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Bricio-Moreno L, Barreto de Albuquerque J, Neary JM, Nguyen T, Kuhn LF, Yeung Y, Hastie KM, Landeras-Bueno S, Olmedillas E, Hariharan C, Nathan A, Getz MA, Gayton AC, Khatri A, Gaiha GD, Ollmann Saphire E, Luster AD, Moon JJ. Identification of mouse CD4 + T cell epitopes in SARS-CoV-2 BA.1 spike and nucleocapsid for use in peptide:MHCII tetramers. Front Immunol 2024; 15:1329846. [PMID: 38529279 PMCID: PMC10961420 DOI: 10.3389/fimmu.2024.1329846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 01/29/2024] [Indexed: 03/27/2024] Open
Abstract
Understanding adaptive immunity against SARS-CoV-2 is a major requisite for the development of effective vaccines and treatments for COVID-19. CD4+ T cells play an integral role in this process primarily by generating antiviral cytokines and providing help to antibody-producing B cells. To empower detailed studies of SARS-CoV-2-specific CD4+ T cell responses in mouse models, we comprehensively mapped I-Ab-restricted epitopes for the spike and nucleocapsid proteins of the BA.1 variant of concern via IFNγ ELISpot assay. This was followed by the generation of corresponding peptide:MHCII tetramer reagents to directly stain epitope-specific T cells. Using this rigorous validation strategy, we identified 6 immunogenic epitopes in spike and 3 in nucleocapsid, all of which are conserved in the ancestral Wuhan strain. We also validated a previously identified epitope from Wuhan that is absent in BA.1. These epitopes and tetramers will be invaluable tools for SARS-CoV-2 antigen-specific CD4+ T cell studies in mice.
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Affiliation(s)
- Laura Bricio-Moreno
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, United States
- Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Juliana Barreto de Albuquerque
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, United States
- Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Jake M. Neary
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, United States
- Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, Boston, MA, United States
| | - Thao Nguyen
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, United States
- Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, Boston, MA, United States
| | - Lucy F. Kuhn
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, United States
- Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, Boston, MA, United States
| | - YeePui Yeung
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, United States
- Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, Boston, MA, United States
| | - Kathryn M. Hastie
- Center for Vaccine Innovation, La Jolla Institute for Immunology, La Jolla, CA, United States
| | - Sara Landeras-Bueno
- Center for Vaccine Innovation, La Jolla Institute for Immunology, La Jolla, CA, United States
| | - Eduardo Olmedillas
- Center for Vaccine Innovation, La Jolla Institute for Immunology, La Jolla, CA, United States
| | - Chitra Hariharan
- Center for Vaccine Innovation, La Jolla Institute for Immunology, La Jolla, CA, United States
| | - Anusha Nathan
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, United States
- Program in Health Sciences and Technology, Harvard Medical School and Massachusetts Institute of Technology, Boston, MA, United States
| | - Matthew A. Getz
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, United States
| | - Alton C. Gayton
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, United States
| | - Ashok Khatri
- Harvard Medical School, Boston, MA, United States
- Endocrine Division, MGH, Boston, MA, United States
| | - Gaurav D. Gaiha
- Harvard Medical School, Boston, MA, United States
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, United States
- Division of Gastroenterology, MGH, Boston, MA, United States
| | - Erica Ollmann Saphire
- Center for Vaccine Innovation, La Jolla Institute for Immunology, La Jolla, CA, United States
- Department of Medicine, University of California San Diego, La Jolla, CA, United States
| | - Andrew D. Luster
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, United States
- Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - James J. Moon
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, United States
- Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Division of Pulmonary and Critical Care Medicine, MGH, Boston, MA, United States
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2
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Wang R, Wang S, Guo W, Zhang T, Kang Q, Wang P, Zhou F, Yang L. Flow injection analysis coupled with photoelectrochemical immunoassay for simultaneous detection of anti-SARS-CoV-2-spike and anti-SARS-CoV-2-nucleocapsid antibodies in serum samples. Anal Chim Acta 2023; 1280:341857. [PMID: 37858551 DOI: 10.1016/j.aca.2023.341857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 09/28/2023] [Accepted: 09/28/2023] [Indexed: 10/21/2023]
Abstract
A thin-layer flow cell of low internal volume (12 μL) is incorporated in a flow injection analysis (FIA) system for simultaneous and real-time photoelectrochemical (PEC) immunoassay of anti-SARS-CoV-2 spike 1 (S1) and anti-SARS-CoV-2 nucleocapsid (N) antibodies. Covalent linkage of S1 and N proteins to two separate polyethylene glycol (PEG)-covered gold nanoparticles (AuNPs)/TiO2 nanotube array (NTA) electrodes affords 10 consecutive analyses with surface regenerations in between. An indium tin oxide (ITO) allows visible light to impinge onto the two electrodes. The detection limits for anti-S1 and anti-N antibodies were estimated to be 177 and 97 ng mL-1, respectively. Such values compare well with those achieved with other reported methods and satisfy the requirement for screening convalescent patients with low antibody levels. Additionally, our method exhibits excellent intra-batch (RSD = 1.3%), inter-batch (RSD = 3.4%), intra-day (RSD = 1.0%), and inter-day (RSD = 1.6%) reproducibility. The obviation of an enzyme label and continuous analysis markedly decreased the assay cost and duration, rendering this method cost-effective. The excellent anti-fouling property of PEG enables accuracy validation by comparing our PEC immunoassays of patient sera to those of ELISA. In addition, the simultaneous detection of two antibodies holds great potential in disease diagnosis and immunity studies.
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Affiliation(s)
- Ruimin Wang
- Institute of Surface Analysis and Chemical Biology, University of Jinan, Jinan, Shandong, 250022, PR China
| | - Shuai Wang
- Institute of Surface Analysis and Chemical Biology, University of Jinan, Jinan, Shandong, 250022, PR China
| | - Wanze Guo
- Institute of Surface Analysis and Chemical Biology, University of Jinan, Jinan, Shandong, 250022, PR China
| | - Tiantian Zhang
- University Hospital, University of Jinan, Jinan, Shandong, 250022, PR China
| | - Qing Kang
- Institute of Surface Analysis and Chemical Biology, University of Jinan, Jinan, Shandong, 250022, PR China.
| | - Pengcheng Wang
- Institute of Surface Analysis and Chemical Biology, University of Jinan, Jinan, Shandong, 250022, PR China.
| | - Feimeng Zhou
- School of Life Sciences, Tiangong University, Tianjin, 300387, PR China
| | - Lixia Yang
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, PR China
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3
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Nepal S, Holmstrom ED. Single-molecule-binding studies of antivirals targeting the hepatitis C virus core protein. J Virol 2023; 97:e0089223. [PMID: 37772835 PMCID: PMC10617558 DOI: 10.1128/jvi.00892-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/10/2023] [Indexed: 09/30/2023] Open
Abstract
IMPORTANCE The hepatitis C virus is associated with nearly 300,000 deaths annually. At the core of the virus is an RNA-protein complex called the nucleocapsid, which consists of the viral genome and many copies of the core protein. Because the assembly of the nucleocapsid is a critical step in viral replication, a considerable amount of effort has been devoted to identifying antiviral therapeutics that can bind to the core protein and disrupt assembly. Although several candidates have been identified, little is known about how they interact with the core protein or how those interactions alter the structure and thus the function of this viral protein. Our work biochemically characterizes several of these binding interactions, highlighting both similarities and differences as well as strengths and weaknesses. These insights bolster the notion that this viral protein is a viable target for novel therapeutics and will help to guide future developments of these candidate antivirals.
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Affiliation(s)
- Sudip Nepal
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - Erik D. Holmstrom
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
- Department of Chemistry, University of Kansas, Lawrence, Kansas, USA
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4
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Lee E, Redzic JS, Saviola AJ, Li X, Ebmeier CC, Kutateladze T, Hansen KC, Zhao R, Ahn N, Sluchanko NN, Eisenmesser E. Molecular insight into the specific interactions of the SARS-Coronavirus-2 nucleocapsid with RNA and host protein. Protein Sci 2023; 32:e4603. [PMID: 36807437 PMCID: PMC10019451 DOI: 10.1002/pro.4603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 02/23/2023]
Abstract
The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) nucleocapsid protein is the most abundantly expressed viral protein during infection where it targets both RNA and host proteins. However, identifying how a single viral protein interacts with so many different targets remains a challenge, providing the impetus here for identifying the interaction sites through multiple methods. Through a combination of nuclear magnetic resonance (NMR), electron microscopy, and biochemical methods, we have characterized nucleocapsid interactions with RNA and with three host proteins, which include human cyclophilin-A, Pin1, and 14-3-3τ. Regarding RNA interactions, the nucleocapsid protein N-terminal folded domain preferentially interacts with smaller RNA fragments relative to the C-terminal region, suggesting an initial RNA engagement is largely dictated by this N-terminal region followed by weaker interactions to the C-terminal region. The nucleocapsid protein forms 10 nm ribonuclear complexes with larger RNA fragments that include 200 and 354 nucleic acids, revealing its potential diversity in sequestering different viral genomic regions during viral packaging. Regarding host protein interactions, while the nucleocapsid targets all three host proteins through its serine-arginine-rich region, unstructured termini of the nucleocapsid protein also engage host cyclophilin-A and host 14-3-3τ. Considering these host proteins play roles in innate immunity, the SARS-CoV-2 nucleocapsid protein may block the host response by competing interactions. Finally, phosphorylation of the nucleocapsid protein quenches an inherent dynamic exchange process within its serine-arginine-rich region. Our studies identify many of the diverse interactions that may be important for SARS-CoV-2 pathology during infection.
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Affiliation(s)
- Eunjeong Lee
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
| | - Jasmina S. Redzic
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
| | - Anthony J. Saviola
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
| | - Xueni Li
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
| | | | - Tatiana Kutateladze
- Department of PharmacologySchool of Medicine, University of Colorado DenverAuroraColoradoUSA
| | - Kirk Charles Hansen
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
| | - Rui Zhao
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
| | - Natalie Ahn
- Department of BiochemistryUniversity of Colorado BoulderBoulderColoradoUSA
| | - Nikolai N. Sluchanko
- A.N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of SciencesMoscowRussia
| | - Elan Eisenmesser
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
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Wang Y, Binning JM, Pintilie GD, Chiu W, Amarasinghe GK, Leung DW, Su Z. Cryo-EM analysis of Ebola virus nucleocapsid-like assembly. STAR Protoc 2022; 3:101030. [PMID: 34977676 PMCID: PMC8689349 DOI: 10.1016/j.xpro.2021.101030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
This protocol describes the reconstitution of the filamentous Ebola virus nucleocapsid-like assembly in vitro. This is followed by solving the cryo-EM structure using helical reconstruction, and flexible fitting of the existing model into the 5.8 Å cryo-EM map. The protocol can be applied to other filamentous viral protein assemblies, particularly those with high flexibility and moderate resolution maps, which present technical challenges to model building. For complete details on the use and execution of this profile, please refer to Su et al. (2018). Preparation of Ebola nucleocapsid-like assembly for cryo-EM Cryo-EM helical reconstruction of flexible filamentous protein assembly Flexible fitting of protein model into cryo-EM density at moderate resolution
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Affiliation(s)
- Yan Wang
- The State Key Laboratory of Biotherapy and Cancer Center, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610044, China
| | - Jennifer M. Binning
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA
| | - Grigore D. Pintilie
- Department of Bioengineering and Department of Microbiology and Immunology, James H. Clark Center, Stanford University, Stanford, CA 94305, USA
- Division of Cryo-EM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Wah Chiu
- Department of Bioengineering and Department of Microbiology and Immunology, James H. Clark Center, Stanford University, Stanford, CA 94305, USA
- Division of Cryo-EM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Gaya K. Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Corresponding author
| | - Daisy W. Leung
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
- Corresponding author
| | - Zhaoming Su
- The State Key Laboratory of Biotherapy and Cancer Center, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610044, China
- Corresponding author
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6
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Zabalza A, Arrambide G, Tagliani P, Cárdenas-Robledo S, Otero-Romero S, Esperalba J, Fernandez-Naval C, Trocoli Campuzano J, Martínez Gallo M, Castillo M, Bonastre M, Resina Sallés M, Beltran J, Carbonell-Mirabent P, Rodríguez-Barranco M, López-Maza S, Melgarejo Otálora PJ, Ruiz-Ortiz M, Pappolla A, Rodríguez Acevedo B, Midaglia L, Vidal-Jordana A, Cobo-Calvo A, Tur C, Galán I, Castilló J, Río J, Espejo C, Comabella M, Nos C, Sastre-Garriga J, Tintore M, Montalban X. Humoral and Cellular Responses to SARS-CoV-2 in Convalescent COVID-19 Patients With Multiple Sclerosis. Neurol Neuroimmunol Neuroinflamm 2022; 9:9/2/e1143. [PMID: 35105687 PMCID: PMC8808353 DOI: 10.1212/nxi.0000000000001143] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 12/21/2021] [Indexed: 01/22/2023]
Abstract
Background and Objectives Information about humoral and cellular responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and antibody persistence in convalescent (COVID-19) patients with multiple sclerosis (PwMS) is scarce. The objectives of this study were to investigate factors influencing humoral and cellular responses to SARS-CoV-2 and its persistence in convalescent COVID-19 PwMS. Methods This is a retrospective study of confirmed COVID-19 convalescent PwMS identified between February 2020 and May 2021 by SARS-CoV-2 antibody testing. We examined relationships between demographics, MS characteristics, disease-modifying therapy (DMT), and humoral (immunoglobulin G against spike and nucleocapsid proteins) and cellular (interferon-gamma [IFN-γ]) responses to SARS-CoV-2. Results A total of 121 (83.45%) of 145 PwMS were seropositive, and 25/42 (59.5%) presented a cellular response up to 13.1 months after COVID-19. Anti–CD20-treated patients had lower antibody titers than those under other DMTs (p < 0.001), but severe COVID-19 and a longer time from last infusion increased the likelihood of producing a humoral response. IFN-γ levels did not differ among DMT. Five of 7 (71.4%) anti-–CD20-treated seronegative patients had a cellular response. The humoral response persisted for more than 6 months in 41/56(81.13%) PwMS. In multivariate analysis, seropositivity decreased due to anti-CD20 therapy (OR 0.08 [95% CI 0.01–0.55]) and increased in males (OR 3.59 [1.02–12.68]), whereas the cellular response decreased in those with progressive disease (OR 0.04 [0.001–0.88]). No factors were associated with antibody persistence. Discussion Humoral and cellular responses to SARS-CoV-2 are present in COVID-19 convalescent PwMS up to 13.10 months after COVID-19. The humoral response decreases under anti-CD20 treatment, although the cellular response can be detected in anti–CD20-treated patients, even in the absence of antibodies.
