1
|
Cantero M, Cvirkaite-Krupovic V, Krupovic M, de Pablo PJ. Mechanical tomography of an archaeal lemon-shaped virus reveals membrane-like fluidity of the capsid and liquid nucleoprotein cargo. Proc Natl Acad Sci U S A 2023; 120:e2307717120. [PMID: 37824526 PMCID: PMC10589707 DOI: 10.1073/pnas.2307717120] [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: 05/08/2023] [Accepted: 09/08/2023] [Indexed: 10/14/2023] Open
Abstract
Archaeal lemon-shaped viruses have unique helical capsids composed of highly hydrophobic protein strands which can slide past each other resulting in remarkable morphological reorganization. Here, using atomic force microscopy, we explore the biomechanical properties of the lemon-shaped virions of Sulfolobus monocaudavirus 1 (SMV1), a double-stranded DNA virus which infects hyperthermophilic (~80 °C) and acidophilic (pH ~ 2) archaea. Our results reveal that SMV1 virions are extremely soft and withstand repeated extensive deformations, reaching remarkable strains of 80% during multiple cycles of consecutive mechanical assaults, yet showing scarce traces of disruption. SMV1 virions can reversibly collapse wall-to-wall, reducing their volume by ~90%. Beyond revealing the exceptional malleability of the SMV1 protein shell, our data also suggest a fluid-like nucleoprotein cargo which can flow inside the capsid, resisting and accommodating mechanical deformations without further alteration. Our experiments suggest a packing fraction of the virus core to be as low as 11%, with the amount of the accessory proteins almost four times exceeding that of the viral genome. Our findings indicate that SMV1 protein capsid displays biomechanical properties of lipid membranes, which is not found among protein capsids of other viruses. The remarkable malleability and fluidity of the SMV1 virions are likely necessary for the structural transformations during the infection and adaptation to extreme environmental conditions.
Collapse
Affiliation(s)
- Miguel Cantero
- Departamento de Física de la Materia Condensada C03, Universidad Autónoma de Madrid, Madrid28049, Spain
| | | | - Mart Krupovic
- Institut Pasteur, Université Paris Cité, Archaeal Virology Unit, Paris75015, France
| | - Pedro J. de Pablo
- Departamento de Física de la Materia Condensada C03, Universidad Autónoma de Madrid, Madrid28049, Spain
- Instituto de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid28049, Spain
| |
Collapse
|
2
|
Tittes C, Schwarzer S, Quax TEF. Viral Hijack of Filamentous Surface Structures in Archaea and Bacteria. Viruses 2021; 13:v13020164. [PMID: 33499367 PMCID: PMC7911016 DOI: 10.3390/v13020164] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 12/30/2022] Open
Abstract
The bacterial and archaeal cell surface is decorated with filamentous surface structures that are used for different functions, such as motility, DNA exchange and biofilm formation. Viruses hijack these structures and use them to ride to the cell surface for successful entry. In this review, we describe currently known mechanisms for viral attachment, translocation, and entry via filamentous surface structures. We describe the different mechanisms used to exploit various surface structures bacterial and archaeal viruses. This overview highlights the importance of filamentous structures at the cell surface for entry of prokaryotic viruses.
Collapse
|
3
|
Baquero DP, Liu Y, Wang F, Egelman EH, Prangishvili D, Krupovic M. Structure and assembly of archaeal viruses. Adv Virus Res 2020; 108:127-164. [PMID: 33837715 DOI: 10.1016/bs.aivir.2020.09.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Viruses of archaea represent one of the most enigmatic parts of the virosphere. Most of the characterized archaeal viruses infect extremophilic hosts and display remarkable diversity of virion morphotypes, many of which have never been observed among bacteriophages or viruses of eukaryotes. However, recent environmental studies have shown that archaeal viruses are widespread also in moderate ecosystems, where they play an important ecological role by influencing the turnover of microbial communities, with a global impact on the carbon and nitrogen cycles. In this review, we summarize recent advances in understanding the molecular details of virion organization and assembly of archaeal viruses. We start by briefly introducing the 20 officially recognized families of archaeal viruses and then outline the similarities and differences of archaeal virus assembly with the morphogenesis pathways used by bacterial and eukaryotic viruses, and discuss the evolutionary implications of these observations. Generally, the assembly of the icosahedral archaeal viruses closely follows the mechanisms employed by evolutionarily related bacterial and eukaryotic viruses with the HK97 fold and double jelly-roll major capsid proteins, emphasizing the overall conservation of these pathways over billions of years of evolution. By contrast, archaea-specific viruses employ unique virion assembly mechanisms. We also highlight some of the molecular adaptations underlying the stability of archaeal viruses in extreme environments. Despite considerable progress during the past few years, the archaeal virosphere continues to represent one of the least studied parts of the global virome, with many molecular features awaiting to be discovered and characterized.
