1
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Datler J, Hansen JM, Thader A, Schlögl A, Bauer LW, Hodirnau VV, Schur FKM. Multi-modal cryo-EM reveals trimers of protein A10 to form the palisade layer in poxvirus cores. Nat Struct Mol Biol 2024; 31:1114-1123. [PMID: 38316877 PMCID: PMC11257981 DOI: 10.1038/s41594-023-01201-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 12/06/2023] [Indexed: 02/07/2024]
Abstract
Poxviruses are among the largest double-stranded DNA viruses, with members such as variola virus, monkeypox virus and the vaccination strain vaccinia virus (VACV). Knowledge about the structural proteins that form the viral core has remained sparse. While major core proteins have been annotated via indirect experimental evidence, their structures have remained elusive and they could not be assigned to individual core features. Hence, which proteins constitute which layers of the core, such as the palisade layer and the inner core wall, has remained enigmatic. Here we show, using a multi-modal cryo-electron microscopy (cryo-EM) approach in combination with AlphaFold molecular modeling, that trimers formed by the cleavage product of VACV protein A10 are the key component of the palisade layer. This allows us to place previously obtained descriptions of protein interactions within the core wall into perspective and to provide a detailed model of poxvirus core architecture. Importantly, we show that interactions within A10 trimers are likely generalizable over members of orthopox- and parapoxviruses.
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Affiliation(s)
- Julia Datler
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Jesse M Hansen
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Andreas Thader
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Alois Schlögl
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Lukas W Bauer
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | | | - Florian K M Schur
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria.
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2
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Krause M, Samolej J, Yakimovich A, Kriston-Vizi J, Huttunen M, Lara-Reyna S, Frickel EM, Mercer J. Vaccinia virus subverts xenophagy through phosphorylation and nuclear targeting of p62. J Cell Biol 2024; 223:e202104129. [PMID: 38709216 PMCID: PMC11076808 DOI: 10.1083/jcb.202104129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 11/13/2023] [Accepted: 02/12/2024] [Indexed: 05/07/2024] Open
Abstract
Autophagy is an essential degradation program required for cell homeostasis. Among its functions is the engulfment and destruction of cytosolic pathogens, termed xenophagy. Not surprisingly, many pathogens use various strategies to circumvent or co-opt autophagic degradation. For poxviruses, it is known that infection activates autophagy, which however is not required for successful replication. Even though these complex viruses replicate exclusively in the cytoplasm, autophagy-mediated control of poxvirus infection has not been extensively explored. Using the prototypic poxvirus, vaccinia virus (VACV), we show that overexpression of the xenophagy receptors p62, NDP52, and Tax1Bp1 restricts poxvirus infection. While NDP52 and Tax1Bp1 were degraded, p62 initially targeted cytoplasmic virions before being shunted to the nucleus. Nuclear translocation of p62 was dependent upon p62 NLS2 and correlated with VACV kinase mediated phosphorylation of p62 T269/S272. This suggests that VACV targets p62 during the early stages of infection to avoid destruction and further implies that poxviruses exhibit multi-layered control of autophagy to facilitate cytoplasmic replication.
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Affiliation(s)
- Melanie Krause
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Jerzy Samolej
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Artur Yakimovich
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Janos Kriston-Vizi
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Moona Huttunen
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Samuel Lara-Reyna
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Eva-Maria Frickel
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Jason Mercer
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
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3
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Aggarwal T, Kondabagil K. Assembly and Evolution of Poxviruses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1451:35-54. [PMID: 38801570 DOI: 10.1007/978-3-031-57165-7_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Poxvirus assembly has been an intriguing area of research for several decades. While advancements in experimental techniques continue to yield fresh insights, many questions are still unresolved. Large genome sizes of up to 380 kbp, asymmetrical structure, an exterior lipid bilayer, and a cytoplasmic life cycle are some notable characteristics of these viruses. Inside the particle are two lateral bodies and a protein wall-bound-biconcave core containing the viral nucleocapsid. The assembly progresses through five major stages-endoplasmic reticulum (ER) membrane alteration and rupture, crescent formation, immature virion formation, genome encapsidation, virion maturation and in a subset of viruses, additional envelopment of the virion prior to its dissemination. Several large dsDNA viruses have been shown to follow a comparable sequence of events. In this chapter, we recapitulate our understanding of the poxvirus morphogenesis process while reviewing the most recent advances in the field. We also briefly discuss how virion assembly aids in our knowledge of the evolutionary links between poxviruses and other Nucleocytoplasmic Large DNA Viruses (NCLDVs).
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Affiliation(s)
- Tanvi Aggarwal
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400076, India
| | - Kiran Kondabagil
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400076, India.
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4
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Zhao Z, Huang Y, Liu C, Zhu D, Gao S, Liu S, Peng R, Zhang Y, Huang X, Qi J, Wong CCL, Zhang X, Wang P, Qin Q, Gao GF. Near-atomic architecture of Singapore grouper iridovirus and implications for giant virus assembly. Nat Commun 2023; 14:2050. [PMID: 37041173 PMCID: PMC10090177 DOI: 10.1038/s41467-023-37681-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 03/28/2023] [Indexed: 04/13/2023] Open
Abstract
Singapore grouper iridovirus (SGIV), one of the nucleocytoviricota viruses (NCVs), is a highly pathogenic iridovirid. SGIV infection results in massive economic losses to the aquaculture industry and significantly threatens global biodiversity. In recent years, high morbidity and mortality in aquatic animals have been caused by iridovirid infections worldwide. Effective control and prevention strategies are urgently needed. Here, we present a near-atomic architecture of the SGIV capsid and identify eight types of capsid proteins. The viral inner membrane-integrated anchor protein colocalizes with the endoplasmic reticulum (ER), supporting the hypothesis that the biogenesis of the inner membrane is associated with the ER. Additionally, immunofluorescence assays indicate minor capsid proteins (mCPs) could form various building blocks with major capsid proteins (MCPs) before the formation of a viral factory (VF). These results expand our understanding of the capsid assembly of NCVs and provide more targets for vaccine and drug design to fight iridovirid infections.
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Affiliation(s)
- Zhennan Zhao
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Youhua Huang
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Congcong Liu
- Cryo-EM Center, Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen, 518112, China
| | - Dongjie Zhu
- School of Life Science, University of Science and Technology of China, Hefei, 230026, China
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shuaixin Gao
- Clinical Research Institute, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, 100730, China
- Department of Human Sciences & James Comprehensive Cancer Center, The Ohio State University, Columbus, 43210, USA
| | - Sheng Liu
- Cryo-EM Center, Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Ruchao Peng
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104, USA
| | - Ya Zhang
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Xiaohong Huang
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Jianxun Qi
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Beijing Life Science Academy, Beijing, 102209, China.
| | - Catherine C L Wong
- Clinical Research Institute, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, 100730, China.
| | - Xinzheng Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Peiyi Wang
- Cryo-EM Center, Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Qiwei Qin
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China.
| | - George F Gao
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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5
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Wang J, Shahed-Ai-Mahmud M, Chen A, Li K, Tan H, Joyce R. An Overview of Antivirals against Monkeypox Virus and Other Orthopoxviruses. J Med Chem 2023; 66:4468-4490. [PMID: 36961984 DOI: 10.1021/acs.jmedchem.3c00069] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2023]
Abstract
The current monkeypox outbreaks during the COVID-19 pandemic have reignited interest in orthopoxvirus antivirals. Monkeypox belongs to the Orthopoxvirus genus of the Poxviridae family, which also includes the variola virus, vaccinia virus, and cowpox virus. Two orally bioavailable drugs, tecovirimat and brincidofovir, have been approved for treating smallpox infections. Given their human safety profiles and in vivo antiviral efficacy in animal models, both drugs have also been recommended to treat monkeypox infection. To facilitate the development of additional orthopoxvirus antivirals, we summarize the antiviral activity, mechanism of action, and mechanism of resistance of orthopoxvirus antivirals. This perspective covers both direct-acting and host-targeting antivirals with an emphasis on drug candidates showing in vivo antiviral efficacy in animal models. We hope to speed the orthopoxvirus antiviral drug discovery by providing medicinal chemists with insights into prioritizing proper drug targets and hits for further development.
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Affiliation(s)
- Jun Wang
- Department of Medicinal Chemistry, Ernest Mario School of Pharmacy, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Md Shahed-Ai-Mahmud
- Department of Medicinal Chemistry, Ernest Mario School of Pharmacy, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Angelo Chen
- Department of Medicinal Chemistry, Ernest Mario School of Pharmacy, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Kan Li
- Department of Medicinal Chemistry, Ernest Mario School of Pharmacy, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Haozhou Tan
- Department of Medicinal Chemistry, Ernest Mario School of Pharmacy, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Ryan Joyce
- Department of Medicinal Chemistry, Ernest Mario School of Pharmacy, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, United States
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6
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Guan H, Gul I, Xiao C, Ma S, Liang Y, Yu D, Liu Y, Liu H, Zhang CY, Li J, Qin P. Emergence, phylogeography, and adaptive evolution of mpox virus. New Microbes New Infect 2023; 52:101102. [PMID: 36815201 PMCID: PMC9937731 DOI: 10.1016/j.nmni.2023.101102] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 02/19/2023] Open
Abstract
Mpox (Monkeypox) is a zoonotic disease caused by mpox virus (MPXV). A multi-country MPXV outbreak in non-endemic demographics was identified in May 2022. A systematic evaluation of MPXV evolutionary trajectory and genetic diversity could be a timely addition to the MPXV diagnostics and prophylaxis. Herein, we integrated a systematic evolution analysis including phylogenomic and phylogeographic, followed by an in-depth analysis of the adaptive evolution and amino acid variations in type I interferon binding protein (IFNα/βBP). Mutations in IFNα/βBP protein may impair its binding capacity, affecting the MPXV immune evasion strategy. Based on the equilibrated data, we found an evolutionary rate of 7.75 × 10 - 5 substitutions/site/year, and an earlier original time (2021.25) of the clade IIb. We further discovered significant genetic variations in MPXV genomes from different regions and obtained six plausible spread trajectories from its intricate viral flow network, implying that North America might have acted as a bridge for the spread of MPXV from Africa to other continents. We identified two amino acids under positive selection in the Rifampicin resistance protein and extracellular enveloped virus (EEV) type-I membrane glycoprotein, indicating a role in adaptive evolution. Our research sheds light on the emergence, dispersal, and adaptive evolution of MPXV, providing theoretical support for mitigating and containing its expansion.