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7
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Ker DS, Jenkins HT, Greive SJ, Antson AA. CryoEM structure of the Nipah virus nucleocapsid assembly. PLoS Pathog 2021; 17:e1009740. [PMID: 34270629 PMCID: PMC8318291 DOI: 10.1371/journal.ppat.1009740] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/28/2021] [Accepted: 06/22/2021] [Indexed: 11/18/2022] Open
Abstract
Nipah and its close relative Hendra are highly pathogenic zoonotic viruses, storing their ssRNA genome in a helical nucleocapsid assembly formed by the N protein, a major viral immunogen. Here, we report the first cryoEM structure for a Henipavirus RNA-bound nucleocapsid assembly, at 3.5 Å resolution. The helical assembly is stabilised by previously undefined N- and C-terminal segments, contributing to subunit-subunit interactions. RNA is wrapped around the nucleocapsid protein assembly with a periodicity of six nucleotides per protomer, in the “3-bases-in, 3-bases-out” conformation, with protein plasticity enabling non-sequence specific interactions. The structure reveals commonalities in RNA binding pockets and in the conformation of bound RNA, not only with members of the Paramyxoviridae family, but also with the evolutionarily distant Filoviridae Ebola virus. Significant structural differences with other Paramyxoviridae members are also observed, particularly in the position and length of the exposed α-helix, residues 123–139, which may serve as a valuable epitope for surveillance and diagnostics. Nipah virus is a highly pathogenic RNA virus which, along with the closely related Hendra virus, emerged relatively recently. Due to ~40% mortality rate and evidence of animal-to-human as well as human-to-human transmission, development of antivirals against the Nipah and henipaviral disease is particularly urgent. In common with other single-stranded RNA viruses, including Ebola and coronaviruses, the nucleocapsid assembly of the Nipah virus safeguards the viral genome, protecting it from degradation and facilitating its encapsidation and storage inside the virion. Here, we used cryo-electron microscopy to determine accurate three-dimensional structure for several different assemblies of the Nipah virus nucleocapsid protein, in particular a detailed structure for the complex of this protein with RNA. This structural information is important for understanding detailed molecular interactions driving and stabilizing the nucleocapsid assembly formation that are of fundamental importance for understanding similar processes in a large group of ssRNA viruses. Apart from highlighting structural similarities and differences with nucleocapsid proteins of other viruses of the Paramyxoviridae family, these data will inform the development of new antiviral approaches for the henipaviruses.
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Affiliation(s)
- De-Sheng Ker
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, United Kingdom
| | - Huw T. Jenkins
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, United Kingdom
| | - Sandra J. Greive
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, United Kingdom
| | - Alfred A. Antson
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, United Kingdom
- * E-mail:
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8
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Voss C, Esmail S, Liu X, Knauer MJ, Ackloo S, Kaneko T, Lowes L, Stogios P, Seitova A, Hutchinson A, Yusifov F, Skarina T, Evdokimova E, Loppnau P, Ghiabi P, Haijan T, Zhong S, Abdoh H, Hedley BD, Bhayana V, Martin CM, Slessarev M, Chin-Yee B, Fraser DD, Chin-Yee I, Li SS. Epitope-specific antibody responses differentiate COVID-19 outcomes and variants of concern. JCI Insight 2021; 6:148855. [PMID: 34081630 PMCID: PMC8410046 DOI: 10.1172/jci.insight.148855] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 06/02/2021] [Indexed: 12/23/2022] Open
Abstract
BACKGROUNDThe role of humoral immunity in COVID-19 is not fully understood, owing, in large part, to the complexity of antibodies produced in response to the SARS-CoV-2 infection. There is a pressing need for serology tests to assess patient-specific antibody response and predict clinical outcome.METHODSUsing SARS-CoV-2 proteome and peptide microarrays, we screened 146 COVID-19 patients' plasma samples to identify antigens and epitopes. This enabled us to develop a master epitope array and an epitope-specific agglutination assay to gauge antibody responses systematically and with high resolution.RESULTSWe identified linear epitopes from the spike (S) and nucleocapsid (N) proteins and showed that the epitopes enabled higher resolution antibody profiling than the S or N protein antigen. Specifically, we found that antibody responses to the S-811-825, S-881-895, and N-156-170 epitopes negatively or positively correlated with clinical severity or patient survival. Moreover, we found that the P681H and S235F mutations associated with the coronavirus variant of concern B.1.1.7 altered the specificity of the corresponding epitopes.CONCLUSIONEpitope-resolved antibody testing not only affords a high-resolution alternative to conventional immunoassays to delineate the complex humoral immunity to SARS-CoV-2 and differentiate between neutralizing and non-neutralizing antibodies, but it also may potentially be used to predict clinical outcome. The epitope peptides can be readily modified to detect antibodies against variants of concern in both the peptide array and latex agglutination formats.FUNDINGOntario Research Fund (ORF) COVID-19 Rapid Research Fund, Toronto COVID-19 Action Fund, Western University, Lawson Health Research Institute, London Health Sciences Foundation, and Academic Medical Organization of Southwestern Ontario (AMOSO) Innovation Fund.
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MESH Headings
- Agglutination Tests/methods
- Amino Acid Sequence
- Antibodies, Neutralizing/blood
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- Antibody Formation/immunology
- Antibody Specificity/immunology
- COVID-19/blood
- COVID-19/immunology
- COVID-19/mortality
- COVID-19 Serological Testing/methods
- Epitopes/immunology
- Epitopes, B-Lymphocyte/chemistry
- Epitopes, B-Lymphocyte/genetics
- Epitopes, B-Lymphocyte/immunology
- Humans
- Immunity, Humoral
- Microarray Analysis/methods
- Nucleocapsid/chemistry
- Nucleocapsid/genetics
- Nucleocapsid/immunology
- Peptides/immunology
- SARS-CoV-2/genetics
- SARS-CoV-2/immunology
- Severity of Illness Index
- Spike Glycoprotein, Coronavirus/chemistry
- Spike Glycoprotein, Coronavirus/genetics
- Spike Glycoprotein, Coronavirus/immunology
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Affiliation(s)
| | | | | | - Michael J. Knauer
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | | | | | - Lori Lowes
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Peter Stogios
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | | | | | | | - Tatiana Skarina
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Elena Evdokimova
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Peter Loppnau
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Pegah Ghiabi
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Taraneh Haijan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | | | - Husam Abdoh
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Benjamin D. Hedley
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Vipin Bhayana
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Claudio M. Martin
- Department of Medicine, Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
| | - Marat Slessarev
- Department of Medicine, Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
| | | | - Douglas D. Fraser
- Department of Medicine, Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
- Department of Paediatrics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Ian Chin-Yee
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
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Croll TI, Williams CJ, Chen VB, Richardson DC, Richardson JS. Improving SARS-CoV-2 structures: Peer review by early coordinate release. Biophys J 2021; 120:1085-1096. [PMID: 33460600 PMCID: PMC7834719 DOI: 10.1016/j.bpj.2020.12.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/17/2020] [Accepted: 12/22/2020] [Indexed: 01/18/2023] Open
Abstract
This work builds upon the record-breaking speed and generous immediate release of new experimental three-dimensional structures of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins and complexes, which are crucial to downstream vaccine and drug development. We have surveyed those structures to catch the occasional errors that could be significant for those important uses and for which we were able to provide demonstrably higher-accuracy corrections. This process relied on new validation and correction methods such as CaBLAM and ISOLDE, which are not yet in routine use. We found such important and correctable problems in seven early SARS-CoV-2 structures. Two of the structures were soon superseded by new higher-resolution data, confirming our proposed changes. For the other five, we emailed the depositors a documented and illustrated report and encouraged them to make the model corrections themselves and use the new option at the worldwide Protein Data Bank for depositors to re-version their coordinates without changing the Protein Data Bank code. This quickly and easily makes the better-accuracy coordinates available to anyone who examines or downloads their structure, even before formal publication. The changes have involved sequence misalignments, incorrect RNA conformations near a bound inhibitor, incorrect metal ligands, and cis-trans or peptide flips that prevent good contact at interaction sites. These improvements have propagated into nearly all related structures done afterward. This process constitutes a new form of highly rigorous peer review, which is actually faster and more strict than standard publication review because it has access to coordinates and maps; journal peer review would also be strengthened by such access.
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Affiliation(s)
| | | | - Vincent B Chen
- Department of Biochemistry, Duke University, Durham, North Carolina
| | | | - Jane S Richardson
- Department of Biochemistry, Duke University, Durham, North Carolina.
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10
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Abstract
Negative strand RNA viruses (NSVs) include many important human pathogens, such as influenza virus, Ebola virus, and rabies virus. One of the unique characteristics that NSVs share is the assembly of the nucleocapsid and its role in viral RNA synthesis. In NSVs, the single strand RNA genome is encapsidated in the linear nucleocapsid throughout the viral replication cycle. Subunits of the nucleocapsid protein are parallelly aligned along the RNA genome that is sandwiched between two domains composed of conserved helix motifs. The viral RNA-dependent-RNA polymerase (vRdRp) must recognize the protein-RNA complex of the nucleocapsid and unveil the protected genomic RNA in order to initiate viral RNA synthesis. In addition, vRdRp must continuously translocate along the protein-RNA complex during elongation in viral RNA synthesis. This unique mechanism of viral RNA synthesis suggests that the nucleocapsid may play a regulatory role during NSV replication.
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Affiliation(s)
- Ming Luo
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, USA; (J.R.T.); (S.A.M.)
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11
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Liu R, Han H, Liu F, Lv Z, Wu K, Liu Y, Feng Y, Zhu C. Positive rate of RT-PCR detection of SARS-CoV-2 infection in 4880 cases from one hospital in Wuhan, China, from Jan to Feb 2020. Clin Chim Acta 2020; 505:172-175. [PMID: 32156607 PMCID: PMC7094385 DOI: 10.1016/j.cca.2020.03.009] [Citation(s) in RCA: 363] [Impact Index Per Article: 90.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 03/06/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND There's an outbreak of a novel coronavirus (SARS-CoV-2) infection since December 2019, first in China, and currently with more than 80 thousand confirmed infection globally in 29 countries till March 2, 2020. Identification, isolation and caring for patients early are essential to limit human-to-human transmission including reducing secondary infections among close contacts and health care workers, preventing transmission amplification events. The RT-PCR detection of viral nucleic acid test (NAT) was one of the most quickly established laboratory diagnosis method in a novel viral pandemic, just as in this COVID-19 outbreak. METHODS 4880 cases that had respiratory infection symptoms or close contact with COVID-19 patients in hospital in Wuhan, China, were tested for SARS-CoV-2 infection by use of quantitative RT-PCR (qRT-PCR) on samples from the respiratory tract. Positive rates were calculated in groups divided by genders or ages. RESULTS The positive rate was about 38% for the total 4880 specimens. Male and older population had a significant higher positive rates. However, 57% was positive among the specimens from the Fever Clinics. Binary logistic regression analysis showed that age, not gender, was the risk factor for SARS-CoV-2 infection in fever clinics. CONCLUSIONS Therefore, we concluded that viral NAT played an important role in identifying SARS-CoV-2 infection.
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Affiliation(s)
- Rui Liu
- Dept. of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, China
| | - Huan Han
- Dept. of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, China
| | - Fang Liu
- Dept. State Key Laboratory of Virology (Wuhan University), College of Life Sciences of Wuhan University, Wuhan 430072, Hubei, China; Dept. Wuhan Institute of Biotechnology, Wuhan 430075, Hubei, China
| | - Zhihua Lv
- Dept. of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, China
| | - Kailang Wu
- Dept. State Key Laboratory of Virology (Wuhan University), College of Life Sciences of Wuhan University, Wuhan 430072, Hubei, China
| | - Yingle Liu
- Dept. State Key Laboratory of Virology (Wuhan University), College of Life Sciences of Wuhan University, Wuhan 430072, Hubei, China
| | - Yong Feng
- School of Basic Medical Sciences, Wuhan University, Wuhan 430071, Hubei, China.
| | - Chengliang Zhu
- Dept. of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, China.
