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Truchon AR, Chase EE, Gann ER, Moniruzzaman M, Creasey BA, Aylward FO, Xiao C, Gobler CJ, Wilhelm SW. Kratosvirus quantuckense: the history and novelty of an algal bloom disrupting virus and a model for giant virus research. Front Microbiol 2023; 14:1284617. [PMID: 38098665 PMCID: PMC10720644 DOI: 10.3389/fmicb.2023.1284617] [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: 08/28/2023] [Accepted: 10/30/2023] [Indexed: 12/17/2023] Open
Abstract
Since the discovery of the first "giant virus," particular attention has been paid toward isolating and culturing these large DNA viruses through Acanthamoeba spp. bait systems. While this method has allowed for the discovery of plenty novel viruses in the Nucleocytoviricota, environmental -omics-based analyses have shown that there is a wealth of diversity among this phylum, particularly in marine datasets. The prevalence of these viruses in metatranscriptomes points toward their ecological importance in nutrient turnover in our oceans and as such, in depth study into non-amoebal Nucleocytoviricota should be considered a focal point in viral ecology. In this review, we report on Kratosvirus quantuckense (née Aureococcus anophagefferens Virus), an algae-infecting virus of the Imitervirales. Current systems for study in the Nucleocytoviricota differ significantly from this virus and its relatives, and a litany of trade-offs within physiology, coding potential, and ecology compared to these other viruses reveal the importance of K. quantuckense. Herein, we review the research that has been performed on this virus as well as its potential as a model system for algal-virus interactions.
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Affiliation(s)
- Alexander R Truchon
- Department of Microbiology, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Emily E Chase
- Department of Microbiology, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Eric R Gann
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
- Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Surgical Critical Care Initiative (SC2i), Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Mohammad Moniruzzaman
- Department of Marine Biology and Ecology, University of Miami, Miami, FL, United States
| | - Brooke A Creasey
- Department of Microbiology, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Frank O Aylward
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Chuan Xiao
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, TX, United States
| | | | - Steven W Wilhelm
- Department of Microbiology, University of Tennessee, Knoxville, Knoxville, TN, United States
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2
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Lobb B, Shapter A, Doxey AC, Nissimov JI. Functional Profiling and Evolutionary Analysis of a Marine Microalgal Virus Pangenome. Viruses 2023; 15:v15051116. [PMID: 37243202 DOI: 10.3390/v15051116] [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: 01/12/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023] Open
Abstract
Phycodnaviridae are large double-stranded DNA viruses, which facilitate studies of host-virus interactions and co-evolution due to their prominence in algal infection and their role in the life cycle of algal blooms. However, the genomic interpretation of these viruses is hampered by a lack of functional information, stemming from the surprising number of hypothetical genes of unknown function. It is also unclear how many of these genes are widely shared within the clade. Using one of the most extensively characterized genera, Coccolithovirus, as a case study, we combined pangenome analysis, multiple functional annotation tools, AlphaFold structural modeling, and literature analysis to compare the core and accessory pangenome and assess support for novel functional predictions. We determined that the Coccolithovirus pangenome shares 30% of its genes with all 14 strains, making up the core. Notably, 34% of its genes were found in at most three strains. Core genes were enriched in early expression based on a transcriptomic dataset of Coccolithovirus EhV-201 algal infection, were more likely to be similar to host proteins than the non-core set, and were more likely to be involved in vital functions such as replication, recombination, and repair. In addition, we generated and collated annotations for the EhV representative EhV-86 from 12 different annotation sources, building up information for 142 previously hypothetical and putative membrane proteins. AlphaFold was further able to predict structures for 204 EhV-86 proteins with a modelling accuracy of good-high. These functional clues, combined with generated AlphaFold structures, provide a foundational framework for the future characterization of this model genus (and other giant viruses) and a further look into the evolution of the Coccolithovirus proteome.
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Affiliation(s)
- Briallen Lobb
- Department of Biology, University of Waterloo, 200 University Ave. West., Waterloo, ON N2L 3G1, Canada
| | - Anson Shapter
- Department of Biology, University of Waterloo, 200 University Ave. West., Waterloo, ON N2L 3G1, Canada
| | - Andrew C Doxey
- Department of Biology, University of Waterloo, 200 University Ave. West., Waterloo, ON N2L 3G1, Canada
| | - Jozef I Nissimov
- Department of Biology, University of Waterloo, 200 University Ave. West., Waterloo, ON N2L 3G1, Canada
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3
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Speciale I, Notaro A, Abergel C, Lanzetta R, Lowary TL, Molinaro A, Tonetti M, Van Etten JL, De Castro C. The Astounding World of Glycans from Giant Viruses. Chem Rev 2022; 122:15717-15766. [PMID: 35820164 PMCID: PMC9614988 DOI: 10.1021/acs.chemrev.2c00118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
![]()
Viruses are a heterogeneous ensemble of entities, all
sharing the
need for a suitable host to replicate. They are extremely diverse,
varying in morphology, size, nature, and complexity of their genomic
content. Typically, viruses use host-encoded glycosyltransferases
and glycosidases to add and remove sugar residues from their glycoproteins.
Thus, the structure of the glycans on the viral proteins have, to
date, typically been considered to mimick those of the host. However,
the more recently discovered large and giant viruses differ from this
paradigm. At least some of these viruses code for an (almost) autonomous
glycosylation pathway. These viral genes include those that encode
the production of activated sugars, glycosyltransferases, and other
enzymes able to manipulate sugars at various levels. This review focuses
on large and giant viruses that produce carbohydrate-processing enzymes.
A brief description of those harboring these features at the genomic
level will be discussed, followed by the achievements reached with
regard to the elucidation of the glycan structures, the activity of
the proteins able to manipulate sugars, and the organic synthesis
of some of these virus-encoded glycans. During this progression, we
will also comment on many of the challenging questions on this subject
that remain to be addressed.