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Affiliation(s)
- Haifei Guan
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Ijaz Gul
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Chufan Xiao
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Shuyue Ma
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Yingshan Liang
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Dongmei Yu
- School of Mechanical, Electrical & Information Engineering, Shandong University, Weihai, Shandong, 264209, China
| | - Ying Liu
- Food Inspection & Quarantine Center, Shenzhen Custom, Shenzhen, Guangdong, 518060, China
| | - Hong Liu
- Food Inspection & Quarantine Center, Shenzhen Custom, Shenzhen, Guangdong, 518060, China
| | - Can Yang Zhang
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Juan Li
- Advanced Research Institute for Multidisciplinary Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Peiwu Qin
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
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7
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Hernandez-Gonzalez M, Calcraft T, Nans A, Rosenthal PB, Way M. A succession of two viral lattices drives vaccinia virus assembly. PLoS Biol 2023; 21:e3002005. [PMID: 36862727 PMCID: PMC10013923 DOI: 10.1371/journal.pbio.3002005] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 03/14/2023] [Accepted: 01/19/2023] [Indexed: 03/03/2023] Open
Abstract
During its cytoplasmic replication, vaccinia virus assembles non-infectious spherical immature virions (IV) coated by a viral D13 lattice. Subsequently, IV mature into infectious brick-shaped intracellular mature virions (IMV) that lack D13. Here, we performed cryo-electron tomography (cryo-ET) of frozen-hydrated vaccinia-infected cells to structurally characterise the maturation process in situ. During IMV formation, a new viral core forms inside IV with a wall consisting of trimeric pillars arranged in a new pseudohexagonal lattice. This lattice appears as a palisade in cross-section. As maturation occurs, which involves a 50% reduction in particle volume, the viral membrane becomes corrugated as it adapts to the newly formed viral core in a process that does not appear to require membrane removal. Our study suggests that the length of this core is determined by the D13 lattice and that the consecutive D13 and palisade lattices control virion shape and dimensions during vaccinia assembly and maturation.
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Affiliation(s)
- Miguel Hernandez-Gonzalez
- Cellular signalling and cytoskeletal function laboratory, The Francis Crick Institute, London, United Kingdom
| | - Thomas Calcraft
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Andrea Nans
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Peter B Rosenthal
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Michael Way
- Cellular signalling and cytoskeletal function laboratory, The Francis Crick Institute, London, United Kingdom
- Department of Infectious Disease, Imperial College, London, United Kingdom
- * E-mail:
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8
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Lokhande KB, Shrivastava A, Singh A. In silico
discovery of potent inhibitors against monkeypox's major structural proteins. J Biomol Struct Dyn 2023; 41:14259-14274. [PMID: 36841550 DOI: 10.1080/07391102.2023.2183342] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 02/07/2023] [Indexed: 02/27/2023]
Abstract
Monkeypox virus (MPXV) outbreak in non-endemic countries is a worldwide public health emergency. An enveloped double-stranded DNA virus belongs to the genus Orth poxvirus. A viral zoonotic infection known as monkeypox has been a serious risk to public health, especially in Africa. However, it has recently spread to other continents, so it might soon become a worldwide problem. There is an increased risk of transmission of the virus because there is a lack of effective treatment that cures the disease. To stop the multi-country outbreak from spreading, it is important to discover effective medications urgently. The objective of the current study is to swiftly find new treatments for the monkeypox virus using advanced computational approaches. By investigating five potential MPXV targets (DNA ligase, Palmytilated Extracellular Enveloped Virus (EEV) membrane protein, Scaffold protein D13, Thymidylate Kinase, and Viral core cysteine proteinase), this research was carried out using cutting-edge computational techniques against human monkeypox virus infection. Here we present the accurate 3D structures and their binding cavities of the selected targets with higher confidence using AlphaFold 2 and SiteMap analysis. Molecular docking and MD simulation analysis revealed the top five potential lead compounds with higher binding affinity and stability toward selected targets. Binding free energy calculations and other essential dynamics analysis supports the finding. The selected lead compounds utilizing virtual screening and drug repurposing approach reported in this study are beneficial for medical scientists and experimental biologists in drug development for the treatment of human MPXV.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Kiran Bharat Lokhande
- Translational Bioinformatics and Computational Genomics Research Lab, Department of Life Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, Uttar Pradesh, India
| | - Ashish Shrivastava
- Translational Bioinformatics and Computational Genomics Research Lab, Department of Life Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, Uttar Pradesh, India
| | - Ashutosh Singh
- Translational Bioinformatics and Computational Genomics Research Lab, Department of Life Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, Uttar Pradesh, India
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9
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Current Insights into Diagnosis, Prevention Strategies, Treatment, Therapeutic Targets, and Challenges of Monkeypox (Mpox) Infections in Human Populations. LIFE (BASEL, SWITZERLAND) 2023; 13:life13010249. [PMID: 36676198 PMCID: PMC9863601 DOI: 10.3390/life13010249] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 01/18/2023]
Abstract
In the wake of the emergence and worldwide respread of a viral infection called Monkeypox (Mpox), there is a serious threat to the health and safety of the global population. This viral infection was endemic to the western and central parts of Africa, but has recently spread out of this endemic area to various countries, including the United Kingdom (UK), Portugal, Spain, the United States of America (USA), Canada, Sweden, Belgium, Italy, Australia, Germany, France, the Netherlands, Israel, and Mexico. This is a timely review focusing on recent findings and developments in the epidemiology, clinical features, therapeutic targets, diagnosis, prevention mechanisms, research challenges and possible treatment for Mpox. To date (29 November 2022), there have been around 81,225 reported cases of Mpox. In most cases, this illness is mild; however, there is a fatality rate ranging from 1 to 10%, which might be increased due to associated complications and/or secondary infections. There is a real challenge in the diagnosis of Mpox, since its symptoms are very similar to those of other infections, including smallpox and chickenpox. Generally, to prevent/limit the risk and transmission of Mpox, the detection and isolation of infected individuals, as well as hand hygiene and cleanliness, are essential and effective approaches to control/combat this viral infection. Nevertheless, updated information about Mpox from different angles is lacking. Thus, this review provides updated and comprehensive information about the Mpox illness, which should highlight the global burden, pathogenicity, symptoms, diagnosis, prevention measures and possible treatment of this emerging disease.
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10
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Cryo-EM structure of ssDNA bacteriophage ΦCjT23 provides insight into early virus evolution. Nat Commun 2022; 13:7478. [PMID: 36463224 PMCID: PMC9719478 DOI: 10.1038/s41467-022-35123-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 11/18/2022] [Indexed: 12/07/2022] Open
Abstract
The origin of viruses remains an open question. While lack of detectable sequence similarity hampers the analysis of distantly related viruses, structural biology investigations of conserved capsid protein structures facilitate the study of distant evolutionary relationships. Here we characterize the lipid-containing ssDNA temperate bacteriophage ΦCjT23, which infects Flavobacterium sp. (Bacteroidetes). We report ΦCjT23-like sequences in the genome of strains belonging to several Flavobacterium species. The virion structure determined by cryogenic electron microscopy reveals similarities to members of the viral kingdom Bamfordvirae that currently consists solely of dsDNA viruses with a major capsid protein composed of two upright β-sandwiches. The minimalistic structure of ΦCjT23 suggests that this phage serves as a model for the last common ancestor between ssDNA and dsDNA viruses in the Bamfordvirae. Both ΦCjT23 and the related phage FLiP infect Flavobacterium species found in several environments, suggesting that these types of viruses have a global distribution and a shared evolutionary origin. Detailed comparisons to related, more complex viruses not only expand our knowledge about this group of viruses but also provide a rare glimpse into early virus evolution.
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11
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Hyun J. Poxvirus under the eyes of electron microscope. Appl Microsc 2022; 52:11. [DOI: 10.1186/s42649-022-00080-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/10/2022] [Indexed: 11/15/2022] Open
Abstract
AbstractZoonotic poxvirus infections pose significant threat to human health as we have witnessed recent spread of monkeypox. Therefore, insights into molecular mechanism behind poxvirus replication cycle are needed for the development of efficient antiviral strategies. Virion assembly is one of the key steps that determine the fate of replicating poxviruses. However, in-depth understanding of poxvirus assembly is challenging due to the complex nature of multi-step morphogenesis and heterogeneous virion structures. Despite these challenges, decades of research have revealed virion morphologies at various maturation stages, critical protein components and interactions with host cell compartments. Transmission electron microscopy has been employed as an indispensable tool for the examination of virion morphology, and more recently for the structure determination of protein complexes. In this review, we describe some of the major findings in poxvirus morphogenesis and the contributions of continuously advancing electron microscopy techniques.
