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Balke I, Silamikelis I, Radovica-Spalvina I, Zeltina V, Resevica G, Fridmanis D, Zeltins A. Ryegrass mottle virus complete genome determination and development of infectious cDNA by combining two methods- 3' RACE and RNA-Seq. PLoS One 2023; 18:e0287278. [PMID: 38051715 DOI: 10.1371/journal.pone.0287278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 11/21/2023] [Indexed: 12/07/2023] Open
Abstract
Ryegrass mottle virus (RGMoV; genus: Sobemovirus) is a single-stranded positive RNA virus with a 30 nm viral particle size. It exhibits T = 3 symmetry with 180 coat protein (CP) subunits forming a viral structure. The RGMoV genome comprises five open reading frames that encode P1, Px, a membrane-anchored 3C-like serine protease, a viral genome-linked protein, P16, an RNA-dependent RNA polymerase, and CP. The RGMoV genome size varies, ranging from 4175 nt (MW411579.1) to 4253 nt (MW411579.1) in the deposited sequences. An earlier deposited RGMoV complete genome sequence of 4212 nt length (EF091714.1) was used to develop an infectious complementary DNA (icDNA) construct for in vitro gRNA transcription from the T7 promoter. However, viral infection was not induced when the transcribed gRNA was introduced into oat plants, indicating the potential absence of certain sequences in either the 5' or 3' untranslated regions (UTR) or both. The complete sequence of the 3' UTR was determined through 3' end RACE, while the 5' UTR was identified using high-throughput sequencing (HTS)-RNA-Seq to resolve the potential absences. Only the icDNA vector containing the newly identified UTR sequences proved infectious, resulting in typical viral infection symptoms and subsequent propagation of progeny viruses, exhibiting the ability to cause repeated infections in oat plants after at least one passage. The successful generation of icDNA highlighted the synergistic potential of utilizing both methods when a single approach failed. Furthermore, this study demonstrated the reliability of HTS as a method for determining the complete genome sequence of viral genomes.
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Affiliation(s)
- Ina Balke
- Plant Virus Protein Research Group, Latvian Biomedical Research and Study Centre, Riga, Latvia
| | - Ivars Silamikelis
- Bioinformatics Core Facility, Latvian Biomedical Research and Study Centre, Riga, Latvia
| | - Ilze Radovica-Spalvina
- Genome Centre, Genotyping and Sequencing Unit, Latvian Biomedical Research and Study Centre, Riga, Latvia
| | - Vilija Zeltina
- Plant Virology Group, Latvian Biomedical Research and Study Centre, Riga, Latvia
| | - Gunta Resevica
- Plant Virology Group, Latvian Biomedical Research and Study Centre, Riga, Latvia
| | - Davids Fridmanis
- "Exotic" Site Microbiome and G-Protein Coupled Receptor Functional Research Group, Latvian Biomedical Research and Study Centre, Riga, Latvia
| | - Andris Zeltins
- Plant Virology Group, Latvian Biomedical Research and Study Centre, Riga, Latvia
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Edula SR, Bag S, Milner H, Kumar M, Suassuna ND, Chee PW, Kemerait RC, Hand LC, Snider JL, Srinivasan R, Roberts PM. Cotton leafroll dwarf disease: An enigmatic viral disease in cotton. MOLECULAR PLANT PATHOLOGY 2023; 24:513-526. [PMID: 37038256 PMCID: PMC10189767 DOI: 10.1111/mpp.13335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/18/2023] [Accepted: 03/21/2023] [Indexed: 05/18/2023]
Abstract
TAXONOMY Cotton leafroll dwarf virus (CLRDV) is a member of the genus Polerovirus, family Solemoviridae. Geographical Distribution: CLRDV is present in most cotton-producing regions worldwide, prominently in North and South America. PHYSICAL PROPERTIES The virion is a nonenveloped icosahedron with T = 3 icosahedral lattice symmetry that has a diameter of 26-34 nm and comprises 180 molecules of the capsid protein. The CsCl buoyant density of the virion is 1.39-1.42 g/cm3 and S20w is 115-127S. Genome: CLRDV shares genomic features with other poleroviruses; its genome consists of monopartite, single-stranded, positive-sense RNA, is approximately 5.7-5.8 kb in length, and is composed of seven open reading frames (ORFs) with an intergenic region between ORF2 and ORF3a. TRANSMISSION CLRDV is transmitted efficiently by the cotton aphid (Aphis gossypii Glover) in a circulative and nonpropagative manner. Host: CLRDV has a limited host range. Cotton is the primary host, and it has also been detected in different weeds in and around commercial cotton fields in Georgia, USA. SYMPTOMS Cotton plants infected early in the growth stage exhibit reddening or bronzing of foliage, maroon stems and petioles, and drooping. Plants infected in later growth stages exhibit intense green foliage with leaf rugosity, moderate to severe stunting, shortened internodes, and increased boll shedding/abortion, resulting in poor boll retention. These symptoms are variable and are probably influenced by the time of infection, plant growth stage, varieties, soil health, and geographical location. CLRDV is also often detected in symptomless plants. CONTROL Vector management with the application of chemical insecticides is ineffective. Some host plant varieties grown in South America are resistant, but all varieties grown in the United States are susceptible. Integrated disease management strategies, including weed management and removal of volunteer stalks, could reduce the abundance of virus inoculum in the field.