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Affiliation(s)
- Immacolata Speciale
- Department of Agricultural Sciences, University of Napoli, Via Università 100, 80055 Portici, Italy
| | - Anna Notaro
- Department of Agricultural Sciences, University of Napoli, Via Università 100, 80055 Portici, Italy.,Centre National de la Recherche Scientifique, Information Génomique & Structurale, Aix-Marseille University, Unité Mixte de Recherche 7256, IMM, IM2B, 13288 Marseille, Cedex 9, France
| | - Chantal Abergel
- Centre National de la Recherche Scientifique, Information Génomique & Structurale, Aix-Marseille University, Unité Mixte de Recherche 7256, IMM, IM2B, 13288 Marseille, Cedex 9, France
| | - Rosa Lanzetta
- Department of Chemical Sciences, University of Napoli, Via Cintia 4, 80126 Napoli, Italy
| | - Todd L Lowary
- Institute of Biological Chemistry, Academia Sinica, Academia Road, Section 2, Nangang 11529, Taipei, Taiwan
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Napoli, Via Cintia 4, 80126 Napoli, Italy
| | - Michela Tonetti
- Department of Experimental Medicine and Center of Excellence for Biomedical Research, University of Genova, 16132 Genova, Italy
| | - James L Van Etten
- Nebraska Center for Virology, University of Nebraska, Lincoln, Nebraska 68583-0900, United States.,Department of Plant Pathology, University of Nebraska, Lincoln, Nebraska 68583-0722, United States
| | - Cristina De Castro
- Department of Agricultural Sciences, University of Napoli, Via Università 100, 80055 Portici, Italy
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4
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Brahim Belhaouari D, Pires De Souza GA, Lamb DC, Kelly SL, Goldstone JV, Stegeman JJ, Colson P, La Scola B, Aherfi S. Metabolic arsenal of giant viruses: Host hijack or self-use? eLife 2022; 11:e78674. [PMID: 35801640 PMCID: PMC9270025 DOI: 10.7554/elife.78674] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 06/22/2022] [Indexed: 12/11/2022] Open
Abstract
Viruses generally are defined as lacking the fundamental properties of living organisms in that they do not harbor an energy metabolism system or protein synthesis machinery. However, the discovery of giant viruses of amoeba has fundamentally challenged this view because of their exceptional genome properties, particle sizes and encoding of the enzyme machinery for some steps of protein synthesis. Although giant viruses are not able to replicate autonomously and still require a host for their multiplication, numerous metabolic genes involved in energy production have been recently detected in giant virus genomes from many environments. These findings have further blurred the boundaries that separate viruses and living organisms. Herein, we summarize information concerning genes and proteins involved in cellular metabolic pathways and their orthologues that have, surprisingly, been discovered in giant viruses. The remarkable diversity of metabolic genes described in giant viruses include genes encoding enzymes involved in glycolysis, gluconeogenesis, tricarboxylic acid cycle, photosynthesis, and β-oxidation. These viral genes are thought to have been acquired from diverse biological sources through lateral gene transfer early in the evolution of Nucleo-Cytoplasmic Large DNA Viruses, or in some cases more recently. It was assumed that viruses are capable of hijacking host metabolic networks. But the giant virus auxiliary metabolic genes also may represent another form of host metabolism manipulation, by expanding the catalytic capabilities of the host cells especially in harsh environments, providing the infected host cells with a selective evolutionary advantage compared to non-infected cells and hence favoring the viral replication. However, the mechanism of these genes' functionality remains unclear to date.
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Affiliation(s)
- Djamal Brahim Belhaouari
- Microbes, Evolution, Phylogeny and Infection (MEPHI), UM63, Institut de Recherche pour le Développement (IRD), IHU Méditerranée Infection, Marseille, France, Aix-Marseille UniversitéMarseilleFrance
| | - Gabriel Augusto Pires De Souza
- Microbes, Evolution, Phylogeny and Infection (MEPHI), UM63, Institut de Recherche pour le Développement (IRD), IHU Méditerranée Infection, Marseille, France, Aix-Marseille UniversitéMarseilleFrance
| | - David C Lamb
- Faculty of Medicine, Health and Life Sciences, Institute of Life Science, Swansea UniversitySwanseaUnited Kingdom
| | - Steven L Kelly
- Faculty of Medicine, Health and Life Sciences, Institute of Life Science, Swansea UniversitySwanseaUnited Kingdom
| | - Jared V Goldstone
- Biology Department, Woods Hole Oceanographic InstitutionWoods HoleUnited States
| | - John J Stegeman
- Biology Department, Woods Hole Oceanographic InstitutionWoods HoleUnited States
| | - Philippe Colson
- Microbes, Evolution, Phylogeny and Infection (MEPHI), UM63, Institut de Recherche pour le Développement (IRD), IHU Méditerranée Infection, Marseille, France, Aix-Marseille UniversitéMarseilleFrance
- Assistance Publique - Hôpitaux de Marseille (AP-HM)MarseilleFrance
| | - Bernard La Scola
- Microbes, Evolution, Phylogeny and Infection (MEPHI), UM63, Institut de Recherche pour le Développement (IRD), IHU Méditerranée Infection, Marseille, France, Aix-Marseille UniversitéMarseilleFrance
- Assistance Publique - Hôpitaux de Marseille (AP-HM)MarseilleFrance
| | - Sarah Aherfi
- Microbes, Evolution, Phylogeny and Infection (MEPHI), UM63, Institut de Recherche pour le Développement (IRD), IHU Méditerranée Infection, Marseille, France, Aix-Marseille UniversitéMarseilleFrance
- Assistance Publique - Hôpitaux de Marseille (AP-HM)MarseilleFrance
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5
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Retel C, Kowallik V, Becks L, Feulner PGD. Strong Selection and High Mutation Supply Characterize Experimental Chlorovirus Evolution. Virus Evol 2022; 8:veac003. [PMID: 35169490 PMCID: PMC8838748 DOI: 10.1093/ve/veac003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 01/14/2022] [Accepted: 01/25/2022] [Indexed: 11/24/2022] Open
Abstract
Characterizing how viruses evolve expands our understanding of the underlying fundamental processes, such as mutation, selection and drift. One group of viruses whose evolution has not yet been extensively studied is the Phycodnaviridae, a globally abundant family of aquatic large double-stranded (ds) DNA viruses. Here we studied the evolutionary change of Paramecium bursaria chlorella virus 1 during experimental coevolution with its algal host. We used pooled genome sequencing of six independently evolved populations to characterize genomic change over five time points. Across six experimental replicates involving either strong or weak demographic fluctuations, we found single nucleotide polymorphisms (SNPs) at sixty-seven sites. The occurrence of genetic variants was highly repeatable, with just two of the SNPs found in only a single experimental replicate. Three genes A122/123R, A140/145R and A540L showed an excess of variable sites, providing new information about potential targets of selection during Chlorella–Chlorovirus coevolution. Our data indicated that the studied populations were not mutation-limited and experienced strong positive selection. Our investigation highlighted relevant processes governing the evolution of aquatic large dsDNA viruses, which ultimately contributes to a better understanding of the functioning of natural aquatic ecosystems.
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Affiliation(s)
- Cas Retel
- Department of Fish Ecology and Evolution, Center for Ecology, Evolution and Bio-geochemistry, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Seestrasse 79, Kastanienbaum 6047, Switzerland
- Division of Aquatic Ecology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, Bern 3012, Switzerland
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6
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Speciale I, Di Lorenzo F, Notaro A, Noel E, Agarkova I, Molinaro A, Van Etten JL, De Castro C. N-glycans from Paramecium bursaria chlorella virus MA-1D: Re-evaluation of the oligosaccharide common core structure. Glycobiology 2021; 32:260-273. [DOI: 10.1093/glycob/cwab113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/29/2021] [Accepted: 10/30/2021] [Indexed: 11/12/2022] Open
Abstract
Abstract
Paramecium bursaria chlorella virus MA-1D is a chlorovirus that infects Chlorella variabilis strain NC64A, a symbiont of the protozoan Paramecium bursaria. MA-1D has a 339-kb genome encoding ca. 366 proteins and 11 tRNAs. Like other chloroviruses, its major capsid protein (MCP) is decorated with N-glycans, whose structures have been solved in this work by using nuclear magnetic (NMR) spectroscopy and MALDI-TOF mass spectrometry along with MS/MS experiments. This analysis identified three N-linked oligosaccharides that differ in the non-stoichiometric presence of three monosaccharides, with the largest oligosaccharide composed of eight residues organized in a highly branched fashion. The N-glycans described here share several features with those of the other chloroviruses except that they lack a distal xylose unit that was believed to be part of a conserved core region for all the chloroviruses. Examination of the MA-1D genome detected a gene with strong homology to the putative xylosyltransferase in the reference chlorovirus PBCV-1 and in virus NY-2A, albeit mutated with a premature stop codon. This discovery means that we need to reconsider the essential features of the common core glycan region in the chloroviruses.
