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González-Madrid G, Navarro CA, Acevedo-López J, Orellana LH, Jerez CA. Possible Role of CHAD Proteins in Copper Resistance. Microorganisms 2024; 12:409. [PMID: 38399813 PMCID: PMC10892726 DOI: 10.3390/microorganisms12020409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/14/2024] [Accepted: 02/16/2024] [Indexed: 02/25/2024] Open
Abstract
Conserved Histidine Alpha-helical Domain (CHAD) proteins attached to the surface of polyphosphate (PolyP) have been studied in some bacteria and one archaeon. However, the activity of CHAD proteins is unknown beyond their interaction with PolyP granules. By using bioinformatic analysis, we report that several species of the biomining acidophilic bacteria contain orthologs of CHAD proteins with high sequence identity. Furthermore, the gene coding for the CHAD protein is in the same genetic context of the enzyme polyphosphate kinase (PPK), which is in charge of PolyP synthesis. Particularly, the group of ppk and CHAD genes is highly conserved. Metallosphaera sedula and other acidophilic archaea used in biomining also contain CHAD proteins. These archaea show high levels of identity in genes coding for a cluster having the same organization. Amongst these genes are chad and ppx. In general, both biomining bacteria and archaea contain high PolyP levels and are highly resistant to heavy metals. Therefore, the presence of this conserved genetic organization suggests a high relevance for their metabolism. It has been formerly reported that a crystallized CHAD protein contains a copper-binding site. Based on this previous knowledge, in the present report, it was determined that all analyzed CHAD proteins are very conserved at their structural level. In addition, it was found that the lack of YgiF, an Escherichia coli CHAD-containing protein, decreases copper resistance in this bacterium. This phenotype was not only complemented by transforming E. coli with YgiF but also by expressing CHAD from Acidithiobacillus ferrooxidans in it. Interestingly, the strains in which the possible copper-binding sites were mutated were also more metal sensitive. Based on these results, we propose that CHAD proteins are involved in copper resistance in microorganisms. These findings are very interesting and may eventually improve biomining operations in the future.
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Affiliation(s)
| | | | | | | | - Carlos A. Jerez
- Laboratory of Molecular Microbiology and Biotechnology, Department of Biology, Faculty of Sciences, University of Chile, Santiago 7800003, Chile; (G.G.-M.); (C.A.N.); (J.A.-L.); (L.H.O.)
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Werten S, Waack P, Palm GJ, Virolle MJ, Hinrichs W. Crystal structures of free and ligand-bound forms of the TetR/AcrR-like regulator SCO3201 from Streptomyces coelicolor suggest a novel allosteric mechanism. FEBS J 2023; 290:521-532. [PMID: 36017630 PMCID: PMC10087246 DOI: 10.1111/febs.16606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 07/14/2022] [Accepted: 08/25/2022] [Indexed: 02/05/2023]
Abstract
TetR/AcrR-like transcription regulators enable bacteria to sense a wide variety of chemical compounds and to dynamically adapt the expression levels of specific genes in response to changing growth conditions. Here, we describe the structural characterisation of SCO3201, an atypical TetR/AcrR family member from Streptomyces coelicolor that strongly represses antibiotic production and morphological development under conditions of overexpression. We present crystal structures of SCO3201 in its ligand-free state as well as in complex with an unknown inducer, potentially a polyamine. In the ligand-free state, the DNA-binding domains of the SCO3201 dimer are held together in an unusually compact conformation and, as a result, the regulator cannot span the distance between the two half-sites of its operator. Interaction with the ligand coincides with a major structural rearrangement and partial conversion of the so-called hinge helix (α4) to a 310 -conformation, markedly increasing the distance between the DNA-binding domains. In sharp contrast to what was observed for other TetR/AcrR-like regulators, the increased interdomain distance might facilitate rather than abrogate interaction of the dimer with the operator. Such a 'reverse' induction mechanism could expand the regulatory repertoire of the TetR/AcrR family and may explain the dramatic impact of SCO3201 overexpression on the ability of S. coelicolor to generate antibiotics and sporulate.