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Affiliation(s)
| | - Sudeep Bag
- Department of Plant PathologyUniversity of GeorgiaTiftonGeorgiaUSA
| | - Hayley Milner
- Department of Plant PathologyUniversity of GeorgiaTiftonGeorgiaUSA
| | - Manish Kumar
- Department of Plant PathologyUniversity of GeorgiaTiftonGeorgiaUSA
| | | | - Peng W. Chee
- Institute of Plant, Breeding, Genetics, and GenomicsUniversity of GeorgiaTiftonGeorgiaUSA
| | | | - Lavesta C. Hand
- Department of Crop and Soil SciencesUniversity of GeorgiaTiftonGeorgiaUSA
| | - John L. Snider
- Department of Crop and Soil SciencesUniversity of GeorgiaTiftonGeorgiaUSA
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Odongo PJ, Onaga G, Ricardo O, Natsuaki KT, Alicai T, Geuten K. Insights Into Natural Genetic Resistance to Rice Yellow Mottle Virus and Implications on Breeding for Durable Resistance. FRONTIERS IN PLANT SCIENCE 2021; 12:671355. [PMID: 34267770 PMCID: PMC8276079 DOI: 10.3389/fpls.2021.671355] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/14/2021] [Indexed: 06/13/2023]
Abstract
Rice is the main food crop for people in low- and lower-middle-income countries in Asia and sub-Saharan Africa (SSA). Since 1982, there has been a significant increase in the demand for rice in SSA, and its growing importance is reflected in the national strategic food security plans of several countries in the region. However, several abiotic and biotic factors undermine efforts to meet this demand. Rice yellow mottle virus (RYMV) caused by Solemoviridae is a major biotic factor affecting rice production and continues to be an important pathogen in SSA. To date, six pathogenic strains have been reported. RYMV infects rice plants through wounds and rice feeding vectors. Once inside the plant cells, viral genome-linked protein is required to bind to the rice translation initiation factor [eIF(iso)4G1] for a compatible interaction. The development of resistant cultivars that can interrupt this interaction is the most effective method to manage this disease. Three resistance genes are recognized to limit RYMV virulence in rice, some of which have nonsynonymous single mutations or short deletions in the core domain of eIF(iso)4G1 that impair viral host interaction. However, deployment of these resistance genes using conventional methods has proved slow and tedious. Molecular approaches are expected to be an alternative to facilitate gene introgression and/or pyramiding and rapid deployment of these resistance genes into elite cultivars. In this review, we summarize the knowledge on molecular genetics of RYMV-rice interaction, with emphasis on host plant resistance. In addition, we provide strategies for sustainable utilization of the novel resistant sources. This knowledge is expected to guide breeding programs in the development and deployment of RYMV resistant rice varieties.