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12
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Lam HYI, Guan JS, Mu Y. In Silico Repurposed Drugs against Monkeypox Virus. Molecules 2022; 27:molecules27165277. [PMID: 36014515 PMCID: PMC9415168 DOI: 10.3390/molecules27165277] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/05/2022] [Accepted: 08/12/2022] [Indexed: 12/30/2022] Open
Abstract
Monkeypox is an emerging epidemic of concern. The disease is caused by the monkeypox virus and an increasing global incidence with a 2022 outbreak that has spread to Europe amid the COVID-19 pandemic. The new outbreak is associated with novel, previously undiscovered mutations and variants. Currently, the US Food and Drug Administration (FDA) approved poxvirus treatment involves the use of tecovirimat. However, there is otherwise limited pharmacopoeia and research interest in monkeypox. In this study, virtual screening and molecular dynamics were employed to explore the potential repurposing of multiple drugs previously approved by the FDA or other jurisdictions for other applications. Several drugs are predicted to tightly bind to viral proteins, which are crucial in viral replication, including molecules which show high potential for binding the monkeypox D13L capsid protein, whose inhibition has previously been demonstrated to suppress viral replication.
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Affiliation(s)
- Hilbert Yuen In Lam
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Dr, Singapore 637551, Singapore
- A*STAR Skin Research Labs, Agency of Science, Technology and Research, Singapore, 11 Mandalay Rd, #17-01, Singapore 308232, Singapore
| | - Jia Sheng Guan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Dr, Singapore 637551, Singapore
| | - Yuguang Mu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Dr, Singapore 637551, Singapore
- Correspondence:
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13
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Schönborn L, Greinacher A. Longitudinal Aspects of VITT. Semin Hematol 2022; 59:108-114. [PMID: 35512899 PMCID: PMC8898788 DOI: 10.1053/j.seminhematol.2022.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/16/2022] [Accepted: 03/01/2022] [Indexed: 02/08/2023]
Abstract
In hundreds of patients worldwide, vaccination against COVID-19 with adenovirus vector vaccines (ChAdOx1 nCoV-19; Ad26.COV2.S) triggered platelet-activating anti-platelet factor 4 (PF4) antibodies inducing vaccine-induced immune thrombotic thrombocytopenia (VITT). In most VITT patients, platelet-activating anti-PF4-antibodies are transient and the disorder is discrete and non-recurring. However, in some patients platelet-activating antibodies persist, associated with recurrent thrombocytopenia and sometimes with relapse of thrombosis despite therapeutic-dose anticoagulation. Anti-PF4 IgG antibodies measured by enzyme-immunoassay (EIA) are usually detectable for longer than platelet-activating antibodies in functional assays, but duration of detectability is highly assay-dependent. As more than 1 vaccination dose against COVID-19 is required to achieve sufficient protection, at least 69 VITT patients have undergone subsequent vaccination with an mRNA vaccine, with no relevant subsequent increase in anti-PF4 antibody titers, thrombocytopenia, or thrombotic complications. Also, re-exposure to adenoviral vector-based vaccines in 5 VITT patients was not associated with adverse reactions. Although data are limited, vaccination against influenza also appears to be safe. SARS-CoV-2 infection reported in 1 patient with preceding VITT did not influence anti-PF4 antibody levels. We discuss how these temporal characteristics of VITT provide insights into pathogenesis.
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Affiliation(s)
| | - Andreas Greinacher
- Corresponding author. Andreas Greinacher, Professor, Institut für Transfusionsmedizin, Universitätsmedizin Greifswald, Sauerbruchstraße, Greifswald, D-17489, Germany. Tel.: +49 3834 865482; Fax: +49 3834 865489
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14
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Hyun J, Matsunami H, Kim TG, Wolf M. Assembly mechanism of the pleomorphic immature poxvirus scaffold. Nat Commun 2022; 13:1704. [PMID: 35361762 PMCID: PMC8971458 DOI: 10.1038/s41467-022-29305-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 03/04/2022] [Indexed: 11/26/2022] Open
Abstract
In Vaccinia virus (VACV), the prototype poxvirus, scaffold protein D13 forms a honeycomb-like lattice on the viral membrane that results in formation of the pleomorphic immature virion (IV). The structure of D13 is similar to those of major capsid proteins that readily form icosahedral capsids in nucleocytoplasmic large DNA viruses (NCLDVs). However, the detailed assembly mechanism of the nonicosahedral poxvirus scaffold has never been understood. Here we show the cryo-EM structures of the D13 trimer and scaffold intermediates produced in vitro. The structures reveal that the displacement of the short N-terminal α-helix is critical for initiation of D13 self-assembly. The continuous curvature of the IV is mediated by electrostatic interactions that induce torsion between trimers. The assembly mechanism explains the semiordered capsid-like arrangement of D13 that is distinct from icosahedral NCLDVs. Our structures explain how a single protein can self-assemble into different capsid morphologies and represent a local exception to the universal Caspar-Klug theory of quasi-equivalence. Immature poxviruses are characterized by nonicosahedral semiordered protein scaffolds critical for morphogenesis. Here, the authors use cryo-EM structures of Vaccinia virus D13 scaffold intermediates to explain their assembly mechanism.
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Affiliation(s)
- Jaekyung Hyun
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, 904-0495, Onna-son, Okinawa, Japan. .,Department of Convergence Medicine, School of Medicine, Pusan National University, 50612, Yangsan-si, Gyeongsangnamdo, Republic of Korea.
| | - Hideyuki Matsunami
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, 904-0495, Onna-son, Okinawa, Japan
| | - Tae Gyun Kim
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, 904-0495, Onna-son, Okinawa, Japan.,Center for Vaccine Commercialization, R&D Planning Team, Gyeongbuk Institute for Bio Industry, 36618, Andong-si, Gyeongsanbukdo, Republic of Korea
| | - Matthias Wolf
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, 904-0495, Onna-son, Okinawa, Japan. .,Institute of Biological Chemistry, Academia Sinica, 128 Academia Road Sec. 2, 115, Taipei, Taiwan.
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15
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Krupovic M, Makarova KS, Koonin EV. Cellular homologs of the double jelly-roll major capsid proteins clarify the origins of an ancient virus kingdom. Proc Natl Acad Sci U S A 2022; 119:e2120620119. [PMID: 35078938 PMCID: PMC8812541 DOI: 10.1073/pnas.2120620119] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 12/18/2021] [Indexed: 12/26/2022] Open
Abstract
Viruses are a distinct type of replicators that encode structural proteins encasing virus genomes in virions. For some of the widespread virus capsid proteins and other major components of virions, likely ancestors encoded by cellular life forms are identifiable. In particular, one of the most common capsid proteins, with the single jelly-roll (SJR) fold, appears to have evolved from a particular family of cellular carbohydrate-binding proteins. However, the double jelly-roll major capsid protein (DJR-MCP), the hallmark of the enormously diverse viruses of the kingdom Bamfordvirae within the realm Varidnaviria, which includes bacterial and archaeal icosahedral viruses as well as eukaryotic giant viruses, has been perceived as a virus innovation that evolved by duplication and fusion of the SJR capsid proteins. Here we employ protein structure comparison to show that the DJR fold is represented in several widespread families of cellular proteins, including several groups of carbohydrate-active enzymes. We show that DJR-MCPs share a common ancestry with a distinct family of bacterial DJR proteins (DUF2961) involved in carbohydrate metabolism. Based on this finding, we propose a scenario in which bamfordviruses evolved from nonviral replicators, in particular plasmids, by recruiting a host protein for capsid formation. This sequence of events appears to be the general route of virus origin. The results of this work indicate that virus kingdoms Bamfordvirae, with the DJR-MCPs, and Helvetiavirae that possess two SJR-MCPs, have distinct origins, suggesting a reappraisal of the realm Varidnaviria.
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Affiliation(s)
- Mart Krupovic
- Archaeal Virology Unit, Institut Pasteur, Université de Paris, F-75015 Paris, France;
| | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894
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16
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Mönttinen HAM, Bicep C, Williams TA, Hirt RP. The genomes of nucleocytoplasmic large DNA viruses: viral evolution writ large. Microb Genom 2021; 7. [PMID: 34542398 PMCID: PMC8715426 DOI: 10.1099/mgen.0.000649] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The nucleocytoplasmic large DNA viruses (NCLDVs) are a diverse group that currently contain the largest known virions and genomes, also called giant viruses. The first giant virus was isolated and described nearly 20 years ago. Their genome sizes were larger than for any other known virus at the time and it contained a number of genes that had not been previously described in any virus. The origin and evolution of these unusually complex viruses has been puzzling, and various mechanisms have been put forward to explain how some NCLDVs could have reached genome sizes and coding capacity overlapping with those of cellular microbes. Here we critically discuss the evidence and arguments on this topic. We have also updated and systematically reanalysed protein families of the NCLDVs to further study their origin and evolution. Our analyses further highlight the small number of widely shared genes and extreme genomic plasticity among NCLDVs that are shaped via combinations of gene duplications, deletions, lateral gene transfers and de novo creation of protein-coding genes. The dramatic expansions of the genome size and protein-coding gene capacity characteristic of some NCLDVs is now increasingly understood to be driven by environmental factors rather than reflecting relationships to an ancient common ancestor among a hypothetical cellular lineage. Thus, the evolution of NCLDVs is writ large viral, and their origin, like all other viral lineages, remains unknown.