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Affiliation(s)
- Immacolata Speciale
- Department of Agricultural Sciences, University of Napoli Federico II, Via Università 100, 80055, Portici, Italy
| | - Flaviana Di Lorenzo
- Department of Agricultural Sciences, University of Napoli Federico II, Via Università 100, 80055, Portici, Italy
| | - Anna Notaro
- Department of Agricultural Sciences, University of Napoli Federico II, Via Università 100, 80055, Portici, Italy
| | - Eric Noel
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE, 68583-0900, USA
- School of Biological Sciences, University of Nebraska, Lincoln, NE, 68588-0118, USA
- Innovative Genomics Institute, University of California, Berkeley, CA, 94720, USA
| | - Irina Agarkova
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE, 68583-0900, USA
- Department of Plant Pathology, University of Nebraska, Lincoln, NE, 68583-0722, USA
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Napoli Federico II, Via Cintia 26, 80126, Napoli, Italy
| | - James L Van Etten
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE, 68583-0900, USA
- Department of Plant Pathology, University of Nebraska, Lincoln, NE, 68583-0722, USA
| | - Cristina De Castro
- Department of Agricultural Sciences, University of Napoli Federico II, Via Università 100, 80055, Portici, Italy
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7
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Functional genomic analyses reveal an open pan-genome for the chloroviruses and a potential for genetic innovation in new isolates. J Virol 2021; 96:e0136721. [PMID: 34669449 DOI: 10.1128/jvi.01367-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chloroviruses (family Phycodnaviridae) are large dsDNA viruses that infect unicellular green algae present in inland waters. These viruses have been isolated using three main chlorella-like green algal host cells, traditionally called NC64A, SAG and Pbi, revealing extensive genetic diversity. In this study, we performed a functional genomic analysis on 36 chloroviruses that infected the three different hosts. Phylogenetic reconstruction based on the DNA polymerase B family gene clustered the chloroviruses into three distinct clades. The viral pan-genome consists of 1,345 clusters of orthologous groups of genes (COGs), with 126 COGs conserved in all viruses. 368, 268 and 265 COGs are found exclusively in viruses that infect NC64A, SAG, and Pbi algal hosts, respectively. Two-thirds of the COGs have no known function, constituting the "dark pan-genome" of chloroviruses, and further studies focusing on these genes may identify important novelties. The proportion of functionally characterized COGs composing the pan- and the core-genome are similar, but those related to transcription and RNA processing, protein metabolism, and virion morphogenesis are at least 4-fold more represented in the core-genome. Bipartite network construction evidencing the COG-sharing among host-specific viruses identified 270 COGs shared by at least one virus from each of the different host groups. Finally, our results reveal an open pan-genome for chloroviruses and a well-established core-genome, indicating that the isolation of new chloroviruses can be a valuable source of genetic discovery. Importance Chloroviruses are large dsDNA viruses that infect unicellular green algae distributed worldwide in freshwater environments. They comprise a genetically diverse group of viruses; however, a comprehensive investigation of the genomic evolution of these viruses is still missing. Here we performed a functional pan-genome analysis comprising 36 chloroviruses associated with three different algal hosts in the family Chlorellaceae, referred to as zoochlorellae because of their endosymbiotic lifestyle. We identified a set of 126 highly conserved genes, most of which are related to essential functions in the viral replicative cycle. Several genes are unique to distinct isolates, resulting in an open pan-genome for chloroviruses. This profile is associated with generalist organisms, and new insights into the evolution and ecology of chloroviruses are presented. Ultimately, our results highlight the potential for genetic diversity in new isolates.
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8
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Notaro A, Couté Y, Belmudes L, Laugeri ME, Salis A, Damonte G, Molinaro A, Tonetti MG, Abergel C, De Castro C. Expanding the Occurrence of Polysaccharides to the Viral World: The Case of Mimivirus. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202106671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Anna Notaro
- Department of Chemical Sciences University of Naples Federico II Via Cinthia 21 80126 Naples Italy
- Information Génomique & Structurale Unité Mixte de Recherche 7256 Aix-Marseille University Centre National de la Recherche Scientifique, IMM, IM2B 13288 Marseille Cedex 9 France
| | - Yohann Couté
- INSERM, CEA, UMR BioSanté U1292 Univ. Grenoble Alpes CNRS, CEA, FR2048 38000 Grenoble France
| | - Lucid Belmudes
- INSERM, CEA, UMR BioSanté U1292 Univ. Grenoble Alpes CNRS, CEA, FR2048 38000 Grenoble France
| | - Maria Elena Laugeri
- Department of Experimental Medicine and Center of Excellence for Biomedical Research University of Genova Genova Italy
| | - Annalisa Salis
- Department of Experimental Medicine and Center of Excellence for Biomedical Research University of Genova Genova Italy
| | - Gianluca Damonte
- Department of Experimental Medicine and Center of Excellence for Biomedical Research University of Genova Genova Italy
| | - Antonio Molinaro
- Department of Chemical Sciences University of Naples Federico II Via Cinthia 21 80126 Naples Italy
| | - Michela G. Tonetti
- Department of Experimental Medicine and Center of Excellence for Biomedical Research University of Genova Genova Italy
| | - Chantal Abergel
- Information Génomique & Structurale Unité Mixte de Recherche 7256 Aix-Marseille University Centre National de la Recherche Scientifique, IMM, IM2B 13288 Marseille Cedex 9 France
| | - Cristina De Castro
- Department of Agricultural Sciences University of Naples Federico II Via Università, 100 80055 Portici (NA) Italy
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9
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Nelson DR, Hazzouri KM, Lauersen KJ, Jaiswal A, Chaiboonchoe A, Mystikou A, Fu W, Daakour S, Dohai B, Alzahmi A, Nobles D, Hurd M, Sexton J, Preston MJ, Blanchette J, Lomas MW, Amiri KMA, Salehi-Ashtiani K. Large-scale genome sequencing reveals the driving forces of viruses in microalgal evolution. Cell Host Microbe 2021; 29:250-266.e8. [PMID: 33434515 DOI: 10.1016/j.chom.2020.12.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/08/2020] [Accepted: 11/18/2020] [Indexed: 01/08/2023]
Abstract
Being integral primary producers in diverse ecosystems, microalgal genomes could be mined for ecological insights, but representative genome sequences are lacking for many phyla. We cultured and sequenced 107 microalgae species from 11 different phyla indigenous to varied geographies and climates. This collection was used to resolve genomic differences between saltwater and freshwater microalgae. Freshwater species showed domain-centric ontology enrichment for nuclear and nuclear membrane functions, while saltwater species were enriched in organellar and cellular membrane functions. Further, marine species contained significantly more viral families in their genomes (p = 8e-4). Sequences from Chlorovirus, Coccolithovirus, Pandoravirus, Marseillevirus, Tupanvirus, and other viruses were found integrated into the genomes of algal from marine environments. These viral-origin sequences were found to be expressed and code for a wide variety of functions. Together, this study comprehensively defines the expanse of protein-coding and viral elements in microalgal genomes and posits a unified adaptive strategy for algal halotolerance.