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Affiliation(s)
- Patrick J. Odongo
- Molecular Biotechnology of Plants and Micro-Organisms, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium
- National Crops Resources Research Institute, National Agriculture Research Organization, Kampala, Uganda
| | - Geoffrey Onaga
- National Crops Resources Research Institute, National Agriculture Research Organization, Kampala, Uganda
- M’bé Research Station, Africa Rice Center (AfricaRice), Bouaké, Côte d’Ivoire
| | - Oliver Ricardo
- Breeding Innovations Platform, International Rice Research Institute, Metro Manila, Philippines
| | - Keiko T. Natsuaki
- Graduate School of Agriculture, Tokyo University of Agriculture, Tokyo, Japan
| | - Titus Alicai
- National Crops Resources Research Institute, National Agriculture Research Organization, Kampala, Uganda
| | - Koen Geuten
- Molecular Biotechnology of Plants and Micro-Organisms, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium
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Raza A, Al-Shahwan IM, Abdalla OA, Al-Saleh MA, Amer MA. Lucerne transient streak virus; a Recently Detected Virus Infecting Alfafa ( Medicago sativa) in Central Saudi Arabia. THE PLANT PATHOLOGY JOURNAL 2017; 33:43-52. [PMID: 28167887 PMCID: PMC5291397 DOI: 10.5423/ppj.oa.06.2016.0143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 10/27/2016] [Indexed: 06/06/2023]
Abstract
A survey was conducted to determine the status of Lucerne transient streak virus (LTSV) in three high-yielding alfalfa regions in central Saudi Arabia (Riyadh, Qassim, and Hail) during 2014. Three hundred and eight symptomatic alfalfa, and seven Sonchus oleraceus samples were collected. DAS-ELISA indicated that 59 of these samples were positive to LTSV. Two isolates of LTSV from each region were selected for molecular studies. RT-PCR confirmed the presence of LTSV in the selected samples using a specific primer pair. Percentage identity and homology tree comparisons revealed that all Saudi isolates were more closely related to each other but also closely related to the Canadian isolate-JQ782213 (97.1-97.6%) and the New Zealand isolate-U31286 (95.8-97.1%). Comparing Saudi isolates of LTSV with ten other sobemoviruses based on the coat protein gene sequences confirmed the distant relationship between them. Eleven out of fourteen plant species used in host range study were positive to LTSV. This is the first time to document that Trifolium alexandrinum, Nicotiana occidentalis, Chenopodium glaucum, and Lathyrus sativus are new host plant species for LTSV and that N. occidentalis being a good propagative host for it.
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Affiliation(s)
- Ahmed Raza
- Corresponding author. Phone) +86-13121767637, FAX) +966-11-4678366, E-mail)
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Sõmera M, Sarmiento C, Truve E. Overview on Sobemoviruses and a Proposal for the Creation of the Family Sobemoviridae. Viruses 2015; 7:3076-115. [PMID: 26083319 PMCID: PMC4488728 DOI: 10.3390/v7062761] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 05/18/2015] [Accepted: 06/02/2015] [Indexed: 12/26/2022] Open
Abstract
The genus Sobemovirus, unassigned to any family, consists of viruses with single-stranded plus-oriented single-component RNA genomes and small icosahedral particles. Currently, 14 species within the genus have been recognized by the International Committee on Taxonomy of Viruses (ICTV) but several new species are to be recognized in the near future. Sobemovirus genomes are compact with a conserved structure of open reading frames and with short untranslated regions. Several sobemoviruses are important pathogens. Moreover, over the last decade sobemoviruses have become important model systems to study plant virus evolution. In the current review we give an overview of the structure and expression of sobemovirus genomes, processing and functions of individual proteins, particle structure, pathology and phylogenesis of sobemoviruses as well as of satellite RNAs present together with these viruses. Based on a phylogenetic analysis we propose that a new family Sobemoviridae should be recognized including the genera Sobemovirus and Polemovirus. Finally, we outline the future perspectives and needs for the research focusing on sobemoviruses.
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Affiliation(s)
- Merike Sõmera
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia.
| | - Cecilia Sarmiento
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia.
| | - Erkki Truve
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia.
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6
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Serwer P, Wright ET, Liu Z, Jiang W. Length quantization of DNA partially expelled from heads of a bacteriophage T3 mutant. Virology 2014; 456-457:157-70. [PMID: 24889235 DOI: 10.1016/j.virol.2014.03.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 02/20/2014] [Accepted: 03/14/2014] [Indexed: 11/30/2022]
Abstract
DNA packaging of phages phi29, T3 and T7 sometimes produces incompletely packaged DNA with quantized lengths, based on gel electrophoretic band formation. We discover here a packaging ATPase-free, in vitro model for packaged DNA length quantization. We use directed evolution to isolate a five-site T3 point mutant that hyper-produces tail-free capsids with mature DNA (heads). Three tail gene mutations, but no head gene mutations, are present. A variable-length DNA segment leaks from some mutant heads, based on DNase I-protection assay and electron microscopy. The protected DNA segment has quantized lengths, based on restriction endonuclease analysis: six sharp bands of DNA missing 3.7-12.3% of the last end packaged. Native gel electrophoresis confirms quantized DNA expulsion and, after removal of external DNA, provides evidence that capsid radius is the quantization-ruler. Capsid-based DNA length quantization possibly evolved via selection for stalling that provides time for feedback control during DNA packaging and injection.