Collapse
Affiliation(s)
- Diana P Baquero
- Archaeal Virology Unit, Department of Microbiology, Institut Pasteur, Paris, France; Sorbonne Université, Collège Doctoral, Paris, France
| | - Ying Liu
- Archaeal Virology Unit, Department of Microbiology, Institut Pasteur, Paris, France
| | - Fengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, United States
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, United States
| | - David Prangishvili
- Archaeal Virology Unit, Department of Microbiology, Institut Pasteur, Paris, France; Ivane Javakhishvili Tbilisi State University, Tbilisi, Georgia
| | - Mart Krupovic
- Archaeal Virology Unit, Department of Microbiology, Institut Pasteur, Paris, France.
| |
Collapse
|
4
|
Hartman R, Eilers BJ, Bollschweiler D, Munson-McGee JH, Engelhardt H, Young MJ, Lawrence CM. The Molecular Mechanism of Cellular Attachment for an Archaeal Virus. Structure 2019; 27:1634-1646.e3. [PMID: 31587916 DOI: 10.1016/j.str.2019.09.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/21/2019] [Accepted: 09/16/2019] [Indexed: 12/17/2022]
Abstract
Sulfolobus turreted icosahedral virus (STIV) is a model archaeal virus and member of the PRD1-adenovirus lineage. Although STIV employs pyramidal lysis structures to exit the host, knowledge of the viral entry process is lacking. We therefore initiated studies on STIV attachment and entry. Negative stain and cryoelectron micrographs showed virion attachment to pili-like structures emanating from the Sulfolobus host. Tomographic reconstruction and sub-tomogram averaging revealed pili recognition by the STIV C381 turret protein. Specifically, the triple jelly roll structure of C381 determined by X-ray crystallography shows that pilus recognition is mediated by conserved surface residues in the second and third domains. In addition, the STIV petal protein (C557), when present, occludes the pili binding site, suggesting that it functions as a maturation protein. Combined, these results demonstrate a role for the namesake STIV turrets in initial cellular attachment and provide the first molecular model for viral attachment in the archaeal domain of life.
Collapse
Affiliation(s)
- Ross Hartman
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Brian J Eilers
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Daniel Bollschweiler
- Department of Molecular Structural Biology, Max-Planck-Institute for Biochemistry, Martinsried, Germany
| | - Jacob H Munson-McGee
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Harald Engelhardt
- Department of Molecular Structural Biology, Max-Planck-Institute for Biochemistry, Martinsried, Germany
| | - Mark J Young
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA; Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717, USA; The Thermal Biology Institute, Montana State University, Bozeman, MT 59717, USA.
| | - C Martin Lawrence
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA; The Thermal Biology Institute, Montana State University, Bozeman, MT 59717, USA.