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Affiliation(s)
- David R Nelson
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE.
| | - Khaled M Hazzouri
- Khalifa Center for Genetic Engineering and Biotechnology (KCGEB), UAE University, Al Ain, Abu Dhabi, UAE; Biology Department, College of Science, UAE University, Al Ain, Abu Dhabi, UAE
| | - Kyle J Lauersen
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Ashish Jaiswal
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi, UAE
| | | | - Alexandra Mystikou
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Weiqi Fu
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Sarah Daakour
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Bushra Dohai
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Amnah Alzahmi
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - David Nobles
- UTEX Culture Collection of Algae at the University of Texas at Austin, Austin, TX, USA
| | - Mark Hurd
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Julie Sexton
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Michael J Preston
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Joan Blanchette
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Michael W Lomas
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Khaled M A Amiri
- Khalifa Center for Genetic Engineering and Biotechnology (KCGEB), UAE University, Al Ain, Abu Dhabi, UAE; Biology Department, College of Science, UAE University, Al Ain, Abu Dhabi, UAE
| | - Kourosh Salehi-Ashtiani
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE; Division of Science and Math, New York University Abu Dhabi, Abu Dhabi, UAE.
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10
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Notaro A, Couté Y, Belmudes L, Laugeri ME, Salis A, Damonte G, Molinaro A, Tonetti MG, Abergel C, De Castro C. Expanding the Occurrence of Polysaccharides to the Viral World: The Case of Mimivirus. Angew Chem Int Ed Engl 2021; 60:19897-19904. [PMID: 34241943 PMCID: PMC8456856 DOI: 10.1002/anie.202106671] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Indexed: 11/05/2022]
Abstract
The general perception of viruses is that they are small in terms of size and genome, and that they hijack the host machinery to glycosylate their capsid. Giant viruses subvert all these concepts: their particles are not small, and their genome is more complex than that of some bacteria. Regarding glycosylation, this concept has been already challenged by the finding that Chloroviruses have an autonomous glycosylation machinery that produces oligosaccharides similar in size to those of small viruses (6-12 units), albeit different in structure compared to the viral counterparts. We report herein that Mimivirus possesses a glycocalyx made of two different polysaccharides, now challenging the concept that all viruses coat their capsids with oligosaccharides of discrete size. This discovery contradicts the paradigm that such macromolecules are absent in viruses, blurring the boundaries between giant viruses and the cellular world and opening new avenues in the field of viral glycobiology.
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Affiliation(s)
- Anna Notaro
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 21, 80126, Naples, Italy.,Information Génomique & Structurale, Unité Mixte de Recherche 7256, Aix-Marseille University, Centre National de la Recherche Scientifique, IMM, IM2B, 13288, Marseille Cedex 9, France
| | - Yohann Couté
- INSERM, CEA, UMR BioSanté U1292, Univ. Grenoble Alpes, CNRS, CEA, FR2048, 38000, Grenoble, France
| | - Lucid Belmudes
- INSERM, CEA, UMR BioSanté U1292, Univ. Grenoble Alpes, CNRS, CEA, FR2048, 38000, Grenoble, France
| | - Maria Elena Laugeri
- Department of Experimental Medicine and Center of Excellence for Biomedical Research, University of Genova, Genova, Italy
| | - Annalisa Salis
- Department of Experimental Medicine and Center of Excellence for Biomedical Research, University of Genova, Genova, Italy
| | - Gianluca Damonte
- Department of Experimental Medicine and Center of Excellence for Biomedical Research, University of Genova, Genova, Italy
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 21, 80126, Naples, Italy
| | - Michela G Tonetti
- Department of Experimental Medicine and Center of Excellence for Biomedical Research, University of Genova, Genova, Italy
| | - Chantal Abergel
- Information Génomique & Structurale, Unité Mixte de Recherche 7256, Aix-Marseille University, Centre National de la Recherche Scientifique, IMM, IM2B, 13288, Marseille Cedex 9, France
| | - Cristina De Castro
- Department of Agricultural Sciences, University of Naples Federico II, Via Università, 100, 80055, Portici (NA), Italy
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11
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Mishra B, Manmode S, Walke G, Chakraborty S, Neralkar M, Hotha S. Synthesis of the hyper-branched core tetrasaccharide motif of chloroviruses. Org Biomol Chem 2021; 19:1315-1328. [PMID: 33459320 DOI: 10.1039/d0ob02176h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Chemical synthesis of complex oligosaccharides, especially those possessing hyper-branched structures with one or multiple 1,2-cis glycosidic bonds, is a challenging task. Complementary reactivity of glycosyl donors and acceptors and proper tuning of the solvent/temperature/activator coupled with compromised glycosylation yields for sterically congested glycosyl acceptors are among several factors that make such syntheses daunting. Herein, we report the synthesis of a semi-conserved hyper-branched core tetrasaccharide motif from chloroviruses which are associated with reduced cognitive function in humans as well as in mouse models. The target tetrasaccharide contains four different sugar residues in which l-fucose is connected to d-xylose and l-rhamnose via a 1,2-trans glycosidic bond, whereas with the d-galactose residue is connected through a 1,2-cis glycosidic bond. A thorough and comprehensive study of various accountable factors enabled us to install a 1,2-cis galactopyranosidic linkage in a stereoselective fashion under [Au]/[Ag]-catalyzed glycosidation conditions en route to the target tetrasaccharide motif in 14 steps.
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Affiliation(s)
- Bijoyananda Mishra
- Department of Chemistry, Indian Institute of Science Education and Research, Pune - 411 008, MH, India.
| | - Sujit Manmode
- Department of Chemistry, Indian Institute of Science Education and Research, Pune - 411 008, MH, India.
| | - Gulab Walke
- Department of Chemistry, Indian Institute of Science Education and Research, Pune - 411 008, MH, India.
| | - Saptashwa Chakraborty
- Department of Chemistry, Indian Institute of Science Education and Research, Pune - 411 008, MH, India.
| | - Mahesh Neralkar
- Department of Chemistry, Indian Institute of Science Education and Research, Pune - 411 008, MH, India.
| | - Srinivas Hotha
- Department of Chemistry, Indian Institute of Science Education and Research, Pune - 411 008, MH, India.
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12
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Prospects for viruses infecting eukaryotic microalgae in biotechnology. Biotechnol Adv 2021; 54:107790. [PMID: 34182051 DOI: 10.1016/j.biotechadv.2021.107790] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 06/02/2021] [Accepted: 06/18/2021] [Indexed: 12/16/2022]
Abstract
Besides being considered pathogens, viruses are important drivers of evolution and they can shape large ecological and biogeochemical processes, by influencing host fitness, population dynamics, and community structures. Moreover, they are simple systems that can be used and manipulated to be beneficial and useful for biotechnological applications. In this context, microalgae biotechnology is a growing field of research, which investigated the usage of photosynthetic microorganisms for the sustainable production of food, fuel, chemical, and pharmaceutical sectors. Viruses infecting microalgae have become important subject of ecological studies related to marine and aquatic environments only four decades ago when virus-like-particles associated with bloom-forming algae were discovered. These first findings have opened new questions on evolution and identity. To date, 63 viruses that infect eukaryotic microalgae have been isolated and cultured. In this short review we briefly summarize what is known about viruses infecting eukaryotic microalgae, and how acknowledging their importance can shape future research focussed not only on marine ecology and evolutionary biology but also on biotechnological applications related to microalgae cell factories.
