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Fukushima M, Toyonaga T, O. Tahara Y, Nakane D, Miyata M. Internal structure of Mycoplasma mobile gliding machinery analyzed by negative staining electron tomography. Biophys Physicobiol 2024; 21:e210015. [PMID: 39206130 PMCID: PMC11347822 DOI: 10.2142/biophysico.bppb-v21.0015] [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: 02/14/2024] [Accepted: 05/21/2024] [Indexed: 09/04/2024] Open
Abstract
Mycoplasma mobile is a parasitic bacterium that forms gliding machinery on the cell pole and glides on a solid surface in the direction of the cell pole. The gliding machinery consists of both internal and surface structures. The internal structure is divided into a bell at the front and chain structure extending from the bell. In this study, the internal structures prepared under several conditions were analyzed using negative-staining electron microscopy and electron tomography. The chains were constructed by linked motors containing two complexes similar to ATP synthase. A cylindrical spacer with a maximum diameter of 6 nm and a height of 13 nm, and anonymous linkers with a diameter of 0.9-8.3 nm and length of 14.7±6.9 nm were found between motors. The bell is bowl-shaped and features a honeycomb surface with a periodicity of 8.4 nm. The chains of the motor are connected to the rim of the bell through a wedge-shaped structure. These structures may play roles in the assembly and cooperation of gliding machinery units.
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Affiliation(s)
- Minoru Fukushima
- Graduate School of Science, Osaka Metropolitan University, Osaka 558-8585, Japan
| | - Takuma Toyonaga
- Graduate School of Science, Osaka Metropolitan University, Osaka 558-8585, Japan
- The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka Metropolitan University, Osaka 558-8585, Japan
| | - Yuhei O. Tahara
- Graduate School of Science, Osaka Metropolitan University, Osaka 558-8585, Japan
| | - Daisuke Nakane
- Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan
| | - Makoto Miyata
- Graduate School of Science, Osaka Metropolitan University, Osaka 558-8585, Japan
- The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka Metropolitan University, Osaka 558-8585, Japan
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Knobloch S, Skirnisdóttir S, Dubois M, Mayolle L, Kolypczuk L, Leroi F, Leeper A, Passerini D, Marteinsson VÞ. The gut microbiome of farmed Arctic char ( Salvelinus alpinus) is shaped by feeding stage and nutrient presence. FEMS MICROBES 2024; 5:xtae011. [PMID: 38745980 PMCID: PMC11092275 DOI: 10.1093/femsmc/xtae011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/06/2024] [Accepted: 04/22/2024] [Indexed: 05/16/2024] Open
Abstract
The gut microbiome plays an important role in maintaining health and productivity of farmed fish. However, the functional role of most gut microorganisms remains unknown. Identifying the stable members of the gut microbiota and understanding their functional roles could aid in the selection of positive traits or act as a proxy for fish health in aquaculture. Here, we analyse the gut microbial community of farmed juvenile Arctic char (Salvelinus alpinus) and reconstruct the metabolic potential of its main symbionts. The gut microbiota of Arctic char undergoes a succession in community composition during the first weeks post-hatch, with a decrease in Shannon diversity and the establishment of three dominant bacterial taxa. The genome of the most abundant bacterium, a Mycoplasma sp., shows adaptation to rapid growth in the nutrient-rich gut environment. The second most abundant taxon, a Brevinema sp., has versatile metabolic potential, including genes involved in host mucin degradation and utilization. However, during periods of absent gut content, a Ruminococcaceae bacterium becomes dominant, possibly outgrowing all other bacteria through the production of secondary metabolites involved in quorum sensing and cross-inhibition while benefiting the host through short-chain fatty acid production. Whereas Mycoplasma is often present as a symbiont in farmed salmonids, we show that the Ruminococcaceae species is also detected in wild Arctic char, suggesting a close evolutionary relationship between the host and this symbiotic bacterium.