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Affiliation(s)
- Philip Serwer
- Department of Biochemistry, The University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA.
| | - Elena T Wright
- Department of Biochemistry, The University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA
| | - Zheng Liu
- Markey Center for Structural Biology, Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Wen Jiang
- Markey Center for Structural Biology, Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
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7
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Mahalik JP, Muthukumar M. Langevin dynamics simulation of polymer-assisted virus-like assembly. J Chem Phys 2012; 136:135101. [PMID: 22482588 DOI: 10.1063/1.3698408] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Starting from a coarse grained representation of the building units of the minute virus of mice and a flexible polyelectrolyte molecule, we have explored the mechanism of assembly into icosahedral structures with the help of Langevin dynamics simulations and the parallel tempering technique. Regular icosahedra with appropriate symmetry form only in a narrow range of temperature and polymer length. Within this region of parameters where successful assembly would proceed, we have systematically investigated the growth kinetics. The assembly of icosahedra is found to follow the classical nucleation and growth mechanism in the absence of the polymer, with the three regimes of nucleation, linear growth, and slowing down in the later stage. The calculated average nucleation time obeys the laws expected from the classical nucleation theory. The linear growth rate is found to obey the laws of secondary nucleation as in the case of lamellar growth in polymer crystallization. The same mechanism is seen in the simulations of the assembly of icosahedra in the presence of the polymer as well. The polymer reduces the nucleation barrier significantly by enhancing the local concentration of subunits via adsorbing them on their backbone. The details of growth in the presence of the polymer are also found to be consistent with the classical nucleation theory, despite the smallness of the assembled structures.
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Affiliation(s)
- J P Mahalik
- Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003, USA
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8
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Bakker SE, Ford RJ, Barker AM, Robottom J, Saunders K, Pearson AR, Ranson NA, Stockley PG. Isolation of an asymmetric RNA uncoating intermediate for a single-stranded RNA plant virus. J Mol Biol 2012; 417:65-78. [PMID: 22306464 PMCID: PMC4330335 DOI: 10.1016/j.jmb.2012.01.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 12/30/2011] [Accepted: 01/13/2012] [Indexed: 11/25/2022]
Abstract
We have determined the three-dimensional structures of both native and expanded forms of turnip crinkle virus (TCV), using cryo-electron microscopy, which allows direct visualization of the encapsidated single-stranded RNA and coat protein (CP) N-terminal regions not seen in the high-resolution X-ray structure of the virion. The expanded form, which is a putative disassembly intermediate during infection, arises from a separation of the capsid-forming domains of the CP subunits. Capsid expansion leads to the formation of pores that could allow exit of the viral RNA. A subset of the CP N-terminal regions becomes proteolytically accessible in the expanded form, although the RNA remains inaccessible to nuclease. Sedimentation velocity assays suggest that the expanded state is metastable and that expansion is not fully reversible. Proteolytically cleaved CP subunits dissociate from the capsid, presumably leading to increased electrostatic repulsion within the viral RNA. Consistent with this idea, electron microscopy images show that proteolysis introduces asymmetry into the TCV capsid and allows initial extrusion of the genome from a defined site. The apparent formation of polysomes in wheat germ extracts suggests that subsequent uncoating is linked to translation. The implication is that the viral RNA and its capsid play multiple roles during primary infections, consistent with ribosome-mediated genome uncoating to avoid host antiviral activity.
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Affiliation(s)
- Saskia E Bakker
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
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Ochola D, Tusiime G. Pathogenicity of Rice Yellow Mottle Virus and the Potential Sources of Resistance against the Disease in Eastern Uganda. ACTA ACUST UNITED AC 2010. [DOI: 10.3923/ajppaj.2011.1.15] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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10
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Forrey C, Muthukumar M. Electrostatics of capsid-induced viral RNA organization. J Chem Phys 2009. [DOI: 10.1063/1.3216550] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Siber A, Podgornik R. Nonspecific interactions in spontaneous assembly of empty versus functional single-stranded RNA viruses. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 78:051915. [PMID: 19113163 DOI: 10.1103/physreve.78.051915] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Indexed: 05/21/2023]
Abstract
We investigate the influence of salt concentration, charge on viral proteins and the length of single-stranded RNA (ssRNA) molecule on the spontaneous assembly of viruses. Only the nonspecific interactions are assumed to guide the assembly, i.e., we exclude any chemical specificity that may lock the viral proteins and ssRNA in preferred configurations. We demonstrate that the electrostatic interactions screened by the salt in the solution impose strong limits on viral composition that can be achieved by spontaneous assembly. In particular, we show that viruses whose ssRNA carries more than twice the amount of charge that is located on the viral proteins, cannot be assembled spontaneously. We find that the spatial distribution of protein charge is important for the energetics of the assembly. We also show that the pressures that act on the viruses as a result of attractive protein-ssRNA electrostatic interactions are at least an order of magnitude smaller than is the case with bacteriophage viruses that contain double-stranded DNA molecule.