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Affiliation(s)
- Heli A M Mönttinen
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.,Present address: Institute of Biotechnology, Helsinki Institute of Life Sciences (HiLIFE), University of Helsinki, Viikki Biocenter 2, Helsinki 00014, Finland
| | - Cedric Bicep
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.,Present address: Université Clermont Auvergne, CNRS, LMGE, F-63000 Clermont Ferrand, France
| | - Tom A Williams
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.,School of Biological Sciences, University of Bristol, 24 Tyndall Ave., Bristol, BS8 1TH, UK
| | - Robert P Hirt
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
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17
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Structure-Based Deep Mining Reveals First-Time Annotations for 46 Percent of the Dark Annotation Space of the 9,671-Member Superproteome of the Nucleocytoplasmic Large DNA Viruses. J Virol 2020; 94:JVI.00854-20. [PMID: 32999026 DOI: 10.1128/jvi.00854-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 09/16/2020] [Indexed: 12/20/2022] Open
Abstract
We conducted an exhaustive search for three-dimensional structural homologs to the proteins of 20 key phylogenetically distinct nucleocytoplasmic DNA viruses (NCLDV). Structural matches covered 429 known protein domain superfamilies, with the most highly represented being ankyrin repeat, P-loop NTPase, F-box, protein kinase, and membrane occupation and recognition nexus (MORN) repeat. Domain superfamily diversity correlated with genome size, but a diversity of around 200 superfamilies appeared to correlate with an abrupt switch to paralogization. Extensive structural homology was found across the range of eukaryotic RNA polymerase II subunits and their associated basal transcription factors, with the coordinated gain and loss of clusters of subunits on a virus-by-virus basis. The total number of predicted endonucleases across the 20 NCLDV was nearly quadrupled from 36 to 132, covering much of the structural and functional diversity of endonucleases throughout the biosphere in DNA restriction, repair, and homing. Unexpected findings included capsid protein-transcription factor chimeras; endonuclease chimeras; enzymes for detoxification; antimicrobial peptides and toxin-antitoxin systems associated with symbiosis, immunity, and addiction; and novel proteins for membrane abscission and protein turnover.IMPORTANCE We extended the known annotation space for the NCLDV by 46%, revealing high-probability structural matches for fully 45% of the 9,671 query proteins and confirming up to 98% of existing annotations per virus. The most prevalent protein families included ankyrin repeat- and MORN repeat-containing proteins, many of which included an F-box, suggesting extensive host cell modulation among the NCLDV. Regression suggested a minimum requirement for around 36 protein structural superfamilies for a viable NCLDV, and beyond around 200 superfamilies, genome expansion by the acquisition of new functions was abruptly replaced by paralogization. We found homologs to herpesvirus surface glycoprotein gB in cytoplasmic viruses. This study provided the first prediction of an endonuclease in 10 of the 20 viruses examined; the first report in a virus of a phenolic acid decarboxylase, proteasomal subunit, or cysteine knot (defensin) protein; and the first report of a prokaryotic-type ribosomal protein in a eukaryotic virus.
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18
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Xian Y, Avila R, Pant A, Yang Z, Xiao C. The Role of Tape Measure Protein in Nucleocytoplasmic Large DNA Virus Capsid Assembly. Viral Immunol 2020; 34:41-48. [PMID: 33074779 DOI: 10.1089/vim.2020.0038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Nucleocytoplasmic large DNA viruses (NCLDVs) are a group of large viruses that infect a wide range of hosts, from animals to protists. These viruses are grouped together in NCLDV based on genomic sequence analyses. They share a set of essential genes for virion morphogenesis and replication. Most NCLDVs generally have large physical sizes while their morphologies vary in different families, such as icosahedral, brick, or oval shape, raising the question of the possible regulatory factor on their morphogenesis. The capsids of icosahedral NCLDVs are assembled from small building blocks, named capsomers, which are the trimeric form of the major capsid proteins. Note that the capsids of immature poxvirus are spherical even though they are assembled from capsomers that share high structural conservation with those icosahedral NCLDVs. The recently published high resolution structure of NCLDVs, Paramecium bursaria Chlorella virus 1 and African swine fever virus, described the intensive network of minor capsid proteins that are located underneath the capsomers. Among these minor proteins is the elongated tape measure protein (TmP) that spans from one icosahedral fivefold vertex to another. In this study, we focused on the critical roles that TmP plays in the assembly of icosahedral NCLDV capsids, answering a question raised in a previously proposed spiral mechanism. Interestingly, basic local alignment search on the TmPs showed no significant hits in poxviruses, which might be the factor that differentiates poxviruses and icosahedral NCLDVs in their morphogenesis.
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Affiliation(s)
- Yuejiao Xian
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, Texas, USA
| | - Ricardo Avila
- Bioinformatics Program, University of Texas at El Paso, El Paso, Texas, USA
| | - Anil Pant
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Zhilong Yang
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Chuan Xiao
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, Texas, USA
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19
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Ravantti JJ, Martinez-Castillo A, Abrescia NG. Superimposition of Viral Protein Structures: A Means to Decipher the Phylogenies of Viruses. Viruses 2020; 12:v12101146. [PMID: 33050291 PMCID: PMC7600307 DOI: 10.3390/v12101146] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/02/2020] [Accepted: 10/02/2020] [Indexed: 02/07/2023] Open
Abstract
Superimposition of protein structures is key in unravelling structural homology across proteins whose sequence similarity is lost. Structural comparison provides insights into protein function and evolution. Here, we review some of the original findings and thoughts that have led to the current established structure-based phylogeny of viruses: starting from the original observation that the major capsid proteins of plant and animal viruses possess similar folds, to the idea that each virus has an innate “self”. This latter idea fueled the conceptualization of the PRD1-adenovirus lineage whose members possess a major capsid protein (innate “self”) with a double jelly roll fold. Based on this approach, long-range viral evolutionary relationships can be detected allowing the virosphere to be classified in four structure-based lineages. However, this process is not without its challenges or limitations. As an example of these hurdles, we finally touch on the difficulty of establishing structural “self” traits for enveloped viruses showcasing the coronaviruses but also the power of structure-based analysis in the understanding of emerging viruses
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Affiliation(s)
- Janne J. Ravantti
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, FI-00014 Helsinki, Finland;
| | - Ane Martinez-Castillo
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160 Derio, Spain;
| | - Nicola G.A. Abrescia
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160 Derio, Spain;
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence: ; Tel.: +34-946572502
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20
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Xian Y, Xiao C. Current capsid assembly models of icosahedral nucleocytoviricota viruses. Adv Virus Res 2020; 108:275-313. [PMID: 33837719 PMCID: PMC8328511 DOI: 10.1016/bs.aivir.2020.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Nucleocytoviricota viruses (NCVs) belong to a newly established phylum originally grouped as Nucleocytoplasmic large DNA viruses. NCVs are unique because of their large and complicated genomes that contain cellular genes with homologs from all kingdoms of life, raising intensive debates on their evolutional origins. Many NCVs pack their genomes inside massive icosahedral capsids assembled from thousands of proteins. Studying the assembly mechanism of such capsids has been challenging until breakthroughs from structural studies. Subsequently, several models of the capsid assembly were proposed, which provided some interesting insights on this elaborate process. In this review, we discuss three of the most recent assembly models as well as supporting experimental observations. Furthermore, we propose a new model that combines research developments from multiple sources. Investigation of the assembly process of these vast NCV capsids will facilitate future deciphering of the molecular mechanisms driving the formation of similar supramolecular complexes.
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Affiliation(s)
- Yuejiao Xian
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, Texas, United States
| | - Chuan Xiao
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, Texas, United States.
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21
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Mata CP, Rodríguez JM, Suzuki N, Castón JR. Structure and assembly of double-stranded RNA mycoviruses. Adv Virus Res 2020; 108:213-247. [PMID: 33837717 DOI: 10.1016/bs.aivir.2020.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mycoviruses are a diverse group that includes ssRNA, dsRNA, and ssDNA viruses, with or without a protein capsid, as well as with a complex envelope. Most mycoviruses are transmitted by cytoplasmic interchange and are thought to lack an extracellular phase in their infection cycle. Structural analysis has focused on dsRNA mycoviruses, which usually package their genome in a 120-subunit T=1 icosahedral capsid, with a capsid protein (CP) dimer as the asymmetric unit. The atomic structure is available for four dsRNA mycovirus from different families: Saccharomyces cerevisiae virus L-A (ScV-L-A), Penicillium chrysogenum virus (PcV), Penicillium stoloniferum virus F (PsV-F), and Rosellinia necatrix quadrivirus 1 (RnQV1). Their capsids show structural variations of the same framework, with asymmetric or symmetric CP dimers respectively for ScV-L-A and PsV-F, dimers of similar domains of a single CP for PcV, or of two different proteins for RnQV1. The CP dimer is the building block, and assembly proceeds through dimers of dimers or pentamers of dimers, in which the genome is packed as ssRNA by interaction with CP and/or viral polymerase. These capsids remain structurally undisturbed throughout the viral cycle. The T=1 capsid participates in RNA synthesis, organizing the viral polymerase (1-2 copies) and a single loosely packaged genome segment. It also acts as a molecular sieve, to allow the passage of viral transcripts and nucleotides, but to prevent triggering of host defense mechanisms. Due to the close mycovirus-host relationship, CP evolved to allocate peptide insertions with enzyme activity, as reflected in a rough outer capsid surface.
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Affiliation(s)
- Carlos P Mata
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain; Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Javier M Rodríguez
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - Nobuhiro Suzuki
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - José R Castón
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.
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22
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Koonin EV, Dolja VV, Krupovic M, Varsani A, Wolf YI, Yutin N, Zerbini FM, Kuhn JH. Global Organization and Proposed Megataxonomy of the Virus World. Microbiol Mol Biol Rev 2020; 84:e00061-19. [PMID: 32132243 PMCID: PMC7062200 DOI: 10.1128/mmbr.00061-19] [Citation(s) in RCA: 324] [Impact Index Per Article: 81.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Viruses and mobile genetic elements are molecular parasites or symbionts that coevolve with nearly all forms of cellular life. The route of virus replication and protein expression is determined by the viral genome type. Comparison of these routes led to the classification of viruses into seven "Baltimore classes" (BCs) that define the major features of virus reproduction. However, recent phylogenomic studies identified multiple evolutionary connections among viruses within each of the BCs as well as between different classes. Due to the modular organization of virus genomes, these relationships defy simple representation as lines of descent but rather form complex networks. Phylogenetic analyses of virus hallmark genes combined with analyses of gene-sharing networks show that replication modules of five BCs (three classes of RNA viruses and two classes of reverse-transcribing viruses) evolved from a common ancestor that encoded an RNA-directed RNA polymerase or a reverse transcriptase. Bona fide viruses evolved from this ancestor on multiple, independent occasions via the recruitment of distinct cellular proteins as capsid subunits and other structural components of virions. The single-stranded DNA (ssDNA) viruses are a polyphyletic class, with different groups evolving by recombination between rolling-circle-replicating plasmids, which contributed the replication protein, and positive-sense RNA viruses, which contributed the capsid protein. The double-stranded DNA (dsDNA) viruses are distributed among several large monophyletic groups and arose via the combination of distinct structural modules with equally diverse replication modules. Phylogenomic analyses reveal the finer structure of evolutionary connections among RNA viruses and reverse-transcribing viruses, ssDNA viruses, and large subsets of dsDNA viruses. Taken together, these analyses allow us to outline the global organization of the virus world. Here, we describe the key aspects of this organization and propose a comprehensive hierarchical taxonomy of viruses.
