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Zhou S, Liu D, Fan K, Liu H, Zhang XD. Atomic-level design of biomimetic iron-sulfur clusters for biocatalysis. NANOSCALE 2024. [PMID: 39257356 DOI: 10.1039/d4nr02883j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
Designing biomimetic materials with high activity and customized biological functions by mimicking the central structure of biomolecules has become an important avenue for the development of medical materials. As an essential electron carrier, the iron-sulfur (Fe-S) clusters have the advantages of simple structure and high electron transport capacity. To rationally design and accurately construct functional materials, it is crucial to clarify the electronic structure and conformational relationships of Fe-S clusters. However, due to the complex catalytic mechanism and synthetic process in vitro, it is hard to reveal the structure-activity relationship of Fe-S clusters accurately. This review introduces the main structural types of Fe-S clusters and their catalytic mechanisms first. Then, several typical structural design strategies of biomimetic Fe-S clusters are systematically introduced. Furthermore, the development of Fe-S clusters in the biocatalytic field is enumerated, including tumor treatment, antibacterial, virus inhibition and plant photoprotection. Finally, the problems and development directions of Fe-S clusters are summarized. This review aims to guide people to accurately understand and regulate the electronic structure of Fe-S at the atomic level, which is of great significance for designing biomimetic materials with specific functions and expanding their applications in biocatalysis.
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Affiliation(s)
- Sufei Zhou
- Tianjin Key Laboratory of Brain Science and Neuroengineering, Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China.
| | - Di Liu
- Tianjin Key Laboratory of Brain Science and Neuroengineering, Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China.
| | - Kelong Fan
- Key Laboratory of Protein and Peptide Drugs, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Haile Liu
- Key Laboratory of Water Security and Water Environment Protection in Plateau Intersection (NWNU), Ministry of Education; Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
| | - Xiao-Dong Zhang
- Tianjin Key Laboratory of Brain Science and Neuroengineering, Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China.
- Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Sciences, Tianjin University, Tianjin 300350, China
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2
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Mettert EL, Kiley PJ. Fe-S cluster homeostasis and beyond: The multifaceted roles of IscR. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119749. [PMID: 38763301 PMCID: PMC11309008 DOI: 10.1016/j.bbamcr.2024.119749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 03/29/2024] [Accepted: 05/08/2024] [Indexed: 05/21/2024]
Abstract
The role of IscR in regulating the transcription of genes involved in Fe-S cluster homeostasis has been well established for the model organism Escherichia coli K12. In this bacterium, IscR coordinates expression of the Isc and Suf Fe-S cluster assembly pathways to meet cellular Fe-S cluster demands shaped by a variety of environmental cues. However, since its initial discovery nearly 25 years ago, there has been growing evidence that IscR function extends well beyond Fe-S cluster homeostasis, not only in E. coli, but in bacteria of diverse lifestyles. Notably, pathogenic bacteria have exploited the ability of IscR to respond to changes in oxygen tension, oxidative and nitrosative stress, and iron availability to navigate their trajectory in their respective hosts as changes in these cues are frequently encountered during host infection. In this review, we highlight these broader roles of IscR in different cellular processes and, in particular, discuss the importance of IscR as a virulence factor for many bacterial pathogens.
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Affiliation(s)
- Erin L Mettert
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Patricia J Kiley
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA.
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3
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Sourice M, Oriol C, Aubert C, Mandin P, Py B. Genetic dissection of the bacterial Fe-S protein biogenesis machineries. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119746. [PMID: 38719030 DOI: 10.1016/j.bbamcr.2024.119746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 04/12/2024] [Accepted: 05/03/2024] [Indexed: 05/13/2024]
Abstract
Iron‑sulfur (Fe-S) clusters are one of the most ancient and versatile inorganic cofactors present in the three domains of life. Fe-S clusters are essential cofactors for the activity of a large variety of metalloproteins that play crucial physiological roles. Fe-S protein biogenesis is a complex process that starts with the acquisition of the elements (iron and sulfur atoms) and their assembly into an Fe-S cluster that is subsequently inserted into the target proteins. The Fe-S protein biogenesis is ensured by multiproteic systems conserved across all domains of life. Here, we provide an overview on how bacterial genetics approaches have permitted to reveal and dissect the Fe-S protein biogenesis process in vivo.
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Affiliation(s)
- Mathieu Sourice
- Laboratoire de Chimie Bactérienne (UMR7283), Institut de Microbiologie de la Méditerranée, Institut Microbiologie Bioénergies et Biotechnologie, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France
| | - Charlotte Oriol
- Laboratoire de Chimie Bactérienne (UMR7283), Institut de Microbiologie de la Méditerranée, Institut Microbiologie Bioénergies et Biotechnologie, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France
| | - Corinne Aubert
- Laboratoire de Chimie Bactérienne (UMR7283), Institut de Microbiologie de la Méditerranée, Institut Microbiologie Bioénergies et Biotechnologie, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France
| | - Pierre Mandin
- Laboratoire de Chimie Bactérienne (UMR7283), Institut de Microbiologie de la Méditerranée, Institut Microbiologie Bioénergies et Biotechnologie, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France
| | - Béatrice Py
- Laboratoire de Chimie Bactérienne (UMR7283), Institut de Microbiologie de la Méditerranée, Institut Microbiologie Bioénergies et Biotechnologie, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France.
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4
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Gray E, Stewart MYY, Hanwell L, Crack JC, Devine R, Stevenson CEM, Volbeda A, Johnston AWB, Fontecilla-Camps JC, Hutchings MI, Todd JD, Le Brun NE. Stabilisation of the RirA [4Fe-4S] cluster results in loss of iron-sensing function. Chem Sci 2023; 14:9744-9758. [PMID: 37736639 PMCID: PMC10510648 DOI: 10.1039/d3sc03020b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 08/21/2023] [Indexed: 09/23/2023] Open
Abstract
RirA is a global iron regulator in diverse Alphaproteobacteria that belongs to the Rrf2 superfamily of transcriptional regulators, which can contain an iron-sulfur (Fe-S) cluster. Under iron-replete conditions, RirA contains a [4Fe-4S] cluster, enabling high-affinity binding to RirA-regulated operator sequences, thereby causing the repression of cellular iron uptake. Under iron deficiency, one of the cluster irons dissociates, generating an unstable [3Fe-4S] form that subsequently degrades to a [2Fe-2S] form and then to apo RirA, resulting in loss of high-affinity DNA-binding. The cluster is coordinated by three conserved cysteine residues and an unknown fourth ligand. Considering the lability of one of the irons and the resulting cluster fragility, we hypothesized that the fourth ligand may not be an amino acid residue. To investigate this, we considered that the introduction of an amino acid residue that could coordinate the cluster might stabilize it. A structural model of RirA, based on the Rrf2 family nitrosative stress response regulator NsrR, highlighted residue 8, an Asn in the RirA sequence, as being appropriately positioned to coordinate the cluster. Substitution of Asn8 with Asp, the equivalent, cluster-coordinating residue of NsrR, or with Cys, resulted in proteins that contained a [4Fe-4S] cluster, with N8D RirA exhibiting spectroscopic properties very similar to NsrR. The variant proteins retained the ability to bind RirA-regulated DNA, and could still act as repressors of RirA-regulated genes in vivo. However, they were significantly more stable than wild-type RirA when exposed to O2 and/or low iron. Importantly, they exhibited reduced capacity to respond to cellular iron levels, even abolished in the case of the N8D version, and thus were no longer iron sensing. This work demonstrates the importance of cluster fragility for the iron-sensing function of RirA, and more broadly, how a single residue substitution can alter cluster coordination and functional properties in the Rrf2 superfamily of regulators.