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Affiliation(s)
- Stephen Knobloch
- Matís ohf., Microbiology Research Group, Vínlandsleið 12, 113 Reykjavík, Iceland
- Department of Food Technology, University of Applied Sciences Fulda, Leipziger Strasse 123, 36037 Fulda, Germany
| | | | - Marianne Dubois
- ESBS/University of Strasbourg, 300 Bd Sébastien Brant, 67085 Strasbourg, France
| | - Lucie Mayolle
- University of Technology of Compiègne, Rue Roger Couttolenc, 60203 Compiègne, France
| | - Laetitia Kolypczuk
- Ifremer, MASAE Microbiologie Aliment Santé Environnement, BP 21105, F-44000 Nantes, France
| | - Françoise Leroi
- Ifremer, MASAE Microbiologie Aliment Santé Environnement, BP 21105, F-44000 Nantes, France
| | - Alexandra Leeper
- Matís ohf., Microbiology Research Group, Vínlandsleið 12, 113 Reykjavík, Iceland
- Department of Animal and Aquaculture Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Arboretveien 6, 1430 Ås, Norway
- Iceland Ocean Cluster, Department of Research and Innovation, Grandagarður 16, 101 Reykjavík, Iceland
| | - Delphine Passerini
- Ifremer, MASAE Microbiologie Aliment Santé Environnement, BP 21105, F-44000 Nantes, France
| | - Viggó Þ Marteinsson
- Matís ohf., Microbiology Research Group, Vínlandsleið 12, 113 Reykjavík, Iceland
- Faculty of Food Science and Nutrition, University of Iceland, Sæmundargata 2, 101 Reykjavik, Iceland
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Nakane D. Rheotaxis in Mycoplasma gliding. Microbiol Immunol 2023; 67:389-395. [PMID: 37430383 DOI: 10.1111/1348-0421.13090] [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: 06/01/2023] [Revised: 06/22/2023] [Accepted: 06/23/2023] [Indexed: 07/12/2023]
Abstract
This review describes the upstream-directed movement in the small parasitic bacterium Mycoplasma. Many Mycoplasma species exhibit gliding motility, a form of biological motion over surfaces without the aid of general surface appendages such as flagella. The gliding motility is characterized by a constant unidirectional movement without changes in direction or backward motion. Unlike flagellated bacteria, Mycoplasma lacks the general chemotactic signaling system to control their moving direction. Therefore, the physiological role of directionless travel in Mycoplasma gliding remains unclear. Recently, high-precision measurements under an optical microscope have revealed that three species of Mycoplasma exhibited rheotaxis, that is, the direction of gliding motility is lead upstream by the water flow. This intriguing response appears to be optimized for the flow patterns encountered at host surfaces. This review provides a comprehensive overview of the morphology, behavior, and habitat of Mycoplasma gliding, and discusses the possibility that the rheotaxis is ubiquitous among them.
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Affiliation(s)
- Daisuke Nakane
- Department of Engineering Science, Graduate School of Informatics and Engineering, Tokyo, Japan
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Matsuike D, Tahara YO, Nonaka T, Wu HN, Hamaguchi T, Kudo H, Hayashi Y, Arai M, Miyata M. Structure and Function of Gli123 Involved in Mycoplasma mobile Gliding. J Bacteriol 2023; 205:e0034022. [PMID: 36749051 PMCID: PMC10029712 DOI: 10.1128/jb.00340-22] [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] [Indexed: 02/08/2023] Open
Abstract
Mycoplasma mobile is a fish pathogen that glides on solid surfaces by means of its own gliding machinery composed of internal and surface structures. In the present study, we focused on the function and structure of Gli123, a surface protein that is essential for the localization of other surface proteins. The amino acid sequence of Gli123, which is 1,128 amino acids long, contains lipoprotein-specific repeats. We isolated the native Gli123 protein from M. mobile cells and a recombinant protein, rGli123, from Escherichia coli. The isolated rGli123 complemented a nonbinding and nongliding mutant of M. mobile that lacked Gli123. Circular dichroism and rotary-shadowing electron microscopy (EM) showed that rGli123 has a structure that is not significantly different from that of the native protein. Rotary-shadowing EM suggested that Gli123 adopts two distinct globular and rod-like structures, depending on the ionic strength of the solution. Negative-staining EM coupled with single-particle analysis revealed that Gli123 forms a globular structure featuring a small protrusion with dimensions of approximately 15.7, 14.7, and 14.1 nm for the "height," major axis and minor axis, respectively. Small-angle X-ray scattering analyses indicated a rod-like structure composed of several tandem globular domains with total dimensions of approximately 34 nm in length and 6 nm in width. Both molecular structures were suggested to be dimers, based on the predicted molecular size and structure. Gli123 may have evolved by multiplication of repeating lipoprotein units and acquired a role for Gli521 and Gli349 assembly. IMPORTANCE Mycoplasmas are pathogenic bacteria that are widespread in animals. They are characterized by small cell and genome sizes but are equipped with unique abilities for infection, such as surface variation and gliding. Here, we focused on a surface-localizing protein named Gli123 that is essential for Mycoplasma mobile gliding. This study suggested that Gli123 undergoes drastic conformational changes between its rod-like and globular structures. These changes may be caused by a repetitive structure common in the surface proteins that is responsible for the modulation of the cell surface structure and related to the assembly process for the surface gliding machinery. An evolutionary process for surface proteins essential for this mycoplasma gliding was also suggested in the present study.