| |
Collapse
|
5
|
Shannon's information, Bernal's biopoiesis and Bernoulli distribution as pillars for building a definition of life. J Theor Biol 2019; 470:101-107. [DOI: 10.1016/j.jtbi.2019.03.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 03/08/2019] [Accepted: 03/11/2019] [Indexed: 01/19/2023]
|
6
|
Vlok M, Gibbs AJ, Suttle CA. Metagenomes of a Freshwater Charavirus from British Columbia Provide a Window into Ancient Lineages of Viruses. Viruses 2019; 11:v11030299. [PMID: 30934644 PMCID: PMC6466400 DOI: 10.3390/v11030299] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 03/19/2019] [Accepted: 03/21/2019] [Indexed: 02/06/2023] Open
Abstract
Charophyte algae, not chlorophyte algae, are the ancestors of ‘higher plants’; hence, viruses infecting charophytes may be related to those that first infected higher plants. Streamwaters from British Columbia, Canada, yielded single-stranded RNA metagenomes of Charavirus canadensis (CV-Can), that are similar in genomic architecture, length (9593 nt), nucleotide identity (63.4%), and encoded amino-acid sequence identity (53.0%) to those of Charavirus australis (CV-Aus). The sequences of their RNA-dependent RNA-polymerases (RdRp) resemble those found in benyviruses, their helicases those of hepaciviruses and hepegiviruses, and their coat-proteins (CP) those of tobamoviruses; all from the alphavirus/flavivirus branch of the ‘global RNA virome’. The 5’-terminus of the CV-Can genome, but not that of CV-Aus, is complete and encodes a methyltransferase domain. Comparisons of CP sequences suggests that Canadian and Australian charaviruses diverged 29–46 million years ago (mya); whereas, the CPs of charaviruses and tobamoviruses last shared a common ancestor 212 mya, and the RdRps of charaviruses and benyviruses 396 mya. CV-Can is sporadically abundant in low-nutrient freshwater rivers in British Columbia, where Chara braunii, a close relative of C. australis, occurs, and which may be its natural host. Charaviruses, like their hosts, are ancient and widely distributed, and thus provide a window to the viromes of early eukaryotes and, even, Archaea.
Collapse
Affiliation(s)
- Marli Vlok
- Department of Botany, University of British Columbia, Vancouver, BCV6T 1Z4, Canada.
| | - Adrian J Gibbs
- Emeritus Faculty, Australian National University, Canberra, ACT 2601, Australia.
| | - Curtis A Suttle
- Department of Botany, University of British Columbia, Vancouver, BCV6T 1Z4, Canada.
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
| |
Collapse
|
7
|
Structural conservation in a membrane-enveloped filamentous virus infecting a hyperthermophilic acidophile. Nat Commun 2018; 9:3360. [PMID: 30135568 PMCID: PMC6105669 DOI: 10.1038/s41467-018-05684-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 07/20/2018] [Indexed: 01/06/2023] Open
Abstract
Different forms of viruses that infect archaea inhabiting extreme environments continue to be discovered at a surprising rate, suggesting that the current sampling of these viruses is sparse. We describe here Sulfolobus filamentous virus 1 (SFV1), a membrane-enveloped virus infecting Sulfolobus shibatae. The virus encodes two major coat proteins which display no apparent sequence similarity with each other or with any other proteins in databases. We have used cryo-electron microscopy at 3.7 Å resolution to show that these two proteins form a nearly symmetrical heterodimer, which wraps around A-form DNA, similar to what has been shown for SIRV2 and AFV1, two other archaeal filamentous viruses. The thin (∼ 20 Å) membrane of SFV1 is mainly archaeol, a lipid species that accounts for only 1% of the host lipids. Our results show how relatively conserved structural features can be maintained across evolution by both proteins and lipids that have diverged considerably. Only a few archaeal filamentous viruses have been structurally characterized. Here the authors describe the membrane-enveloped Sulfolobus filamentous virus 1 that infects Sulfolobus shibatae and present its 3.7 Å resolution cryo-EM structure, which reveals that major coat proteins are structurally conserved among archaeal filamentous viruses.
Collapse
|
8
|
Dharmavaram S, Rudnick J, Lawrence CM, Bruinsma RF. Smectic viral capsids and the aneurysm instability. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:204004. [PMID: 29578447 PMCID: PMC7100389 DOI: 10.1088/1361-648x/aab99a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/13/2018] [Accepted: 03/26/2018] [Indexed: 06/08/2023]
Abstract
The capsids of certain Archaea-infecting viruses undergo large shape changes, while maintaining their integrity against rupture by osmotic pressure. We propose that these capsids are in a smectic liquid crystalline state, with the capsid proteins assembling along spirals. We show that smectic capsids are intrinsically stabilized against the formation of localized bulges with non-zero Gauss curvature while still allowing for large-scale cooperative shape transformation that involves global changes in the Gauss curvature.