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Affiliation(s)
- Elizabeth Gray
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia Norwich Research Park Norwich NR4 7TJ UK +44 (0)1603 592003 +44 (0)1603 592699
| | - Melissa Y Y Stewart
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia Norwich Research Park Norwich NR4 7TJ UK +44 (0)1603 592003 +44 (0)1603 592699
| | - Libby Hanwell
- School of Biological Sciences, University of East Anglia Norwich Research Park Norwich NR4 7TJ UK
| | - Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia Norwich Research Park Norwich NR4 7TJ UK +44 (0)1603 592003 +44 (0)1603 592699
| | - Rebecca Devine
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - Clare E M Stevenson
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - Anne Volbeda
- Metalloproteins Unit, Institut de Biologie Structurale, CEA, CNRS, Université Grenoble-Alpes 71, Avenue des Martyrs, CS 10090 38044 Grenoble Cedex 9 France
| | - Andrew W B Johnston
- School of Biological Sciences, University of East Anglia Norwich Research Park Norwich NR4 7TJ UK
| | - Juan C Fontecilla-Camps
- Metalloproteins Unit, Institut de Biologie Structurale, CEA, CNRS, Université Grenoble-Alpes 71, Avenue des Martyrs, CS 10090 38044 Grenoble Cedex 9 France
| | - Matthew I Hutchings
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - Jonathan D Todd
- School of Biological Sciences, University of East Anglia Norwich Research Park Norwich NR4 7TJ UK
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia Norwich Research Park Norwich NR4 7TJ UK +44 (0)1603 592003 +44 (0)1603 592699
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5
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Zhang H, Sun T, Cao X, Wang Y, Ma Z, Wang Y, Yang N, Xu M, Deng X, Li H, Wang B, Yi J, Wang Z, Zhang Q, Chen C. Scanning iron response regulator binding sites using Dap-seq in the Brucella genome. PLoS Negl Trop Dis 2023; 17:e0011481. [PMID: 37459300 PMCID: PMC10374146 DOI: 10.1371/journal.pntd.0011481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 07/27/2023] [Accepted: 06/26/2023] [Indexed: 07/28/2023] Open
Abstract
Iron is an essential element required for all organisms. Iron response regulator (Irr) is a crucial transcriptional regulator and can affect the growth and iron uptake of Brucella. The growth rate of Brucella melitensis M5-90 irr mutant was significantly lower than that of B. melitensis M5-90 under normal or iron-sufficient conditions, however, the growth rate of the B. melitensis M5-90 irr mutant was significantly higher than that of B. melitensis M5-90 under iron-limited conditions. In addition, irr mutation significantly reduced iron uptake under iron-limited conditions. Previous studies suggested that the Irr protein has multiple target genes in the Brucella genome that are involved in iron metabolism. Therefore, in the present study, a Dap-seq approach was used to investigate the other iron metabolism genes that are also regulated by the Irr protein in Brucella. A total of seven genes were identified as target genes for Irr in this study and the expression levels of these seven genes was identified using qRT-PCR. The electrophoretic mobility shift assay confirmed that six out of the seven genes, namely rirA (BME_RS13665), membrane protein (BME_RS01725), hypothetical protein (BME_RS09560), ftrA (BME_RS14525), cation-transporting P-type ATPase (zntA) (BME_RS10660), and 2Fe-2S binding protein (BME_RS13655), interact with the Irr protein. Furthermore, the iron utilization and growth assay experiments confirmed that rirA was involve in iron metabolism and growth of Brucella. In summary, our results identified six genes regulated by the Irr protein that may participate in iron metabolism, and the rirA was identified as a regulon of Irr and it also plays a role in iron metabolism of Brucella. Collectively, these results provide valuable insights for the exploration of Brucella iron metabolism.
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Affiliation(s)
- Huan Zhang
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Tianhao Sun
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Xudong Cao
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
- School of Medicine, HeXi University, Zhangye City, Gansu, China
| | - Yifan Wang
- State key Laboratory of Agricultural Microbiology/College of Veterinary Medicine Huazhong Agricultural University 1 Wuhan, China
| | - Zhongchen Ma
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Yueli Wang
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Ningning Yang
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Mingguo Xu
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Xiaoyu Deng
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Honghuan Li
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Benben Wang
- School of Life Science, Shihezi University, Shihezi City, Xinjiang, China
| | - Jihai Yi
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Zhen Wang
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
| | - Qian Zhang
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
- State Key Laboratory for Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agriculture and Reclamation Science,Shihezi, Xinjiang, China
| | - Chuangfu Chen
- School of Animal Science and Technology, Shihezi University, Shihezi City, Xinjiang, China
- Collaborative Innovation Center for Prevention and Control of High Incidence Zoonotic Infectious Diseases in Western China, Shihezi, Xinjiang, China
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6
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Soto MJ, Pérez J, Muñoz-Dorado J, Contreras-Moreno FJ, Moraleda-Muñoz A. Transcriptomic response of Sinorhizobium meliloti to the predatory attack of Myxococcus xanthus. Front Microbiol 2023; 14:1213659. [PMID: 37405170 PMCID: PMC10315480 DOI: 10.3389/fmicb.2023.1213659] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/01/2023] [Indexed: 07/06/2023] Open
Abstract
Bacterial predation impacts microbial community structures, which can have both positive and negative effects on plant and animal health and on environmental sustainability. Myxococcus xanthus is an epibiotic soil predator with a broad range of prey, including Sinorhizobium meliloti, which establishes nitrogen-fixing symbiosis with legumes. During the M. xanthus-S. meliloti interaction, the predator must adapt its transcriptome to kill and lyse the target (predatosome), and the prey must orchestrate a transcriptional response (defensome) to protect itself against the biotic stress caused by the predatory attack. Here, we describe the transcriptional changes taking place in S. meliloti in response to myxobacterial predation. The results indicate that the predator induces massive changes in the prey transcriptome with up-regulation of protein synthesis and secretion, energy generation, and fatty acid (FA) synthesis, while down-regulating genes required for FA degradation and carbohydrate transport and metabolism. The reconstruction of up-regulated pathways suggests that S. meliloti modifies the cell envelop by increasing the production of different surface polysaccharides (SPSs) and membrane lipids. Besides the barrier role of SPSs, additional mechanisms involving the activity of efflux pumps and the peptide uptake transporter BacA, together with the production of H2O2 and formaldehyde have been unveiled. Also, the induction of the iron-uptake machinery in both predator and prey reflects a strong competition for this metal. With this research we complete the characterization of the complex transcriptional changes that occur during the M. xanthus-S. meliloti interaction, which can impact the establishment of beneficial symbiosis with legumes.