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Affiliation(s)
- Antonio Siber
- Institute of Physics, Bijenicka Cesta 46, 10000 Zagreb, Croatia.
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12
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Persson M, Tars K, Liljas L. The Capsid of the Small RNA Phage PRR1 Is Stabilized by Metal Ions. J Mol Biol 2008; 383:914-22. [DOI: 10.1016/j.jmb.2008.08.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 06/16/2008] [Accepted: 08/18/2008] [Indexed: 10/21/2022]
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Abstract
Many ssRNA/ssDNA viruses bind their genome by highly basic semiflexible peptide arms of capsid proteins. Here, we show that nonspecific electrostatic interactions control both the length of the genome and genome conformations. Analysis of available experimental data shows that the genome length is linear in the net charge on the capsid peptide arms, irrespective of the actual amino acid sequence, with a proportionality coefficient of 1.61 +/- 0.03. This ratio is conserved across all ssRNA/ssDNA viruses with highly basic peptide arms, and is different from the one-to-one charge balance expected of specific binding. Genomic nucleotides are predicted to occupy a radially symmetric spherical shell detached from the viral capsid, in agreement with experimental data.
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Affiliation(s)
- Vladimir A. Belyi
- Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA 01003
| | - M. Muthukumar
- Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA 01003
- *To whom correspondence should be addressed. E-mail:
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Sherman MB, Guenther RH, Tama F, Sit TL, Brooks CL, Mikhailov AM, Orlova EV, Baker TS, Lommel SA. Removal of divalent cations induces structural transitions in red clover necrotic mosaic virus, revealing a potential mechanism for RNA release. J Virol 2006; 80:10395-406. [PMID: 16920821 PMCID: PMC1641784 DOI: 10.1128/jvi.01137-06] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The structure of Red clover necrotic mosaic virus (RCNMV), an icosahedral plant virus, was resolved to 8.5 A by cryoelectron microscopy. The virion capsid has prominent surface protrusions and subunits with a clearly defined shell and protruding domains. The structures of both the individual capsid protein (CP) subunits and the entire virion capsid are consistent with other species in the Tombusviridae family. Within the RCNMV capsid, there is a clearly defined inner cage formed by complexes of genomic RNA and the amino termini of CP subunits. An RCNMV virion has approximately 390 +/- 30 Ca2+ ions bound to the capsid and 420 +/- 25 Mg2+ ions thought to be in the interior of the capsid. Depletion of both Ca2+ and Mg2+ ions from RCNMV leads to significant structural changes, including (i) formation of 11- to 13-A-diameter channels that extend through the capsid and (ii) significant reorganization within the interior of the capsid. Genomic RNA within native capsids containing both Ca2+ and Mg2+ ions is extremely resistant to nucleases, but depletion of both of these cations results in nuclease sensitivity, as measured by a significant reduction in RCNMV infectivity. These results indicate that divalent cations play a central role in capsid dynamics and suggest a mechanism for the release of viral RNA in low-divalent-cation environments such as those found within the cytoplasm of a cell.
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Affiliation(s)
- Michael B Sherman
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA.