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Muñoz-Gómez SA, Kreutz M, Hess S. A microbial eukaryote with a unique combination of purple bacteria and green algae as endosymbionts. SCIENCE ADVANCES 2021; 7:eabg4102. [PMID: 34117067 PMCID: PMC8195481 DOI: 10.1126/sciadv.abg4102] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 04/27/2021] [Indexed: 05/08/2023]
Abstract
Oxygenic photosynthesizers (cyanobacteria and eukaryotic algae) have repeatedly become endosymbionts throughout evolution. In contrast, anoxygenic photosynthesizers (e.g., purple bacteria) are exceedingly rare as intracellular symbionts. Here, we report on the morphology, ultrastructure, lifestyle, and metagenome of the only "purple-green" eukaryote known. The ciliate Pseudoblepharisma tenue harbors green algae and hundreds of genetically reduced purple bacteria. The latter represent a new candidate species of the Chromatiaceae that lost known genes for sulfur dissimilation. The tripartite consortium is physiologically complex because of the versatile energy metabolism of each partner but appears to be ecologically specialized as it prefers hypoxic sediments. The emergent niche of this complex symbiosis is predicted to be a partial overlap of each partners' niches and may be largely defined by anoxygenic photosynthesis and possibly phagotrophy. This purple-green ciliate thus represents an extraordinary example of how symbiosis merges disparate physiologies and allows emergent consortia to create novel ecological niches.
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Affiliation(s)
- Sergio A Muñoz-Gómez
- Institute for Zoology, Cologne Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany.
- Center for Mechanism of Evolution, The Biodesign Institute, School of Life Sciences, Arizona State University, 727 E. Tyler St., Tempe, AZ 85281-5001, USA
| | - Martin Kreutz
- Private Laboratory, Am See 27, 78465 Constance, Germany
| | - Sebastian Hess
- Institute for Zoology, Cologne Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany.
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Identification of a Chlorovirus PBCV-1 Protein Involved in Degrading the Host Cell Wall during Virus Infection. Viruses 2021; 13:v13050782. [PMID: 33924931 PMCID: PMC8145301 DOI: 10.3390/v13050782] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/25/2021] [Accepted: 04/26/2021] [Indexed: 12/22/2022] Open
Abstract
Chloroviruses are unusual among viruses infecting eukaryotic organisms in that they must, like bacteriophages, penetrate a rigid cell wall to initiate infection. Chlorovirus PBCV-1 infects its host, Chlorella variabilis NC64A by specifically binding to and degrading the cell wall of the host at the point of contact by a virus-packaged enzyme(s). However, PBCV-1 does not use any of the five previously characterized virus-encoded polysaccharide degrading enzymes to digest the Chlorella host cell wall during virus entry because none of the enzymes are packaged in the virion. A search for another PBCV-1-encoded and virion-associated protein identified protein A561L. The fourth domain of A561L is a 242 amino acid C-terminal domain, named A561LD4, with cell wall degrading activity. An A561LD4 homolog was present in all 52 genomically sequenced chloroviruses, infecting four different algal hosts. A561LD4 degraded the cell walls of all four chlorovirus hosts, as well as several non-host Chlorella spp. Thus, A561LD4 was not cell-type specific. Finally, we discovered that exposure of highly purified PBCV-1 virions to A561LD4 increased the specific infectivity of PBCV-1 from about 25–30% of the particles forming plaques to almost 50%. We attribute this increase to removal of residual host receptor that attached to newly replicated viruses in the cell lysates.
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15
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Chlorovirus PBCV-1 Multidomain Protein A111/114R Has Three Glycosyltransferase Functions Involved in the Synthesis of Atypical N-Glycans. Viruses 2021; 13:v13010087. [PMID: 33435207 PMCID: PMC7826918 DOI: 10.3390/v13010087] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/03/2021] [Accepted: 01/08/2021] [Indexed: 12/04/2022] Open
Abstract
The structures of the four N-linked glycans from the prototype chlorovirus PBCV-1 major capsid protein do not resemble any other glycans in the three domains of life. All known chloroviruses and antigenic variants (or mutants) share a unique conserved central glycan core consisting of five sugars, except for antigenic mutant virus P1L6, which has four of the five sugars. A combination of genetic and structural analyses indicates that the protein coded by PBCV-1 gene a111/114r, conserved in all chloroviruses, is a glycosyltransferase with three putative domains of approximately 300 amino acids each. Here, in addition to in silico sequence analysis and protein modeling, we measured the hydrolytic activity of protein A111/114R. The results suggest that domain 1 is a galactosyltransferase, domain 2 is a xylosyltransferase and domain 3 is a fucosyltransferase. Thus, A111/114R is the protein likely responsible for the attachment of three of the five conserved residues of the core region of this complex glycan, and, if biochemically corroborated, it would be the second three-domain protein coded by PBCV-1 that is involved in glycan synthesis. Importantly, these findings provide additional support that the chloroviruses do not use the canonical host endoplasmic reticulum–Golgi glycosylation pathway to glycosylate their glycoproteins; instead, they perform glycosylation independent of cellular organelles using virus-encoded enzymes.
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Eukaryotic virus composition can predict the efficiency of carbon export in the global ocean. iScience 2020; 24:102002. [PMID: 33490910 PMCID: PMC7811142 DOI: 10.1016/j.isci.2020.102002] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 11/13/2020] [Accepted: 12/23/2020] [Indexed: 11/24/2022] Open
Abstract
The biological carbon pump, in which carbon fixed by photosynthesis is exported to the deep ocean through sinking, is a major process in Earth's carbon cycle. The proportion of primary production that is exported is termed the carbon export efficiency (CEE). Based on in-lab or regional scale observations, viruses were previously suggested to affect the CEE (i.e., viral “shunt” and “shuttle”). In this study, we tested associations between viral community composition and CEE measured at a global scale. A regression model based on relative abundance of viral marker genes explained 67% of the variation in CEE. Viruses with high importance in the model were predicted to infect ecologically important hosts. These results are consistent with the view that the viral shunt and shuttle functions at a large scale and further imply that viruses likely act in this process in a way dependent on their hosts and ecosystem dynamics. Eukaryotic virus community composition is shown to predict carbon export efficiency Tens of viruses are highly important in the prediction of the efficiency These viruses are inferred to infect ecologically important hosts
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Sun TW, Yang CL, Kao TT, Wang TH, Lai MW, Ku C. Host Range and Coding Potential of Eukaryotic Giant Viruses. Viruses 2020; 12:E1337. [PMID: 33233432 PMCID: PMC7700475 DOI: 10.3390/v12111337] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 11/19/2020] [Accepted: 11/19/2020] [Indexed: 12/11/2022] Open
Abstract
Giant viruses are a group of eukaryotic double-stranded DNA viruses with large virion and genome size that challenged the traditional view of virus. Newly isolated strains and sequenced genomes in the last two decades have substantially advanced our knowledge of their host diversity, gene functions, and evolutionary history. Giant viruses are now known to infect hosts from all major supergroups in the eukaryotic tree of life, which predominantly comprises microbial organisms. The seven well-recognized viral clades (taxonomic families) have drastically different host range. Mimiviridae and Phycodnaviridae, both with notable intrafamilial genome variation and high abundance in environmental samples, have members that infect the most diverse eukaryotic lineages. Laboratory experiments and comparative genomics have shed light on the unprecedented functional potential of giant viruses, encoding proteins for genetic information flow, energy metabolism, synthesis of biomolecules, membrane transport, and sensing that allow for sophisticated control of intracellular conditions and cell-environment interactions. Evolutionary genomics can illuminate how current and past hosts shape viral gene repertoires, although it becomes more obscure with divergent sequences and deep phylogenies. Continued works to characterize giant viruses from marine and other environments will further contribute to our understanding of their host range, coding potential, and virus-host coevolution.