Collapse
Affiliation(s)
- S Dharmavaram
- Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, United States of America
| | - J Rudnick
- Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, United States of America
| | - C M Lawrence
- Thermal Biology Institute, Montana State University, Bozeman, MT 59717, United States of America
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, United States of America
| | - R F Bruinsma
- Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, United States of America
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, United States of America
| |
Collapse
|
9
|
Archaeal Viruses from High-Temperature Environments. Genes (Basel) 2018; 9:genes9030128. [PMID: 29495485 PMCID: PMC5867849 DOI: 10.3390/genes9030128] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/19/2018] [Accepted: 02/21/2018] [Indexed: 12/21/2022] Open
Abstract
Archaeal viruses are some of the most enigmatic viruses known, due to the small number that have been characterized to date. The number of known archaeal viruses lags behind known bacteriophages by over an order of magnitude. Despite this, the high levels of genetic and morphological diversity that archaeal viruses display has attracted researchers for over 45 years. Extreme natural environments, such as acidic hot springs, are almost exclusively populated by Archaea and their viruses, making these attractive environments for the discovery and characterization of new viruses. The archaeal viruses from these environments have provided insights into archaeal biology, gene function, and viral evolution. This review focuses on advances from over four decades of archaeal virology, with a particular focus on archaeal viruses from high temperature environments, the existing challenges in understanding archaeal virus gene function, and approaches being taken to overcome these limitations.
Collapse
|
10
|
Structural studies of Acidianus tailed spindle virus reveal a structural paradigm used in the assembly of spindle-shaped viruses. Proc Natl Acad Sci U S A 2018; 115:2120-2125. [PMID: 29440399 DOI: 10.1073/pnas.1719180115] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The spindle-shaped virion morphology is common among archaeal viruses, where it is a defining characteristic of many viral families. However, structural heterogeneity intrinsic to spindle-shaped viruses has seriously hindered efforts to elucidate the molecular architecture of these lemon-shaped capsids. We have utilized a combination of cryo-electron microscopy and X-ray crystallography to study Acidianus tailed spindle virus (ATSV). These studies reveal the architectural principles that underlie assembly of a spindle-shaped virus. Cryo-electron tomography shows a smooth transition from the spindle-shaped capsid into the tubular-shaped tail and allows low-resolution structural modeling of individual virions. Remarkably, higher-dose 2D micrographs reveal a helical surface lattice in the spindle-shaped capsid. Consistent with this, crystallographic studies of the major capsid protein reveal a decorated four-helix bundle that packs within the crystal to form a four-start helical assembly with structural similarity to the tube-shaped tail structure of ATSV and other tailed, spindle-shaped viruses. Combined, this suggests that the spindle-shaped morphology of the ATSV capsid is formed by a multistart helical assembly with a smoothly varying radius and allows construction of a pseudoatomic model for the lemon-shaped capsid that extends into a tubular tail. The potential advantages that this novel architecture conveys to the life cycle of spindle-shaped viruses, including a role in DNA ejection, are discussed.
Collapse
|
11
|
Krupovic M, Cvirkaite-Krupovic V, Iranzo J, Prangishvili D, Koonin EV. Viruses of archaea: Structural, functional, environmental and evolutionary genomics. Virus Res 2017; 244:181-193. [PMID: 29175107 DOI: 10.1016/j.virusres.2017.11.025] [Citation(s) in RCA: 137] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 11/20/2017] [Accepted: 11/20/2017] [Indexed: 11/18/2022]
Abstract
Viruses of archaea represent one of the most enigmatic parts of the virosphere. Most of the characterized archaeal viruses infect extremophilic hosts and display remarkable diversity of virion morphotypes, many of which have never been observed among viruses of bacteria or eukaryotes. The uniqueness of the virion morphologies is matched by the distinctiveness of the genomes of these viruses, with ∼75% of genes encoding unique proteins, refractory to functional annotation based on sequence analyses. In this review, we summarize the state-of-the-art knowledge on various aspects of archaeal virus genomics. First, we outline how structural and functional genomics efforts provided valuable insights into the functions of viral proteins and revealed intricate details of the archaeal virus-host interactions. We then highlight recent metagenomics studies, which provided a glimpse at the diversity of uncultivated viruses associated with the ubiquitous archaea in the oceans, including Thaumarchaeota, Marine Group II Euryarchaeota, and others. These findings, combined with the recent discovery that archaeal viruses mediate a rapid turnover of thaumarchaea in the deep sea ecosystems, illuminate the prominent role of these viruses in the biosphere. Finally, we discuss the origins and evolution of archaeal viruses and emphasize the evolutionary relationships between viruses and non-viral mobile genetic elements. Further exploration of the archaeal virus diversity as well as functional studies on diverse virus-host systems are bound to uncover novel, unexpected facets of the archaeal virome.
