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Farci D, Piano D. Spatial arrangement and density variations in the cell envelope of Deinococcus radiodurans. Can J Microbiol 2024; 70:190-198. [PMID: 38525892 DOI: 10.1139/cjm-2023-0163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
The cell envelope of the poly-extremophile bacterium Deinococcus radiodurans is renowned for its highly organized structure and unique functional characteristics. In this bacterium, a precise regularity characterizes not just the S-layer, but it also extends to the underlying cell envelope layers, resulting in a dense and tightly arranged configuration. This regularity is attributed to a minimum of three protein complexes located at the outer membrane level. Together, they constitute a recurring structural unit that extends across the cell envelope, effectively tiling the entirety of the cell body. Nevertheless, a comprehensive grasp of the vacant spaces within each layer and their functional roles remains limited. In this study, we delve into these aspects by integrating the state of the art with structural calculations. This approach provides crucial evidence supporting an evolutive pressure intricately linked to surface phenomena depending on the environmental conditions.
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Affiliation(s)
- Domenica Farci
- Department of Plant Physiology, Warsaw University of Life Sciences - SGGW, Warsaw, Poland
- Department of Life and Environmental Sciences, Università degli Studi di Cagliari, Cagliari, Italy
| | - Dario Piano
- Department of Plant Physiology, Warsaw University of Life Sciences - SGGW, Warsaw, Poland
- Department of Life and Environmental Sciences, Università degli Studi di Cagliari, Cagliari, Italy
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2
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Farci D, Milenkovic S, Iesu L, Tanas M, Ceccarelli M, Piano D. Structural characterization and functional insights into the type II secretion system of the poly-extremophile Deinococcus radiodurans. J Biol Chem 2024; 300:105537. [PMID: 38072042 PMCID: PMC10828601 DOI: 10.1016/j.jbc.2023.105537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 11/07/2023] [Accepted: 11/28/2023] [Indexed: 01/21/2024] Open
Abstract
The extremophile bacterium D. radiodurans boasts a distinctive cell envelope characterized by the regular arrangement of three protein complexes. Among these, the Type II Secretion System (T2SS) stands out as a pivotal structural component. We used cryo-electron microscopy to reveal unique features, such as an unconventional protein belt (DR_1364) around the main secretin (GspD), and a cap (DR_0940) found to be a separated subunit rather than integrated with GspD. Furthermore, a novel region at the N-terminus of the GspD constitutes an additional second gate, supplementing the one typically found in the outer membrane region. This T2SS was found to contribute to envelope integrity, while also playing a role in nucleic acid and nutrient trafficking. Studies on intact cell envelopes show a consistent T2SS structure repetition, highlighting its significance within the cellular framework.
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Affiliation(s)
- Domenica Farci
- Department of Plant Physiology, Warsaw University of Life Sciences - SGGW, Warsaw, Poland; Department of Life and Environmental Sciences, Università degli Studi di Cagliari, Cagliari, Italy; R&D Department, ReGenFix Laboratories, Sardara, Italy.
| | - Stefan Milenkovic
- Department of Physics and IOM/CNR, Università degli Studi di Cagliari, Monserrato, Italy
| | - Luca Iesu
- Department of Life and Environmental Sciences, Università degli Studi di Cagliari, Cagliari, Italy
| | - Marta Tanas
- Department of Life and Environmental Sciences, Università degli Studi di Cagliari, Cagliari, Italy
| | - Matteo Ceccarelli
- Department of Physics and IOM/CNR, Università degli Studi di Cagliari, Monserrato, Italy
| | - Dario Piano
- Department of Plant Physiology, Warsaw University of Life Sciences - SGGW, Warsaw, Poland; Department of Life and Environmental Sciences, Università degli Studi di Cagliari, Cagliari, Italy; R&D Department, ReGenFix Laboratories, Sardara, Italy.