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Affiliation(s)
- Sebastiaan Werten
- Institute of Genetic Epidemiology, Medical University of Innsbruck, Austria
| | - Paul Waack
- Institute of Biochemistry, University of Greifswald, Germany
| | | | - Marie-Joëlle Virolle
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
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Lejeune C, Sago L, Cornu D, Redeker V, Virolle MJ. A Proteomic Analysis Indicates That Oxidative Stress Is the Common Feature Triggering Antibiotic Production in Streptomyces coelicolor and in the pptA Mutant of Streptomyces lividans. Front Microbiol 2022; 12:813993. [PMID: 35392450 PMCID: PMC8981147 DOI: 10.3389/fmicb.2021.813993] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 12/30/2021] [Indexed: 11/29/2022] Open
Abstract
In most Streptomyces species, antibiotic production is triggered in phosphate limitation and repressed in phosphate proficiency. However, the model strain, Streptomyces coelicolor, escapes this general rule and produces actinorhoddin (ACT), a polyketide antibiotic, even more abundantly in phosphate proficiency than in phosphate limitation. ACT was shown to bear “anti-oxidant” properties suggesting that its biosynthesis is triggered by oxidative stress. Interestingly, Streptomyces lividans, a strain closely related to S. coelicolor, does not produce ACT in any phosphate condition whereas its pptA/sco4144 mutant produces ACT but only in phosphate limitation. In order to define the potentially common features of the ACT producing strains, these three strains were grown in condition of low and high phosphate availability, and a comparative quantitative analysis of their proteomes was carried out. The abundance of proteins of numerous pathways differed greatly between S. coelicolor and the S. lividans strains, especially those of central carbon metabolism and respiration. S. coelicolor is characterized by the high abundance of the complex I of the respiratory chain thought to generate reactive oxygen/nitrogen species and by a weak glycolytic activity causing a low carbon flux through the Pentose Phosphate Pathway resulting into the low generation of NADPH, a co-factor of thioredoxin reductases necessary to combat oxidative stress. Oxidative stress is thus predicted to be high in S. coelicolor. In contrast, the S. lividans strains had rather similar proteins abundance for most pathways except for the transhydrogenases SCO7622-23, involved in the conversion of NADPH into NADH. The poor abundance of these enzymes in the pptA mutant suggested a deficit in NADPH. Indeed, PptA is an accessory protein forcing polyphosphate into a conformation allowing their efficient use by various enzymes taking polyphosphate as a donor of phosphate and energy, including the ATP/Polyphosphate-dependent NAD kinase SCO1781. In phosphate limitation, this enzyme would mainly use polyphosphate to phosphorylate NAD into NADP, but this phosphorylation would be inefficient in the pptA mutant resulting in low NADP(H) levels and thus high oxidative stress. Altogether, our results indicated that high oxidative stress is the common feature triggering ACT biosynthesis in S. coelicolor and in the pptA mutant of S. lividans.
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Affiliation(s)
- Clara Lejeune
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Laila Sago
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - David Cornu
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Virginie Redeker
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
- Institut Francois Jacob, Molecular Imaging Center (MIRCen), Laboratory of Neurodegenerative Diseases, Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Centre National de la Recherche Scientifique, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Marie-Joelle Virolle
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
- *Correspondence: Marie-Joelle Virolle,
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Frank C, Pfeiffer D, Aktas M, Jendrossek D. Migration of Polyphosphate Granules in Agrobacterium tumefaciens. Microb Physiol 2022; 32:71-82. [PMID: 35168233 DOI: 10.1159/000521970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 01/12/2022] [Indexed: 01/29/2023]
Abstract
Agrobacterium tumefaciens has two polyphosphate (polyP) kinases, one of which (PPK1AT) is responsible for the formation of polyP granules, while the other (PPK2AT) is used for replenishing the NTP pools by using polyP as a phosphate donor to phosphorylate nucleoside diphosphates. Fusions of eYFP with PPK2AT or of the polyP granule-associated phosin PptA from Ralstonia eutropha always co-localized with polyP granules in A. tumefaciens and allowed the tracking of polyP granules in time-lapse microscopy experiments without the necessity to label the cells with the toxic dye DAPI. Fusions of PPK1AT with mCherry formed fluorescent signals often attached to, but not completely co-localizing with, polyP granules in wild-type cells. Time-lapse microscopy revealed that polyP granules in about one-third of a cell population migrated from the old pole to the new cell pole shortly before or during cell division. Many cells de novo formed a second (nonmigrating) polyP granule at the opposite cell pole before cell division was completed, resulting in two daughter cells each having a polyP granule at the old pole after septum formation. Migration of polyP granules was disordered in mitomycin C-treated or in PopZ-depleted cells, suggesting that polyP granules can associate with DNA or with other molecules that are segregated during the cell cycle.