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15
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Delalande F, Carapito C, Brizard JP, Brugidou C, Van Dorsselaer A. Multigenic families and proteomics: extended protein characterization as a tool for paralog gene identification. Proteomics 2005; 5:450-60. [PMID: 15627959 DOI: 10.1002/pmic.200400954] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In classical proteomic studies, the searches in protein databases lead mostly to the identification of protein functions by homology due to the non-exhaustiveness of the protein databases. The quality of the identification depends on the studied organism, its complexity and its representation in the protein databases. Nevertheless, this basic function identification is insufficient for certain applications namely for the development of RNA-based gene-silencing strategies, commonly termed RNA interference (RNAi) in animals and post-transcriptional gene silencing (PTGS) in plants, that require an unambiguous identification of the targeted gene sequence. A PTGS strategy was considered in the study of the infection of Oryza sativa by the Rice Yellow Mottle Virus (RYMV). It is suspected that the RYMV recruits host proteins after its entry into plant cells to form a complex facilitating virus multiplication and spreading. The protein partners of this complex were identified by a classical proteomic approach, nano liquid chromatography tandem mass spectrometry. Among the identified proteins, several were retained for a PTGS strategy. Nevertheless most of the protein candidates appear to be members of multigenic families for which all paralog genes are not present in protein databases. Thus the identification of the real expressed paralog gene with classical protein database searches is impossible. Consequently, as the genome contains all genes and thus all paralog genes, a whole genome search strategy was developed to determine the specific expressed paralog gene. With this approach, the identification of peptides matching only a single gene, called discriminant peptides, allows definitive proof of the expression of this identified gene. This strategy has several requirements: (i) a genome completely sequenced and accessible; (ii) high protein sequence coverage. In the present work, through three examples, we report and validate for the first time a genome database search strategy to specifically identify paralog genes belonging to multigenic families expressed under specific conditions.
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Affiliation(s)
- François Delalande
- Laboratoire de Spectrométrie de Masse Bio-Organique, Strasbourg, France.
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16
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Hébrard E, Pinel-Galzi A, Catherinot V, Labesse G, Brugidou C, Fargette D. Internal point mutations of the capsid modify the serotype of Rice yellow mottle virus. J Virol 2005; 79:4407-14. [PMID: 15767440 PMCID: PMC1061534 DOI: 10.1128/jvi.79.7.4407-4414.2005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rice yellow mottle virus is classified in five major serotypes; the molecular diversity of the coat protein (CP) is well established, but the amino acids involved in the recognition by discriminant monoclonal antibodies (MAbs) remain unknown. Reconstruction of a phylogenetic tree and sequence alignment of the CP gene of a sample representative of the continental-large diversity were used to identify 10 serospecific amino acids (i.e., conserved in all isolates belonging to the same serotype and distinct in other serotypes). Positions occupied by serospecific residues were localized on the crystal structure of the CP monomer and on modeled capsomers. Structural, molecular, and serological properties of each serotype were analyzed, and subsequently, hypotheses on the potential role of amino acids in discriminating reactions with antibodies were formulated. The residues 114 and 115 (serospecific of Sr1) and 190 (serospecific of Sr2) were localized on the outer surface of the capsid and might be directly involved in the immunoreactivity with MAb D and MAb A, respectively. In contrast, residues 180 (Sr3) and 178 (Sr5) lay within the inner surface of the capsid. To understand the role of these internal positions in the recognition with the antibodies, two substitutions (T180K and G178D) were introduced in the CP of an infectious clone. These mutations modified the antigenicity with MAb G and MAb E discriminating Sr3 and Sr5, respectively, while the reaction with MAb D remained unaffected. This result suggests an indirect effect of these two internal mutations on local immunostructure while the global structure was maintained.
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Affiliation(s)
- Eugénie Hébrard
- Institut de Recherche pour le Dévelopment, Montpellier, France.
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Kouassi NK, N'Guessan P, Albar L, Fauquet CM, Brugidou C. Distribution and Characterization of Rice yellow mottle virus: A Threat to African Farmers. PLANT DISEASE 2005; 89:124-133. [PMID: 30795214 DOI: 10.1094/pd-89-0124] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Affiliation(s)
- N K Kouassi
- Centre National de Recherche Agronomique (CNRA), Laboratoire Central de Biotechnologies, Côte d'Ivoire
| | - P N'Guessan
- CNRA, Station de Recherche de Man, Côte d'Ivoire
| | - L Albar
- Institut de Recherche pour le Développement (IRD), France
| | - C M Fauquet
- ILTAB, Donald Danforth Plant Science Center, St. Louis, MO, USA
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18
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Tama F, Brooks CL. Diversity and Identity of Mechanical Properties of Icosahedral Viral Capsids Studied with Elastic Network Normal Mode Analysis. J Mol Biol 2005; 345:299-314. [PMID: 15571723 DOI: 10.1016/j.jmb.2004.10.054] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2004] [Revised: 10/12/2004] [Accepted: 10/16/2004] [Indexed: 11/30/2022]
Abstract
We analyze the mechanical properties and putative dynamical fluctuations of a variety of viral capsids comprising different sizes and quasi-equivalent symmetries by performing normal mode analysis using the elastic network model. The expansion of the capsid to a swollen state is studied using normal modes and is compared with the experimentally observed conformational change for three of the viruses for which experimental data exist. We show that a combination of one or two normal modes captures remarkably well the overall translation that dominates the motion between the two conformational states, and reproduces the overall conformational change. We observe for all of the viral capsids that the nature of the modes is different. In particular for the T=7 virus, HK97, for which the shape of the capsid changes from spherical to faceted polyhedra, two modes are necessary to accomplish the conformational transition. In addition, we extend our study to viral capsids with other T numbers, and discuss the similarities and differences in the features of virus capsid conformational dynamics. We note that the pentamers generally have higher flexibility and propensity to move freely from the other capsomers, which facilitates the shape adaptation that may be important in the viral life cycle.