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3
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Farci D, Graça AT, Iesu L, de Sanctis D, Piano D. The SDBC is active in quenching oxidative conditions and bridges the cell envelope layers in Deinococcus radiodurans. J Biol Chem 2022; 299:102784. [PMID: 36502921 PMCID: PMC9823218 DOI: 10.1016/j.jbc.2022.102784] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 11/30/2022] [Accepted: 12/04/2022] [Indexed: 12/14/2022] Open
Abstract
Deinococcus radiodurans is known for its remarkable ability to withstand harsh stressful conditions. The outermost layer of its cell envelope is a proteinaceous coat, the S-layer, essential for resistance to and interactions with the environment. The S-layer Deinoxanthin-binding complex (SDBC), one of the main units of the characteristic multilayered cell envelope of this bacterium, protects against environmental stressors and allows exchanges with the environment. So far, specific regions of this complex, the collar and the stalk, remained unassigned. Here, these regions are resolved by cryo-EM and locally refined. The resulting 3D map shows that the collar region of this multiprotein complex is a trimer of the protein DR_0644, a Cu-only superoxide dismutase (SOD) identified here to be efficient in quenching reactive oxygen species. The same data also showed that the stalk region consists of a coiled coil that extends into the cell envelope for ∼280 Å, reaching the inner membrane. Finally, the orientation and localization of the complex are defined by in situ cryo-electron crystallography. The structural organization of the SDBC couples fundamental UV antenna properties with the presence of a Cu-only SOD, showing here coexisting photoprotective and chemoprotective functions. These features suggests how the SDBC and similar protein complexes, might have played a primary role as evolutive templates for the origin of photoautotrophic processes by combining primary protective needs with more independent energetic strategies.
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Affiliation(s)
- Domenica Farci
- Department of Plant Physiology, Warsaw University of Life Sciences - SGGW, Warsaw, Poland,Department of Chemistry, Umeå University, Umeå, Sweden,Department of Life and Environmental Sciences, Laboratory of Plant Physiology and Photobiology, University of Cagliari, Cagliari, Italy,For correspondence: Dario Piano; Domenica Farci
| | | | - Luca Iesu
- Department of Life and Environmental Sciences, Laboratory of Plant Physiology and Photobiology, University of Cagliari, Cagliari, Italy
| | - Daniele de Sanctis
- Structural Biology group, ESRF, The European Synchrotron Radiation Facility, Grenoble, France
| | - Dario Piano
- Department of Plant Physiology, Warsaw University of Life Sciences - SGGW, Warsaw, Poland,Department of Life and Environmental Sciences, Laboratory of Plant Physiology and Photobiology, University of Cagliari, Cagliari, Italy,For correspondence: Dario Piano; Domenica Farci
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Farci D, Haniewicz P, de Sanctis D, Iesu L, Kereïche S, Winterhalter M, Piano D. The cryo-EM structure of the S-layer deinoxanthin-binding complex of Deinococcus radiodurans informs properties of its environmental interactions. J Biol Chem 2022; 298:102031. [PMID: 35577074 PMCID: PMC9189128 DOI: 10.1016/j.jbc.2022.102031] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 12/22/2022] Open
Abstract
The radiation-resistant bacterium Deinococcus radiodurans is known as the world’s toughest bacterium. The S-layer of D. radiodurans, consisting of several proteins on the surface of the cellular envelope and intimately associated with the outer membrane, has therefore been useful as a model for structural and functional studies. Its main proteinaceous unit, the S-layer deinoxanthin-binding complex (SDBC), is a hetero-oligomeric assembly known to contribute to the resistance against environmental stress and have porin functional features; however, its precise structure is unknown. Here, we resolved the structure of the SDBC at ∼2.5 Å resolution by cryo-EM and assigned the sequence of its main subunit, the protein DR_2577. This structure is characterized by a pore region, a massive β-barrel organization, a stalk region consisting of a trimeric coiled coil, and a collar region at the base of the stalk. We show that each monomer binds three Cu ions and one Fe ion and retains one deinoxanthin molecule and two phosphoglycolipids, all exclusive to D. radiodurans. Finally, electrophysiological characterization of the SDBC shows that it exhibits transport properties with several amino acids. Taken together, these results highlight the SDBC as a robust structure displaying both protection and sieving functions that facilitates exchanges with the environment.
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Affiliation(s)
- Domenica Farci
- Department of Plant Physiology, Warsaw University of Life Sciences - SGGW, Warsaw, 02-776, Poland; Department of Chemistry, Umeå University, Linnaeus väg 6, Umeå, 90736, Sweden.
| | - Patrycja Haniewicz
- Department of Plant Physiology, Warsaw University of Life Sciences - SGGW, Warsaw, 02-776, Poland
| | - Daniele de Sanctis
- ESRF, The European Synchrotron Radiation Facility, Grenoble, 38043, France
| | - Luca Iesu
- Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, Cagliari, 09123, Italy
| | - Sami Kereïche
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague, 12800, Czech Republic
| | - Mathias Winterhalter
- Department of Life Sciences & Chemistry, Jacobs University Bremen, Bremen, 28759, Germany
| | - Dario Piano
- Department of Plant Physiology, Warsaw University of Life Sciences - SGGW, Warsaw, 02-776, Poland; Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, Cagliari, 09123, Italy.