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Affiliation(s)
- Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Valerian V Dolja
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA
| | - Mart Krupovic
- Institut Pasteur, Archaeal Virology Unit, Department of Microbiology, Paris, France
| | - Arvind Varsani
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, Arizona, USA
- Structural Biology Research Unit, Department of Clinical Laboratory Sciences, University of Cape Town, Observatory, Cape Town, South Africa
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Natalya Yutin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - F Murilo Zerbini
- Departamento de Fitopatologia/Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
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23
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Luque D, Castón JR. Cryo-electron microscopy for the study of virus assembly. Nat Chem Biol 2020; 16:231-239. [PMID: 32080621 DOI: 10.1038/s41589-020-0477-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 01/13/2020] [Indexed: 12/11/2022]
Abstract
Although viruses are extremely diverse in shape and size, evolution has led to a limited number of viral classes or lineages, which is probably linked to the assembly constraints of a viable capsid. Viral assembly mechanisms are restricted to two general pathways, (i) co-assembly of capsid proteins and single-stranded nucleic acids and (ii) a sequential mechanism in which scaffolding-mediated capsid precursor assembly is followed by genome packaging. Cryo-electron microscopy (cryo-EM) and cryo-electron tomography (cryo-ET), which are revolutionizing structural biology, are central to determining the high-resolution structures of many viral assemblies as well as those of assembly intermediates. This wealth of cryo-EM data has also led to the development and redesign of virus-based platforms for biomedical and biotechnological applications. In this Review, we will discuss recent viral assembly analyses by cryo-EM and cryo-ET showing how natural assembly mechanisms are used to encapsulate heterologous cargos including chemicals, enzymes, and/or nucleic acids for a variety of nanotechnological applications.
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Affiliation(s)
- Daniel Luque
- Centro Nacional de Microbiología/ISCIII, Majadahonda, Madrid, Spain
| | - José R Castón
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología (CNB-CSIC), Campus Cantoblanco, Madrid, Spain.
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24
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Ng WM, Stelfox AJ, Bowden TA. Unraveling virus relationships by structure-based phylogenetic classification. Virus Evol 2020; 6:veaa003. [PMID: 32064119 PMCID: PMC7015158 DOI: 10.1093/ve/veaa003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Delineation of the intricacies of protein function from macromolecular structure constitutes a continual obstacle in the study of cell and pathogen biology. Structure-based phylogenetic analysis has emerged as a powerful tool for addressing this challenge, allowing the detection and quantification of conserved architectural properties between proteins, including those with low or no detectable sequence homology. With a focus on viral protein structure, we highlight how a number of investigations have utilized this powerful method to infer common functionality and ancestry.
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Affiliation(s)
- Weng M Ng
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Alice J Stelfox
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Thomas A Bowden
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
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25
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Andrés G, Charro D, Matamoros T, Dillard RS, Abrescia NGA. The cryo-EM structure of African swine fever virus unravels a unique architecture comprising two icosahedral protein capsids and two lipoprotein membranes. J Biol Chem 2020; 295:1-12. [PMID: 31649031 PMCID: PMC6952596 DOI: 10.1074/jbc.ac119.011196] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/22/2019] [Indexed: 11/06/2022] Open
Abstract
African swine fever virus (ASFV) is a complex nucleocytoplasmic large DNA virus (NCLDV) that causes a devastating swine disease currently present in many countries of Africa, Europe, and Asia. Despite intense research efforts, relevant gaps in the architecture of the infectious virus particle remain. Here, we used single-particle cryo-EM to analyze the three-dimensional structure of the mature ASFV particle. Our results show that the ASFV virion, with a radial diameter of ∼2,080 Å, encloses a genome-containing nucleoid surrounded by two distinct icosahedral protein capsids and two lipoprotein membranes. The outer capsid forms a hexagonal lattice (triangulation number T = 277) composed of 8,280 copies of the double jelly-roll major capsid protein (MCP) p72, arranged in trimers displaying a pseudo-hexameric morphology, and of 60 copies of a penton protein at the vertices. The inner protein layer, organized as a T = 19 capsid, confines the core shell, and it is composed of the mature products derived from the ASFV polyproteins pp220 and pp62. Also, an icosahedral membrane lies between the two protein layers, whereas a pleomorphic envelope wraps the outer capsid. This high-level organization confers to ASFV a unique architecture among the NCLDVs that likely reflects the complexity of its infection process and may help explain current challenges in controlling it.
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Affiliation(s)
- German Andrés
- Centro de Biología Molecular Severo Ochoa, CSIC and Universidad Autónoma de Madrid, 28049 Madrid, Spain.
| | - Diego Charro
- Molecular Recognition and Host-Pathogen Interactions Programme, CIC bioGUNE, CIBERehd, Bizkaia Technology Park, 48160 Derio, Spain
| | - Tania Matamoros
- Centro de Biología Molecular Severo Ochoa, CSIC and Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Rebecca S Dillard
- NeCEN, Institute of Biology Leiden, Leiden University, 2333_CC Leiden, Netherlands
| | - Nicola G A Abrescia
- Molecular Recognition and Host-Pathogen Interactions Programme, CIC bioGUNE, CIBERehd, Bizkaia Technology Park, 48160 Derio, Spain; IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain.
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26
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Ismail AM, Zhou X, Dyer DW, Seto D, Rajaiya J, Chodosh J. Genomic foundations of evolution and ocular pathogenesis in human adenovirus species D. FEBS Lett 2019; 593:3583-3608. [PMID: 31769017 PMCID: PMC7185199 DOI: 10.1002/1873-3468.13693] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/16/2019] [Accepted: 11/20/2019] [Indexed: 12/27/2022]
Abstract
Human adenovirus commonly causes infections of respiratory, gastrointestinal, genitourinary, and ocular surface mucosae. Although most adenovirus eye infections are mild and self-limited, specific viruses within human adenovirus species D are associated with epidemic keratoconjunctivitis (EKC), a severe and highly contagious ocular surface infection, which can lead to chronic and/or recurrent, visually disabling keratitis. In this review, we discuss the links between adenovirus ontogeny, genomics, immune responses, and corneal pathogenesis, for those viruses that cause EKC.
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Affiliation(s)
- Ashrafali M. Ismail
- Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
| | - Xiaohong Zhou
- Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
| | - David W. Dyer
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Donald Seto
- Bioinformatics and Computational Biology Program, School of Systems Biology, George Mason University, Manassas, Virginia, USA
| | - Jaya Rajaiya
- Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
| | - James Chodosh
- Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
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27
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Liu S, Luo Y, Wang Y, Li S, Zhao Z, Bi Y, Sun J, Peng R, Song H, Zhu D, Sun Y, Li S, Zhang L, Wang W, Sun Y, Qi J, Yan J, Shi Y, Zhang X, Wang P, Qiu HJ, Gao GF. Cryo-EM Structure of the African Swine Fever Virus. Cell Host Microbe 2019; 26:836-843.e3. [PMID: 31787524 DOI: 10.1016/j.chom.2019.11.004] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/01/2019] [Accepted: 11/07/2019] [Indexed: 11/18/2022]
Abstract
African swine fever virus (ASFV) is a large double-stranded DNA virus with an icosahedral multilayered structure. ASFV causes a lethal swine hemorrhagic disease and is currently responsible for widespread damage to the pork industry in Asia. Neither vaccines nor antivirals are available and the molecular characterization of the ASFV particle is outstanding. Here, we describe the cryogenic electron microscopy (cryo-EM) structure of the icosahedral capsid of ASFV at 4.6-Å. The ASFV particle consists of 8,280 copies of the major capsid protein p72, 60 copies of the penton protein, and at least 8,340 minor capsid proteins, of which there might be 3 different types. Like other nucleocytoplasmic large DNA viruses, the minor capsid proteins form a hexagonal network below the outer capsid shell, functioning as stabilizers by "gluing" neighboring capsomers together. Our findings provide a comprehensive molecular model of the ASFV capsid architecture that will contribute to the future development of countermeasures, including vaccines.
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Affiliation(s)
- Sheng Liu
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuzi Luo
- State Key Laboratory of Veterinary Biotechnology and National High-Containment Laboratory for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Yajuan Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Shihua Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhennan Zhao
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuhai Bi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Center for Influenza Research and Early-warning (CASCIRE), CAS-TWAS Center of Excellence for Emerging Infectious Diseases (CEEID), Chinese Academy of Sciences, Beijing 100101, China
| | - Junqing Sun
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Ruchao Peng
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hao Song
- Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China
| | - Dongjie Zhu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuan Sun
- State Key Laboratory of Veterinary Biotechnology and National High-Containment Laboratory for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Su Li
- State Key Laboratory of Veterinary Biotechnology and National High-Containment Laboratory for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Li Zhang
- State Key Laboratory of Veterinary Biotechnology and National High-Containment Laboratory for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Wei Wang
- State Key Laboratory of Veterinary Biotechnology and National High-Containment Laboratory for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Yeping Sun
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jianxun Qi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jinghua Yan
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yi Shi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Center for Influenza Research and Early-warning (CASCIRE), CAS-TWAS Center of Excellence for Emerging Infectious Diseases (CEEID), Chinese Academy of Sciences, Beijing 100101, China; Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Xinzheng Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Peiyi Wang
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China; SUSTech Cryo-EM Centre, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Hua-Ji Qiu
- State Key Laboratory of Veterinary Biotechnology and National High-Containment Laboratory for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - George F Gao
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Center for Influenza Research and Early-warning (CASCIRE), CAS-TWAS Center of Excellence for Emerging Infectious Diseases (CEEID), Chinese Academy of Sciences, Beijing 100101, China; Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China; Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China; National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Beijing 102206, China.