Collapse
Affiliation(s)
- Mart Krupovic
- Department of Microbiology, Institut Pasteur, 25 rue du Dr. Roux, Paris 75015, Paris, France.
| | | | - Jaime Iranzo
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, USA
| | - David Prangishvili
- Department of Microbiology, Institut Pasteur, 25 rue du Dr. Roux, Paris 75015, Paris, France
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, USA
| |
Collapse
|
12
|
Wu L, Uldahl KB, Chen F, Benasutti H, Logvinski D, Vu V, Banda NK, Peng X, Simberg D, Moghimi SM. Interaction of extremophilic archaeal viruses with human and mouse complement system and viral biodistribution in mice. Mol Immunol 2017; 90:273-279. [PMID: 28846925 DOI: 10.1016/j.molimm.2017.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/06/2017] [Accepted: 08/14/2017] [Indexed: 12/19/2022]
Abstract
Archaeal viruses offer exceptional biophysical properties for modification and exploration of their potential in bionanotechnology, bioengineering and nanotherapeutic developments. However, the interaction of archaeal viruses with elements of the innate immune system has not been explored, which is a necessary prerequisite if their potential for biomedical applications to be realized. Here we show complement activation through lectin (via direct binding of MBL/MASPs) and alternative pathways by two extremophilic archaeal viruses (Sulfolobus monocaudavirus 1 and Sulfolobus spindle-shaped virus 2) in human serum. We further show some differences in initiation of complement activation pathways between these viruses. Since, Sulfolobus monocaudavirus 1 was capable of directly triggering the alternative pathway, we also demonstrate that the complement regulator factor H has no affinity for the viral surface, but factor H deposition is purely C3-dependent. This suggests that unlike some virulent pathogens Sulfolobus monocaudavirus 1 does not acquire factor H for protection. Complement activation with Sulfolobus monocaudavirus 1 also proceeds in murine sera through MBL-A/C as well as factor D-dependent manner, but C3 deficiency has no overall effect on viral clearance by organs of the reticuloendothelial system on intravenous injection. However, splenic deposition was significantly higher in C3 knockout animals compared with the corresponding wild type mice. We discuss the potential application of these viruses in biomedicine in relation to their complement activating properties.
Collapse
Affiliation(s)
- Linping Wu
- Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, People's Republic of China
| | - Kristine Buch Uldahl
- Danish Archaea Center, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, Copenhagen 2200, Denmark
| | - Fangfang Chen
- Department of Gastrointestinal Surgery, China-Japan Union Hospital, Jilin University, 126 Xiantai Street, Changchun, Jilin 130033, People's Republic of China; Tranlational Bio-Nanosciences Laboratory and Colorado Center for Nanomedicine and Nanosafety, The Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmaceutical Sciences, University of Colorado Denver, Anschutz Medical Campus, 1250 East Mountview Blvd., Aurora, CO 80045, USA
| | - Halli Benasutti
- Tranlational Bio-Nanosciences Laboratory and Colorado Center for Nanomedicine and Nanosafety, The Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmaceutical Sciences, University of Colorado Denver, Anschutz Medical Campus, 1250 East Mountview Blvd., Aurora, CO 80045, USA
| | - Deborah Logvinski
- Tranlational Bio-Nanosciences Laboratory and Colorado Center for Nanomedicine and Nanosafety, The Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmaceutical Sciences, University of Colorado Denver, Anschutz Medical Campus, 1250 East Mountview Blvd., Aurora, CO 80045, USA
| | - Vivian Vu
- Tranlational Bio-Nanosciences Laboratory and Colorado Center for Nanomedicine and Nanosafety, The Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmaceutical Sciences, University of Colorado Denver, Anschutz Medical Campus, 1250 East Mountview Blvd., Aurora, CO 80045, USA
| | - Nirmal K Banda
- Division of Rheumatology, School of Medicine, University of Colorado Denver, Anschutz Medical Campus, 1775 Aurora Court, Aurora, CO 80045, USA
| | - Xu Peng
- Danish Archaea Center, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, Copenhagen 2200, Denmark
| | - Dmitri Simberg
- Tranlational Bio-Nanosciences Laboratory and Colorado Center for Nanomedicine and Nanosafety, The Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmaceutical Sciences, University of Colorado Denver, Anschutz Medical Campus, 1250 East Mountview Blvd., Aurora, CO 80045, USA
| | - Seyed Moein Moghimi
- Tranlational Bio-Nanosciences Laboratory and Colorado Center for Nanomedicine and Nanosafety, The Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmaceutical Sciences, University of Colorado Denver, Anschutz Medical Campus, 1250 East Mountview Blvd., Aurora, CO 80045, USA; School of Medicine, Pharmacy and Health, Durham University, Queen's Campus, Stockton-on-Tees TS17 6BH, United Kingdom.