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Affiliation(s)
- Celina Frank
- Institute of Microbiology, University of Stuttgart, Stuttgart, Germany
| | - Daniel Pfeiffer
- Department of Microbiology, University Bayreuth, Bayreuth, Germany
| | - Meriyem Aktas
- Microbial Biology, Ruhr University Bochum, Bochum, Germany
| | - Dieter Jendrossek
- Institute of Microbiology, University of Stuttgart, Stuttgart, Germany
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Rosigkeit H, Kneißle L, Obruča S, Jendrossek D. The Multiple Roles of Polyphosphate in Ralstonia eutropha and Other Bacteria. Microb Physiol 2021; 31:163-177. [PMID: 34015783 DOI: 10.1159/000515741] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/06/2021] [Indexed: 11/19/2022]
Abstract
An astonishing variety of functions has been attributed to polyphosphate (polyP) in prokaryotes. Besides being a reservoir of phosphorus, functions in exopolysaccharide formation, motility, virulence and in surviving various forms of stresses such as exposure to heat, extreme pH, oxidative agents, high osmolarity, heavy metals and others have been ascribed to polyP. In this contribution, we will provide a historical overview on polyP, will then describe the key proteins of polyP synthesis, the polyP kinases, before we will critically assess of the underlying data on the multiple functions of polyP and provide evidence that - with the exception of a P-storage-function - most other functions of polyP are not relevant for survival of Ralstonia eutropha, a biotechnologically important beta-proteobacterial species.
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Affiliation(s)
- Hanna Rosigkeit
- Institute of Microbiology, University of Stuttgart, Stuttgart, Germany
| | - Lea Kneißle
- Institute of Microbiology, University of Stuttgart, Stuttgart, Germany
| | - Stanislav Obruča
- Faculty of Chemistry, Brno University of Technology, Brno, Czechia
| | - Dieter Jendrossek
- Institute of Microbiology, University of Stuttgart, Stuttgart, Germany
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Shikura N, Darbon E, Esnault C, Deniset-Besseau A, Xu D, Lejeune C, Jacquet E, Nhiri N, Sago L, Cornu D, Werten S, Martel C, Virolle MJ. The Phosin PptA Plays a Negative Role in the Regulation of Antibiotic Production in Streptomyces lividans. Antibiotics (Basel) 2021; 10:325. [PMID: 33804592 PMCID: PMC8003754 DOI: 10.3390/antibiotics10030325] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 12/30/2022] Open
Abstract
In Streptomyces, antibiotic biosynthesis is triggered in phosphate limitation that is usually correlated with energetic stress. Polyphosphates constitute an important reservoir of phosphate and energy and a better understanding of their role in the regulation of antibiotic biosynthesis is of crucial importance. We previously characterized a gene, SLI_4384/ppk, encoding a polyphosphate kinase, whose disruption greatly enhanced the weak antibiotic production of Streptomyces lividans. In the condition of energetic stress, Ppk utilizes polyP as phosphate and energy donor, to generate ATP from ADP. In this paper, we established that ppk is co-transcribed with its two downstream genes, SLI_4383, encoding a phosin called PptA possessing a CHAD domain constituting a polyphosphate binding module and SLI_4382 encoding a nudix hydrolase. The expression of the ppk/pptA/SLI_4382 operon was shown to be under the positive control of the two-component system PhoR/PhoP and thus mainly expressed in condition of phosphate limitation. However, pptA and SLI_4382 can also be transcribed alone from their own promoter. The deletion of pptA resulted into earlier and stronger actinorhodin production and lower lipid content than the disruption of ppk, whereas the deletion of SLI_4382 had no obvious phenotypical consequences. The disruption of ppk was shown to have a polar effect on the expression of pptA, suggesting that the phenotype of the ppk mutant might be linked, at least in part, to the weak expression of pptA in this strain. Interestingly, the expression of phoR/phoP and that of the genes of the pho regulon involved in phosphate supply or saving were strongly up-regulated in pptA and ppk mutants, revealing that both mutants suffer from phosphate stress. Considering the presence of a polyphosphate binding module in PptA, but absence of similarities between PptA and known exo-polyphosphatases, we proposed that PptA constitutes an accessory factor for exopolyphosphatases or general phosphatases involved in the degradation of polyphosphates into phosphate.