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Affiliation(s)
- María José Soto
- Departamento de Biotecnología y Protección Ambiental, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Juana Pérez
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - José Muñoz-Dorado
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | | | - Aurelio Moraleda-Muñoz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
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7
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Mihelj P, Abreu I, Moreyra T, González-Guerrero M, Raimunda D. Functional Characterization of the Co 2+ Transporter AitP in Sinorhizobium meliloti: A New Player in Fe 2+ Homeostasis. Appl Environ Microbiol 2023; 89:e0190122. [PMID: 36853042 PMCID: PMC10057888 DOI: 10.1128/aem.01901-22] [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: 11/11/2022] [Accepted: 01/27/2023] [Indexed: 03/01/2023] Open
Abstract
Co2+ induces the increase of the labile-Fe pool (LIP) by Fe-S cluster damage, heme synthesis inhibition, and "free" iron import, which affects cell viability. The N2-fixing bacteria, Sinorhizobium meliloti, is a suitable model to determine the roles of Co2+-transporting cation diffusion facilitator exporters (Co-eCDF) in Fe2+ homeostasis because it has a putative member of this subfamily, AitP, and two specific Fe2+-export systems. An insertional mutant of AitP showed Co2+ sensitivity and accumulation, Fe accumulation and hydrogen peroxide sensitivity, but not Fe2+ sensitivity, despite AitP being a bona fide low affinity Fe2+ exporter as demonstrated by the kinetic analyses of Fe2+ uptake into everted membrane vesicles. Suggesting concomitant Fe2+-dependent induced stress, Co2+ sensitivity was increased in strains carrying mutations in AitP and Fe2+ exporters which did not correlate with the Co2+ accumulation. Growth in the presence of sublethal Fe2+ and Co2+ concentrations suggested that free Fe-import might contribute to Co2+ toxicity. Supporting this, Co2+ induced transcription of Fe-import system and genes associated with Fe homeostasis. Analyses of total protoporphyrin content indicates Fe-S cluster attack as the major source for LIP. AitP-mediated Fe2+-export is likely counterbalanced via a nonfutile Fe2+-import pathway. Two lines of evidence support this: (i) an increased hemin uptake in the presence of Co2+ was observed in wild-type (WT) versus AitP mutant, and (ii) hemin reversed the Co2+ sensitivity in the AitP mutant. Thus, the simultaneous detoxification mediated by AitP aids cells to orchestrate an Fe-S cluster salvage response, avoiding the increase in the LIP caused by the disassembly of Fe-S clusters or free iron uptake. IMPORTANCE Cross-talk between iron and cobalt has been long recognized in biological systems. This is due to the capacity of cobalt to interfere with proper iron utilization. Cells can detoxify cobalt by exporting mechanisms involving membrane proteins known as exporters. Highlighting the cross-talk, the capacity of several cobalt exporters to also export iron is emerging. Although biologically less important than Fe2+, Co2+ induces toxicity by promoting intracellular Fe release, which ultimately causes additional toxic effects. In this work, we describe how the rhizobia cells solve this perturbation by clearing Fe through a Co2+ exporter, in order to reestablish intracellular Fe levels by importing nonfree Fe, heme. This piggyback-ride type of transport may aid bacterial cells to survive in free-living conditions where high anthropogenic Co2+ content may be encountered.
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Affiliation(s)
- Paula Mihelj
- Instituto de Investigación Médica Mercedes y Martín Ferreyra-INIMEC-CONICET, UNC, Córdoba, Argentina
| | - Isidro Abreu
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Madrid, Spain
| | - Tomás Moreyra
- Instituto de Investigación Médica Mercedes y Martín Ferreyra-INIMEC-CONICET, UNC, Córdoba, Argentina
| | - Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Madrid, Spain
| | - Daniel Raimunda
- Instituto de Investigación Médica Mercedes y Martín Ferreyra-INIMEC-CONICET, UNC, Córdoba, Argentina
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8
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Sankari S, Babu VM, Bian K, Alhhazmi A, Andorfer MC, Avalos DM, Smith TA, Yoon K, Drennan CL, Yaffe MB, Lourido S, Walker GC. A haem-sequestering plant peptide promotes iron uptake in symbiotic bacteria. Nat Microbiol 2022; 7:1453-1465. [PMID: 35953657 PMCID: PMC9420810 DOI: 10.1038/s41564-022-01192-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 06/29/2022] [Indexed: 11/09/2022]
Abstract
Symbiotic partnerships with rhizobial bacteria enable legumes to grow without nitrogen fertilizer because rhizobia convert atmospheric nitrogen gas into ammonia via nitrogenase. After Sinorhizobium meliloti penetrate the root nodules that they have elicited in Medicago truncatula, the plant produces a family of about 700 nodule cysteine-rich (NCR) peptides that guide the differentiation of endocytosed bacteria into nitrogen-fixing bacteroids. The sequences of the NCR peptides are related to the defensin class of antimicrobial peptides, but have been adapted to play symbiotic roles. Using a variety of spectroscopic, biophysical and biochemical techniques, we show here that the most extensively characterized NCR peptide, 24 amino acid NCR247, binds haem with nanomolar affinity. Bound haem molecules and their iron are initially made biologically inaccessible through the formation of hexamers (6 haem/6 NCR247) and then higher-order complexes. We present evidence that NCR247 is crucial for effective nitrogen-fixing symbiosis. We propose that by sequestering haem and its bound iron, NCR247 creates a physiological state of haem deprivation. This in turn induces an iron-starvation response in rhizobia that results in iron import, which itself is required for nitrogenase activity. Using the same methods as for L-NCR247, we show that the D-enantiomer of NCR247 can bind and sequester haem in an equivalent manner. The special abilities of NCR247 and its D-enantiomer to sequester haem suggest a broad range of potential applications related to human health.