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Affiliation(s)
- Daiki Matsuike
- Graduate School of Science, Osaka Metropolitan University, Osaka, Japan
| | - Yuhei O Tahara
- Graduate School of Science, Osaka Metropolitan University, Osaka, Japan
- OCU Advanced Research Institute for Natural Science and Technology, Osaka Metropolitan University, Osaka, Japan
| | - Takahiro Nonaka
- Graduate School of Science, Osaka City University, Osaka, Japan
| | - Heng Ning Wu
- Graduate School of Science, Osaka City University, Osaka, Japan
| | - Tasuku Hamaguchi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Miyagi, Japan
| | - Hisashi Kudo
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo, Japan
- Graduate School of Science, Technology and Innovation, Kobe University, Nada, Kobe, Japan
| | - Yuuki Hayashi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo, Japan
- Environmental Science Center, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Munehito Arai
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo, Japan
- Department of Physics, Graduate School of Science, The University of Tokyo, Meguro, Tokyo, Japan
| | - Makoto Miyata
- Graduate School of Science, Osaka Metropolitan University, Osaka, Japan
- OCU Advanced Research Institute for Natural Science and Technology, Osaka Metropolitan University, Osaka, Japan
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Hyperactive nanobacteria with host-dependent traits pervade Omnitrophota. Nat Microbiol 2023; 8:727-744. [PMID: 36928026 PMCID: PMC10066038 DOI: 10.1038/s41564-022-01319-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 12/30/2022] [Indexed: 03/18/2023]
Abstract
Candidate bacterial phylum Omnitrophota has not been isolated and is poorly understood. We analysed 72 newly sequenced and 349 existing Omnitrophota genomes representing 6 classes and 276 species, along with Earth Microbiome Project data to evaluate habitat, metabolic traits and lifestyles. We applied fluorescence-activated cell sorting and differential size filtration, and showed that most Omnitrophota are ultra-small (~0.2 μm) cells that are found in water, sediments and soils. Omnitrophota genomes in 6 classes are reduced, but maintain major biosynthetic and energy conservation pathways, including acetogenesis (with or without the Wood-Ljungdahl pathway) and diverse respirations. At least 64% of Omnitrophota genomes encode gene clusters typical of bacterial symbionts, suggesting host-associated lifestyles. We repurposed quantitative stable-isotope probing data from soils dominated by andesite, basalt or granite weathering and identified 3 families with high isotope uptake consistent with obligate bacterial predators. We propose that most Omnitrophota inhabit various ecosystems as predators or parasites.
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Kasai T, Miyata M. Motility Assays of Mycoplasma mobile Under Light Microscopy. Methods Mol Biol 2023; 2646:321-325. [PMID: 36842126 DOI: 10.1007/978-1-0716-3060-0_26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Mycoplasma mobile forms a membrane protrusion at a pole as an organelle. M. mobile cells bind to solid surfaces and glide in the direction of the protrusion. In gliding motility, M. mobile cells catch, pull and release sialylated oligosaccharides on host cells. The observation of Mycoplasma species under light microscopy is useful for the analysis of adhesion ability and the motility mechanism.