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Affiliation(s)
- Florence Tama
- Department of Molecular Biology (TPC6), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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19
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Moreno IM, Thompson JR, García-Arenal F. Analysis of the systemic colonization of cucumber plants by Cucumber green mottle mosaic virus. J Gen Virol 2004; 85:749-759. [PMID: 14993661 DOI: 10.1099/vir.0.19540-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Systemic movement of Cucumber green mottle mosaic virus (CGMMV) in cucumber plants was shown to be from photoassimilate source to sink, thus indicating phloem transport. Nevertheless, CGMMV was not detected by immunocytochemical procedures in the intermediary cell-sieve element complex in inoculated cotyledons, where photoassimilate loading occurs. In stem internodes, CGMMV was first localized in the companion cells of the external phloem and subsequently in all tissues except the medulla, therefore suggesting leakage of the virus from, and reloading into, the transport phloem during systemic movement. In systemically infected sink leaves, CGMMV was simultaneously detected in the xylem and phloem. Interestingly, CGMMV accumulated to high levels in the differentiating tracheids of young leaves implying that the xylem could be involved in the systemic movement of CGMMV. This possibility was tested using plants in which cell death was induced in a portion of the stem by steam treatment. At 24 degrees C, steam treatment effectively prevented the systemic movement of CGMMV, even though viral RNA was detected in washes of the xylem above the steamed internode suggesting that xylem circulation occurred. At 29 degrees C, CGMMV systemically infected steam-treated cucumber plants, indicating that CGMMV can move systemically via the xylem. Xylem transport of CGMMV was, however, less efficient than phloem transport in terms of the time required for systemic infection and the percentage of plants infected.
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Affiliation(s)
- I M Moreno
- Departamento de Biotecnología, ETSI Agrónomos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - J R Thompson
- Departamento de Biotecnología, ETSI Agrónomos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - F García-Arenal
- Departamento de Biotecnología, ETSI Agrónomos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
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20
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Tihova M, Dryden KA, Le TVL, Harvey SC, Johnson JE, Yeager M, Schneemann A. Nodavirus coat protein imposes dodecahedral RNA structure independent of nucleotide sequence and length. J Virol 2004; 78:2897-905. [PMID: 14990708 PMCID: PMC353755 DOI: 10.1128/jvi.78.6.2897-2905.2004] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The nodavirus Flock house virus (FHV) has a bipartite, positive-sense RNA genome that is packaged into an icosahedral particle displaying T=3 symmetry. The high-resolution X-ray structure of FHV has shown that 10 bp of well-ordered, double-stranded RNA are located at each of the 30 twofold axes of the virion, but it is not known which portions of the genome form these duplex regions. The regular distribution of double-stranded RNA in the interior of the virus particle indicates that large regions of the encapsidated genome are engaged in secondary structure interactions. Moreover, the RNA is restricted to a topology that is unlikely to exist during translation or replication. We used electron cryomicroscopy and image reconstruction to determine the structure of four types of FHV particles that differed in RNA and protein content. RNA-capsid interactions were primarily mediated via the N and C termini, which are essential for RNA recognition and particle assembly. A substantial fraction of the packaged nucleic acid, either viral or heterologous, was organized as a dodecahedral cage of duplex RNA. The similarity in tertiary structure suggests that RNA folding is independent of sequence and length. Computational modeling indicated that RNA duplex formation involves both short-range and long-range interactions. We propose that the capsid protein is able to exploit the plasticity of the RNA secondary structures, capturing those that are compatible with the geometry of the dodecahedral cage.