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Affiliation(s)
- Siva Sankari
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Vignesh M.P. Babu
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Ke Bian
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Areej Alhhazmi
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Mary C. Andorfer
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Dante M. Avalos
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Harvard Graduate Program in Biophysics, Harvard University, Cambridge, MA 02138, USA
| | - Tyler A. Smith
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Kwan Yoon
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Catherine L. Drennan
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02142
| | - Michael B. Yaffe
- Departments of Biology and Biological Engineering, and Center for Precision Cancer Medicine, David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute for Technology, Cambridge, MA 02139, USA.,Divisions of Acute Care Surgery, Trauma, and Surgical Critical Care, and Surgical Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215 USA
| | - Sebastian Lourido
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Graham C. Walker
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
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9
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Rohac R, Crack JC, de Rosny E, Gigarel O, Le Brun NE, Fontecilla-Camps JC, Volbeda A. Structural determinants of DNA recognition by the NO sensor NsrR and related Rrf2-type [FeS]-transcription factors. Commun Biol 2022; 5:769. [PMID: 35908109 PMCID: PMC9338935 DOI: 10.1038/s42003-022-03745-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 07/21/2022] [Indexed: 11/20/2022] Open
Abstract
Several transcription factors of the Rrf2 family use an iron-sulfur cluster to regulate DNA binding through effectors such as nitric oxide (NO), cellular redox status and iron levels. [4Fe-4S]-NsrR from Streptomyces coelicolor (ScNsrR) modulates expression of three different genes via reaction and complex formation with variable amounts of NO, which results in detoxification of this gas. Here, we report the crystal structure of ScNsrR complexed with an hmpA1 gene operator fragment and compare it with those previously reported for [2Fe-2S]-RsrR/rsrR and apo-IscR/hyA complexes. Important structural differences reside in the variation of the DNA minor and major groove widths. In addition, different DNA curvatures and different interactions with the protein sensors are observed. We also report studies of NsrR binding to four hmpA1 variants, which indicate that flexibility in the central region is not a key binding determinant. Our study explores the promotor binding specificities of three closely related transcriptional regulators. The crystal structure of the iron-sulfur protein NsrR from Streptomyces coelicolor bound to a gene operator fragment is reported and compared with other structures, giving insight into the structural determinants of DNA recognition by the NO sensor.
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Affiliation(s)
- Roman Rohac
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Metalloproteins Unit, F-38000, Grenoble, France
| | - Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Eve de Rosny
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Metalloproteins Unit, F-38000, Grenoble, France
| | - Océane Gigarel
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Metalloproteins Unit, F-38000, Grenoble, France
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Juan C Fontecilla-Camps
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Metalloproteins Unit, F-38000, Grenoble, France
| | - Anne Volbeda
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Metalloproteins Unit, F-38000, Grenoble, France.
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Boncella AE, Sabo ET, Santore RM, Carter J, Whalen J, Hudspeth JD, Morrison CN. The expanding utility of iron-sulfur clusters: Their functional roles in biology, synthetic small molecules, maquettes and artificial proteins, biomimetic materials, and therapeutic strategies. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214229] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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12
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He H, Tang J, Chen J, Hu J, Zhu Z, Liu Y, Shuai L, Cao L, Liu Z, Xia Z, Ding X, Hu S, Zhang Y, Rang J, Xia L. Flaviolin-Like Gene Cluster Deletion Optimized the Butenyl-Spinosyn Biosynthesis Route in Saccharopolyspora pogona. ACS Synth Biol 2021; 10:2740-2752. [PMID: 34601869 DOI: 10.1021/acssynbio.1c00344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Reduction and optimization of the microbial genome is an important strategy for constructing synthetic biological chassis cells and overcoming obstacles in natural product discovery and production. However, it is of great challenge to discover target genes that can be deleted and optimized due to the complicated genome of actinomycetes. Saccharopolyspora pogona can produce butenyl-spinosyn during aerobic fermentation, and its genome contains 32 different gene clusters. This suggests that there is a large amount of potential competitive metabolism in S. pogona, which affects the biosynthesis of butenyl-spinosyn. By analyzing the genome of S. pogona, six polyketide gene clusters were identified. From those, the complete deletion of clu13, a flaviolin-like gene cluster, generated a high butenyl-spinosyn-producing strain. Production of this strain was 4.06-fold higher than that of the wildtype strain. Transcriptome profiling revealed that butenyl-spinosyn biosynthesis was not primarily induced by the polyketide synthase RppA-like but was related to hypothetical protein Sp1764. However, the repression of sp1764 was not enough to explain the enormous enhancement of butenyl-spinosyn yields in S. pogona-Δclu13. After the comparative proteomic analysis of S. pogona-Δclu13 and S. pogona, two proteins, biotin carboxyl carrier protein (BccA) and response regulator (Reg), were investigated, whose overexpression led to great advantages of butenyl-spinosyn biosynthesis. In this way, we successfully discovered three key genes that obviously optimize the biosynthesis of butenyl-spinosyn. Gene cluster simplification performed in conjunction with multiomics analysis is of great practical significance for screening dominant chassis strains and optimizing secondary metabolism. This work provided an idea about screening key factors and efficient construction of production strains.
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Affiliation(s)
- Haocheng He
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Jianli Tang
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Jianming Chen
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Jinjuan Hu
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Zirong Zhu
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Yang Liu
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Ling Shuai
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Li Cao
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Zhudong Liu
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Ziyuan Xia
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Xuezhi Ding
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Shengbiao Hu
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Youming Zhang
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Jie Rang
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
| | - Liqiu Xia
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha 410083, China
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Crack JC, Gray E, Le Brun NE. Sensing mechanisms of iron-sulfur cluster regulatory proteins elucidated using native mass spectrometry. Dalton Trans 2021; 50:7887-7897. [PMID: 34037038 PMCID: PMC8204329 DOI: 10.1039/d1dt00993a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/17/2021] [Indexed: 12/02/2022]
Abstract
The ability to sense and respond to various key environmental cues is important for the survival and adaptability of many bacteria, including pathogens. The particular sensitivity of iron-sulfur (Fe-S) clusters is exploited in nature, such that multiple sensor-regulator proteins, which coordinate the detection of analytes with a (in many cases) global transcriptional response, are Fe-S cluster proteins. The fragility and sensitivity of these Fe-S clusters make studying such proteins difficult, and gaining insight of what they sense, and how they sense it and transduce the signal to affect transcription, is a major challenge. While mass spectrometry is very widely used in biological research, it is normally employed under denaturing conditions where non-covalently attached cofactors are lost. However, mass spectrometry under conditions where the protein retains its native structure and, thus, cofactors, is now itself a flourishing field, and the application of such 'native' mass spectrometry to study metalloproteins is now relatively widespread. Here we describe recent advances in using native MS to study Fe-S cluster proteins. Through its ability to accurately measure mass changes that reflect chemistry occurring at the cluster, this approach has yielded a remarkable richness of information that is not accessible by other, more traditional techniques.