| |
Collapse
|
13
|
Repression of RNA polymerase by the archaeo-viral regulator ORF145/RIP. Nat Commun 2016; 7:13595. [PMID: 27882920 PMCID: PMC5123050 DOI: 10.1038/ncomms13595] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 10/18/2016] [Indexed: 12/15/2022] Open
Abstract
Little is known about how archaeal viruses perturb the transcription machinery of their hosts. Here we provide the first example of an archaeo-viral transcription factor that directly targets the host RNA polymerase (RNAP) and efficiently represses its activity. ORF145 from the temperate Acidianus two-tailed virus (ATV) forms a high-affinity complex with RNAP by binding inside the DNA-binding channel where it locks the flexible RNAP clamp in one position. This counteracts the formation of transcription pre-initiation complexes in vitro and represses abortive and productive transcription initiation, as well as elongation. Both host and viral promoters are subjected to ORF145 repression. Thus, ORF145 has the properties of a global transcription repressor and its overexpression is toxic for Sulfolobus. On the basis of its properties, we have re-named ORF145 RNAP Inhibitory Protein (RIP).
Collapse
|
14
|
Life Cycle Characterization of Sulfolobus Monocaudavirus 1, an Extremophilic Spindle-Shaped Virus with Extracellular Tail Development. J Virol 2016; 90:5693-5699. [PMID: 27053548 DOI: 10.1128/jvi.00075-16] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/15/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED We provide here, for the first time, insights into the initial infection stages of a large spindle-shaped archaeal virus and explore the following life cycle events. Our observations suggest that Sulfolobus monocaudavirus 1 (SMV1) exhibits a high adsorption rate and that virions adsorb to the host cells via three distinct attachment modes: nosecone association, body association, and body/tail association. In the body/tail association mode, the entire virion, including the tail(s), aligns to the host cell surface and the main body is greatly flattened, suggesting a possible fusion entry mechanism. Upon infection, the intracellular replication cycle lasts about 8 h, at which point the virions are released as spindle-shaped tailless particles. Replication of the virus retarded host growth but did not cause lysis of the host cells. Once released from the host and at temperatures resembling that of its natural habitat, SMV1 starts developing one or two tails. This exceptional property of undergoing a major morphological development outside, and independently of, the host cell has been reported only once before for the related Acidianus two-tailed virus. Here, we show that SMV1 can develop tails of more than 900 nm in length, more than quadrupling the total virion length. IMPORTANCE Very little is known about the initial life cycle stages of viruses infecting hosts of the third domain of life, Archaea This work describes the first example of an archaeal virus employing three distinct association modes. The virus under study, Sulfolobus monocaudavirus 1, is a representative of the large spindle-shaped viruses that are frequently found in acidic hot springs. The results described here will add valuable knowledge about Archaea, the least studied domain in the virology field.