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Affiliation(s)
- Tsu-Wang Sun
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; (T.-W.S.); (C.-L.Y.); (T.-T.K.); (T.-H.W.); (M.-W.L.)
- Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei 10617, Taiwan
| | - Chia-Ling Yang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; (T.-W.S.); (C.-L.Y.); (T.-T.K.); (T.-H.W.); (M.-W.L.)
| | - Tzu-Tong Kao
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; (T.-W.S.); (C.-L.Y.); (T.-T.K.); (T.-H.W.); (M.-W.L.)
| | - Tzu-Haw Wang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; (T.-W.S.); (C.-L.Y.); (T.-T.K.); (T.-H.W.); (M.-W.L.)
| | - Ming-Wei Lai
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; (T.-W.S.); (C.-L.Y.); (T.-T.K.); (T.-H.W.); (M.-W.L.)
| | - Chuan Ku
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; (T.-W.S.); (C.-L.Y.); (T.-T.K.); (T.-H.W.); (M.-W.L.)
- Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei 10617, Taiwan
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18
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Moniruzzaman M, Weinheimer AR, Martinez-Gutierrez CA, Aylward FO. Widespread endogenization of giant viruses shapes genomes of green algae. Nature 2020; 588:141-145. [PMID: 33208937 DOI: 10.1038/s41586-020-2924-2] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 09/01/2020] [Indexed: 12/21/2022]
Abstract
Endogenous viral elements (EVEs)-viruses that have integrated their genomes into those of their hosts-are prevalent in eukaryotes and have an important role in genome evolution1,2. The vast majority of EVEs that have been identified to date are small genomic regions comprising a few genes2, but recent evidence suggests that some large double-stranded DNA viruses may also endogenize into the genome of the host1. Nucleocytoplasmic large DNA viruses (NCLDVs) have recently become of great interest owing to their large genomes and complex evolutionary origins3-6, but it is not yet known whether they are a prominent component of eukaryotic EVEs. Here we report the widespread endogenization of NCLDVs in diverse green algae; these giant EVEs reached sizes greater than 1 million base pairs and contained as many as around 10% of the total open reading frames in some genomes, substantially increasing the scale of known viral genes in eukaryotic genomes. These endogenized elements often shared genes with host genomic loci and contained numerous spliceosomal introns and large duplications, suggesting tight assimilation into host genomes. NCLDVs contain large and mosaic genomes with genes derived from multiple sources, and their endogenization represents an underappreciated conduit of new genetic material into eukaryotic lineages that can substantially impact genome composition.
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Affiliation(s)
| | | | | | - Frank O Aylward
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.
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19
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Chlorovirus PBCV-1 protein A064R has three of the transferase activities necessary to synthesize its capsid protein N-linked glycans. Proc Natl Acad Sci U S A 2020; 117:28735-28742. [PMID: 33139538 DOI: 10.1073/pnas.2016626117] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Paramecium bursaria chlorella virus-1 (PBCV-1) is a large double-stranded DNA (dsDNA) virus that infects the unicellular green alga Chlorella variabilis NC64A. Unlike many other viruses, PBCV-1 encodes most, if not all, of the enzymes involved in the synthesis of the glycans attached to its major capsid protein. Importantly, these glycans differ from those reported from the three domains of life in terms of structure and asparagine location in the sequon of the protein. Previous data collected from 20 PBCV-1 spontaneous mutants (or antigenic variants) suggested that the a064r gene encodes a glycosyltransferase (GT) with three domains, each with a different function. Here, we demonstrate that: domain 1 is a β-l-rhamnosyltransferase; domain 2 is an α-l-rhamnosyltransferase resembling only bacterial proteins of unknown function, and domain 3 is a methyltransferase that methylates the C-2 hydroxyl group of the terminal α-l-rhamnose (Rha) unit. We also establish that methylation of the C-3 hydroxyl group of the terminal α-l-Rha is achieved by another virus-encoded protein A061L, which requires an O-2 methylated substrate. This study, thus, identifies two of the glycosyltransferase activities involved in the synthesis of the N-glycan of the viral major capsid protein in PBCV-1 and establishes that a single protein A064R possesses the three activities needed to synthetize the 2-OMe-α-l-Rha-(1→2)-β-l-Rha fragment. Remarkably, this fragment can be attached to any xylose unit.
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20
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Lin S, Lowary TL. Synthesis of a Highly Branched Nonasaccharide Chlorella Virus N-Glycan Using a "Counterclockwise" Assembly Approach. Org Lett 2020; 22:7645-7649. [PMID: 32940477 DOI: 10.1021/acs.orglett.0c02839] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Chloroviruses produce a capsid protein containing N-linked glycans differing in structure from those found in all other organisms. These species feature a core "hyper-branched" fucose residue in which every hydroxyl group is glycosylated. We describe the synthesis of a nonasaccharide from Paramecium bursaria chlorella virus 1, one of most complex chlorovirus N-glycans reported, using a "counterclockwise" strategy involving the sequential addition of trisaccharide, disaccharide, and monosaccharide motifs to a trisaccharide containing the core fucose residue.
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Affiliation(s)
- Sicheng Lin
- Department of Chemistry, The University of Alberta, Edmonton, Alberta, Canada, T6G 2G2
| | - Todd L Lowary
- Department of Chemistry, The University of Alberta, Edmonton, Alberta, Canada, T6G 2G2.,Institute of Biological Chemistry, Academia Sinica, Academia Road, Section 2, #128, Nangang, Taipei 11529, Taiwan
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21
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Gann ER, Xian Y, Abraham PE, Hettich RL, Reynolds TB, Xiao C, Wilhelm SW. Structural and Proteomic Studies of the Aureococcus anophagefferens Virus Demonstrate a Global Distribution of Virus-Encoded Carbohydrate Processing. Front Microbiol 2020; 11:2047. [PMID: 33013751 PMCID: PMC7507832 DOI: 10.3389/fmicb.2020.02047] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/04/2020] [Indexed: 01/28/2023] Open
Abstract
Viruses modulate the function(s) of environmentally relevant microbial populations, yet considerations of the metabolic capabilities of individual virus particles themselves are rare. We used shotgun proteomics to quantitatively identify 43 virus-encoded proteins packaged within purified Aureococcus anophagefferens Virus (AaV) particles, normalizing data to the per-virion level using a 9.5-Å-resolution molecular reconstruction of the 1900-Å (AaV) particle that we generated with cryogenic electron microscopy. This packaged proteome was used to determine similarities and differences between members of different giant virus families. We noted that proteins involved in sugar degradation and binding (e.g., carbohydrate lyases) were unique to AaV among characterized giant viruses. To determine the extent to which this virally encoded metabolic capability was ecologically relevant, we examined the TARA Oceans dataset and identified genes and transcripts of viral origin. Our analyses demonstrated that putative giant virus carbohydrate lyases represented up to 17% of the marine pool for this function. In total, our observations suggest that the AaV particle has potential prepackaged metabolic capabilities and that these may be found in other giant viruses that are widespread and abundant in global oceans.