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Affiliation(s)
- Taishi Kasai
- College of Science, Department of Life Science, Rikkyo University, Tokyo, Japan.
| | - Makoto Miyata
- Graduate School of Science, Osaka City University, Osaka, Japan.,Graduate School of Science, Osaka Metropolitan University, Osaka, Japan.,The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University, Osaka, Japan.,The OMU Advanced Research Center for Natural Science and Technology, Osaka Metropolitan University, Osaka, Japan
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Imaging Minimal Bacteria at the Nanoscale: a Reliable and Versatile Process to Perform Single-Molecule Localization Microscopy in Mycoplasmas. Microbiol Spectr 2022; 10:e0064522. [PMID: 35638916 PMCID: PMC9241803 DOI: 10.1128/spectrum.00645-22] [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] [Indexed: 11/24/2022] Open
Abstract
Mycoplasmas are the smallest free-living organisms. These bacteria are important models for both fundamental and synthetic biology, owing to their highly reduced genomes. They are also relevant in the medical and veterinary fields, as they are pathogenic to both humans and most livestock species. Mycoplasma cells have minute sizes, often in the 300- to 800-nm range. As these dimensions are close to the diffraction limit of visible light, fluorescence imaging in mycoplasmas is often poorly informative. Recently developed superresolution imaging techniques can break this diffraction limit, improving the imaging resolution by an order of magnitude and offering a new nanoscale vision of the organization of these bacteria. These techniques have, however, not been applied to mycoplasmas before. Here, we describe an efficient and reliable protocol to perform single-molecule localization microscopy (SMLM) imaging in mycoplasmas. We provide a polyvalent transposon-based system to express the photoconvertible fluorescent protein mEos3.2, enabling photo-activated localization microscopy (PALM) in most Mycoplasma species. We also describe the application of direct stochastic optical reconstruction microscopy (dSTORM). We showcase the potential of these techniques by studying the subcellular localization of two proteins of interest. Our work highlights the benefits of state-of-the-art microscopy techniques for mycoplasmology and provides an incentive to further the development of SMLM strategies to study these organisms in the future. IMPORTANCE Mycoplasmas are important models in biology, as well as highly problematic pathogens in the medical and veterinary fields. The very small sizes of these bacteria, well below a micron, limits the usefulness of traditional fluorescence imaging methods, as their resolution limit is similar to the dimensions of the cells. Here, to bypass this issue, we established a set of state-of-the-art superresolution microscopy techniques in a wide range of Mycoplasma species. We describe two strategies: PALM, based on the expression of a specific photoconvertible fluorescent protein, and dSTORM, based on fluorophore-coupled antibody labeling. With these methods, we successfully performed single-molecule imaging of proteins of interest at the surface of the cells and in the cytoplasm, at lateral resolutions well below 50 nm. Our work paves the way toward a better understanding of mycoplasma biology through imaging of subcellular structures at the nanometer scale.
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Abstract
Mycoplasma mobile, a fish pathogen, exhibits gliding motility using ATP hydrolysis on solid surfaces, including animal cells. The gliding machinery can be divided into surface and internal structures. The internal structure of the motor is composed of 28 so-called “chains” that are each composed of 17 repeating protein units called “particles.” These proteins include homologs of the catalytic α and β subunits of F1-ATPase. In this study, we isolated the particles and determined their structures using negative-staining electron microscopy and high-speed atomic force microscopy. The isolated particles were composed of five proteins, MMOB1660 (α-subunit homolog), -1670 (β-subunit homolog), -1630, -1620, and -4530, and showed ATP hydrolyzing activity. The two-dimensional (2D) structure, with dimensions of 35 and 26 nm, showed a dimer of hexameric ring approximately 12 nm in diameter, resembling F1-ATPase catalytic (αβ)3. We isolated the F1-like ATPase unit, which is composed of MMOB1660, -1670, and -1630. Furthermore, we isolated the chain and analyzed the three-dimensional (3D) structure, showing that dimers of mushroom-like structures resembling F1-ATPase were connected and aligned along the dimer axis at 31-nm intervals. An atomic model of F1-ATPase catalytic (αβ)3 from Bacillus PS3 was successfully fitted to each hexameric ring of the mushroom-like structure. These results suggest that the motor for M. mobile gliding shares an evolutionary origin with F1-ATPase. Based on the obtained structure, we propose possible force transmission processes in the gliding mechanism.