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28
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Wang N, Zhao D, Wang J, Zhang Y, Wang M, Gao Y, Li F, Wang J, Bu Z, Rao Z, Wang X. Architecture of African swine fever virus and implications for viral assembly. Science 2019; 366:640-644. [PMID: 31624094 DOI: 10.1126/science.aaz1439] [Citation(s) in RCA: 239] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 10/09/2019] [Indexed: 01/27/2023]
Abstract
African swine fever virus (ASFV) is a giant and complex DNA virus that causes a highly contagious and often lethal swine disease for which no vaccine is available. Using an optimized image reconstruction strategy, we solved the ASFV capsid structure up to 4.1 angstroms, which is built from 17,280 proteins, including one major (p72) and four minor (M1249L, p17, p49, and H240R) capsid proteins organized into pentasymmetrons and trisymmetrons. The atomic structure of the p72 protein informs putative conformational epitopes, distinguishing ASFV from other nucleocytoplasmic large DNA viruses. The minor capsid proteins form a complicated network below the outer capsid shell, stabilizing the capsid by holding adjacent capsomers together. Acting as core organizers, 100-nanometer-long M1249L proteins run along each edge of the trisymmetrons that bridge two neighboring pentasymmetrons and form extensive intermolecular networks with other capsid proteins, driving the formation of the capsid framework. These structural details unveil the basis of capsid stability and assembly, opening up new avenues for African swine fever vaccine development.
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Affiliation(s)
- Nan Wang
- CAS Key Laboratory of Infection and Immunity, National Laboratory of Macromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dongming Zhao
- State Key Laboratory of Veterinary Biotechnology and National High Containment Laboratory for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Jialing Wang
- CAS Key Laboratory of Infection and Immunity, National Laboratory of Macromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yangling Zhang
- CAS Key Laboratory of Infection and Immunity, National Laboratory of Macromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ming Wang
- State Key Laboratory of Veterinary Biotechnology and National High Containment Laboratory for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Yan Gao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.,Laboratory of Structural Biology, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Fang Li
- State Key Laboratory of Veterinary Biotechnology and National High Containment Laboratory for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Jingfei Wang
- State Key Laboratory of Veterinary Biotechnology and National High Containment Laboratory for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Zhigao Bu
- State Key Laboratory of Veterinary Biotechnology and National High Containment Laboratory for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Zihe Rao
- CAS Key Laboratory of Infection and Immunity, National Laboratory of Macromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China. .,Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.,Laboratory of Structural Biology, School of Medicine, Tsinghua University, Beijing 100084, China.,State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300353, China
| | - Xiangxi Wang
- CAS Key Laboratory of Infection and Immunity, National Laboratory of Macromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
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29
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Membrane-Containing Icosahedral Bacteriophage PRD1: The Dawn of Viral Lineages. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1215:85-109. [DOI: 10.1007/978-3-030-14741-9_5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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30
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Koonin EV, Yutin N. Evolution of the Large Nucleocytoplasmic DNA Viruses of Eukaryotes and Convergent Origins of Viral Gigantism. Adv Virus Res 2019; 103:167-202. [PMID: 30635076 DOI: 10.1016/bs.aivir.2018.09.002] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Nucleocytoplasmic Large DNA Viruses (NCLDV) of eukaryotes (proposed order "Megavirales") comprise an expansive group of eukaryotic viruses that consists of the families Poxviridae, Asfarviridae, Iridoviridae, Ascoviridae, Phycodnaviridae, Marseilleviridae, Pithoviridae, and Mimiviridae, as well as Pandoraviruses, Molliviruses, and Faustoviruses that so far remain unaccounted by the official virus taxonomy. All these viruses have double-stranded DNA genomes that range in size from about 100 kilobases (kb) to more than 2.5 megabases. The viruses with genomes larger than 500kb are informally considered "giant," and the largest giant viruses surpass numerous bacteria and archaea in both particle and genome size. The discovery of giant viruses has been highly unexpected and has changed the perception of viral size and complexity, and even, arguably, the entire concept of a virus. Given that giant viruses encode multiple proteins that are universal among cellular life forms and are components of the translation system, the quintessential cellular molecular machinery, attempts have been made to incorporate these viruses in the evolutionary tree of cellular life. Moreover, evolutionary scenarios of the origin of giant viruses from a fourth, supposedly extinct domain of cellular life have been proposed. However, despite all the differences in the genome size and gene repertoire, the NCLDV can be confidently defined as monophyletic group, on the strength of the presence of about 40 genes that can be traced back to their last common ancestor. Using several most strongly conserved genes from this ancestral set, a well-resolved phylogenetic tree of the NCLDV was built and employed as the scaffold to reconstruct the history of gene gain and loss throughout the course of the evolution of this group of viruses. This reconstruction reveals extremely dynamic evolution that involved extensive gene gain and loss in many groups of viruses and indicates that giant viruses emerged independently in several clades of the NCLDV. Thus, these giants of the virus world evolved repeatedly from smaller and simpler viruses, rather than from a fourth domain of cellular life, and captured numerous genes, including those for translation system components, from eukaryotes, along with some bacterial genes. Even deeper evolutionary reconstructions reveal apparent links between the NCLDV and smaller viruses of eukaryotes, such as adenoviruses, and ultimately, derive all these viruses from tailless bacteriophages.
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Affiliation(s)
- Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, United States.
| | - Natalya Yutin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, United States
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31
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San Martín C. Virus Maturation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1215:129-158. [DOI: 10.1007/978-3-030-14741-9_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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32
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San Martín C, van Raaij MJ. The so far farthest reaches of the double jelly roll capsid protein fold. Virol J 2018; 15:181. [PMID: 30470230 PMCID: PMC6260650 DOI: 10.1186/s12985-018-1097-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 11/16/2018] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND During the last two decades, structural biology analyses have shown that viruses infecting hosts far apart in evolution share similar architectural features, prompting a new virus classification based on structural lineages. Until recently, only a few prokaryotic viruses had been described for one of the lineages, whose main characteristic is a capsid protein with a perpendicular double jelly roll. MAIN BODY Metagenomics analyses are showing that the variety of prokaryotic viruses encoding double jelly roll capsid proteins is much larger than previously thought. The newly discovered viruses have novel genome organisations with interesting implications for virus structure, function and evolution. There are also indications of their having a significant ecological impact. CONCLUSION Viruses with double jelly roll capsid proteins that infect prokaryotic hosts form a large part of the virosphere that had so far gone unnoticed. Their discovery by metagenomics is only a first step towards many more exciting findings. Work needs to be invested in isolating these viruses and their hosts, characterizing the structure and function of the proteins their genomes encode, and eventually access the wealth of biological information they may hold.
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Affiliation(s)
- Carmen San Martín
- Departamento de Estructura de Macromoléculas, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain.
| | - Mark J van Raaij
- Departamento de Estructura de Macromoléculas, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain.
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33
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Structural basis for the inhibition of poxvirus assembly by the antibiotic rifampicin. Proc Natl Acad Sci U S A 2018; 115:8424-8429. [PMID: 30068608 DOI: 10.1073/pnas.1810398115] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Poxviruses are large DNA viruses that cause disease in animals and humans. They differ from classical enveloped viruses, because their membrane is acquired from cytoplasmic membrane precursors assembled onto a viral protein scaffold formed by the D13 protein rather than budding through cellular compartments. It was found three decades ago that the antibiotic rifampicin blocks this process and prevents scaffold formation. To elucidate the mechanism of action of rifampicin, we have determined the crystal structures of six D13-rifamycin complexes. These structures reveal that rifamycin compounds bind to a phenylalanine-rich region, or F-ring, at the membrane-proximal opening of the central channel of the D13 trimer. We show by NMR, surface plasmon resonance (SPR), and site-directed mutagenesis that A17, a membrane-associated viral protein, mediates the recruitment of the D13 scaffold by also binding to the F-ring. This interaction is the target of rifampicin, which prevents A17 binding, explaining the inhibition of viral morphogenesis. The F-ring of D13 is both conserved in sequence in mammalian poxviruses and essential for interaction with A17, defining a target for the development of assembly inhibitors. The model of the A17-D13 interaction describes a two-component system for remodeling nascent membranes that may be conserved in other large and giant DNA viruses.
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34
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Qureshi A, Tantray VG, Kirmani AR, Ahangar AG. A review on current status of antiviral siRNA. Rev Med Virol 2018; 28:e1976. [PMID: 29656441 PMCID: PMC7169094 DOI: 10.1002/rmv.1976] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/18/2018] [Accepted: 02/12/2018] [Indexed: 01/12/2023]
Abstract
Viral diseases like influenza, AIDS, hepatitis, and Ebola cause severe epidemics worldwide. Along with their resistant strains, new pathogenic viruses continue to be discovered so creating an ongoing need for new antiviral treatments. RNA interference is a cellular gene‐silencing phenomenon in which sequence‐specific degradation of target mRNA is achieved by means of complementary short interfering RNA (siRNA) molecules. Short interfering RNA technology affords a potential tractable strategy to combat viral pathogenesis because siRNAs are specific, easy to design, and can be directed against multiple strains of a virus by targeting their conserved gene regions. In this review, we briefly summarize the current status of siRNA therapy for representative examples from different virus families. In addition, other aspects like their design, delivery, medical significance, bioinformatics resources, and limitations are also discussed.