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12
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Yang YL, Liang QZ, Xu SY, Mazing E, Xu GH, Peng L, Qin P, Wang B, Huang YW. Characterization of a novel bat-HKU2-like swine enteric alphacoronavirus (SeACoV) infection in cultured cells and development of a SeACoV infectious clone. Virology 2019; 536:110-118. [PMID: 31419711 PMCID: PMC7112019 DOI: 10.1016/j.virol.2019.08.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 08/08/2019] [Accepted: 08/08/2019] [Indexed: 01/08/2023]
Abstract
Swine enteric alphacoronavirus (SeACoV), also known as swine acute diarrhea syndrome coronavirus (SADS-CoV), belongs to the species Rhinolophus bat coronavirus HKU2. Herein, we report on the primary characterization of SeACoV in vitro. Four antibodies against the SeACoV spike, membrane, nucleocapsid and nonstructural protein 3 capable of reacting with viral antigens in SeACoV-infected Vero cells were generated. We established a DNA-launched SeACoV infectious clone based on the cell adapted passage-10 virus and rescued the recombinant virus with a unique genetic marker in cultured cells. Six subgenomic mRNAs containing the leader-body junction sites, including a bicistronic mRNA encoding the accessory NS7a and NS7b genes, were experimentally identified in SeACoV-infected cells. Cellular ultrastructural changes induced by SeACoV infection were visualized by electron microscopy. The availability of the SeACoV infectious clone and a panel of antibodies against different viral proteins will facilitate further studies on understanding the molecular mechanisms of SeACoV replication and pathogenesis.
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MESH Headings
- Alphacoronavirus/genetics
- Alphacoronavirus/metabolism
- Alphacoronavirus/pathogenicity
- Animals
- Antibodies, Viral/biosynthesis
- Antibodies, Viral/chemistry
- Antigens, Viral/chemistry
- Antigens, Viral/immunology
- Base Sequence
- Cell Membrane/ultrastructure
- Cell Membrane/virology
- Chiroptera
- Chlorocebus aethiops
- Clone Cells
- Coronavirus Infections/diagnosis
- Coronavirus Infections/veterinary
- Coronavirus Infections/virology
- DNA, Complementary/genetics
- DNA, Complementary/metabolism
- Microscopy, Electron
- Nucleocapsid/chemistry
- Nucleocapsid/immunology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Viral/genetics
- RNA, Viral/metabolism
- RNA-Dependent RNA Polymerase/chemistry
- RNA-Dependent RNA Polymerase/immunology
- Rabbits
- Spike Glycoprotein, Coronavirus/chemistry
- Spike Glycoprotein, Coronavirus/immunology
- Swine
- Swine Diseases/diagnosis
- Swine Diseases/virology
- Vero Cells
- Viral Nonstructural Proteins/chemistry
- Viral Nonstructural Proteins/immunology
- Virus Replication
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Affiliation(s)
- Yong-Le Yang
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, Department of Veterinary Medicine, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Qi-Zhang Liang
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, Department of Veterinary Medicine, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Shu-Ya Xu
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, Department of Veterinary Medicine, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Evgeniia Mazing
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, Department of Veterinary Medicine, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Guo-Han Xu
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, Department of Veterinary Medicine, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Lei Peng
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, Department of Veterinary Medicine, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Pan Qin
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, Department of Veterinary Medicine, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Bin Wang
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, Department of Veterinary Medicine, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Yao-Wei Huang
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, Department of Veterinary Medicine, Zhejiang University, Hangzhou, 310058, Zhejiang, China.
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13
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Marchetti M, Kamsma D, Cazares Vargas E, Hernandez García A, van der Schoot P, de Vries R, Wuite GJL, Roos WH. Real-Time Assembly of Viruslike Nucleocapsids Elucidated at the Single-Particle Level. Nano Lett 2019; 19:5746-5753. [PMID: 31368710 PMCID: PMC6696885 DOI: 10.1021/acs.nanolett.9b02376] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/24/2019] [Indexed: 05/20/2023]
Abstract
While the structure of a multitude of viral particles has been resolved to atomistic detail, their assembly pathways remain largely elusive. Key unresolved issues are particle nucleation, particle growth, and the mode of genome compaction. These issues are difficult to address in bulk approaches and are effectively only accessible by the real-time tracking of assembly dynamics of individual particles. This we do here by studying the assembly into rod-shaped viruslike particles (VLPs) of artificial capsid polypeptides. Using fluorescence optical tweezers, we establish that small oligomers perform one-dimensional diffusion along the DNA. Larger oligomers are immobile and nucleate VLP growth. A multiplexed acoustic force spectroscopy approach reveals that DNA is compacted in regular steps, suggesting packaging via helical wrapping into a nucleocapsid. By reporting how real-time assembly tracking elucidates viral nucleation and growth principles, our work opens the door to a fundamental understanding of the complex assembly pathways of both VLPs and naturally evolved viruses.
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Affiliation(s)
- Margherita Marchetti
- Department
of Physics and Astronomy and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
- Moleculaire
Biofysica, Zernike Instituut, Rijksuniversiteit
Groningen, 9712 CP Groningen, The Netherlands
| | - Douwe Kamsma
- Department
of Physics and Astronomy and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Ernesto Cazares Vargas
- Institute
of Chemistry, Department of Chemistry of Biomacromolecules, National Autonomous University of Mexico, 04510 Mexico City, Mexico
| | - Armando Hernandez García
- Institute
of Chemistry, Department of Chemistry of Biomacromolecules, National Autonomous University of Mexico, 04510 Mexico City, Mexico
| | - Paul van der Schoot
- Institute
for Theoretical Physics, Utrecht University, 3512 JE Utrecht, The Netherlands
- Department
of Applied Physics, Eindhoven University
of Technology, 5612 AZ Eindhoven, The Netherlands
| | - Renko de Vries
- Laboratory
of Physical Chemistry and Colloid Science, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Gijs J. L. Wuite
- Department
of Physics and Astronomy and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
- E-mail:
| | - Wouter H. Roos
- Moleculaire
Biofysica, Zernike Instituut, Rijksuniversiteit
Groningen, 9712 CP Groningen, The Netherlands
- E-mail:
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14
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Meulia T, Stewart L, Goodin M. Sonchus yellow net virus core particles form on ring-like nuclear structure enriched in viral phosphoprotein. Virus Res 2018; 258:64-67. [PMID: 30308212 DOI: 10.1016/j.virusres.2018.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/05/2018] [Accepted: 10/08/2018] [Indexed: 12/27/2022]
Abstract
The phosphoprotein (P) of the nucleorhabdovirus sonchus yellow net virus has been shown to accumulate in ring-shaped structures in virus-infected nuclei. Further examination by live-cell imaging, in combination with structural examination by transmission electron microscopy and immunolocalization demonstrated that P-rings do not form in association with nucleoli. Furthermore, viral cores were shown to condense on the nucleoplasm-contacting surface of the rings. The data presented here offer evidence for the site of nucleocapsid assembly in SYNV-infected nuclei.
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Affiliation(s)
- Tea Meulia
- Molecular and Cellular Imaging Center, Department of Plant Pathology, The Ohio State University, Wooster, OH, 44691, USA
| | - Lucy Stewart
- USDA-ARS Plant Pathology, 1680 Madison Ave, Wooster, OH, 44691, USA
| | - Michael Goodin
- Department of Plant Pathology, University of Kentucky, Lexington, KY, 40546, USA.
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15
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Chen JY, Gan CY, Cai XF, Zhang WL, Long QX, Wei XF, Hu Y, Tang N, Chen J, Guo H, Huang AL, Hu JL. Fluorescent protein tagged hepatitis B virus capsid protein with long glycine-serine linker that supports nucleocapsid formation. J Virol Methods 2018; 255:52-59. [PMID: 29447911 DOI: 10.1016/j.jviromet.2018.02.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 01/06/2018] [Accepted: 02/11/2018] [Indexed: 02/05/2023]
Abstract
Fusion core proteins of Hepatitis B virus can be used to study core protein functions or capsid trafficking. A problem in constructing fusion core proteins is functional impairment of the individual domains in these fusion proteins, might due to structural interference. We reported a method to construct fusion proteins of Hepatitis B virus core protein (HBc) in which the functions of fused domains were partially kept. This method follows two principles: (1) fuse heterogeneous proteins at the N terminus of HBc; (2) use long Glycine-serine linkers between the two domains. Using EGFP and RFP as examples, we showed that long flexible G4S linkers can effectively separate the two domains in function. Among these fusion proteins constructed, GFP-G4S186-HBc and RFP-G4S47-HBc showed the best efficiency in rescuing the replication of an HBV replicon deficient in the core protein expression, though both of the two fusion proteins failed to support the formation of the relaxed circular DNA. These fluorescent protein-tagged HBcs might help study related to HBc or capsids tracking in cells.
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Affiliation(s)
- Jiang-Yan Chen
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Department of Infectious Diseases, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China; Department of Clinical Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (CCID), Hangzhou, China
| | - Chun-Yang Gan
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Department of Infectious Diseases, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xue-Fei Cai
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Department of Infectious Diseases, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Wen-Lu Zhang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Department of Infectious Diseases, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Quan-Xin Long
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Department of Infectious Diseases, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xia-Fei Wei
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Department of Infectious Diseases, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yuan Hu
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Department of Infectious Diseases, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Ni Tang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Department of Infectious Diseases, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Juan Chen
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Department of Infectious Diseases, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Haitao Guo
- Department of Microbiology and Immunology, Indiana University School of Medicine, United States
| | - Ai-Long Huang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Department of Infectious Diseases, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (CCID), Hangzhou, China.
| | - Jie-Li Hu
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Department of Infectious Diseases, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (CCID), Hangzhou, China.
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16
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Thuenemann EC, Lomonossoff GP. Delivering Cargo: Plant-Based Production of Bluetongue Virus Core-Like and Virus-Like Particles Containing Fluorescent Proteins. Methods Mol Biol 2018; 1776:319-334. [PMID: 29869252 DOI: 10.1007/978-1-4939-7808-3_22] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This chapter provides a practical guide to the in planta transient production of bluetongue virus-like particles containing a fluorescent cargo protein. Bluetongue virus (BTV) particles are icosahedral, multishelled entities of a relatively large size. Heterologous expression of the four main structural proteins of BTV results in the assembly of empty virus-like particles which resemble the native virus externally, but are devoid of nucleic acid. The space within the particles is sufficient to allow incorporation of relatively large cargo proteins, such as green fluorescent protein (GFP), by genetic fusion to the structural protein VP3. The method described utilizes the pEAQ vectors for high-level transient expression of such particles in Nicotiana benthamiana.
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Affiliation(s)
- Eva C Thuenemann
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, UK.
| | - George P Lomonossoff
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, UK
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17
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Wan W, Kolesnikova L, Clarke M, Koehler A, Noda T, Becker S, Briggs JAG. Structure and assembly of the Ebola virus nucleocapsid. Nature 2017; 551:394-397. [PMID: 29144446 PMCID: PMC5714281 DOI: 10.1038/nature24490] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 10/04/2017] [Indexed: 12/11/2022]
Abstract
Ebola and Marburg viruses are filoviruses: filamentous, enveloped viruses that cause haemorrhagic fever. Filoviruses are within the order Mononegavirales, which also includes rabies virus, measles virus, and respiratory syncytial virus. Mononegaviruses have non-segmented, single-stranded negative-sense RNA genomes that are encapsidated by nucleoprotein and other viral proteins to form a helical nucleocapsid. The nucleocapsid acts as a scaffold for virus assembly and as a template for genome transcription and replication. Insights into nucleoprotein-nucleoprotein interactions have been derived from structural studies of oligomerized, RNA-encapsidating nucleoprotein, and cryo-electron microscopy of nucleocapsid or nucleocapsid-like structures. There have been no high-resolution reconstructions of complete mononegavirus nucleocapsids. Here we apply cryo-electron tomography and subtomogram averaging to determine the structure of Ebola virus nucleocapsid within intact viruses and recombinant nucleocapsid-like assemblies. These structures reveal the identity and arrangement of the nucleocapsid components, and suggest that the formation of an extended α-helix from the disordered carboxy-terminal region of nucleoprotein-core links nucleoprotein oligomerization, nucleocapsid condensation, RNA encapsidation, and accessory protein recruitment.