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9
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Abstract
Mycoplasma mobile, a parasitic bacterium, glides on solid surfaces, such as animal cells and glass, by a special mechanism. This process is driven by the force generated through ATP hydrolysis on an internal structure. However, the spatial and temporal behaviors of the internal structures in living cells are unclear. In this study, we detected the movements of the internal structure by scanning cells immobilized on a glass substrate using high-speed atomic force microscopy (HS-AFM). By scanning the surface of a cell, we succeeded in visualizing particles, 2 nm in height and aligned mostly along the cell axis with a pitch of 31.5 nm, consistent with previously reported features based on electron microscopy. Movements of individual particles were then analyzed by HS-AFM. In the presence of sodium azide, the average speed of particle movements was reduced, suggesting that movement is linked to ATP hydrolysis. Partial inhibition of the reaction by sodium azide enabled us to analyze particle behavior in detail, showing that the particles move 9 nm right, relative to the gliding direction, and 2 nm into the cell interior in 330 ms and then return to their original position, based on ATP hydrolysis.
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Nottelet P, Bataille L, Gourgues G, Anger R, Lartigue C, Sirand-Pugnet P, Marza E, Fronzes R, Arfi Y. The mycoplasma surface proteins MIB and MIP promote the dissociation of the antibody-antigen interaction. SCIENCE ADVANCES 2021; 7:7/10/eabf2403. [PMID: 33674316 PMCID: PMC7935358 DOI: 10.1126/sciadv.abf2403] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 01/22/2021] [Indexed: 05/04/2023]
Abstract
Mycoplasma immunoglobulin binding (MIB) and mycoplasma immunoglobulin protease (MIP) are surface proteins found in the majority of mycoplasma species, acting sequentially to capture antibodies and cleave off their VH domains. Cryo-electron microscopy structures show how MIB and MIP bind to a Fab fragment in a "hug of death" mechanism. As a result, the orientation of the VL and VH domains is twisted out of alignment, disrupting the antigen binding site. We also show that MIB-MIP has the ability to promote the dissociation of the antibody-antigen complex. This system is functional in cells and protects mycoplasmas from antibody-mediated agglutination. These results highlight the key role of the MIB-MIP system in immunity evasion by mycoplasmas through an unprecedented mechanism, and open exciting perspectives to use these proteins as potential tools in the antibody field.
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Affiliation(s)
- Pierre Nottelet
- Structure and Function of Bacterial Nanomachines, UMR 5234, Univ. Bordeaux, CNRS, Institut Européen de Chimie et Biologie, F-33600 Pessac, France
| | - Laure Bataille
- Univ. Bordeaux, INRAE, Biologie du Fruit et Pathologie, UMR 1332, F-33140 Villenave d'Ornon, France
| | - Geraldine Gourgues
- Univ. Bordeaux, INRAE, Biologie du Fruit et Pathologie, UMR 1332, F-33140 Villenave d'Ornon, France
| | - Robin Anger
- Structure and Function of Bacterial Nanomachines, UMR 5234, Univ. Bordeaux, CNRS, Institut Européen de Chimie et Biologie, F-33600 Pessac, France
| | - Carole Lartigue
- Univ. Bordeaux, INRAE, Biologie du Fruit et Pathologie, UMR 1332, F-33140 Villenave d'Ornon, France
| | - Pascal Sirand-Pugnet
- Univ. Bordeaux, INRAE, Biologie du Fruit et Pathologie, UMR 1332, F-33140 Villenave d'Ornon, France
| | - Esther Marza
- Structure and Function of Bacterial Nanomachines, UMR 5234, Univ. Bordeaux, CNRS, Institut Européen de Chimie et Biologie, F-33600 Pessac, France
| | - Remi Fronzes
- Structure and Function of Bacterial Nanomachines, UMR 5234, Univ. Bordeaux, CNRS, Institut Européen de Chimie et Biologie, F-33600 Pessac, France.
| | - Yonathan Arfi
- Univ. Bordeaux, INRAE, Biologie du Fruit et Pathologie, UMR 1332, F-33140 Villenave d'Ornon, France.
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