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Affiliation(s)
- Jason C. Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research ParkNorwichNR4 7TJUK
| | - Elizabeth Gray
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research ParkNorwichNR4 7TJUK
| | - Nick E. Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research ParkNorwichNR4 7TJUK
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Bradley JM, Svistunenko DA, Wilson MT, Hemmings AM, Moore GR, Le Brun NE. Bacterial iron detoxification at the molecular level. J Biol Chem 2021; 295:17602-17623. [PMID: 33454001 PMCID: PMC7762939 DOI: 10.1074/jbc.rev120.007746] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 10/07/2020] [Indexed: 01/18/2023] Open
Abstract
Iron is an essential micronutrient, and, in the case of bacteria, its availability is commonly a growth-limiting factor. However, correct functioning of cells requires that the labile pool of chelatable "free" iron be tightly regulated. Correct metalation of proteins requiring iron as a cofactor demands that such a readily accessible source of iron exist, but overaccumulation results in an oxidative burden that, if unchecked, would lead to cell death. The toxicity of iron stems from its potential to catalyze formation of reactive oxygen species that, in addition to causing damage to biological molecules, can also lead to the formation of reactive nitrogen species. To avoid iron-mediated oxidative stress, bacteria utilize iron-dependent global regulators to sense the iron status of the cell and regulate the expression of proteins involved in the acquisition, storage, and efflux of iron accordingly. Here, we survey the current understanding of the structure and mechanism of the important members of each of these classes of protein. Diversity in the details of iron homeostasis mechanisms reflect the differing nutritional stresses resulting from the wide variety of ecological niches that bacteria inhabit. However, in this review, we seek to highlight the similarities of iron homeostasis between different bacteria, while acknowledging important variations. In this way, we hope to illustrate how bacteria have evolved common approaches to overcome the dual problems of the insolubility and potential toxicity of iron.
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Affiliation(s)
- Justin M Bradley
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom.
| | | | - Michael T Wilson
- School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Andrew M Hemmings
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom; Centre for Molecular and Structural Biochemistry, School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Geoffrey R Moore
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom.
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Rhizobiales-Specific RirA Represses a Naturally "Synthetic" Foreign Siderophore Gene Cluster To Maintain Sinorhizobium-Legume Mutualism. mBio 2021; 13:e0290021. [PMID: 35130720 PMCID: PMC8822346 DOI: 10.1128/mbio.02900-21] [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] [Indexed: 12/14/2022] Open
Abstract
Iron homeostasis is strictly regulated in cellular organisms. The Rhizobiales order enriched with symbiotic and pathogenic bacteria has evolved a lineage-specific regulator, RirA, responding to iron fluctuations. However, the regulatory role of RirA in bacterium-host interactions remains largely unknown. Here, we report that RirA is essential for mutualistic interactions of Sinorhizobium fredii with its legume hosts by repressing a gene cluster directing biosynthesis and transport of petrobactin siderophore. Genes encoding an inner membrane ABC transporter (fat) and the biosynthetic machinery (asb) of petrobactin siderophore are sporadically distributed in Gram-positive and Gram-negative bacteria. An outer membrane siderophore receptor gene (fprA) was naturally assembled with asb and fat, forming a long polycistron in S. fredii. An indigenous regulation cascade harboring an inner membrane protease (RseP), a sigma factor (FecI), and its anti-sigma protein (FecR) were involved in direct activation of the fprA-asb-fat polycistron. Operons harboring fecI and fprA-asb-fat, and those encoding the indigenous TonB-ExbB-ExbD complex delivering energy to the outer membrane transport activity, were directly repressed by RirA under iron-replete conditions. The rirA deletion led to upregulation of these operons and iron overload in nodules, impaired intracellular persistence, and symbiotic nitrogen fixation of rhizobia. Mutualistic defects of the rirA mutant can be rescued by blocking activities of this naturally "synthetic" circuit for siderophore biosynthesis and transport. These findings not only are significant for understanding iron homeostasis of mutualistic interactions but also provide insights into assembly and integration of foreign machineries for biosynthesis and transport of siderophores, horizontal transfer of which is selected in microbiota. IMPORTANCE Iron is a public good explored by both eukaryotes and prokaryotes. The abundant ferric form is insoluble under neutral and basic pH conditions, and many bacteria secrete siderophores forming soluble ferric siderophore complexes, which can be then taken up by specific receptors and transporters. Siderophore biosynthesis and uptake machineries can be horizontally transferred among bacteria in nature. Despite increasing attention on the importance of siderophores in host-microbiota interactions, the regulatory integration process of transferred siderophore biosynthesis and transport genes is poorly understood in an evolutionary context. By focusing on the mutualistic rhizobium-legume symbiosis, here, we report how a naturally synthetic foreign siderophore gene cluster was integrated with the rhizobial indigenous regulation cascade, which is essential for maintaining mutualistic interactions.
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Abstract
Iron-sulfur clusters constitute a large and widely distributed group of protein cofactors that play key roles in a wide range of metabolic processes. The inherent reactivity of iron-sulfur clusters toward small molecules, for example, O2, NO, or free Fe, makes them ideal for sensing changes in the cellular environment. Nondenaturing, or native, MS is unique in its ability to preserve the noncovalent interactions of many (if not all) species, including stable intermediates, while providing accurate mass measurements in both thermodynamic and kinetic experimental regimes. Here, we provide practical guidance for the study of iron-sulfur proteins by native MS, illustrated by examples where it has been used to unambiguously determine the type of cluster coordinated to the protein framework. We also describe the use of time-resolved native MS to follow the kinetics of cluster conversion, allowing the elucidation of the precise series of molecular events for all species involved. Finally, we provide advice on a unique approach to a typical thermodynamic titration, uncovering early, quasi-stable, intermediates in the reaction of a cluster with nitric oxide, resulting in cluster nitrosylation.
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Affiliation(s)
- Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, UK
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, UK.