Collapse
|
15
|
Acidianus Tailed Spindle Virus: a New Archaeal Large Tailed Spindle Virus Discovered by Culture-Independent Methods. J Virol 2016; 90:3458-68. [PMID: 26763997 DOI: 10.1128/jvi.03098-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 01/07/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The field of viral metagenomics has expanded our understanding of viral diversity from all three domains of life (Archaea, Bacteria, and Eukarya). Traditionally, viral metagenomic studies provide information about viral gene content but rarely provide knowledge about virion morphology and/or cellular host identity. Here we describe a new virus, Acidianus tailed spindle virus (ATSV), initially identified by bioinformatic analysis of viral metagenomic data sets from a high-temperature (80°C) acidic (pH 2) hot spring located in Yellowstone National Park, followed by more detailed characterization using only environmental samples without dependency on culturing. Characterization included the identification of the large tailed spindle virion morphology, determination of the complete 70.8-kb circular double-stranded DNA (dsDNA) viral genome content, and identification of its cellular host. Annotation of the ATSV genome revealed a potential three-domain gene product containing an N-terminal leucine-rich repeat domain, followed by a likely posttranslation regulatory region consisting of high serine and threonine content, and a C-terminal ESCRT-III domain, suggesting interplay with the host ESCRT system. The host of ATSV, which is most closely related to Acidianus hospitalis, was determined by a combination of analysis of cellular clustered regularly interspaced short palindromic repeat (CRISPR)/Cas loci and dual viral and cellular fluorescence in situ hybridization (viral FISH) analysis of environmental samples and confirmed by culture-based infection studies. This work provides an expanded pathway for the discovery, isolation, and characterization of new viruses using culture-independent approaches and provides a platform for predicting and confirming virus hosts. IMPORTANCE Virus discovery and characterization have been traditionally accomplished by using culture-based methods. While a valuable approach, it is limited by the availability of culturable hosts. In this research, we report a virus-centered approach to virus discovery and characterization, linking viral metagenomic sequences to a virus particle, its sequenced genome, and its host directly in environmental samples, without using culture-dependent methods. This approach provides a pathway for the discovery, isolation, and characterization of new viruses. While this study used an acidic hot spring environment to characterize a new archaeal virus, Acidianus tailed spindle virus (ATSV), the approach can be generally applied to any environment to expand knowledge of virus diversity in all three domains of life.
Collapse
|
16
|
Sulfolobus Spindle-Shaped Virus 1 Contains Glycosylated Capsid Proteins, a Cellular Chromatin Protein, and Host-Derived Lipids. J Virol 2015; 89:11681-91. [PMID: 26355093 DOI: 10.1128/jvi.02270-15] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 09/04/2015] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED Geothermal and hypersaline environments are rich in virus-like particles, among which spindle-shaped morphotypes dominate. Currently, viruses with spindle- or lemon-shaped virions are exclusive to Archaea and belong to two distinct viral families. The larger of the two families, the Fuselloviridae, comprises tail-less, spindle-shaped viruses, which infect hosts from phylogenetically distant archaeal lineages. Sulfolobus spindle-shaped virus 1 (SSV1) is the best known member of the family and was one of the first hyperthermophilic archaeal viruses to be isolated. SSV1 is an attractive model for understanding virus-host interactions in Archaea; however, the constituents and architecture of SSV1 particles remain only partially characterized. Here, we have conducted an extensive biochemical characterization of highly purified SSV1 virions and identified four virus-encoded structural proteins, VP1 to VP4, as well as one DNA-binding protein of cellular origin. The virion proteins VP1, VP3, and VP4 undergo posttranslational modification by glycosylation, seemingly at multiple sites. VP1 is also proteolytically processed. In addition to the viral DNA-binding protein VP2, we show that viral particles contain the Sulfolobus solfataricus chromatin protein Sso7d. Finally, we provide evidence indicating that SSV1 virions contain glycerol dibiphytanyl glycerol tetraether (GDGT) lipids, resolving a long-standing debate on the presence of lipids within SSV1 virions. A comparison of the contents of lipids isolated from the virus and its host cell suggests that GDGTs are acquired by the virus in a selective manner from the host cytoplasmic membrane, likely during progeny egress. IMPORTANCE Although spindle-shaped viruses represent one of the most prominent viral groups in Archaea, structural data on their virion constituents and architecture still are scarce. The comprehensive biochemical characterization of the hyperthermophilic virus SSV1 presented here brings novel and significant insights into the organization and architecture of spindle-shaped virions. The obtained data permit the comparison between spindle-shaped viruses residing in widely different ecological niches, improving our understanding of the adaptation of viruses with unusual morphotypes to extreme environmental conditions.
Collapse
|