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Affiliation(s)
- William Wan
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Larissa Kolesnikova
- Institut für Virologie, Philipps-Universität Marburg, Hans-Meerwein-Straße, 35043 Marburg, Germany
| | - Mairi Clarke
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Alexander Koehler
- Institut für Virologie, Philipps-Universität Marburg, Hans-Meerwein-Straße, 35043 Marburg, Germany
| | - Takeshi Noda
- Laboratory of Ultrastructural virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan; PRESTO, Japan Science and Technology Agency, Saitama, Japan
| | - Stephan Becker
- Institut für Virologie, Philipps-Universität Marburg, Hans-Meerwein-Straße, 35043 Marburg, Germany
| | - John A. G. Briggs
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
- Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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18
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Hammel M, Amlanjyoti D, Reyes FE, Chen JH, Parpana R, Tang HYH, Larabell CA, Tainer JA, Adhya S. HU multimerization shift controls nucleoid compaction. Sci Adv 2016; 2:e1600650. [PMID: 27482541 PMCID: PMC4966879 DOI: 10.1126/sciadv.1600650] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 06/14/2016] [Indexed: 05/05/2023]
Abstract
Molecular mechanisms controlling functional bacterial chromosome (nucleoid) compaction and organization are surprisingly enigmatic but partly depend on conserved, histone-like proteins HUαα and HUαβ and their interactions that span the nanoscale and mesoscale from protein-DNA complexes to the bacterial chromosome and nucleoid structure. We determined the crystal structures of these chromosome-associated proteins in complex with native duplex DNA. Distinct DNA binding modes of HUαα and HUαβ elucidate fundamental features of bacterial chromosome packing that regulate gene transcription. By combining crystal structures with solution x-ray scattering results, we determined architectures of HU-DNA nucleoproteins in solution under near-physiological conditions. These macromolecular conformations and interactions result in contraction at the cellular level based on in vivo imaging of native unlabeled nucleoid by soft x-ray tomography upon HUβ and ectopic HUα38 expression. Structural characterization of charge-altered HUαα-DNA complexes reveals an HU molecular switch that is suitable for condensing nucleoid and reprogramming noninvasive Escherichia coli into an invasive form. Collective findings suggest that shifts between networking and cooperative and noncooperative DNA-dependent HU multimerization control DNA compaction and supercoiling independently of cellular topoisomerase activity. By integrating x-ray crystal structures, x-ray scattering, mutational tests, and x-ray imaging that span from protein-DNA complexes to the bacterial chromosome and nucleoid structure, we show that defined dynamic HU interaction networks can promote nucleoid reorganization and transcriptional regulation as efficient general microbial mechanisms to help synchronize genetic responses to cell cycle, changing environments, and pathogenesis.
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Affiliation(s)
- Michal Hammel
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Corresponding author. (M.H.); (J.A.T.)
| | - Dhar Amlanjyoti
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Francis E. Reyes
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jian-Hua Chen
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA
| | - Rochelle Parpana
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Henry Y. H. Tang
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Carolyn A. Larabell
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA
| | - John A. Tainer
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
- Corresponding author. (M.H.); (J.A.T.)
| | - Sankar Adhya
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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19
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Jesus DM, Moussatche N, Condit RC. An improved high pressure freezing and freeze substitution method to preserve the labile vaccinia virus nucleocapsid. J Struct Biol 2016; 195:41-8. [PMID: 27155322 DOI: 10.1016/j.jsb.2016.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 04/13/2016] [Accepted: 05/04/2016] [Indexed: 11/19/2022]
Abstract
In recent years, high pressure freezing and freeze substitution have been widely used for electron microscopy to reveal viral and cellular structures that are difficult to preserve. Vaccinia virus, a member of the Poxviridae family, presents one of the most complex viral structures. The classical view of vaccinia virus structure consists of an envelope surrounding a biconcave core, with a lateral body in each concavity of the core. This classical view was challenged by Peters and Muller (1963), who demonstrated the presence of a folded tubular structure inside the virus core and stated the difficulty in visualizing this structure, possibly because it is labile and cannot be preserved by conventional sample preparation. Therefore, this tubular structure, now called the nucleocapsid, has been mostly neglected over the years. Earlier studies were able to preserve the nucleocapsid, but with low efficiency. In this study, we report the protocol (and troubleshooting) that resulted in preservation of the highest numbers of nucleocapsids in several independent preparations. Using this protocol, we were able to demonstrate an interdependence between the formation of the virus core wall and the nucleocapsid, leading to the hypothesis that an interaction exists between the major protein constituents of these compartments, A3 (core wall) and L4 (nucleocapsid). Our results show that high pressure freezing and freeze substitution can be used in more in-depth studies concerning the nucleocapsid structure and function.
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Affiliation(s)
| | - Nissin Moussatche
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32610, USA
| | - Richard C Condit
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32610, USA
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Ouizougun-Oubari M, Pereira N, Tarus B, Galloux M, Lassoued S, Fix J, Tortorici MA, Hoos S, Baron B, England P, Desmaële D, Couvreur P, Bontems F, Rey FA, Eléouët JF, Sizun C, Slama-Schwok A, Duquerroy S. A Druggable Pocket at the Nucleocapsid/Phosphoprotein Interaction Site of Human Respiratory Syncytial Virus. J Virol 2015; 89:11129-43. [PMID: 26246564 PMCID: PMC4621127 DOI: 10.1128/jvi.01612-15] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 07/28/2015] [Indexed: 02/03/2023] Open
Abstract
UNLABELLED Presently, respiratory syncytial virus (RSV), the main cause of severe respiratory infections in infants, cannot be treated efficiently with antivirals. However, its RNA-dependent polymerase complex offers potential targets for RSV-specific drugs. This includes the recognition of its template, the ribonucleoprotein complex (RNP), consisting of genomic RNA encapsidated by the RSV nucleoprotein, N. This recognition proceeds via interaction between the phosphoprotein P, which is the main polymerase cofactor, and N. The determinant role of the C terminus of P, and more particularly of the last residue, F241, in RNP binding and viral RNA synthesis has been assessed previously. Here, we provide detailed structural insight into this crucial interaction for RSV polymerase activity. We solved the crystallographic structures of complexes between the N-terminal domain of N (N-NTD) and C-terminal peptides of P and characterized binding by biophysical approaches. Our results provide a rationale for the pivotal role of F241, which inserts into a well-defined N-NTD pocket. This primary binding site is completed by transient contacts with upstream P residues outside the pocket. Based on the structural information of the N-NTD:P complex, we identified inhibitors of this interaction, selected by in silico screening of small compounds, that efficiently bind to N and compete with P in vitro. One of the compounds displayed inhibitory activity on RSV replication, thereby strengthening the relevance of N-NTD for structure-based design of RSV-specific antivirals. IMPORTANCE Respiratory syncytial virus (RSV) is a widespread pathogen that is a leading cause of acute lower respiratory infections in infants worldwide. RSV cannot be treated efficiently with antivirals, and no vaccine is presently available, with the development of pediatric vaccines being particularly challenging. Therefore, there is a need for new therapeutic strategies that specifically target RSV. The interaction between the RSV phosphoprotein P and the ribonucleoprotein complex is critical for viral replication. In this study, we identified the main structural determinants of this interaction, and we used them to screen potential inhibitors in silico. We found a family of molecules that were efficient competitors of P in vitro and showed inhibitory activity on RSV replication in cellular assays. These compounds provide a basis for a pharmacophore model that must be improved but that holds promises for the design of new RSV-specific antivirals.
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Affiliation(s)
- Mohamed Ouizougun-Oubari
- Institut Pasteur, Département de Virologie, Unité de Virologie Structurale, Paris, France CNRS UMR 3569 Virologie, Paris, France
| | - Nelson Pereira
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Gif-sur-Yvette, France
| | - Bogdan Tarus
- Unité de Virologie et Immunologie Moléculaires (UR892), INRA, Jouy-en-Josas, France
| | - Marie Galloux
- Unité de Virologie et Immunologie Moléculaires (UR892), INRA, Jouy-en-Josas, France
| | - Safa Lassoued
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Gif-sur-Yvette, France
| | - Jenna Fix
- Unité de Virologie et Immunologie Moléculaires (UR892), INRA, Jouy-en-Josas, France
| | - M Alejandra Tortorici
- Institut Pasteur, Département de Virologie, Unité de Virologie Structurale, Paris, France CNRS UMR 3569 Virologie, Paris, France
| | - Sylviane Hoos
- Institut Pasteur, Protéopôle, CNRS UMR 3528, Paris, France
| | - Bruno Baron
- Institut Pasteur, Protéopôle, CNRS UMR 3528, Paris, France
| | | | - Didier Desmaële
- UMR CNRS 8612, Institut Galien Paris-Sud, Châtenay-Malabry, France
| | - Patrick Couvreur
- UMR CNRS 8612, Institut Galien Paris-Sud, Châtenay-Malabry, France
| | - François Bontems
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Gif-sur-Yvette, France
| | - Félix A Rey
- Institut Pasteur, Département de Virologie, Unité de Virologie Structurale, Paris, France CNRS UMR 3569 Virologie, Paris, France
| | | | - Christina Sizun
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Gif-sur-Yvette, France
| | - Anny Slama-Schwok
- Unité de Virologie et Immunologie Moléculaires (UR892), INRA, Jouy-en-Josas, France
| | - Stéphane Duquerroy
- Institut Pasteur, Département de Virologie, Unité de Virologie Structurale, Paris, France CNRS UMR 3569 Virologie, Paris, France Université Paris-Sud, Faculté des Sciences, Orsay, France
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Ucisik MH, Küpcü S, Breitwieser A, Gelbmann N, Schuster B, Sleytr UB. S-layer fusion protein as a tool functionalizing emulsomes and CurcuEmulsomes for antibody binding and targeting. Colloids Surf B Biointerfaces 2015; 128:132-139. [PMID: 25734967 PMCID: PMC4406452 DOI: 10.1016/j.colsurfb.2015.01.055] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 01/28/2015] [Accepted: 01/29/2015] [Indexed: 11/13/2022]
Abstract
Selective targeting of tumor cells by nanoparticle-based drug delivery systems is highly desirable because it maximizes the drug concentration at the desired target while simultaneously protecting the surrounding healthy tissues. Here, we show a design for smart nanocarriers based on a biomimetic approach that utilizes the building principle of virus envelope structures. Emulsomes and CurcuEmulsomes comprising a tripalmitin solid core surrounded by phospholipid layers are modified by S-layer proteins that self-assemble into a two-dimensional array to form a surface layer. One significant advantage of this nanoformulation is that it increases the solubility of the lipophilic anti-cancer agent curcumin in the CurcuEmulsomes by a factor of 2700. In order to make the emulsomes specific for IgG, the S-layer protein is fused with two protein G domains. This S-layer fusion protein preserves its recrystallization characteristics, forming an ordered surface layer (square lattice with 13 nm unit-by-unit distance). The GG domains are presented in a predicted orientation and exhibit a selective binding affinity for IgG.
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Affiliation(s)
- Mehmet H Ucisik
- Institute for Synthetic Bioarchitectures, Department of Nanobiotechnology, University of Natural Resources and Life Sciences (BOKU) Vienna, Muthgasse 11, 1190 Vienna, Austria; Department of Biomedical Engineering, School of Engineering and Natural Sciences, Istanbul Medipol University, Ekinciler Cad. No. 19 Kavacık Kavşağı, Beykoz 34810, Istanbul, Turkey.
| | - Seta Küpcü
- Institute for Synthetic Bioarchitectures, Department of Nanobiotechnology, University of Natural Resources and Life Sciences (BOKU) Vienna, Muthgasse 11, 1190 Vienna, Austria
| | - Andreas Breitwieser
- Institute for Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences (BOKU) Vienna, Muthgasse 11, 1190 Vienna, Austria
| | | | - Bernhard Schuster
- Institute for Synthetic Bioarchitectures, Department of Nanobiotechnology, University of Natural Resources and Life Sciences (BOKU) Vienna, Muthgasse 11, 1190 Vienna, Austria
| | - Uwe B Sleytr
- Institute for Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences (BOKU) Vienna, Muthgasse 11, 1190 Vienna, Austria
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Tripathi D, Raikhy G, Goodin MM, Dietzgen RG, Pappu HR. In vivo localization of iris yellow spot tospovirus (Bunyaviridae)-encoded proteins and identification of interacting regions of nucleocapsid and movement proteins. PLoS One 2015; 10:e0118973. [PMID: 25781476 PMCID: PMC4363525 DOI: 10.1371/journal.pone.0118973] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 01/27/2015] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Localization and interaction studies of viral proteins provide important information about their replication in their host plants. Tospoviruses (Family Bunyaviridae) are economically important viruses affecting numerous field and horticultural crops. Iris yellow spot virus (IYSV), one of the tospoviruses, has recently emerged as an important viral pathogen of Allium spp. in many parts of the world. We studied the in vivo localization and interaction patterns of the IYSV proteins in uninfected and infected Nicotiana benthamiana and identified the interacting partners. PRINCIPAL FINDINGS Bimolecular fluorescence complementation (BiFC) analysis demonstrated homotypic and heterotypic interactions between IYSV nucleocapsid (N) and movement (NSm) proteins. These interactions were further confirmed by pull-down assays. Additionally, interacting regions of IYSV N and NSm were identified by the yeast-2-hybrid system and β-galactosidase assay. The N protein self-association was found to be mediated through the N- and C-terminal regions making head to tail interaction. Self-interaction of IYSV NSm was shown to occur through multiple interacting regions. In yeast-2-hybrid assay, the N- and C-terminal regions of IYSV N protein interacted with an N-terminal region of IYSV NSm protein. CONCLUSION/SIGNIFICANCE Our studies provide new insights into localization and interactions of IYSV N and NSm proteins. Molecular basis of these interactions was studied and is discussed in the context of tospovirus assembly, replication, and infection processes.