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Affiliation(s)
- Noriyasu Shikura
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (N.S.); (E.D.); (C.E.); (D.X.); (C.L.); (L.S.); (D.C.); (C.M.)
| | - Emmanuelle Darbon
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (N.S.); (E.D.); (C.E.); (D.X.); (C.L.); (L.S.); (D.C.); (C.M.)
| | - Catherine Esnault
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (N.S.); (E.D.); (C.E.); (D.X.); (C.L.); (L.S.); (D.C.); (C.M.)
| | - Ariane Deniset-Besseau
- Laboratoire de Chimie Physique (LCP), CNRS UMR 8000, Université Paris-Saclay, 91405 Orsay, France;
| | - Delin Xu
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (N.S.); (E.D.); (C.E.); (D.X.); (C.L.); (L.S.); (D.C.); (C.M.)
- Department of Ecology, Institute of Hydrobiology, School of Life Science and Technology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Engineering Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education, Jinan University, Guangzhou 510632, China
| | - Clara Lejeune
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (N.S.); (E.D.); (C.E.); (D.X.); (C.L.); (L.S.); (D.C.); (C.M.)
| | - Eric Jacquet
- Institut de Chimie des Substances Naturelles, CNRS, Université Paris Saclay, 91190 Gif-sur-Yvette, France; (E.J.); (N.N.)
| | - Naima Nhiri
- Institut de Chimie des Substances Naturelles, CNRS, Université Paris Saclay, 91190 Gif-sur-Yvette, France; (E.J.); (N.N.)
| | - Laila Sago
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (N.S.); (E.D.); (C.E.); (D.X.); (C.L.); (L.S.); (D.C.); (C.M.)
| | - David Cornu
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (N.S.); (E.D.); (C.E.); (D.X.); (C.L.); (L.S.); (D.C.); (C.M.)
| | - Sebastiaan Werten
- Institute of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innrain 80, 6020 Innsbruck, Austria;
| | - Cécile Martel
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (N.S.); (E.D.); (C.E.); (D.X.); (C.L.); (L.S.); (D.C.); (C.M.)
| | - Marie-Joelle Virolle
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (N.S.); (E.D.); (C.E.); (D.X.); (C.L.); (L.S.); (D.C.); (C.M.)
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Molecular Mechanisms of Phosphate Sensing, Transport and Signalling in Streptomyces and Related Actinobacteria. Int J Mol Sci 2021; 22:ijms22031129. [PMID: 33498785 PMCID: PMC7866108 DOI: 10.3390/ijms22031129] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 01/18/2021] [Accepted: 01/20/2021] [Indexed: 12/13/2022] Open
Abstract
Phosphorous, in the form of phosphate, is a key element in the nutrition of all living beings. In nature, it is present in the form of phosphate salts, organophosphates, and phosphonates. Bacteria transport inorganic phosphate by the high affinity phosphate transport system PstSCAB, and the low affinity PitH transporters. The PstSCAB system consists of four components. PstS is the phosphate binding protein and discriminates between arsenate and phosphate. In the Streptomyces species, the PstS protein, attached to the outer side of the cell membrane, is glycosylated and released as a soluble protein that lacks its phosphate binding ability. Transport of phosphate by the PstSCAB system is drastically regulated by the inorganic phosphate concentration and mediated by binding of phosphorylated PhoP to the promoter of the PstSCAB operon. In Mycobacterium smegmatis, an additional high affinity transport system, PhnCDE, is also under PhoP regulation. Additionally, Streptomyces have a duplicated low affinity phosphate transport system encoded by the pitH1–pitH2 genes. In this system phosphate is transported as a metal-phosphate complex in simport with protons. Expression of pitH2, but not that of pitH1 in Streptomyces coelicolor, is regulated by PhoP. Interestingly, in many Streptomyces species, three gene clusters pitH1–pstSCAB–ppk (for a polyphosphate kinase), are linked in a supercluster formed by nine genes related to phosphate metabolism. Glycerol-3-phosphate may be transported by the actinobacteria Corynebacterium glutamicum that contains a ugp gene cluster for glycerol-3-P uptake, but the ugp cluster is not present in Streptomyces genomes. Sugar phosphates and nucleotides are used as phosphate source by the Streptomyces species, but there is no evidence of the uhp gene involved in the transport of sugar phosphates. Sugar phosphates and nucleotides are dephosphorylated by extracellular phosphatases and