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Affiliation(s)
- Abid Qureshi
- Biomedical Informatics Center, Sher-i-Kashmir Institute of Medical Sciences (SKIMS), Srinagar, India
| | - Vaqar Gani Tantray
- Biomedical Informatics Center, Sher-i-Kashmir Institute of Medical Sciences (SKIMS), Srinagar, India
| | - Altaf Rehman Kirmani
- Biomedical Informatics Center, Sher-i-Kashmir Institute of Medical Sciences (SKIMS), Srinagar, India
| | - Abdul Ghani Ahangar
- Biomedical Informatics Center, Sher-i-Kashmir Institute of Medical Sciences (SKIMS), Srinagar, India
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35
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Weisberg AS, Maruri-Avidal L, Bisht H, Hansen BT, Schwartz CL, Fischer ER, Meng X, Xiang Y, Moss B. Enigmatic origin of the poxvirus membrane from the endoplasmic reticulum shown by 3D imaging of vaccinia virus assembly mutants. Proc Natl Acad Sci U S A 2017; 114:E11001-E11009. [PMID: 29203656 PMCID: PMC5754806 DOI: 10.1073/pnas.1716255114] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The long-standing inability to visualize connections between poxvirus membranes and cellular organelles has led to uncertainty regarding the origin of the viral membrane. Indeed, there has been speculation that viral membranes form de novo in cytoplasmic factories. Another possibility, that the connections are too short-lived to be captured by microscopy during a normal infection, motivated us to identify and characterize virus mutants that are arrested in assembly. Five conserved vaccinia virus proteins, referred to as Viral Membrane Assembly Proteins (VMAPs), that are necessary for formation of immature virions were found. Transmission electron microscopy studies of two VMAP deletion mutants had suggested retention of connections between viral membranes and the endoplasmic reticulum (ER). We now analyzed cells infected with each of the five VMAP deletion mutants by electron tomography, which is necessary to validate membrane continuity, in addition to conventional transmission electron microscopy. In all cases, connections between the ER and viral membranes were demonstrated by 3D reconstructions, supporting a role for the VMAPs in creating and/or stabilizing membrane scissions. Furthermore, coexpression of the viral reticulon-like transmembrane protein A17 and the capsid-like scaffold protein D13 was sufficient to form similar ER-associated viral structures in the absence of other major virion proteins. Determination of the mechanism of ER disruption during a normal VACV infection and the likely participation of both viral and cell proteins in this process may provide important insights into membrane dynamics.
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Affiliation(s)
- Andrea S Weisberg
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Liliana Maruri-Avidal
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Himani Bisht
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Bryan T Hansen
- Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840
| | - Cindi L Schwartz
- Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840
| | - Elizabeth R Fischer
- Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840
| | - Xiangzhi Meng
- Department of Microbiology, Immunology, and Molecular Genetics, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229
| | - Yan Xiang
- Department of Microbiology, Immunology, and Molecular Genetics, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229
| | - Bernard Moss
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
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36
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Rochal SB, Konevtsova OV, Lorman VL. Static and dynamic hidden symmetries of icosahedral viral capsids. NANOSCALE 2017; 9:12449-12460. [PMID: 28809986 DOI: 10.1039/c7nr04020b] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Viral shells self-assemble from identical proteins, which tend to form equivalent environments in the resulting assembly. However, in icosahedral capsids containing more than 60 proteins, they are enforced to occupy not only the symmetrically equivalent locations but also the quasi-equivalent ones. Due to this important fact, static and dynamic symmetries of viral shells can include additional hidden components. Here, developing the Caspar and Klug ideas concerning the quasi-equivalence of protein environments, we derive the simplest hexagonal tilings, that in principle could correspond to the local protein order in viral shells, and apply the resulting theory to nucleocytoplasmic large dsDNA viruses. In addition, analyzing the dynamic symmetry of the P22 viral shell, we demonstrate that the collective critical modes responsible for the protein reorganization during the procapsid maturation are approximately equivalent to the normal modes of the isotropic spherical membrane with O(3) symmetry. Furthermore, we establish the relationship between the dynamic symmetry of the P22 procapsid and the protein arrangement regularities that appear only in the mature capsid.
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Affiliation(s)
- Sergey B Rochal
- Faculty of Physics, Southern Federal University, 5 Zorge str., 344090 Rostov-on-Don, Russia.
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37
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Demina TA, Pietilä MK, Svirskaitė J, Ravantti JJ, Atanasova NS, Bamford DH, Oksanen HM. HCIV-1 and Other Tailless Icosahedral Internal Membrane-Containing Viruses of the Family Sphaerolipoviridae. Viruses 2017; 9:v9020032. [PMID: 28218714 PMCID: PMC5332951 DOI: 10.3390/v9020032] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 01/10/2017] [Accepted: 02/13/2017] [Indexed: 11/16/2022] Open
Abstract
Members of the virus family Sphaerolipoviridae include both archaeal viruses and bacteriophages that possess a tailless icosahedral capsid with an internal membrane. The genera Alpha- and Betasphaerolipovirus comprise viruses that infect halophilic euryarchaea, whereas viruses of thermophilic Thermus bacteria belong to the genus Gammasphaerolipovirus. Both sequence-based and structural clustering of the major capsid proteins and ATPases of sphaerolipoviruses yield three distinct clades corresponding to these three genera. Conserved virion architectural principles observed in sphaerolipoviruses suggest that these viruses belong to the PRD1-adenovirus structural lineage. Here we focus on archaeal alphasphaerolipoviruses and their related putative proviruses. The highest sequence similarities among alphasphaerolipoviruses are observed in the core structural elements of their virions: the two major capsid proteins, the major membrane protein, and a putative packaging ATPase. A recently described tailless icosahedral haloarchaeal virus, Haloarcula californiae icosahedral virus 1 (HCIV-1), has a double-stranded DNA genome and an internal membrane lining the capsid. HCIV-1 shares significant similarities with the other tailless icosahedral internal membrane-containing haloarchaeal viruses of the family Sphaerolipoviridae. The proposal to include a new virus species, Haloarcula virus HCIV1, into the genus Alphasphaerolipovirus was submitted to the International Committee on Taxonomy of Viruses (ICTV) in 2016.
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Affiliation(s)
- Tatiana A Demina
- Department of Biosciences and Institute of Biotechnology, Viikinkaari 9, FIN-00014, University of Helsinki, Helsinki, Finland.
| | - Maija K Pietilä
- Department of Food and Environmental Sciences, Viikinkaari 9, FIN-00014, University of Helsinki, Helsinki, Finland.
| | - Julija Svirskaitė
- Department of Biosciences and Institute of Biotechnology, Viikinkaari 9, FIN-00014, University of Helsinki, Helsinki, Finland.
| | - Janne J Ravantti
- Department of Biosciences and Institute of Biotechnology, Viikinkaari 9, FIN-00014, University of Helsinki, Helsinki, Finland.
| | - Nina S Atanasova
- Department of Biosciences and Institute of Biotechnology, Viikinkaari 9, FIN-00014, University of Helsinki, Helsinki, Finland.
| | - Dennis H Bamford
- Department of Biosciences and Institute of Biotechnology, Viikinkaari 9, FIN-00014, University of Helsinki, Helsinki, Finland.
| | - Hanna M Oksanen
- Department of Biosciences and Institute of Biotechnology, Viikinkaari 9, FIN-00014, University of Helsinki, Helsinki, Finland.
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Klose T, Reteno DG, Benamar S, Hollerbach A, Colson P, La Scola B, Rossmann MG. Structure of faustovirus, a large dsDNA virus. Proc Natl Acad Sci U S A 2016; 113:6206-11. [PMID: 27185929 PMCID: PMC4896704 DOI: 10.1073/pnas.1523999113] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many viruses protect their genome with a combination of a protein shell with or without a membrane layer. Here we describe the structure of faustovirus, the first DNA virus (to our knowledge) that has been found to use two protein shells to encapsidate and protect its genome. The crystal structure of the major capsid protein, in combination with cryo-electron microscopy structures of two different maturation stages of the virus, shows that the outer virus shell is composed of a double jelly-roll protein that can be found in many double-stranded DNA viruses. The structure of the repeating hexameric unit of the inner shell is different from all other known capsid proteins. In addition to the unique architecture, the region of the genome that encodes the major capsid protein stretches over 17,000 bp and contains a large number of introns and exons. This complexity might help the virus to rapidly adapt to new environments or hosts.