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Affiliation(s)
- Diwaker Tripathi
- Department of Plant Pathology, P.O. Box 646430, Washington State University, Pullman, Washington, United States of America
| | - Gaurav Raikhy
- Department of Plant Pathology, P.O. Box 646430, Washington State University, Pullman, Washington, United States of America
| | - Michael M. Goodin
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Ralf G. Dietzgen
- QAAFI, The University of Queensland, St. Lucia, Queensland, Australia
| | - Hanu R. Pappu
- Department of Plant Pathology, P.O. Box 646430, Washington State University, Pullman, Washington, United States of America
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Abstract
The continuing challenge of HIV-1 treatment resistance in patients creates a need for the development of new antiretroviral inhibitors. The HIV nucleocapsid (NC) protein is a potential therapeutic target. NC is necessary for viral RNA packaging and in the early stages of viral infection. The high level of NC amino acid conservation among all HIV-1 clades suggests a low tolerance for mutations. Thus, NC mutations that could arise during inhibitor treatment to provide resistance may render the virus less fit. Disruption of NC function provides a unique opportunity to strongly dampen replication at multiple points during the viral life cycle with a single inhibitor. Although NC exhibits desirable features for a potential antiviral target, the structural flexibility, size, and the presence of two zinc fingers makes small molecule targeting of NC a challenging task. In this review, we discuss the recent advances in strategies to develop inhibitors of NC function and present a perspective on potential novel approaches that may help to overcome some of the current challenges in the field.
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Affiliation(s)
- Divita Garg
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Bruce E Torbett
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA.
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Green TJ, Cox R, Tsao J, Rowse M, Qiu S, Luo M. Common mechanism for RNA encapsidation by negative-strand RNA viruses. J Virol 2014; 88:3766-75. [PMID: 24429372 PMCID: PMC3993539 DOI: 10.1128/jvi.03483-13] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 01/11/2014] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The nucleocapsid of a negative-strand RNA virus is assembled with a single nucleocapsid protein and the viral genomic RNA. The nucleocapsid protein polymerizes along the length of the single-strand genomic RNA (viral RNA) or its cRNA. This process of encapsidation occurs concomitantly with genomic replication. Structural comparisons of several nucleocapsid-like particles show that the mechanism of RNA encapsidation in negative-strand RNA viruses has many common features. Fundamentally, there is a unifying mechanism to keep the capsid protein protomer monomeric prior to encapsidation of viral RNA. In the nucleocapsid, there is a cavity between two globular domains of the nucleocapsid protein where the viral RNA is sequestered. The viral RNA must be transiently released from the nucleocapsid in order to reveal the template RNA sequence for transcription/replication. There are cross-molecular interactions among the protein subunits linearly along the nucleocapsid to stabilize its structure. Empty capsids can form in the absence of RNA. The common characteristics of RNA encapsidation not only delineate the evolutionary relationship of negative-strand RNA viruses but also provide insights into their mechanism of replication. IMPORTANCE What separates negative-strand RNA viruses (NSVs) from the rest of the virosphere is that the nucleocapsid of NSVs serves as the template for viral RNA synthesis. Their viral RNA-dependent RNA polymerase can induce local conformational changes in the nucleocapsid to temporarily release the RNA genome so that the viral RNA-dependent RNA polymerase can use it as the template for RNA synthesis during both transcription and replication. After RNA synthesis at the local region is completed, the viral RNA-dependent RNA polymerase processes downstream, and the RNA genome is restored in the nucleocapsid. We found that the nucleocapsid assembly of all NSVs shares three essential elements: a monomeric capsid protein protomer, parallel orientation of subunits in the linear nucleocapsid, and a (5H + 3H) motif that forms a proper cavity for sequestration of the RNA. This observation also suggests that all NSVs evolved from a common ancestor that has this unique nucleocapsid.
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Affiliation(s)
- Todd J Green
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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25
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Abstract
As an inanimate virus, herpes simplex virus type 1 (HSV-1) necessarily encodes all of its functions in its DNA. Isolation of pure viral DNA allows multiple downstream applications, including the creation of recombinant HSV strains, cloning of selected regions, and sequencing of viral DNA. The term nucleocapsid refers to the combination of the viral genome with the enclosing capsid; these viral genomes are necessarily linear and have been packaged for egress, even if they are not yet released from the cell. In contrast, viral DNA that is not associated with capsids may include episomal or concatenated forms and may have modifications such as histones that are added within cells. During this protocol, the viral capsid protects the HSV genome from reagents that strip away and destroy most cellular contaminants. This procedure describes the isolation of viral nucleocapsids and their subsequent dissolution to purify clean, linear HSV DNA.
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Affiliation(s)
- Moriah Szpara
- Department of Biochemistry & Molecular Biology, The Huck Institutes of the Life Sciences, Pennsylvania State University, W-208 Millennium Science Complex (MSC), University Park, PA, 16802, USA,
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26
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Weber M, Gawanbacht A, Habjan M, Rang A, Borner C, Schmidt AM, Veitinger S, Jacob R, Devignot S, Kochs G, García-Sastre A, Weber F. Incoming RNA virus nucleocapsids containing a 5'-triphosphorylated genome activate RIG-I and antiviral signaling. Cell Host Microbe 2013; 13:336-46. [PMID: 23498958 PMCID: PMC5515363 DOI: 10.1016/j.chom.2013.01.012] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 10/12/2012] [Accepted: 01/25/2013] [Indexed: 12/24/2022]
Abstract
Host defense to RNA viruses depends on rapid intracellular recognition of viral RNA by two cytoplasmic RNA helicases: RIG-I and MDA5. RNA transfection experiments indicate that RIG-I responds to naked double-stranded RNAs (dsRNAs) with a triphosphorylated 5' (5'ppp) terminus. However, the identity of the RIG-I stimulating viral structures in an authentic infection context remains unresolved. We show that incoming viral nucleocapsids containing a 5'ppp dsRNA "panhandle" structure trigger antiviral signaling that commences with RIG-I, is mediated through the adaptor protein MAVS, and terminates with transcription factor IRF-3. Independent of mammalian cofactors or viral polymerase activity, RIG-I bound to viral nucleocapsids, underwent a conformational switch, and homo-oligomerized. Enzymatic probing and superresolution microscopy suggest that RIG-I interacts with the panhandle structure of the viral nucleocapsids. These results define cytoplasmic entry of nucleocapsids as the proximal RIG-I-sensitive step during infection and establish viral nucleocapsids with a 5'ppp dsRNA panhandle as a RIG-I activator.
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Affiliation(s)
- Michaela Weber
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Ali Gawanbacht
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
| | - Matthias Habjan
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
| | - Andreas Rang
- Institute of Virology, Helmut-Ruska-Haus, University Hospital Charité, Charité Campus Mitte, Berlin, Germany
| | - Christoph Borner
- Institute of Molecular Medicine, Stefan-Meier-Strasse 17, D-79104 Freiburg, Germany
- Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs University Freiburg, Germany
| | - Anna Mareike Schmidt
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
- Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs University Freiburg, Germany
| | - Sophie Veitinger
- Department of Cell Biology and Cell Pathology, Philipps-University Marburg, Marburg, Germany
| | - Ralf Jacob
- Department of Cell Biology and Cell Pathology, Philipps-University Marburg, Marburg, Germany
| | - Stéphanie Devignot
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Georg Kochs
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
| | - Adolfo García-Sastre
- Department of Microbiology, Mount Sinai School of Medicine, New York, NY-10029, USA
- Department of Medicine, Division of Infectious Diseases, Mount Sinai School of Medicine, New York, NY-10029, USA
- Global Health and Emerging Pathogens Institute, Mount Sinai School of Medicine, New York, NY-10029, USA
| | - Friedemann Weber
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
- Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs University Freiburg, Germany
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Beniac DR, Melito PL, deVarennes SL, Hiebert SL, Rabb MJ, Lamboo LL, Jones SM, Booth TF. The organisation of Ebola virus reveals a capacity for extensive, modular polyploidy. PLoS One 2012; 7:e29608. [PMID: 22247782 PMCID: PMC3256159 DOI: 10.1371/journal.pone.0029608] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Accepted: 11/30/2011] [Indexed: 11/29/2022] Open
Abstract
Background Filoviruses, including Ebola virus, are unusual in being filamentous animal viruses. Structural data on the arrangement, stoichiometry and organisation of the component molecules of filoviruses has until now been lacking, partially due to the need to work under level 4 biological containment. The present study provides unique insights into the structure of this deadly pathogen. Methodology and Principal Findings We have investigated the structure of Ebola virus using a combination of cryo-electron microscopy, cryo-electron tomography, sub-tomogram averaging, and single particle image processing. Here we report the three-dimensional structure and architecture of Ebola virus and establish that multiple copies of the RNA genome can be packaged to produce polyploid virus particles, through an extreme degree of length polymorphism. We show that the helical Ebola virus inner nucleocapsid containing RNA and nucleoprotein is stabilized by an outer layer of VP24-VP35 bridges. Elucidation of the structure of the membrane-associated glycoprotein in its native state indicates that the putative receptor-binding site is occluded within the molecule, while a major neutralizing epitope is exposed on its surface proximal to the viral envelope. The matrix protein VP40 forms a regular lattice within the envelope, although its contacts with the nucleocapsid are irregular. Conclusions The results of this study demonstrate a modular organization in Ebola virus that accommodates a well-ordered, symmetrical nucleocapsid within a flexible, tubular membrane envelope.
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Affiliation(s)
- Daniel R. Beniac
- Viral Diseases Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Pasquale L. Melito
- Viral Diseases Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Shauna L. deVarennes
- Viral Diseases Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Shannon L. Hiebert
- Viral Diseases Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Melissa J. Rabb
- Viral Diseases Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
- Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Lindsey L. Lamboo
- Viral Diseases Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Steven M. Jones
- Viral Diseases Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Timothy F. Booth
- Viral Diseases Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
- Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
- * E-mail:
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Chang YS, Liu WJ, Lee CC, Chou TL, Lee YT, Wu TS, Huang JY, Huang WT, Lee TL, Kou GH, Wang AHJ, Lo CF. A 3D model of the membrane protein complex formed by the white spot syndrome virus structural proteins. PLoS One 2010; 5:e10718. [PMID: 20502662 PMCID: PMC2873410 DOI: 10.1371/journal.pone.0010718] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 04/25/2010] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Outbreaks of white spot disease have had a large negative economic impact on cultured shrimp worldwide. However, the pathogenesis of the causative virus, WSSV (whit spot syndrome virus), is not yet well understood. WSSV is a large enveloped virus. The WSSV virion has three structural layers surrounding its core DNA: an outer envelope, a tegument and a nucleocapsid. In this study, we investigated the protein-protein interactions of the major WSSV structural proteins, including several envelope and tegument proteins that are known to be involved in the infection process. PRINCIPAL FINDINGS In the present report, we used coimmunoprecipitation and yeast two-hybrid assays to elucidate and/or confirm all the interactions that occur among the WSSV structural (envelope and tegument) proteins VP51A, VP19, VP24, VP26 and VP28. We found that VP51A interacted directly not only with VP26 but also with VP19 and VP24. VP51A, VP19 and VP24 were also shown to have an affinity for self-interaction. Chemical cross-linking assays showed that these three self-interacting proteins could occur as dimers. CONCLUSIONS From our present results in conjunction with other previously established interactions we construct a 3D model in which VP24 acts as a core protein that directly associates with VP26, VP28, VP38A, VP51A and WSV010 to form a membrane-associated protein complex. VP19 and VP37 are attached to this complex via association with VP51A and VP28, respectively. Through the VP26-VP51C interaction this envelope complex is anchored to the nucleocapsid, which is made of layers of rings formed by VP664. A 3D model of the nucleocapsid and the surrounding outer membrane is presented.
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Affiliation(s)
- Yun-Shiang Chang
- Department of Molecular Biotechnology, Da-Yeh University, Changhua, Taiwan
- * E-mail: (YSC); (AHJW); (CFL)
| | - Wang-Jing Liu
- Institute of Zoology, National Taiwan University, Taipei, Taiwan
| | - Cheng-Chung Lee
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Tsung-Lu Chou
- Department of Molecular Biotechnology, Da-Yeh University, Changhua, Taiwan
| | - Yuan-Ting Lee
- Department of Molecular Biotechnology, Da-Yeh University, Changhua, Taiwan
| | - Tz-Shian Wu
- Department of Molecular Biotechnology, Da-Yeh University, Changhua, Taiwan
| | - Jiun-Yan Huang
- Institute of Zoology, National Taiwan University, Taipei, Taiwan
| | - Wei-Tung Huang
- Department of Molecular Biotechnology, Da-Yeh University, Changhua, Taiwan
| | - Tai-Lin Lee
- Department of Molecular Biotechnology, Da-Yeh University, Changhua, Taiwan
| | - Guang-Hsiung Kou
- Institute of Zoology, National Taiwan University, Taipei, Taiwan
| | - Andrew H.-J. Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
- * E-mail: (YSC); (AHJW); (CFL)
| | - Chu-Fang Lo
- Institute of Zoology, National Taiwan University, Taipei, Taiwan
- * E-mail: (YSC); (AHJW); (CFL)
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Wei H, Cheng RH, Berriman J, Rice WJ, Stokes DL, Katz A, Morgan DG, Gottlieb P. Three-dimensional structure of the enveloped bacteriophage phi12: an incomplete T = 13 lattice is superposed on an enclosed T = 1 shell. PLoS One 2009; 4:e6850. [PMID: 19727406 PMCID: PMC2733035 DOI: 10.1371/journal.pone.0006850] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Accepted: 08/03/2009] [Indexed: 11/19/2022] Open
Abstract
Background Bacteriophage φ12 is a member of the Cystoviridae, a unique group of lipid containing membrane enveloped bacteriophages that infect the bacterial plant pathogen Pseudomonas syringae pv. phaseolicola. The genomes of the virus species contain three double-stranded (dsRNA) segments, and the virus capsid itself is organized in multiple protein shells. The segmented dsRNA genome, the multi-layered arrangement of the capsid and the overall viral replication scheme make the Cystoviridae similar to the Reoviridae. Methodology/Principal Findings We present structural studies of cystovirus φ12 obtained using cryo-electron microscopy and image processing techniques. We have collected images of isolated φ12 virions and generated reconstructions of both the entire particles and the polymerase complex (PC). We find that in the nucleocapsid (NC), the φ12 P8 protein is organized on an incomplete T = 13 icosahedral lattice where the symmetry axes of the T = 13 layer and the enclosed T = 1 layer of the PC superpose. This is the same general protein-component organization found in φ6 NC's but the detailed structure of the entire φ12 P8 layer is distinct from that found in the best classified cystovirus species φ6. In the reconstruction of the NC, the P8 layer includes protein density surrounding the hexamers of P4 that sit at the 5-fold vertices of the icosahedral lattice. We believe these novel features correspond to dimers of protein P7. Conclusions/Significance In conclusion, we have determined that the φ12 NC surface is composed of an incomplete T = 13 P8 layer forming a net-like configuration. The significance of this finding in regard to cystovirus assembly is that vacancies in the lattice could have the potential to accommodate additional viral proteins that are required for RNA packaging and synthesis.