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Affiliation(s)
- Mariana Tihova
- Department of Cell Biology, The Scripps Research Institute, Scripps Clinic, La Jolla, California 92037, USA
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21
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Bárcena J, Verdaguer N, Roca R, Morales M, Angulo I, Risco C, Carrascosa JL, Torres JM, Castón JR. The coat protein of Rabbit hemorrhagic disease virus contains a molecular switch at the N-terminal region facing the inner surface of the capsid. Virology 2004; 322:118-34. [PMID: 15063122 DOI: 10.1016/j.virol.2004.01.021] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Revised: 01/16/2004] [Accepted: 01/19/2004] [Indexed: 11/22/2022]
Abstract
To function adequately, many if not all proteins involved in macromolecular assemblies show conformational polymorphism as an intrinsic feature. This general strategy has been described for many essential cellular processes. Here we describe this structural polymorphism in a viral protein, the coat protein of Rabbit hemorrhagic disease virus (RHDV), which is required during virus capsid assembly. By combining genetic, structure modeling, and cryo-electron microscopy and image processing analysis, we have established the mechanism that allows RHDV coat protein to switch among quasi-equivalent conformational states to achieve the appropriate curvature for the formation of a closed shell. The RHDV capsid structure is based on a T = 3 lattice, containing 180 copies of identical subunits, similar to those of other caliciviruses. The quasi-equivalent interactions between the coat proteins are achieved by the N-terminal region of a subset of subunits, which faces the inner surface of the capsid shell. Mutant coat protein lacking this N-terminal sequence assembles into T = 1 capsids. Our results suggest that the polymorphism of the RHDV T = 3 capsid might bear resemblance to that of plant virus T = 3 capsids.
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Affiliation(s)
- Juan Bárcena
- Centro de Investigación en Sanidad Animal (CISA-INIA), Valdeolmos, 28130, Madrid, Spain
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22
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Brugidou C, Opalka N, Yeager M, Beachy RN, Fauquet C. Stability of rice yellow mottle virus and cellular compartmentalization during the infection process in Oryza sativa (L.). Virology 2002; 297:98-108. [PMID: 12083840 DOI: 10.1006/viro.2002.1398] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Rice yellow mottle virus (RYMV) is icosahedral in morphology and known to swell in vitro, but the biological function of swollen particles remains unknown. Anion-exchange chromatography was used to identify three markedly stable forms of RYMV particles from infected plants: (1) an unstable swollen form lacking Ca2+ and dependent upon basic pH; (2) a more stable transitional form lacking Ca2+ but dependent upon acidic pH; and (3) a pH-independent, stable, compact form containing Ca2+. Particle stability increased over the time course of infection in rice plants: transitional and swollen forms were abundant during early infection (2 weeks postinfection), whereas compact forms increased during later stages of infection. Electron microscopy of infected tissue revealed virus particles in vacuoles of xylem parenchyma and mesophyll cells early in the time course of infection and suggested that vacuoles and other vesicles were the major storage compartments for virus particles. We propose a model in which virus maturation is associated with the virus accumulation in vacuoles. In this acidic compartment, virus particles may bind Ca2+ to produce a highly stable, compact form of the virus. The localization of subcellular RYMV isoforms in infected cells and the corresponding biological properties of the virus are discussed.
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Affiliation(s)
- Christophe Brugidou
- International Laboratory for Tropical Agricultural Biotechnology (ILTAB/DDPSC), Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, Missouri 63132, USA.
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23
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Terradot L, Souchet M, Tran V, Giblot Ducray-Bourdin D. Analysis of a three-dimensional structure of Potato leafroll virus coat protein obtained by homology modeling. Virology 2001; 286:72-82. [PMID: 11448160 DOI: 10.1006/viro.2001.0900] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Viruses of the family Luteoviridae are ssRNA plant viruses that have particles that exhibit icosahedral symmetry. To identify the residues that might be exposed on the surface of the Potato leafroll virus (PLRV; genus Polerovirus, family Luteoviridae) capsid, and therefore involved in biological interactions, we performed a structural analysis of the PLRV coat protein (CP) on the basis of comparisons with protein sequences and known crystal structures of CPs of other viruses. The CP of PLRV displays 33% sequence similarity with that of Rice yellow mottle virus (genus Sobemovirus) when the sequences were aligned by using the hidden Markov model method. A structure model for PLRV CP was designed by protein homology modeling, using the crystal structure of RYMV as a template. The resulting model is consistent with immunological and site-directed mutagenesis data previously reported. On the basis of this model it is possible to predict some surface properties of the PLRV CP and also speculate about the structural evolution of small icosahedral viruses.
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Affiliation(s)
- L Terradot
- Institut National de la Recherche Agronomique, Station de Pathologie Végétale, Le Rheu Cédex, 35653, France.
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