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Sinorhizobium meliloti YrbA binds divalent metal cations using two conserved histidines. Biosci Rep 2020; 40:226508. [PMID: 32970113 PMCID: PMC7538681 DOI: 10.1042/bsr20202956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/22/2020] [Accepted: 09/24/2020] [Indexed: 11/23/2022] Open
Abstract
Sinorhizobium meliloti is a nitrogen-fixing bacterium forming symbiotic nodules with the legume Medicago truncatula. S. meliloti possesses two BolA-like proteins (BolA and YrbA), the function of which is unknown. In organisms where BolA proteins and monothiol glutaredoxins (Grxs) are present, they contribute to the regulation of iron homeostasis by bridging a [2Fe–2S] cluster into heterodimers. A role in the maturation of iron–sulfur (Fe–S) proteins is also attributed to both proteins. In the present study, we have performed a structure–function analysis of SmYrbA showing that it coordinates diverse divalent metal ions (Fe2+, Co2+, Ni2+, Cu2+ and Zn2+) using His32 and His67 residues, that are also used for Fe–S cluster binding in BolA–Grx heterodimers. It also possesses the capacity to form heterodimers with the sole monothiol glutaredoxin (SmGrx2) present in this species. Using cellular approaches analyzing the metal tolerance of S. meliloti mutant strains inactivated in the yrbA and/or bolA genes, we provide evidence for a connection of YrbA with the regulation of iron homeostasis. The mild defects in M. truncatula nodulation reported for the yrbA bolA mutant as compared with the stronger defects in nodule development previously observed for a grx2 mutant suggest functions independent of SmGrx2. These results help in clarifying the physiological role of BolA-type proteins in bacteria.
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RirA of Dinoroseobacter shibae senses iron via a [3Fe-4S]1+ cluster co-ordinated by three cysteine residues. Biochem J 2020; 477:191-212. [PMID: 31860023 DOI: 10.1042/bcj20180734] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 12/17/2019] [Accepted: 12/19/2019] [Indexed: 12/15/2022]
Abstract
In the marine bacterium, Dinoroseobacter shibae the transcription factor rhizobial iron regulator A (RirA) is involved in the adaptation to iron-limited growth conditions. In vitro iron and sulfide content determinations in combination with UV/Vis and electron paramagnetic resonance (EPR) spectroscopic analyses using anaerobically purified, recombinant RirA protein suggested a [3Fe-4S]1+ cluster as a cofactor. In vivo Mössbauer spectroscopy also corroborated the presence of a [3Fe-4S]1+ cluster in RirA. Moreover, the cluster was found to be redox stable. Three out of four highly conserved cysteine residues of RirA (Cys 91, Cys 99, Cys 105) were found essential for the [3Fe-4S]1+ cluster coordination. The dimeric structure of the RirA protein was independent of the presence of the [3Fe-4S]1+ cluster. Electro mobility shift assays demonstrated the essential role of an intact [3Fe-4S]1+ cluster for promoter binding by RirA. The DNA binding site was identified by DNase I footprinting. Mutagenesis studies in combination with DNA binding assays confirmed the promoter binding site as 3'-TTAAN10AATT-5'. This work describes a novel mechanism for the direct sensing of cellular iron levels in bacteria by an iron-responsive transcriptional regulator using the integrity of a redox-inactive [3Fe-4S]1+ cluster, and further contributes to the general understanding of iron regulation in marine bacteria.
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Abreu I, Mihelj P, Raimunda D. Transition metal transporters in rhizobia: tuning the inorganic micronutrient requirements to different living styles. Metallomics 2020; 11:735-755. [PMID: 30734808 DOI: 10.1039/c8mt00372f] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A group of bacteria known as rhizobia are key players in symbiotic nitrogen fixation (SNF) in partnership with legumes. After a molecular exchange, the bacteria end surrounded by a plant membrane forming symbiosomes, organelle-like structures, where they differentiate to bacteroids and fix nitrogen. This symbiotic process is highly dependent on dynamic nutrient exchanges between the partners. Among these are transition metals (TM) participating as inorganic and organic cofactors of fundamental enzymes. While the understanding of how plant transporters facilitate TMs to the very near environment of the bacteroid is expanding, our knowledge on how bacteroid transporters integrate to TM homeostasis mechanisms in the plant host is still limited. This is significantly relevant considering the low solubility and scarcity of TMs in soils, and the in crescendo gradient of TM bioavailability rhizobia faces during the infection and bacteroid differentiation processes. In the present work, we review the main metal transporter families found in rhizobia, their role in free-living conditions and, when known, in symbiosis. We focus on discussing those transporters which could play a significant role in TM-dependent biochemical and physiological processes in the bacteroid, thus paving the way towards an optimized SNF.
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Affiliation(s)
- Isidro Abreu
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Madrid, Spain
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20
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Stewart MYY, Bush MJ, Crack JC, Buttner MJ, Le Brun NE. Interaction of the Streptomyces Wbl protein WhiD with the principal sigma factor σ HrdB depends on the WhiD [4Fe-4S] cluster. J Biol Chem 2020; 295:9752-9765. [PMID: 32303639 PMCID: PMC7363131 DOI: 10.1074/jbc.ra120.012708] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/15/2020] [Indexed: 12/29/2022] Open
Abstract
The bacterial protein WhiD belongs to the Wbl family of iron-sulfur [Fe-S] proteins present only in the actinomycetes. In Streptomyces coelicolor, it is required for the late stages of sporulation, but precisely how it functions is unknown. Here, we report results from in vitro and in vivo experiments with WhiD from Streptomyces venezuelae (SvWhiD), which differs from S. coelicolor WhiD (ScWhiD) only at the C terminus. We observed that, like ScWhiD and other Wbl proteins, SvWhiD binds a [4Fe-4S] cluster that is moderately sensitive to O2 and highly sensitive to nitric oxide (NO). However, although all previous studies have reported that Wbl proteins are monomers, we found that SvWhiD exists in a monomer-dimer equilibrium associated with its unusual C-terminal extension. Several Wbl proteins of Mycobacterium tuberculosis are known to interact with its principal sigma factor SigA. Using bacterial two-hybrid, gel filtration, and MS analyses, we demonstrate that SvWhiD interacts with domain 4 of the principal sigma factor of Streptomyces, σHrdB (σHrdB 4). Using MS, we determined the dissociation constant (Kd ) for the SvWhiD-σHrdB 4 complex as ∼0.7 μm, consistent with a relatively tight binding interaction. We found that complex formation was cluster dependent and that a reaction with NO, which was complete at 8-10 NO molecules per cluster, resulted in dissociation into the separate proteins. The SvWhiD [4Fe-4S] cluster was significantly less sensitive to reaction with O2 and NO when SvWhiD was bound to σHrdB 4, consistent with protection of the cluster in the complex.