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Affiliation(s)
- Eric R. Gann
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Yuejiao Xian
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, TX, United States
| | - Paul E. Abraham
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Robert L. Hettich
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Todd B. Reynolds
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Chuan Xiao
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, TX, United States
| | - Steven W. Wilhelm
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
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Mócsai R, Blaukopf M, Svehla E, Kosma P, Altmann F. The N-glycans of Chlorella sorokiniana and a related strain contain arabinose but have strikingly different structures. Glycobiology 2020; 30:663-676. [PMID: 32039451 DOI: 10.1093/glycob/cwaa012] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/31/2020] [Accepted: 02/05/2020] [Indexed: 12/24/2022] Open
Abstract
The many emerging applications of microalgae such as Chlorella also instigate interest in their ability to conduct protein modifications such as N-glycosylation. Chlorella vulgaris has recently been shown to equip its proteins with highly O-methylated oligomannosidic N-glycans. Two other frequently occurring species names are Chlorella sorokiniana and Chlorella pyrenoidosa-even though the latter is taxonomically ill defined. We analyzed by mass spectrometry and nuclear magnetic resonance spectroscopy the N-glycans of type culture collection strains of C. sorokiniana and of a commercial product labeled C. pyrenoidosa. Both samples contained arabinose, which has hitherto not been found in N-glycans. Apart from this only commonality, the structures differed fundamentally from each other and from that of N-glycans of land plants. Despite these differences, the two algae lines exhibited considerable homology in their ITS1-5.8S-ITS2 rDNA sequences. These drastic differences of N-glycan structures between species belonging to the very same genus provoke questions as to the biological function on a unicellular organism.
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Affiliation(s)
- Réka Mócsai
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria
| | - Markus Blaukopf
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria
| | - Elisabeth Svehla
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria
| | - Paul Kosma
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria
| | - Friedrich Altmann
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria
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Van Etten JL, Agarkova IV, Dunigan DD. Chloroviruses. Viruses 2019; 12:E20. [PMID: 31878033 PMCID: PMC7019647 DOI: 10.3390/v12010020] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 12/13/2019] [Accepted: 12/15/2019] [Indexed: 12/20/2022] Open
Abstract
Chloroviruses are large dsDNA, plaque-forming viruses that infect certain chlorella-like green algae; the algae are normally mutualistic endosymbionts of protists and metazoans and are often referred to as zoochlorellae. The viruses are ubiquitous in inland aqueous environments throughout the world and occasionally single types reach titers of thousands of plaque-forming units per ml of native water. The viruses are icosahedral in shape with a spike structure located at one of the vertices. They contain an internal membrane that is required for infectivity. The viral genomes are 290 to 370 kb in size, which encode up to 16 tRNAs and 330 to ~415 proteins, including many not previously seen in viruses. Examples include genes encoding DNA restriction and modification enzymes, hyaluronan and chitin biosynthetic enzymes, polyamine biosynthetic enzymes, ion channel and transport proteins, and enzymes involved in the glycan synthesis of the virus major capsid glycoproteins. The proteins encoded by many of these viruses are often the smallest or among the smallest proteins of their class. Consequently, some of the viral proteins are the subject of intensive biochemical and structural investigation.
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Affiliation(s)
- James L. Van Etten
- Department of Plant Pathology, Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583-0900, USA; (I.V.A.); (D.D.D.)
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24
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Neochloris oleoabundans cell walls have an altered composition when cultivated under different growing conditions. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101482] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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25
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Speciale I, Duncan GA, Unione L, Agarkova IV, Garozzo D, Jimenez-Barbero J, Lin S, Lowary TL, Molinaro A, Noel E, Laugieri ME, Tonetti MG, Van Etten JL, De Castro C. The N-glycan structures of the antigenic variants of chlorovirus PBCV-1 major capsid protein help to identify the virus-encoded glycosyltransferases. J Biol Chem 2019; 294:5688-5699. [PMID: 30737276 DOI: 10.1074/jbc.ra118.007182] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 02/07/2019] [Indexed: 11/06/2022] Open
Abstract
The chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1) is a large dsDNA virus that infects the microalga Chlorella variabilis NC64A. Unlike most other viruses, PBCV-1 encodes most, if not all, of the machinery required to glycosylate its major capsid protein (MCP). The structures of the four N-linked glycans from the PBCV-1 MCP consist of nonasaccharides, and similar glycans are not found elsewhere in the three domains of life. Here, we identified the roles of three virus-encoded glycosyltransferases (GTs) that have four distinct GT activities in glycan synthesis. Two of the three GTs were previously annotated as GTs, but the third GT was identified in this study. We determined the GT functions by comparing the WT glycan structures from PBCV-1 with those from a set of PBCV-1 spontaneous GT gene mutants resulting in antigenic variants having truncated glycan structures. According to our working model, the virus gene a064r encodes a GT with three domains: domain 1 has a β-l-rhamnosyltransferase activity, domain 2 has an α-l-rhamnosyltransferase activity, and domain 3 is a methyltransferase that decorates two positions in the terminal α-l-rhamnose (Rha) unit. The a075l gene encodes a β-xylosyltransferase that attaches the distal d-xylose (Xyl) unit to the l-fucose (Fuc) that is part of the conserved N-glycan core region. Last, gene a071r encodes a GT that is involved in the attachment of a semiconserved element, α-d-Rha, to the same l-Fuc in the core region. Our results uncover GT activities that assemble four of the nine residues of the PBCV-1 MCP N-glycans.
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Affiliation(s)
- Immacolata Speciale
- From the Department of Agricultural Sciences, University of Napoli Federico II, Via Università 100, 80055 Portici NA, Italy
| | - Garry A Duncan
- the Department of Biology, Nebraska Wesleyan University, Lincoln, Nebraska 68504-2794
| | - Luca Unione
- the Chemical Glycobiology Lab, CIC bioGUNE, Bizkaia Technology Park, Bld 800, 48170 Derio, Spain
| | - Irina V Agarkova
- the Nebraska Center for Virology, University of Nebraska, Lincoln, Nebraska 68583-0900.,the Department of Plant Pathology, University of Nebraska, Lincoln, Nebraska 68583-0722
| | - Domenico Garozzo
- Institute for Polymers, Composites, and Biomaterials, CNR, Via P. Gaifami 18, 95126 Catania, Italy
| | - Jesus Jimenez-Barbero
- the Chemical Glycobiology Lab, CIC bioGUNE, Bizkaia Technology Park, Bld 800, 48170 Derio, Spain.,the Basque Foundation for Science (IKERBASQUE), 48940 Bilbao, Spain.,the Department of Organic Chemistry II, Faculty of Science and Technology, University of the Basque Country, EHU-UPV, 48940 Leioa, Spain
| | - Sicheng Lin
- the Alberta Glycomics Centre and Department of Chemistry, University of Alberta, Gunning-Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
| | - Todd L Lowary
- the Alberta Glycomics Centre and Department of Chemistry, University of Alberta, Gunning-Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
| | - Antonio Molinaro
- the Department of Chemical Sciences, Università of Napoli Federico II, 80126 Napoli, Italy
| | - Eric Noel
- the Nebraska Center for Virology, University of Nebraska, Lincoln, Nebraska 68583-0900.,the School of Biological Sciences, University of Nebraska, Lincoln, Nebraska 68588-0118, and
| | - Maria Elena Laugieri
- the Department of Experimental Medicine and Center of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV/1, 16132 Genova, Italy
| | - Michela G Tonetti
- the Department of Experimental Medicine and Center of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV/1, 16132 Genova, Italy
| | - James L Van Etten
- the Nebraska Center for Virology, University of Nebraska, Lincoln, Nebraska 68583-0900, .,the Department of Plant Pathology, University of Nebraska, Lincoln, Nebraska 68583-0722
| | - Cristina De Castro
- From the Department of Agricultural Sciences, University of Napoli Federico II, Via Università 100, 80055 Portici NA, Italy,
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Lin S, Lowary TL. Synthesis of the Highly Branched Hexasaccharide Core of Chlorella Virus N-Linked Glycans. Chemistry 2018; 24:16992-16996. [PMID: 30280442 DOI: 10.1002/chem.201804795] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Indexed: 01/09/2023]
Abstract
Chlorella viruses produce N-linked glycoproteins with carbohydrate moieties that differ in structure from all other N-linked glycans. In addition, unlike most viruses, these organisms do not hijack the biosynthetic machinery of the host to make glycocoproteins; instead, they produce their own carbohydrate-processing enzymes. A better understanding of the function and assembly of these fascinating and structurally-unprecedented glycans requires access to probe molecules. This work describes the first synthesis of a chlorella virus N-linked glycan, a highly branched hexasaccharide that contains the pentasaccharide present in all of the >15 structures reported to date. The target molecule includes a glucosyl-asparagine linkage and a "hyperbranched" fucose residue in which all of the hydroxyl groups are glycosylated. Both convergent and linear approaches were investigated with the latter being successful in providing the target in 16 steps and 13 % overall yield.