nucleotidases. An isolated uhpT gene for a hexose phosphate antiporter is present in several pathogenic corynebacteria, such as Corynebacterium diphtheriae, but not in non-pathogenic ones. Phosphonates are molecules that contains phosphate linked covalently to a carbon atom through a very stable C–P bond. Their utilization requires the phnCDE genes for phosphonates/phosphate transport and genes for degradation, including those for the subunits of the C–P lyase. Strains of the Arthrobacter and Streptomyces genera were reported to degrade simple phosphonates, but bioinformatic analysis reveals that whole sets of genes for putative phosphonate degradation are present only in three Arthrobacter species and a few Streptomyces species. Genes encoding the C–P lyase subunits occur in several Streptomyces species associated with plant roots or with mangroves, but not in the laboratory model Streptomyces species; however, the phnCDE genes that encode phosphonates/phosphate transport systems are frequent in Streptomyces species, suggesting that these genes, in the absence of C–P lyase genes, might be used as surrogate phosphate transporters. In summary, Streptomyces and related actinobacteria seem to be less versatile in phosphate transport systems than Enterobacteria.
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Frank C, Jendrossek D. Acidocalcisomes and Polyphosphate Granules Are Different Subcellular Structures in Agrobacterium tumefaciens. Appl Environ Microbiol 2020; 86:e02759-19. [PMID: 32060025 PMCID: PMC7117937 DOI: 10.1128/aem.02759-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/11/2020] [Indexed: 12/15/2022] Open
Abstract
Acidocalcisomes are membrane-enclosed, polyphosphate-containing acidic organelles in lower Eukaryota but have also been described for Agrobacterium tumefaciens (M. Seufferheld, M. Vieira, A. Ruiz, C. O. Rodrigues, S. Moreno, and R. Docampo, J Biol Chem 278:29971-29978, 2003, https://doi.org/10.1074/jbc.M304548200). This study aimed at the characterization of polyphosphate-containing acidocalcisomes in this alphaproteobacterium. Unexpectedly, fluorescence microscopic investigation of A. tumefaciens cells using fluorescent dyes and localization of constructed fusions of polyphosphate kinases (PPKs) and of vacuolar H+-translocating pyrophosphatase (HppA) with enhanced yellow fluorescent protein (eYFP) suggested that acidocalcisomes and polyphosphate are different subcellular structures. Acidocalcisomes and polyphosphate granules were frequently located close together, near the cell poles. However, they never shared the same position. Mutant strains of A. tumefaciens with deletions of both ppk genes (Δppk1 Δppk2) were unable to form polyphosphate but still showed cell pole-located eYFP-HppA foci and could be stained with MitoTracker. In conclusion, A. tumefaciens forms polyP granules that are free of a surrounding membrane and thus resemble polyP granules of Ralstonia eutropha and other bacteria. The composition, contents, and function of the subcellular structures that are stainable with MitoTracker and harbor eYFP-HppA remain unclear.IMPORTANCE The uptake of alphaproteobacterium-like cells by ancestors of eukaryotic cells and subsequent conversion of these alphaproteobacterium-like cells to mitochondria are thought to be key steps in the evolution of the first eukaryotic cells. The identification of acidocalcisomes in two alphaproteobacterial species some years ago and the presence of homologs of the vacuolar proton-translocating pyrophosphatase HppA, a marker protein of the acidocalcisome membrane in eukaryotes, in virtually all species within the alphaproteobacteria suggest that eukaryotic acidocalcisomes might also originate from related structures in ancestors of alphaproteobacterial species. Accordingly, alphaproteobacterial acidocalcisomes and eukaryotic acidocalcisomes should have similar features. Since hardly any information is available on bacterial acidocalcisomes, this study aimed at the characterization of organelle-like structures in alphaproteobacterial cells, with A. tumefaciens as an example.
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Affiliation(s)
- Celina Frank
- Institute of Microbiology, University of Stuttgart, Stuttgart, Germany
| | - Dieter Jendrossek
- Institute of Microbiology, University of Stuttgart, Stuttgart, Germany
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