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Affiliation(s)
- Melissa Y Y Stewart
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Matthew J Bush
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom
| | - Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Mark J Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
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Crack JC, Amara P, Volbeda A, Mouesca JM, Rohac R, Pellicer Martinez MT, Huang CY, Gigarel O, Rinaldi C, Le Brun NE, Fontecilla-Camps JC. Electron and Proton Transfers Modulate DNA Binding by the Transcription Regulator RsrR. J Am Chem Soc 2020; 142:5104-5116. [PMID: 32078310 DOI: 10.1021/jacs.9b12250] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The [Fe2S2]-RsrR gene transcription regulator senses the redox status in bacteria by modulating DNA binding, while its cluster cycles between +1 and +2 states-only the latter binds DNA. We have previously shown that RsrR can undergo remarkable conformational changes involving a 100° rotation of tryptophan 9 between exposed (Out) and buried (In) states. Here, we have used the chemical modification of Trp9, site-directed mutagenesis, and crystallographic and computational chemical studies to show that (i) the Out and In states correspond to oxidized and reduced RsrR, respectively, (ii) His33 is protonated in the In state due to a change in its pKa caused by cluster reduction, and (iii) Trp9 rotation is conditioned by the response of its dipole moment to environmental electrostatic changes. Our findings illustrate a novel function of protonation resulting from electron transfer.
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Affiliation(s)
- Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
| | - Patricia Amara
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Metalloproteins Unit, F-38044 Grenoble, France
| | - Anne Volbeda
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Metalloproteins Unit, F-38044 Grenoble, France
| | - Jean-Marie Mouesca
- Université Grenoble Alpes, CEA, CNRS, IRIG-DIESE-SyMMES-CAMPE, 38000 Grenoble, France
| | - Roman Rohac
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Metalloproteins Unit, F-38044 Grenoble, France
| | - Ma Teresa Pellicer Martinez
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
| | - Chia-Ying Huang
- Macromolecular Crystallography, Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, PSI, Switzerland
| | - Océane Gigarel
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Metalloproteins Unit, F-38044 Grenoble, France
| | - Clara Rinaldi
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Metalloproteins Unit, F-38044 Grenoble, France
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
| | - Juan C Fontecilla-Camps
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Metalloproteins Unit, F-38044 Grenoble, France
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Pellicer Martinez MT, Crack JC, Stewart MYY, Bradley JM, Svistunenko DA, Johnston AWB, Cheesman MR, Todd JD, Le Brun NE. Mechanisms of iron- and O 2-sensing by the [4Fe-4S] cluster of the global iron regulator RirA. eLife 2019; 8:e47804. [PMID: 31526471 PMCID: PMC6748827 DOI: 10.7554/elife.47804] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 07/29/2019] [Indexed: 01/05/2023] Open
Abstract
RirA is a global regulator of iron homeostasis in Rhizobium and related α-proteobacteria. In its [4Fe-4S] cluster-bound form it represses iron uptake by binding to IRO Box sequences upstream of RirA-regulated genes. Under low iron and/or aerobic conditions, [4Fe-4S] RirA undergoes cluster conversion/degradation to apo-RirA, which can no longer bind IRO Box sequences. Here, we apply time-resolved mass spectrometry and electron paramagnetic resonance spectroscopy to determine how the RirA cluster senses iron and O2. The data indicate that the key iron-sensing step is the O2-independent, reversible dissociation of Fe2+ from [4Fe-4S]2+ to form [3Fe-4S]0. The dissociation constant for this process was determined as Kd = ~3 µM, which is consistent with the sensing of 'free' iron in the cytoplasm. O2-sensing occurs through enhanced cluster degradation under aerobic conditions, via O2-mediated oxidation of the [3Fe-4S]0 intermediate to form [3Fe-4S]1+. This work provides a detailed mechanistic/functional view of an iron-responsive regulator.
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Affiliation(s)
- Ma Teresa Pellicer Martinez
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | - Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | - Melissa YY Stewart
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | - Justin M Bradley
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | | | - Andrew WB Johnston
- School of Biological SciencesUniversity of East AngliaNorwichUnited Kingdom
| | - Myles R Cheesman
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | - Jonathan D Todd
- School of Biological SciencesUniversity of East AngliaNorwichUnited Kingdom
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
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23
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Amarelle V, Koziol U, Fabiano E. Highly conserved nucleotide motifs present in the 5'UTR of the heme-receptor gene shmR are required for HmuP-dependent expression of shmR in Ensifer meliloti. Biometals 2019; 32:273-291. [PMID: 30810877 DOI: 10.1007/s10534-019-00184-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 02/18/2019] [Indexed: 11/28/2022]
Abstract
Heme may represent a major iron-source for bacteria. In the symbiotic nitrogen-fixing bacterium Ensifer meliloti 1021, iron acquisition from heme depends on the outer-membrane heme-receptor ShmR. Expression of shmR gene is repressed by iron in a RirA dependent manner while under iron-limitation its expression requires the small protein HmuP. In this work, we identified highly conserved nucleotide motifs present upstream the shmR gene. These motifs are widely distributed among Alpha and Beta Proteobacteria, and correlate with the presence of HmuP coding sequences in bacterial genomes. According to data presented in this work, we named these new motifs as HmuP-responsive elements (HPREs). In the analyzed genomes, the HPREs were always present upstream of genes encoding putative heme-receptors. Moreover, in those Alpha and Beta Proteobacteria where transcriptional start sites for shmR homologs are known, HPREs were located in the 5'UTR region. In this work we show that in E. meliloti 1021, HPREs are involved in HmuP-dependent shmR expression. Moreover, we show that changes in sequence composition of the HPREs correlate with changes in a predicted RNA secondary structure element and affect shmR gene expression.
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Affiliation(s)
- Vanesa Amarelle
- Instituto de Investigaciones Biologicas Clemente Estable, Montevideo, Uruguay
| | - Uriel Koziol
- Instituto de Investigaciones Biologicas Clemente Estable, Montevideo, Uruguay
| | - Elena Fabiano
- Instituto de Investigaciones Biologicas Clemente Estable, Montevideo, Uruguay.