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Affiliation(s)
- Hui Wei
- Department of Microbiology and Immunology, Sophie Davis School of Biomedical Education, The City College of New York (CCNY), New York, New York, United States of America
| | - R. Holland Cheng
- Department of Cellular and Molecular Biology, University of California at Davis, Davis, California, United States of America
| | - John Berriman
- The New York Structural Biology Center, New York, New York, United States of America
| | - William J. Rice
- The New York Structural Biology Center, New York, New York, United States of America
| | - David L. Stokes
- Structural Biology Program, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, New York, United States of America
- The New York Structural Biology Center, New York, New York, United States of America
| | - A. Katz
- Institute for Ultrafast Spectroscopy and Lasers, The City College of New York, New York, New York, United States of America
| | - David Gene Morgan
- Nanoscience Center, Department of Chemistry, Indiana University, Bloomington, Indiana, United States of America
| | - Paul Gottlieb
- Department of Microbiology and Immunology, Sophie Davis School of Biomedical Education, The City College of New York (CCNY), New York, New York, United States of America
- Institute for Ultrafast Spectroscopy and Lasers, The City College of New York, New York, New York, United States of America
- * E-mail:
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Abstract
Measles virus belongs to the Paramyxoviridae family within the Mononegavirales order. Its nonsegmented, single-stranded, negative-sense RNA genome is encapsidated by the nucleoprotein (N) to form a helical nucleocapsid. This ribonucleoproteic complex is the substrate for both transcription and replication. The RNA-dependent RNA polymerase binds to the nucleocapsid template via its co-factor, the phosphoprotein (P). This chapter describes the main structural information available on the nucleoprotein, showing that it consists of a structured core (N(CORE)) and an intrinsically disordered C-terminal domain (N(TAIL)). We propose a model where the dynamic breaking and reforming of the interaction between N(TAIL) and P would allow the polymerase complex (L-P) to cartwheel on the nucleocapsid template. We also propose a model where the flexibility of the disordered N and P domains allows the formation of a tripartite complex (No-P-L) during replication, followed by the delivery of N monomers to the newly synthesized genomic RNA chain. Finally, the functional implications of structural disorder are also discussed in light of the ability of disordered regions to establish interactions with multiple partners, thus leading to multiple biological effects.
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Affiliation(s)
- S Longhi
- Architecture et Fonction des Macromolécules Biologiques, UMR 6098 CNRS et Universités Aix-Marseille I et II, 163 avenue de Luminy, Case 932, 13288 Marseille Cedex 09, France.
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31
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Li D, Jans DA, Bardin PG, Meanger J, Mills J, Ghildyal R. Association of respiratory syncytial virus M protein with viral nucleocapsids is mediated by the M2-1 protein. J Virol 2008; 82:8863-70. [PMID: 18579594 PMCID: PMC2519653 DOI: 10.1128/jvi.00343-08] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2008] [Accepted: 06/17/2008] [Indexed: 11/20/2022] Open
Abstract
Cytoplasmic inclusions in respiratory syncytial virus-infected cells comprising viral nucleocapsid proteins (L, N, P, and M2-1) and the viral genome are sites of viral transcription. Although not believed to be necessary for transcription, the matrix (M) protein is also present in these inclusions, and we have previously shown that M inhibits viral transcription. In this study, we have investigated the mechanisms for the association of the M protein with cytoplasmic inclusions. Our data demonstrate for the first time that the M protein associates with cytoplasmic inclusions via an interaction with the M2-1 protein. The M protein colocalizes with M2-1 in the cytoplasm of cells expressing only the M and M2-1 proteins and directly interacts with M2-1 in a cell-free binding assay. Using a cotransfection system, we confirmed that the N and P proteins are sufficient to form cytoplasmic inclusions and that M2-1 localizes to these inclusions; additionally, we show that M associates with cytoplasmic inclusions only in the presence of the M2-1 protein. Using truncated mutants, we show that the N-terminal 110 amino acids of M mediate the interaction with M2-1 and the subsequent association with nucleocapsids. The interaction of M2-1 with M and, in particular, the N-terminal region of M may represent a target for novel antivirals that block the association of M with nucleocapsids, thereby inhibiting virus assembly.
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Affiliation(s)
- Dongsheng Li
- Department of Medicine, Monash Institute of Medical Research, Monash University, Melbourne, Australia
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32
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Abstract
Binding of APOBEC3G to the nucleocapsid (NC) domain of the human immunodeficiency virus (HIV) Gag polyprotein may represent a critical early step in the selective packaging of this antiretroviral factor into HIV virions. Previously, we and others have reported that this interaction is mediated by RNA. Here, we demonstrate that RNA binding by APOBEC3G is key for initiation of APOBEC3G:NC complex formation in vitro. By adding back nucleic acids to purified, RNase-treated APOBEC3G and NC protein preparations in vitro, we demonstrate that complex formation is rescued by short (> or =10 nucleotides) single-stranded RNAs (ssRNAs) containing G residues. In contrast, complex formation is not induced by add-back of short ssRNAs lacking G, by dsRNAs, by ssDNAs, by dsDNAs or by DNA:RNA hybrid molecules. While some highly structured RNA molecules, i.e., tRNAs and rRNAs, failed to rescue APOBEC3G:NC complex formation, other structured RNAs, i.e., human Y RNAs and 7SL RNA, did promote NC binding by APOBEC3G. Together, these results indicate that ternary complex formation requires ssRNA, but suggest this can be presented in the context of an otherwise highly structured RNA molecule. Given previous data arguing that APOBEC3G binds, and edits, ssDNA effectively in vitro, these data may also suggest that APOBEC3G can exist in two different conformational states, with different activities, depending on whether it is bound to ssRNA or ssDNA.
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Affiliation(s)
- Hal P Bogerd
- Center for Virology, Department of Molecular Genetics and Microbiology, Duke University Medical Center, Duke University, Durham, North Carolina 27710, USA
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33
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Abstract
Retroviruses and LTR-retrotransposons are widespread in all living organisms and, in some instances such as for HIV, can be a serious threat to the human health. The retroviral nucleocapsid is the inner structure of the virus where several hundred nucleocapsid protein (NC) molecules coat the dimeric, genomic RNA. During the past twenty years, NC was found to play multiple roles in the viral life cycle (Fig. 1), notably during the copying of the genomic RNA into the proviral DNA by viral reverse transcriptase and integrase, and is therefore considered to be a prime target for anti-HIV therapy. The 6th NC symposium was held in the beautiful city of Amsterdam, the Netherlands, on the 20th and 21st of September 2007. All aspects of NC biology, from structure to function and to anti-HIV vaccination, were covered during this meeting.
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Affiliation(s)
- Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA) Academic Medical Center of the University of Amsterdam K3-110, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Robert Gorelick
- AIDS Vaccine Program SAIC-Frederick, Inc. NCI-Frederick P.O. Box B Frederick, MD 21702-1201, USA
| | - Michael F Summers
- Department of Chemistry and Biochemistry and Howard Hughes Medical Institute, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Yves Mély
- Départment Pharmacologie et Physico-chimie, UMR 7175 CNRS, Institut Gilbert Laustriat, Université Louis Pasteur, 74 route du Rhin, 67401 Illkirch, France
| | - Jean-Luc Darlix
- LaboRetro INSERM #758, Ecole Normale Supérieure de Lyon, IFR 128 Biosciences Lyon-Gerland, 69364 Lyon Cedex 07, France
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34
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Vorreiter J, Leifer I, Rösler C, Jackevica L, Pumpens P, Nassal M. Monoclonal antibodies providing topological information on the duck hepatitis B virus core protein and avihepadnaviral nucleocapsid structure. J Virol 2007; 81:13230-4. [PMID: 17881436 PMCID: PMC2169119 DOI: 10.1128/jvi.00847-07] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The icosahedral capsid of duck hepatitis B virus (DHBV) is formed by a single core protein species (DHBc). DHBc is much larger than HBc from human HBV, and no high-resolution structure is available. In an accompanying study (M. Nassal, I. Leifer, I. Wingert, K. Dallmeier, S. Prinz, and J. Vorreiter, J. Virol. 81:13218-13229, 2007), we used extensive mutagenesis to derive a structural model for DHBc. For independent validation, we here mapped the epitopes of seven anti-DHBc monoclonal antibodies. Using numerous recombinant DHBc proteins and authentic nucleocapsids from different avihepadnaviruses as test antigens, plus a panel of complementary assays, particle-specific and exposed plus buried linear epitopes were revealed. These data fully support key features of the model.
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Affiliation(s)
- Jolanta Vorreiter
- University Hospital Freiburg, Internal Medicine 2/Molecular Biology, Hugstetter Str. 55, D-79106 Freiburg, Germany
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35
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Dibben O, Thorpe LC, Easton AJ. Roles of the PVM M2-1, M2-2 and P gene ORF 2 (P-2) proteins in viral replication. Virus Res 2007; 131:47-53. [PMID: 17881076 DOI: 10.1016/j.virusres.2007.08.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Revised: 08/11/2007] [Accepted: 08/12/2007] [Indexed: 10/22/2022]
Abstract
A plasmid-based reverse genetics system for pneumonia virus of mice (PVM) using a synthetic minigenome is described. The system was used to investigate the functions of several viral proteins. The M2-1 protein of PVM was shown to enhance reporter gene expression when present at low levels, similar to the situation for the equivalent respiratory syncytial virus (RSV) M2-1 protein, but at high levels was shown to reduce gene expression from the minigenome activity, which differs significantly form the situation with RSV. Analysis of levels of nucleocapsid complex RNA showed that high levels of the PVM M2-1 protein inhibits RNA replication rather than transcription. In contrast, expression of the PVM M2-2 protein in conjunction with the polymerase proteins in a minigenome assay greatly reduced the levels of CAT reporter protein. This is similar to the situation with the RSV M2-2 protein although there is no significant sequence identity between the M2-2 proteins of the pneumoviruses. A significant difference between the genome organisations of RSV and PVM is that the P gene of PVM contains a second open reading frame, encoding the P-2 protein, which has no counterpart in the RSV P gene. Co-expression of the PVM P-2 protein with the minigenome inhibited virus gene expression. This resembles the situation seen with the accessory proteins expressed from alternate reading frames of the P gene of other paramyxoviruses. Analysis of levels of antigenome RNA and CAT mRNA produced by the minigenome in the presence of the P2 protein indicated that the protein inhibits viral transcription in a dose-dependent fashion.
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Affiliation(s)
- Oliver Dibben
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK
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36
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Mirambeau G, Lyonnais S, Coulaud D, Hameau L, Lafosse S, Jeusset J, Borde I, Reboud-Ravaux M, Restle T, Gorelick RJ, Le Cam E. HIV-1 protease and reverse transcriptase control the architecture of their nucleocapsid partner. PLoS One 2007; 2:e669. [PMID: 17712401 PMCID: PMC1940317 DOI: 10.1371/journal.pone.0000669] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Accepted: 06/18/2007] [Indexed: 11/18/2022] Open
Abstract
The HIV-1 nucleocapsid is formed during protease (PR)-directed viral maturation, and is transformed into pre-integration complexes following reverse transcription in the cytoplasm of the infected cell. Here, we report a detailed transmission electron microscopy analysis of the impact of HIV-1 PR and reverse transcriptase (RT) on nucleocapsid plasticity, using in vitro reconstitutions. After binding to nucleic acids, NCp15, a proteolytic intermediate of nucleocapsid protein (NC), was processed at its C-terminus by PR, yielding premature NC (NCp9) followed by mature NC (NCp7), through the consecutive removal of p6 and p1. This allowed NC co-aggregation with its single-stranded nucleic-acid substrate. Examination of these co-aggregates for the ability of RT to catalyse reverse transcription showed an effective synthesis of double-stranded DNA that, remarkably, escaped from the aggregates more efficiently with NCp7 than with NCp9. These data offer a compelling explanation for results from previous virological studies that focused on i) Gag processing leading to nucleocapsid condensation, and ii) the disappearance of NCp7 from the HIV-1 pre-integration complexes. We propose that HIV-1 PR and RT, by controlling the nucleocapsid architecture during the steps of condensation and dismantling, engage in a successive nucleoprotein-remodelling process that spatiotemporally coordinates the pre-integration steps of HIV-1. Finally we suggest that nucleoprotein remodelling mechanisms are common features developed by mobile genetic elements to ensure successful replication.