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Farci D, Kereïche S, Pangeni S, Haniewicz P, Bodrenko IV, Ceccarelli M, Winterhalter M, Piano D. Structural analysis of the architecture and in situ localization of the main S-layer complex in Deinococcus radiodurans. Structure 2021; 29:1279-1285.e3. [PMID: 34265277 DOI: 10.1016/j.str.2021.06.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/22/2021] [Accepted: 06/25/2021] [Indexed: 10/20/2022]
Abstract
Bacterial surface layers are paracrystalline assemblies of proteins that provide the first line of defense against environmental shocks. Here, we report the 3D structure, in situ localization, and orientation of the S-layer deinoxanthin-binding complex (SDBC), a hetero-oligomeric assembly of proteins that in Deinococcus radiodurans represents the main S-layer unit. The SDBC is resolved at 11-Å resolution by single-particle analysis, while its in situ localization is determined by cryo-electron crystallography on intact cell-wall fragments leading to a projection map at 4.5-Å resolution. The SDBC exhibits a triangular base with three comma-shaped pores, and a stalk departing orthogonally from the center of the base and oriented toward the intracellular space. Combining state-of-the-art techniques, results show the organization of this S-layer and its connection within the underlying membranes, demonstrating the potential for applications from nanotechnologies to medicine.
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Affiliation(s)
- Domenica Farci
- Department of Plant Physiology, Warsaw University of Life Sciences - SGGW, 02-776 Warsaw, Poland.
| | - Sami Kereïche
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, 12800 Prague, Czech Republic.
| | - Sushil Pangeni
- Department of Life Sciences & Chemistry, Jacobs University Bremen, 28759 Bremen, Germany
| | - Patrycja Haniewicz
- Department of Plant Physiology, Warsaw University of Life Sciences - SGGW, 02-776 Warsaw, Poland
| | - Igor V Bodrenko
- Department of Physics and IOM/CNR, University of Cagliari, 09042 Monserrato, Italy
| | - Matteo Ceccarelli
- Department of Physics and IOM/CNR, University of Cagliari, 09042 Monserrato, Italy
| | - Mathias Winterhalter
- Department of Life Sciences & Chemistry, Jacobs University Bremen, 28759 Bremen, Germany
| | - Dario Piano
- Department of Plant Physiology, Warsaw University of Life Sciences - SGGW, 02-776 Warsaw, Poland; Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, 09123 Cagliari, Italy.
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Late embryogenesis abundant group3 protein (DrLEA3) is involved in antioxidation in the extremophilic bacterium Deinococcus radiodurans. Microbiol Res 2020; 240:126559. [PMID: 32721821 DOI: 10.1016/j.micres.2020.126559] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 07/12/2020] [Accepted: 07/17/2020] [Indexed: 01/06/2023]
Abstract
Deinococcus radiodurans is able to survive under extreme conditions, including high doses of ionizing radiation, desiccation and oxidative stress. In addition to enhanced DNA repair capabilities, an effective antioxidation system plays an important role in its robustness. Previous studies have linked the radiation resistance of D. radiodurans to its prolonged desiccation tolerance phenotype, which both cause DNA damage. In the current study, we investigated the roles of dr_1172 in D. radiodurans, the gene encoding a typical group 3 LEA protein (DrLEA3) conserved within Deinococcus species. In addition to the increased transcriptional level under oxidative stress, the inactivation of dr_1172-sensitized cells to H2O2 treatments and the reduced cellular antioxidation activities suggested that dr_1172 is involved in the cellular defense against oxidative stress. Moreover, DrLEA3 was enriched at the cell membrane and bound to various types of metal ions. Cells devoid of DrLEA3 showed a decreased intracellular Mn/Fe concentration ratio, indicating that DrLEA3 also plays a role in maintaining metal ion homeostasis in vivo.