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24
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Crespo-Rivas JC, Navarro-Gómez P, Alias-Villegas C, Shi J, Zhen T, Niu Y, Cuéllar V, Moreno J, Cubo T, Vinardell JM, Ruiz-Sainz JE, Acosta-Jurado S, Soto MJ. Sinorhizobium fredii HH103 RirA Is Required for Oxidative Stress Resistance and Efficient Symbiosis with Soybean. Int J Mol Sci 2019; 20:E787. [PMID: 30759803 PMCID: PMC6386902 DOI: 10.3390/ijms20030787] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/07/2019] [Accepted: 02/09/2019] [Indexed: 11/28/2022] Open
Abstract
Members of Rhizobiaceae contain a homologue of the iron-responsive regulatory protein RirA. In different bacteria, RirA acts as a repressor of iron uptake systems under iron-replete conditions and contributes to ameliorate cell damage during oxidative stress. In Rhizobium leguminosarum and Sinorhizobium meliloti, mutations in rirA do not impair symbiotic nitrogen fixation. In this study, a rirA mutant of broad host range S. fredii HH103 has been constructed (SVQ780) and its free-living and symbiotic phenotypes evaluated. No production of siderophores could be detected in either the wild-type or SVQ780. The rirA mutant exhibited a growth advantage under iron-deficient conditions and hypersensitivity to hydrogen peroxide in iron-rich medium. Transcription of rirA in HH103 is subject to autoregulation and inactivation of the gene upregulates fbpA, a gene putatively involved in iron transport. The S. fredii rirA mutant was able to nodulate soybean plants, but symbiotic nitrogen fixation was impaired. Nodules induced by the mutant were poorly infected compared to those induced by the wild-type. Genetic complementation reversed the mutant's hypersensitivity to H₂O₂, expression of fbpA, and symbiotic deficiency in soybean plants. This is the first report that demonstrates a role for RirA in the Rhizobium-legume symbiosis.
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Affiliation(s)
- Juan Carlos Crespo-Rivas
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain.
| | - Pilar Navarro-Gómez
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain.
| | - Cynthia Alias-Villegas
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain.
| | - Jie Shi
- Daqing Branch of Heilongjiang Academy of Sciences, Daqing 163000, China.
| | - Tao Zhen
- Institute of Microbiology, Heilongjiang Academy of Sciences, Harbin 150001, China.
| | - Yanbo Niu
- Institute of Microbiology, Heilongjiang Academy of Sciences, Harbin 150001, China.
| | - Virginia Cuéllar
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, c/ Profesor Albareda 1, 18008 Granada, Spain.
| | - Javier Moreno
- Departamento de Biología Celular, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain.
| | - Teresa Cubo
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain.
| | - José María Vinardell
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain.
| | - José Enrique Ruiz-Sainz
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain.
| | - Sebastián Acosta-Jurado
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain.
| | - María José Soto
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, c/ Profesor Albareda 1, 18008 Granada, Spain.
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25
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Crack JC, Stewart MYY, Le Brun NE. Generation of 34S-substituted protein-bound [4Fe-4S] clusters using 34S-L-cysteine. Biol Methods Protoc 2019; 4:bpy015. [PMID: 32395620 PMCID: PMC7200944 DOI: 10.1093/biomethods/bpy015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/03/2018] [Accepted: 12/10/2018] [Indexed: 01/30/2023] Open
Abstract
The ability to specifically label the sulphide ions of protein-bound iron-sulphur (FeS) clusters with 34S isotope greatly facilitates structure-function studies. In particular, it provides insight when using either spectroscopic techniques that probe cluster-associated vibrations, or non-denaturing mass spectrometry, where the ∼+2 Da average increase per sulphide enables unambiguous assignment of the FeS cluster and, where relevant, its conversion/degradation products. Here, we employ a thermostable homologue of the O-acetyl-l-serine sulfhydrylase CysK to generate 34S-substituted l-cysteine and subsequently use it as a substrate for the l-cysteine desulfurase NifS to gradually supply 34S2- for in vitro FeS cluster assembly in an otherwise standard cluster reconstitution protocol.
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Affiliation(s)
- Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR47 TJ, UK
| | - Melissa Y Y Stewart
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR47 TJ, UK
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR47 TJ, UK
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26
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Misslinger M, Lechner BE, Bacher K, Haas H. Iron-sensing is governed by mitochondrial, not by cytosolic iron-sulfur cluster biogenesis in Aspergillus fumigatus. Metallomics 2018; 10:1687-1700. [PMID: 30395137 PMCID: PMC6250123 DOI: 10.1039/c8mt00263k] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 10/09/2018] [Indexed: 12/13/2022]
Abstract
Microorganisms have to adapt their metabolism to the requirements of their ecological niche to avoid iron shortage as well as iron toxicity. Therefore, mechanisms have been evolved to tightly regulate iron uptake, consumption, and detoxification, which depend on sensing the cellular iron status. In the facultative anaerobic yeast Saccharomyces cerevisiae, iron-sensing depends on mitochondrial (ISC) but not cytosolic iron-sulfur cluster assembly (CIA), while in mammals further processing of an ISC product via CIA is required for sensing of the cellular iron state. To address the question of how the obligatory aerobic mold Aspergillus fumigatus senses the cellular iron state, mutant strains allowing the downregulation of ISC and CIA were generated. These studies revealed that: (i) Nfs1 (Afu3g14240) and Nbp35 (Afu2g15960), which are involved in ISC and CIA, respectively, are essential for growth; (ii) a decrease in ISC (Nfs1 depletion) but not CIA (Nbp35 depletion) results in a transcriptional iron starvation response, (iii) a decrease in, ISC as well as CIA, increases the chelatable iron pool, accompanied by increased iron toxicity and increased susceptibility to oxidative stress and phleomycin. In agreement with ISC being essential for iron-sensing, a decrease in mitochondrial iron import by deletion of the mitochondrial iron importer MrsA resulted in an iron starvation response. Taken together, these data underline that iron-sensing in A. fumigatus depends on ISC but not CIA. Moreover, depletion of the glutathione pool via generating a mutant lacking γ-glutamylcysteine synthase, GshA (Afu3g13900), caused an iron starvation response, underlining a crucial role of glutathione in iron-sensing in A. fumigatus.
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Affiliation(s)
- Matthias Misslinger
- Division of Molecular Biology, Biocenter
, Medical University of Innsbruck
,
Innrain 80
, 6020 Innsbruck
, Austria
.
| | - Beatrix E. Lechner
- Division of Molecular Biology, Biocenter
, Medical University of Innsbruck
,
Innrain 80
, 6020 Innsbruck
, Austria
.
| | - Katharina Bacher
- Division of Molecular Biology, Biocenter
, Medical University of Innsbruck
,
Innrain 80
, 6020 Innsbruck
, Austria
.
| | - Hubertus Haas
- Division of Molecular Biology, Biocenter
, Medical University of Innsbruck
,
Innrain 80
, 6020 Innsbruck
, Austria
.
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