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Affiliation(s)
- Gilles Mirambeau
- Laboratoire de Microscopie Moléculaire, UMR 8126: Interactions moléculaires et cancer, CNRS, Université Paris Sud-Institut de Cancérologie Gustave Roussy, Villejuif, France
- Division de Biochimie, UFR des Sciences de la Vie, Université Pierre et Marie Curie-Paris, Paris, France
- * To whom correspondence should be addressed. E-mail: (GM); (ELC)
| | - Sébastien Lyonnais
- Laboratoire de Microscopie Moléculaire, UMR 8126: Interactions moléculaires et cancer, CNRS, Université Paris Sud-Institut de Cancérologie Gustave Roussy, Villejuif, France
| | - Dominique Coulaud
- Laboratoire de Microscopie Moléculaire, UMR 8126: Interactions moléculaires et cancer, CNRS, Université Paris Sud-Institut de Cancérologie Gustave Roussy, Villejuif, France
| | - Laurence Hameau
- Laboratoire de Microscopie Moléculaire, UMR 8126: Interactions moléculaires et cancer, CNRS, Université Paris Sud-Institut de Cancérologie Gustave Roussy, Villejuif, France
| | - Sophie Lafosse
- Laboratoire de Microscopie Moléculaire, UMR 8126: Interactions moléculaires et cancer, CNRS, Université Paris Sud-Institut de Cancérologie Gustave Roussy, Villejuif, France
| | - Josette Jeusset
- Laboratoire de Microscopie Moléculaire, UMR 8126: Interactions moléculaires et cancer, CNRS, Université Paris Sud-Institut de Cancérologie Gustave Roussy, Villejuif, France
| | - Isabelle Borde
- Laboratoire Biologie et Multimedia, Université Pierre et Marie Curie-Paris, Paris, France
| | - Michèle Reboud-Ravaux
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, CNRS FRE 2852, Institut Jacques Monod, CNRS-Université Pierre et Marie Curie-Paris, Paris, France
| | - Tobias Restle
- Institut für Molekulare Medizin, Universitätsklinikum Schleswig-Holstein and ZMSB, Lübeck, Germany
| | - Robert J. Gorelick
- AIDS Vaccine Program, Basic Research Program, Science Applications International Corporation at Frederick, The National Cancer Institute at Frederick, Frederick, Maryland, United States of America
| | - Eric Le Cam
- Laboratoire de Microscopie Moléculaire, UMR 8126: Interactions moléculaires et cancer, CNRS, Université Paris Sud-Institut de Cancérologie Gustave Roussy, Villejuif, France
- * To whom correspondence should be addressed. E-mail: (GM); (ELC)
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Masalova OV, Vishnevskaia TV, Shkurko TV, Garanzha TA, Tupoleva TA, Filatov FP, Blokhina NP, Kushch AA. [Comparative analysis of hepatitis C virus core protein in the plasma and serum samples from HCV-infected blood donors and patients with hepatitis C]. Vopr Virusol 2007; 52:11-7. [PMID: 17722604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The aim of the study was to develop a sensitive and specific method for revealing the direct marker of hepatitis C virus (HCV)--core protein in the serum and to test it in the laboratory setting. Experiments were made on plasma and serum samples from asymptomatic HCV-seropositive blood donors (n=65), patients with acute (AHC) and chronic (CHC) hepatitis C (n=295), and HCV-seronegative blood donors (n=20). The processing protocol for serum included their concentration by means of polyethylene glycol and subsequent treatments of pellets to detect core protein in free virions, nonenveloped nucleocapsids, and immune complexes. This allowed an assay to be developed for the detection of core protein, by using a sandwich ELISA. Inclusion of a combination of three original monoclonal antibodies into the sandwich could reveal in the samples core proteins of at least 3 genotypes of HCV (1, 2, and 3) with a sensitivity of 20 pg/ml in the majority of HCV-infected subjects. The results of determination of core protein and HCV RNA correlated with a high degree of sensitivity. To detect HCV in the blood of patients with AHC, it was shown to be sufficient to find freely circulating virions whereas an analysis of immune complexes should be included in cases of CHC to achieve more sensitivity. The findings are a basis for developing a test system for the diagnosis of hepatitis C, including its early stages before seroconversion and for determining a viral load during interferon therapy. Introduction of the method into practice increases the reliability of the diagnosis of hepatitis C and virus-free safety of blood transfusions.
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Li Z, Lin Q, Chen J, Wu JL, Lim TK, Loh SS, Tang X, Hew CL. Shotgun identification of the structural proteome of shrimp white spot syndrome virus and iTRAQ differentiation of envelope and nucleocapsid subproteomes. Mol Cell Proteomics 2007; 6:1609-20. [PMID: 17545682 DOI: 10.1074/mcp.m600327-mcp200] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
White spot syndrome virus (WSSV) is a major pathogen that causes severe mortality and economic losses to shrimp cultivation worldwide. The genome of WSSV contains a 305-kb double-stranded circular DNA, which encodes 181 predicted ORFs. Previous gel-based proteomics studies on WSSV have identified 38 structural proteins. In this study, we applied shotgun proteomics using off-line coupling of an LC system with MALDI-TOF/TOF MS/MS as a complementary and comprehensive approach to investigate the WSSV proteome. This approach led to the identification of 45 viral proteins; 13 of them are reported for the first time. Seven viral proteins were found to have acetylated N termini. RT-PCR confirmed the mRNA expression of these 13 newly identified viral proteins. Furthermore iTRAQ (isobaric tags for relative and absolute quantification), a quantitative proteomics strategy, was used to distinguish envelope proteins and nucleocapsid proteins of WSSV. Based on iTRAQ ratios, we successfully identified 23 envelope proteins and six nucleocapsid proteins. Our results validated 15 structural proteins with previously known localization in the virion. Furthermore the localization of an additional 12 envelope proteins and two nucleocapsid proteins was determined. We demonstrated that iTRAQ is an effective approach for high throughput viral protein localization determination. Altogether WSSV is assembled by at least 58 structural proteins, including 13 proteins newly identified by shotgun proteomics and one identified by iTRAQ. The localization of 42 structural proteins was determined; 33 are envelope proteins, and nine are nucleocapsid proteins. A comprehensive identification of WSSV structural proteins and their localization should facilitate the studies of its assembly and mechanism of infection.
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Affiliation(s)
- Zhengjun Li
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
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Houben K, Marion D, Tarbouriech N, Ruigrok RWH, Blanchard L. Interaction of the C-terminal domains of sendai virus N and P proteins: comparison of polymerase-nucleocapsid interactions within the paramyxovirus family. J Virol 2007; 81:6807-16. [PMID: 17459940 PMCID: PMC1933331 DOI: 10.1128/jvi.00338-07] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Interaction of the C-terminal domains of Sendai virus (SeV) P and N proteins is crucial for RNA synthesis by correctly positioning the polymerase complex (L+P) onto the nucleocapsid (N/RNA). To better understand this mechanism within the paramyxovirus family, we have studied the complex formed by the SeV C-terminal domains of P (PX) and N (N(TAIL)) proteins by solution nuclear magnetic resonance spectroscopy. We have characterized SeV N(TAIL), which belongs to the class of intrinsically disordered proteins, and precisely defined the binding regions within this latter domain and within PX. SeV N(TAIL) binds with residues 472 to 493, which have a helical propensity (residues 477 to 491) to the surface created by helices alpha2 and alpha3 of PX with a 1:1 stoichiometry, as was also found for measles virus (MV). The binding interface is dominated by charged residues, and the dissociation constant was determined to be 57 +/- 18 microM under conditions of the experiment (i.e., in 0.5 M NaCl). We have also shown that the extreme C terminus of SeV N(TAIL) does not interact with PX, which is in contrast to MV, where a second binding site was identified. In addition, the interaction surfaces of the MV proteins are hydrophobic and a stronger binding constant was found. This gives a good illustration of how selection pressure allowed the C-terminal domains of N and P proteins to evolve concomitantly within this family of viruses in order to lead to protein complexes having the same three-dimensional fold, and thus the same function, but with completely different binding interfaces.
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Affiliation(s)
- Klaartje Houben
- CEA Cadarache, IBEB, LEMiRE, Saint-Paul-lez-Durance, F-13108 France
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40
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Saikatendu KS, Joseph JS, Subramanian V, Neuman BW, Buchmeier MJ, Stevens RC, Kuhn P. Ribonucleocapsid formation of severe acute respiratory syndrome coronavirus through molecular action of the N-terminal domain of N protein. J Virol 2007; 81:3913-21. [PMID: 17229691 PMCID: PMC1866093 DOI: 10.1128/jvi.02236-06] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Accepted: 12/01/2006] [Indexed: 01/06/2023] Open
Abstract
Conserved among all coronaviruses are four structural proteins: the matrix (M), small envelope (E), and spike (S) proteins that are embedded in the viral membrane and the nucleocapsid phosphoprotein (N), which exists in a ribonucleoprotein complex in the lumen. The N-terminal domain of coronaviral N proteins (N-NTD) provides a scaffold for RNA binding, while the C-terminal domain (N-CTD) mainly acts as oligomerization modules during assembly. The C terminus of the N protein anchors it to the viral membrane by associating with M protein. We characterized the structures of N-NTD from severe acute respiratory syndrome coronavirus (SARS-CoV) in two crystal forms, at 1.17 A (monoclinic) and at 1.85 A (cubic), respectively, resolved by molecular replacement using the homologous avian infectious bronchitis virus (IBV) structure. Flexible loops in the solution structure of SARS-CoV N-NTD are now shown to be well ordered around the beta-sheet core. The functionally important positively charged beta-hairpin protrudes out of the core, is oriented similarly to that in the IBV N-NTD, and is involved in crystal packing in the monoclinic form. In the cubic form, the monomers form trimeric units that stack in a helical array. Comparison of crystal packing of SARS-CoV and IBV N-NTDs suggests a common mode of RNA recognition, but they probably associate differently in vivo during the formation of the ribonucleoprotein complex. Electrostatic potential distribution on the surface of homology models of related coronaviral N-NTDs suggests that they use different modes of both RNA recognition and oligomeric assembly, perhaps explaining why their nucleocapsids have different morphologies.
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Affiliation(s)
- Kumar Singh Saikatendu
- Department of Cell Biology, 10550 N. Torrey Pines Rd., CB265, The Scripps Research Institute, La Jolla, CA 92037, USA
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Liu HW, Zeng Y, Landes CF, Kim YJ, Zhu Y, Ma X, Vo MN, Musier-Forsyth K, Barbara PF. Insights on the role of nucleic acid/protein interactions in chaperoned nucleic acid rearrangements of HIV-1 reverse transcription. Proc Natl Acad Sci U S A 2007; 104:5261-7. [PMID: 17372205 PMCID: PMC1828707 DOI: 10.1073/pnas.0700166104] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
HIV-1 reverse transcription requires several nucleic acid rearrangement steps that are "chaperoned" by the nucleocapsid protein (NC), including minus-strand transfer, in which the DNA transactivation response element (TAR) is annealed to the complementary TAR RNA region of the viral genome. These various rearrangement processes occur in NC bound complexes of specific RNA and DNA structures. A major barrier to the investigation of these processes in vitro has been the diversity and heterogeneity of the observed nucleic acid/protein assemblies, ranging from small complexes of only one or two nucleic acid molecules all the way up to large-scale aggregates comprised of thousands of NC and nucleic acid molecules. Herein, we use a flow chamber approach involving rapid NC/nucleic acid mixing to substantially control aggregation for the NC chaperoned irreversible annealing kinetics of a model TAR DNA hairpin sequence to the complementary TAR RNA hairpin, i.e., to form an extended duplex. By combining the flow chamber approach with a broad array of fluorescence single-molecule spectroscopy (SMS) tools (FRET, molecule counting, and correlation spectroscopy), we have unraveled the complex, heterogeneous kinetics that occur during the course of annealing. The SMS results demonstrate that the TAR hairpin reactant is predominantly a single hairpin coated by multiple NCs with a dynamic secondary structure, involving equilibrium between a "Y" shaped conformation and a closed one. The data further indicate that the nucleation of annealing occurs in an encounter complex that is formed by two hairpins with one or both of the hairpins in the "Y" conformation.
