PsaA-Mn(2+) binding is a fast first-order reaction, whereas PsaA-Zn(2+) binding is a slow second-order reaction, implying that PsaA kinetically prefers binding Mn(2+) to Zn(2+). The present results provide complementary information for understanding the mechanisms of metal transport and bacterial virulence via lipoproteins in Streptococcus pneumoniae.
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Affiliation(s)
- Nan Li
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
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