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Affiliation(s)
- Sicheng Lin
- Alberta Glycomics Centre and Department of Chemistry, The University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
| | - Todd L Lowary
- Alberta Glycomics Centre and Department of Chemistry, The University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
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27
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Horas EL, Theodosiou L, Becks L. Why Are Algal Viruses Not Always Successful? Viruses 2018; 10:v10090474. [PMID: 30189587 PMCID: PMC6165140 DOI: 10.3390/v10090474] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/31/2018] [Accepted: 09/02/2018] [Indexed: 12/14/2022] Open
Abstract
Algal viruses are considered to be key players in structuring microbial communities and biogeochemical cycles due to their abundance and diversity within aquatic systems. Their high reproduction rates and short generation times make them extremely successful, often with immediate and strong effects for their hosts and thus in biological and abiotic environments. There are, however, conditions that decrease their reproduction rates and make them unsuccessful with no or little immediate effects. Here, we review the factors that lower viral success and divide them into intrinsic—when they are related to the life cycle traits of the virus—and extrinsic factors—when they are external to the virus and related to their environment. Identifying whether and how algal viruses adapt to disadvantageous conditions will allow us to better understand their role in aquatic systems. We propose important research directions such as experimental evolution or the resurrection of extinct viruses to disentangle the conditions that make them unsuccessful and the effects these have on their surroundings.
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Affiliation(s)
- Elena L Horas
- Community Dynamics Group, Max-Planck for Evolutionary Biology, 24306 Plön, Germany.
- Limnology-Aquatic Ecology and Evolution, Limnological Institute, University of Konstanz, 78464 Konstanz, Germany.
| | - Loukas Theodosiou
- Community Dynamics Group, Max-Planck for Evolutionary Biology, 24306 Plön, Germany.
- Department of Microbial Population Biology, Max-Planck for Evolutionary Biology, 24306 Plön, Germany.
| | - Lutz Becks
- Community Dynamics Group, Max-Planck for Evolutionary Biology, 24306 Plön, Germany.
- Limnology-Aquatic Ecology and Evolution, Limnological Institute, University of Konstanz, 78464 Konstanz, Germany.
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De Castro C, Klose T, Speciale I, Lanzetta R, Molinaro A, Van Etten JL, Rossmann MG. Structure of the chlorovirus PBCV-1 major capsid glycoprotein determined by combining crystallographic and carbohydrate molecular modeling approaches. Proc Natl Acad Sci U S A 2018; 115:E44-E52. [PMID: 29255015 PMCID: PMC5776783 DOI: 10.1073/pnas.1613432115] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The glycans of the major capsid protein (Vp54) of Paramecium bursaria chlorella virus (PBCV-1) were recently described and found to be unusual. This prompted a reexamination of the previously reported Vp54 X-ray structure. A detailed description of the complete glycoprotein was achieved by combining crystallographic data with molecular modeling. The crystallographic data identified most of the monosaccharides located close to the protein backbone, but failed to detect those further from the glycosylation sites. Molecular modeling complemented this model by adding the missing monosaccharides and examined the conformational preference of the whole molecule, alone or within the crystallographic environment. Thus, combining X-ray crystallography with carbohydrate molecular modeling resulted in determining the complete glycosylated structure of a glycoprotein. In this case, it is the chlorovirus PBCV-1 major capsid protein.
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Affiliation(s)
- Cristina De Castro
- Department of Agricultural Sciences, University of Napoli, 80055 Portici, Italy;
| | - Thomas Klose
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-2032
| | | | - Rosa Lanzetta
- Department of Chemical Sciences, University of Napoli, 80126, Napoli, Italy
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Napoli, 80126, Napoli, Italy
| | - James L Van Etten
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68583-0900
| | - Michael G Rossmann
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-2032;
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29
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De Castro C, Duncan GA, Garozzo D, Molinaro A, Sturiale L, Tonetti M, Van Etten JL. Biophysical Approaches to Solve the Structures of the Complex Glycan Shield of Chloroviruses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1104:237-257. [PMID: 30484252 DOI: 10.1007/978-981-13-2158-0_12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The capsid of Paramecium bursaria chlorella virus (PBCV-1) contains a heavily glycosylated major capsid protein, Vp54. The capsid protein contains four glycans, each N-linked to Asn. The glycan structures are unusual in many aspects: (1) they are attached by a β-glucose linkage, which is rare in nature; (2) they are highly branched and consist of 8-10 neutral monosaccharides; (3) all four glycoforms contain a dimethylated rhamnose as the capping residue of the main chain, a hyper-branched fucose residue and two rhamnose residues ''with opposite absolute configurations; (4) the four glycoforms differ by the nonstoichiometric presence of two monosaccharides, L-arabinose and D-mannose ; (5) the N-glycans from all of the chloroviruses have a strictly conserved core structure; and (6) these glycans do not resemble any structures previously reported in the three domains of life.The structures of these N-glycoforms remained elusive for years because initial attempts to solve their structures used tools developed for eukaryotic-like systems, which we now know are not suitable for this noncanonical glycosylation pattern. This chapter summarizes the methods used to solve the chlorovirus complex glycan structures with the hope that these methodologies can be used by scientists facing similar problems.
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Affiliation(s)
- Cristina De Castro
- Department of Agricultural Sciences, University of Napoli, Portici, NA, Italy.
| | - Garry A Duncan
- Department of Biology, Nebraska Wesleyan University, Lincoln, NE, USA
| | - Domenico Garozzo
- CNR, Institute for Polymers, Composites and Biomaterials, Catania, Italy
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Napoli, Napoli, Italy
| | - Luisa Sturiale
- CNR, Institute for Polymers, Composites and Biomaterials, Catania, Italy
| | - Michela Tonetti
- Department of Experimental Medicine and Center of Excellence for Biomedical Research, University of Genova, Genova, Italy
| | - James L Van Etten
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska, Lincoln, NE, USA
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30
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Viruses of Microbes. Viruses 2017; 9:v9090263. [PMID: 28930187 PMCID: PMC5618029 DOI: 10.3390/v9090263] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 09/15/2017] [Accepted: 09/19/2017] [Indexed: 01/15/2023] Open
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