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Affiliation(s)
- Hsiao-Wei Liu
- *Center for Nano and Molecular Science and Technology, University of Texas, Austin, TX 78712; and
| | - Yining Zeng
- *Center for Nano and Molecular Science and Technology, University of Texas, Austin, TX 78712; and
| | - Christy F. Landes
- *Center for Nano and Molecular Science and Technology, University of Texas, Austin, TX 78712; and
| | - Yoen Joo Kim
- *Center for Nano and Molecular Science and Technology, University of Texas, Austin, TX 78712; and
| | - Yongjin Zhu
- *Center for Nano and Molecular Science and Technology, University of Texas, Austin, TX 78712; and
| | - Xiaojing Ma
- *Center for Nano and Molecular Science and Technology, University of Texas, Austin, TX 78712; and
| | - My-Nuong Vo
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455
| | | | - Paul F. Barbara
- *Center for Nano and Molecular Science and Technology, University of Texas, Austin, TX 78712; and
- To whom correspondence should be addressed. E-mail:
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42
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Derse D, Hill SA, Princler G, Lloyd P, Heidecker G. Resistance of human T cell leukemia virus type 1 to APOBEC3G restriction is mediated by elements in nucleocapsid. Proc Natl Acad Sci U S A 2007; 104:2915-20. [PMID: 17299050 PMCID: PMC1815281 DOI: 10.1073/pnas.0609444104] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Human T cell leukemia virus type 1 (HTLV-1) has evolved a remarkable strategy to thwart the antiviral effects of the cellular cytidine deaminase APOBEC3G (hA3G). HTLV-1 infects T lymphocytes in vivo, where, like HIV-1, it is likely to encounter hA3G. HIV-1 counteracts the innate antiviral activity of hA3G by producing an accessory protein, Vif, which hastens the degradation of hA3G. In contrast, HTLV-1 does not encode a Vif homologue; instead, HTLV-1 has evolved a cis-acting mechanism to prevent hA3G restriction. We demonstrate here that a peptide motif in the C terminus of the HTLV-1 nucleocapsid (NC) domain inhibits hA3G packaging into nascent virions. Mutation of amino acids within this region resulted in increased levels of hA3G incorporation into virions and increased susceptibility to hA3G restriction. Elements within the C-terminal extension of the NC domain are highly conserved among the primate T cell leukemia viruses, but this extension is absent in all other retroviral NC proteins.
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Affiliation(s)
- David Derse
- HIV Drug Resistance Program, National Cancer Institute, Frederick, MD 21702-1201, USA.
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43
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Okeoma CM, Lovsin N, Peterlin BM, Ross SR. APOBEC3 inhibits mouse mammary tumour virus replication in vivo. Nature 2007; 445:927-30. [PMID: 17259974 DOI: 10.1038/nature05540] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Accepted: 12/19/2006] [Indexed: 11/09/2022]
Abstract
Genomes of all mammals encode apobec3 genes, which are thought to have a function in intrinsic cellular immunity to several viruses including human immunodeficiency virus type 1 (HIV-1). APOBEC3 (A3) proteins are packaged into virions and inhibit retroviral replication in newly infected cells, at least in part by deaminating cytidines on the negative strand DNA intermediates. However, the role of A3 in innate resistance to mouse retroviruses is not understood. Here we show that A3 functions during retroviral infection in vivo and provides partial protection to mice against infection with mouse mammary tumour virus (MMTV). Both mouse A3 and human A3G proteins interacted with the MMTV nucleocapsid in an RNA-dependent fashion and were packaged into virions. In addition, mouse A3-containing and human A3G-containing virions showed a marked decrease in titre. Last, A3(-/-) mice were more susceptible to MMTV infection, because virus spread was more rapid and extensive than in their wild-type littermates.
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Affiliation(s)
- Chioma M Okeoma
- Department of Microbiology and Abramson Family Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6142, USA
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44
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Németh-Pongrácz V, Snasel J, Rumlova M, Pichova I, Vértessy BG. Interacting partners of M-PMV nucleocapsid-dUTPase. Nucleosides Nucleotides Nucleic Acids 2007; 25:1197-200. [PMID: 17065090 DOI: 10.1080/15257770600894535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The nucleocapsid-dUTPase protein of Mason-Pfizer monkey virus is a truly bifunctional fusion enzyme. The exact role of this fusion protein in the viral life cycle is unclear. To explore its function, we started to identify interacting protein partners of the enzyme in vitro. Three viral proteins, integrase, capsid and nucleocapsid, were found to be capable of physical interaction with NC-dUTPase. Integrase protein is an important component within the preintegration complex; therefore the present results also suggest that NC-dUTPase might be associated with this complex.
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Affiliation(s)
- V Németh-Pongrácz
- Institute of Enzymology, Hungarian Academy of Sciences, Budapest, Hungary.
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45
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Hartlieb B, Muziol T, Weissenhorn W, Becker S. Crystal structure of the C-terminal domain of Ebola virus VP30 reveals a role in transcription and nucleocapsid association. Proc Natl Acad Sci U S A 2007; 104:624-9. [PMID: 17202263 PMCID: PMC2111399 DOI: 10.1073/pnas.0606730104] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Indexed: 11/18/2022] Open
Abstract
Transcription of the highly pathogenic Ebola virus depends on VP30, a nucleocapsid-associated Ebola virus-specific transcription factor. The transcription activator VP30 was shown to play an essential role in Ebola virus replication, most likely by stabilizing nascent mRNA. Here we present the crystal structure of the C-terminal domain (CTD) of VP30 (VP30(CTD)) at 2.0-A resolution. VP30(CTD) folds independently into a dimeric helical assembly. The VP30(CTD) dimers assemble into hexamers that are present in virions, by an oligomerization domain located in the N terminus of VP30. Mutagenesis of conserved charged amino acids on VP30(CTD) revealed that two regions, namely a basic cluster around Lys-180 and Glu-197, are required for nucleocapsid interaction. However, only mutagenesis of the basic cluster was shown to impair transcription activation, suggesting that both processes are regulated independently. The structure and the mutagenesis results reveal a potential pocket for small-molecule inhibitors that might prevent VP30 activity and thus virus propagation as it has been shown previously by peptides, which interfere with VP30 homooligomerization.
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Affiliation(s)
- Bettina Hartlieb
- European Molecular Biology Laboratory (EMBL), 6 Rue Jules Horowitz, 38042 Grenoble, France
- Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany; and
- Institut für Virologie, Hans-Meerwein Strasse 3, 35032 Marburg, Germany
| | - Tadeusz Muziol
- European Molecular Biology Laboratory (EMBL), 6 Rue Jules Horowitz, 38042 Grenoble, France
| | - Winfried Weissenhorn
- European Molecular Biology Laboratory (EMBL), 6 Rue Jules Horowitz, 38042 Grenoble, France
| | - Stephan Becker
- Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany; and
- Institut für Virologie, Hans-Meerwein Strasse 3, 35032 Marburg, Germany
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46
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Luo H, Chen J, Chen K, Shen X, Jiang H. Carboxyl terminus of severe acute respiratory syndrome coronavirus nucleocapsid protein: self-association analysis and nucleic acid binding characterization. Biochemistry 2006; 45:11827-35. [PMID: 17002283 DOI: 10.1021/bi0609319] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Coronavirus nucleocapsid (N) protein envelops the genomic RNA to form long helical nucleocapsid during virion assembly. Since N protein oligomerization is usually a crucial step in this process, characterization of such an oligomerization will help in the understanding of the possible mechanisms for nucleocapsid formation. The N protein of severe acute respiratory syndrome coronavirus (SARS-CoV) was recently discovered to self-associate by its carboxyl terminus. In this study, to further address the detailed understanding of the association feature of this C-terminus, its oligomerization was systematically investigated by size exclusion chromatography and chemical cross-linking assays. Our results clearly indicated that the C-terminal domain of SARS-CoV N protein could form not only dimers but also trimers, tetramers, and hexamers. Further analyses against six deletion mutants showed that residues 343-402 were necessary and sufficient for this C-terminus oligomerization. Although this segment contains many charged residues, differences in ionic strength have no effects on its oligomerization, indicating the absence of electrostatic force in SARS-CoV N protein C-terminus self-association. Gel shift assay results revealed that the SARS-CoV N protein C-terminus is also able to associate with nucleic acids and residues 363-382 are the responsible interaction partner, demonstrating that this fragment might involve genomic RNA binding sites. The fact that nucleic acid binding could promote the SARS-CoV N protein C-terminus to form high-order oligomers implies that the oligomeric SARS-CoV N protein probably combines with the viral genomic RNA in triggering long nucleocapsid formation.
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Affiliation(s)
- Haibin Luo
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
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47
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Xiao N, Zhang X, Dai L, Yuan L, Wang Y, Zhang M, Xu T, Dai H. Isolation and identification of a novel WSSV nucleocapsid protein by cDNA phage display using an scFv antibody. J Virol Methods 2006; 137:272-9. [PMID: 16935355 DOI: 10.1016/j.jviromet.2006.06.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 06/26/2006] [Accepted: 06/29/2006] [Indexed: 11/30/2022]
Abstract
In a previous study, a scFv phage display library against white spot syndrome virus (WSSV) was constructed and yielded a clone designated A1 with conformational specificity against native but not denatured viral antigen. Although the clone A1 has been used successfully as a diagnostic antibody, its precise target antigen has not been elucidated. A different strategy was adopted involving the construction of a second T7 phage display library utilizing mRNA isolated from shrimp infected with WSSV. Following RT-PCR and T7 phage library construction, phages displaying the candidate epitope were selected with A1 scFv. Since successive enrichment steps were not associated with an increased titer of the phages, enrichment after successive tests was confirmed by PCR resulting in the preferred selection of a specific DNA sequence encoding a novel nucleocapsid protein WSSV388. Immune electron microscopy revealed that WSSV388 is located on the nucleocapsid. This result demonstrated that unknown antigen could be identified by phage display using the epitope conformation dependent scFv.
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Affiliation(s)
- Nan Xiao
- Institute of Hydrobiology, Chinese Academy of Sciences, 7 Southern East Lake Road, Wuchang, Wuhan, Hubei 430072, PR China
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Abstract
Electron microscopy and infrared and Raman spectroscopy have been used here to study the morphology, size distribution, secondary and tertiary structures of protein particles assembled from a truncated hepatitis C virus (HCV) core protein covering the first 120 aa. Particles of pure protein, having similar morphology and size distribution of those of nucleocapsids found in sera from HCV-infected patients, have been visualized for the first time. The secondary structure of these protein particles involve beta-sheet enrichment in relation to its protein monomer. Tertiary/quaternary structure has also been studied using the dynamics of H/D exchange. With this aim infrared spectra were measured as a function of H/D exchange time and subsequently analyzed by principal component analysis and two-dimensional correlation spectroscopy. Temporal dynamics of exchange for these protein particles were as follows: arginine residues exchanged first, followed by turn and unordered structures, followed by beta-sheets which may act as linkers of protein monomers.
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49
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Abstract
The assembly of the alphavirus nucleocapsid core has been investigated using an in vitro assembly system. The C-terminal two-thirds of capsid protein (CP), residues 81 to 264 in Sindbis virus (SINV), have been previously shown to have all the RNA-CP and CP-CP contacts required for core assembly in vitro. Helix I, which is located in the N-terminal dispensable region of the CP, has been proposed to stabilize the core by forming a coiled coil in the CP dimer formed by the interaction of residues 81 to 264. We examined the ability of heterologous alphavirus CPs to dimerize and form phenotypically mixed core-like particles (CLPs) using an in vitro assembly system. The CPs of SINV and Ross River virus (RRV) do not form phenotypically mixed CLPs, but SINV and Western equine encephalitis virus CPs do form mixed cores. In addition, CP dimers do not form between SINV and RRV in these assembly reactions. In contrast, an N-terminal truncated SINV CP (residues 81 to 264) forms phenotypically mixed CLPs when it is assembled with full-length heterologous CPs, suggesting that the region that controls the mixing is present in the N-terminal 80 residues. Furthermore, this result suggests that the dimeric interaction, which was absent between SINV and RRV CPs, can be restored by the removal of the N-terminal 80 residues of the SINV CP. We mapped the determinant that is responsible for phenotypic mixing onto helix I by using domain swapping experiments. Thus, discrimination of the CP partner in alphavirus core assembly appears to be dependent on helix I sequence compatibility. These results suggest that helix I provides one of the important interactions during nucleocapsid core formation and may play a regulatory role during the early steps of the assembly process.
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Affiliation(s)
- Eunmee M Hong
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA
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50
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Zhang Y, Kostyuchenko VA, Rossmann MG. Structural analysis of viral nucleocapsids by subtraction of partial projections. J Struct Biol 2006; 157:356-64. [PMID: 17064936 PMCID: PMC1876683 DOI: 10.1016/j.jsb.2006.09.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2006] [Revised: 09/06/2006] [Accepted: 09/06/2006] [Indexed: 11/17/2022]
Abstract
The nucleocapsid of flavivirus particles does not have a recognizable capsid structure when using icosahedral averaging for cryo-electron microscopy structure determinations. The apparent absence of a definitive capsid structure could be due to a lack of synchronization of the symmetry elements of the external glycoprotein layer with those of the core or because the nucleocapsid does not have the same structure within each particle. A technique has been developed to determine the structure of the capsid, and possibly also of the genome, for icosahedral viruses, such as flaviviruses, using cryo-electron microscopy. The method is applicable not only to the analyses of viral cores, but also to the missing structure of multi-component complexes due to symmetry mismatches. The density contributed by external glycoprotein and membrane layers, derived from previously determined three-dimensional icosahedrally averaged reconstructions, was subtracted from the raw images of the virus particles. The resultant difference images were then used for a three-dimensional reconstruction. After appropriate test data sets were constructed and tested, the procedure was applied to examine the nucleocapsids of flaviviruses, which showed that there is no distinct protein density surrounding the genome. Furthermore, there was no evidence of any icosahedral symmetry within the nucleocapsid core.
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Affiliation(s)
- Ying Zhang
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA
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