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Farci D, Aksoyoglu MA, Farci SF, Bafna JA, Bodrenko I, Ceccarelli M, Kirkpatrick J, Winterhalter M, Kereïche S, Piano D. Structural insights into the main S-layer unit of Deinococcus radiodurans reveal a massive protein complex with porin-like features. J Biol Chem 2020; 295:4224-4236. [PMID: 32071085 PMCID: PMC7105295 DOI: 10.1074/jbc.ra119.012174] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 02/13/2020] [Indexed: 11/06/2022] Open
Abstract
In the extremophile bacterium Deinococcus radiodurans, the outermost surface layer is tightly connected with the rest of the cell wall. This integrated organization provides a compact structure that shields the bacterium against environmental stresses. The fundamental unit of this surface layer (S-layer) is the S-layer deinoxanthin-binding complex (SDBC), which binds the carotenoid deinoxanthin and provides both, thermostability and UV radiation resistance. However, the structural organization of the SDBC awaits elucidation. Here, we report the isolation of the SDBC with a gentle procedure consisting of lysozyme treatment and solubilization with the nonionic detergent n-dodecyl-β-d-maltoside, which preserved both hydrophilic and hydrophobic components of the SDBC and allows the retention of several minor subunits. As observed by low-resolution single-particle analysis, we show that the complex possesses a porin-like structural organization, but is larger than other known porins. We also noted that the main SDBC component, the protein DR_2577, shares regions of similarity with known porins. Moreover, results from electrophysiological assays with membrane-reconstituted SDBC disclosed that it is a nonselective channel that has some peculiar gating properties, but also exhibits behavior typically observed in pore-forming proteins, such as porins and ionic transporters. The functional properties of this system and its porin-like organization provide information critical for understanding ion permeability through the outer cell surface of S-layer-carrying bacterial species.
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Affiliation(s)
- Domenica Farci
- Department of Plant Physiology, Warsaw University of Life Sciences-SGGW, Nowoursynowska Str. 159, 02776 Warsaw, Poland.
| | | | - Stefano Francesco Farci
- Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, V.le S. Ignazio da Laconi 13, 09123 Cagliari, Italy
| | - Jayesh Arun Bafna
- Department of Life Sciences and Chemistry, Jacobs University Bremen, 28759 Bremen, Germany
| | - Igor Bodrenko
- Department of Physics and IOM/CNR, University of Cagliari, 09042 Monserrato, Italy
| | - Matteo Ceccarelli
- Department of Physics and IOM/CNR, University of Cagliari, 09042 Monserrato, Italy
| | - Joanna Kirkpatrick
- Leibniz Institute on Ageing-Fritz Lipmann Institute, Beutenbergstrasse 11, 07745 Jena, Germany; The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
| | - Mathias Winterhalter
- Department of Life Sciences and Chemistry, Jacobs University Bremen, 28759 Bremen, Germany
| | - Sami Kereïche
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague 128 00, Czech Republic.
| | - Dario Piano
- Department of Plant Physiology, Warsaw University of Life Sciences-SGGW, Nowoursynowska Str. 159, 02776 Warsaw, Poland.
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Adamec F, Farci D, Bína D, Litvín R, Khan T, Fuciman M, Piano D, Polívka T. Photophysics of deinoxanthin, the keto-carotenoid bound to the main S-layer unit of Deinococcus radiodurans. Photochem Photobiol Sci 2020; 19:495-503. [DOI: 10.1039/d0pp00031k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
An ultrafast transient absorption experiment on the SDBC, which binds the carotenoid deinoxanthin, reveals a non-specific binding site that loosely binds the carotenoid, but protects the carotenoid from the outer environment.
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Affiliation(s)
- František Adamec
- Institute of Physics
- Faculty of Science
- University of South Bohemia
- České Budějovice
- Czech Republic
| | - Domenica Farci
- Department of Plant Physiology
- Warsaw University of Life Sciences - SGGW
- Warsaw
- Poland
| | - David Bína
- Institute of Chemistry
- Faculty of Science
- University of South Bohemia
- Czech Republic
- Biology Centre
| | - Radek Litvín
- Institute of Chemistry
- Faculty of Science
- University of South Bohemia
- Czech Republic
- Biology Centre
| | - Tuhin Khan
- Institute of Physics
- Faculty of Science
- University of South Bohemia
- České Budějovice
- Czech Republic
| | - Marcel Fuciman
- Institute of Physics
- Faculty of Science
- University of South Bohemia
- České Budějovice
- Czech Republic
| | - Dario Piano
- Department of Plant Physiology
- Warsaw University of Life Sciences - SGGW
- Warsaw
- Poland
- Laboratory of Photobiology and Plant Physiology
| | - Tomáš Polívka
- Institute of Physics
- Faculty of Science
- University of South Bohemia
- České Budějovice
- Czech Republic
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