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Affiliation(s)
- Thomas Klose
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907
| | - Dorine G Reteno
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), Unité Mixte de Recherche 63, CNRS 7278, Institut de Recherche pour le Développement 198, INSERM U1095, Aix-Marseille Université, 13005 Marseille, France
| | - Samia Benamar
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), Unité Mixte de Recherche 63, CNRS 7278, Institut de Recherche pour le Développement 198, INSERM U1095, Aix-Marseille Université, 13005 Marseille, France
| | - Adam Hollerbach
- Department of Chemistry, Purdue University, West Lafayette, IN 47907
| | - Philippe Colson
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), Unité Mixte de Recherche 63, CNRS 7278, Institut de Recherche pour le Développement 198, INSERM U1095, Aix-Marseille Université, 13005 Marseille, France
| | - Bernard La Scola
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), Unité Mixte de Recherche 63, CNRS 7278, Institut de Recherche pour le Développement 198, INSERM U1095, Aix-Marseille Université, 13005 Marseille, France
| | - Michael G Rossmann
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907;
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Vaccinia Virus B1 Kinase Is Required for Postreplicative Stages of the Viral Life Cycle in a BAF-Independent Manner in U2OS Cells. J Virol 2015. [PMID: 26223647 DOI: 10.1128/jvi.01252-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
UNLABELLED The vaccinia virus B1R gene encodes a highly conserved protein kinase that is essential for the poxviral life cycle. As demonstrated in many cell types, B1 plays a critical role during viral DNA replication when it inactivates the cellular host defense effector barrier to autointegration factor (BAF or BANF1). To better understand the role of B1 during infection, we have characterized the growth of a B1-deficient temperature-sensitive mutant virus (Cts2 virus) in U2OS osteosarcoma cells. In contrast to all other cell lines tested to date, we found that in U2OS cells, Cts2 viral DNA replication is unimpaired at the nonpermissive temperature. However, the Cts2 viral yield in these cells was reduced more than 10-fold, thus indicating that B1 is required at another stage of the vaccinia virus life cycle. Our results further suggest that the host defense function of endogenous BAF may be absent in U2OS cells but can be recovered through either overexpression of BAF or fusion of U2OS cells with mouse cells in which the antiviral function of BAF is active. Interestingly, examination of late viral proteins during Cts2 virus infection demonstrated that B1 is required for optimal processing of the L4 protein. Finally, execution point analyses as well as electron microscopy studies uncovered a role for B1 during maturation of poxviral virions. Overall, this work demonstrates that U2OS cells are a novel model system for studying the cell type-specific regulation of BAF and reveals a role for B1 beyond DNA replication during the late stages of the viral life cycle. IMPORTANCE The most well characterized role for the vaccinia virus B1 kinase is to facilitate viral DNA replication by phosphorylating and inactivating BAF, a cellular host defense responsive to foreign DNA. Additional roles for B1 later in the viral life cycle have been postulated for decades but are difficult to examine directly due to the importance of B1 during DNA replication. Here, we demonstrate that in U2OS cells, a B1 mutant virus escapes the block in DNA replication observed in other cell types and, instead, this mutant virus exhibits impaired late protein accumulation and incomplete maturation of new virions. These data provide the clearest evidence to date that B1 is needed for multiple critical junctures in the poxviral life cycle in a manner that is both dependent on and independent of BAF.
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Poxvirus membrane biogenesis. Virology 2015; 479-480:619-26. [PMID: 25728299 DOI: 10.1016/j.virol.2015.02.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Revised: 02/02/2015] [Accepted: 02/03/2015] [Indexed: 12/18/2022]
Abstract
Poxviruses differ from most DNA viruses by replicating entirely within the cytoplasm. The first discernible viral structures are crescents and spherical immature virions containing a single lipoprotein membrane bilayer with an external honeycomb lattice. Because this viral membrane displays no obvious continuity with a cellular organelle, a de novo origin was suggested. Nevertheless, transient connections between viral and cellular membranes could be difficult to resolve. Despite the absence of direct evidence, the intermediate compartment (ERGIC) between the endoplasmic reticulum (ER) and Golgi apparatus and the ER itself were considered possible sources of crescent membranes. A break-through in understanding poxvirus membrane biogenesis has come from recent studies of the abortive replication of several vaccinia virus null mutants. Novel images showing continuity between viral crescents and the ER and the accumulation of immature virions in the expanded ER lumen provide the first direct evidence for a cellular origin of this poxvirus membrane.
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Hong C, Oksanen HM, Liu X, Jakana J, Bamford DH, Chiu W. A structural model of the genome packaging process in a membrane-containing double stranded DNA virus. PLoS Biol 2014; 12:e1002024. [PMID: 25514469 PMCID: PMC4267777 DOI: 10.1371/journal.pbio.1002024] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 11/03/2014] [Indexed: 02/01/2023] Open
Abstract
Two crucial steps in the virus life cycle are genome encapsidation to form an infective virion and genome exit to infect the next host cell. In most icosahedral double-stranded (ds) DNA viruses, the viral genome enters and exits the capsid through a unique vertex. Internal membrane-containing viruses possess additional complexity as the genome must be translocated through the viral membrane bilayer. Here, we report the structure of the genome packaging complex with a membrane conduit essential for viral genome encapsidation in the tailless icosahedral membrane-containing bacteriophage PRD1. We utilize single particle electron cryo-microscopy (cryo-EM) and symmetry-free image reconstruction to determine structures of PRD1 virion, procapsid, and packaging deficient mutant particles. At the unique vertex of PRD1, the packaging complex replaces the regular 5-fold structure and crosses the lipid bilayer. These structures reveal that the packaging ATPase P9 and the packaging efficiency factor P6 form a dodecameric portal complex external to the membrane moiety, surrounded by ten major capsid protein P3 trimers. The viral transmembrane density at the special vertex is assigned to be a hexamer of heterodimer of proteins P20 and P22. The hexamer functions as a membrane conduit for the DNA and as a nucleating site for the unique vertex assembly. Our structures show a conformational alteration in the lipid membrane after the P9 and P6 are recruited to the virion. The P8-genome complex is then packaged into the procapsid through the unique vertex while the genome terminal protein P8 functions as a valve that closes the channel once the genome is inside. Comparing mature virion, procapsid, and mutant particle structures led us to propose an assembly pathway for the genome packaging apparatus in the PRD1 virion.
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Affiliation(s)
- Chuan Hong
- Graduate Program in Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Hanna M. Oksanen
- Department of Biosciences and Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Xiangan Liu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Joanita Jakana
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Dennis H. Bamford
- Department of Biosciences and Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Wah Chiu
- Graduate Program in Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
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Liu L, Cooper T, Howley PM, Hayball JD. From crescent to mature virion: vaccinia virus assembly and maturation. Viruses 2014; 6:3787-808. [PMID: 25296112 PMCID: PMC4213562 DOI: 10.3390/v6103787] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 09/29/2014] [Accepted: 10/02/2014] [Indexed: 01/22/2023] Open
Abstract
Vaccinia virus (VACV) has achieved unprecedented success as a live viral vaccine for smallpox which mitigated eradication of the disease. Vaccinia virus has a complex virion morphology and recent advances have been made to answer some of the key outstanding questions, in particular, the origin and biogenesis of the virion membrane, the transformation from immature virion (IV) to mature virus (MV), and the role of several novel genes, which were previously uncharacterized, but have now been shown to be essential for VACV virion formation. This new knowledge will undoubtedly contribute to the rational design of safe, immunogenic vaccine candidates, or effective antivirals in the future. This review endeavors to provide an update on our current knowledge of the VACV maturation processes with a specific focus on the initiation of VACV replication through to the formation of mature virions.
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Affiliation(s)
- Liang Liu
- Experimental Therapeutics Laboratory, Hanson Institute and Sansom Institute, Adelaide, 5000, SA, Australia.
| | - Tamara Cooper
- Experimental Therapeutics Laboratory, Hanson Institute and Sansom Institute, Adelaide, 5000, SA, Australia.
| | - Paul M Howley
- Experimental Therapeutics Laboratory, Hanson Institute and Sansom Institute, Adelaide, 5000, SA, Australia.
| | - John D Hayball
- Experimental Therapeutics Laboratory, Hanson Institute and Sansom Institute, Adelaide, 5000, SA, Australia.
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Forterre P, Krupovic M, Prangishvili D. Cellular domains and viral lineages. Trends Microbiol 2014; 22:554-8. [PMID: 25129822 DOI: 10.1016/j.tim.2014.07.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 07/09/2014] [Accepted: 07/16/2014] [Indexed: 11/25/2022]
Abstract
It has been claimed that giant DNA viruses represent a separate, fourth domain of life in addition to the domains of Bacteria, Archaea, and Eukarya. Such classification disregards fundamental differences between the two types of living entities - viruses and cells - and results in confusion and controversies in evolutionary scenarios. We highlight these problems and emphasize the importance of restricting the term 'domain' to the descendants of the last universal cellular ancestor (LUCA), based on the shared ribosome structure. We suggest tracing phylogeny of viruses along evolutionary lineages primarily defined by virion architectures and the structures of the major capsid proteins.
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Affiliation(s)
- Patrick Forterre
- Institut Pasteur, 25 rue du Dr Roux, 75015, Paris, France; Institut de Génétique et Microbiologie, University Paris-Sud, Centre National de la Recherche Scientifique (CNRS) UMR 8621, 91405 Orsay CEDEX, France.
| | - Mart Krupovic
- Institut Pasteur, 25 rue du Dr Roux, 75015, Paris, France
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Duplication of the A17L locus of vaccinia virus provides an alternate route to rifampin resistance. J Virol 2014; 88:11576-85. [PMID: 25078687 DOI: 10.1128/jvi.00618-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
UNLABELLED Specific gene duplications can enable double-stranded DNA viruses to adapt rapidly to environmental pressures despite the low mutation rate of their high-fidelity DNA polymerases. We report on the rapid positive selection of a novel vaccinia virus genomic duplication mutant in the presence of the assembly inhibitor rifampin. Until now, all known rifampin-resistant vaccinia virus isolates have contained missense mutations in the D13L gene, which encodes a capsid-like scaffold protein required for stabilizing membrane curvature during the early stage of virion assembly. Here we describe a second pathway to rifampin resistance involving A17, a membrane protein that binds and anchors D13 to the immature virion. After one round of selection, a rifampin-resistant virus that contained a genomic duplication in the A17L-A21L region was recovered. The mutant had both C-terminally truncated and full-length A17L open reading frames. Expression of the truncated A17 protein was retained when the virus was passaged in the presence of rifampin but was lost in the absence of the drug, suggesting that the duplication decreased general fitness. Both forms of A17 were bound to the virion membrane and associated with D13. Moreover, insertion of an additional truncated or inducible full-length A17L open reading frame into the genome of the wild-type virus was sufficient to confer rifampin resistance. In summary, this report contains the first evidence of an alternate mechanism for resistance of poxviruses to rifampin, indicates a direct relationship between A17 levels and the resistance phenotype, and provides further evidence of the ability of double-stranded DNA viruses to acquire drug resistance through gene duplication. IMPORTANCE The present study provides the first evidence of a new mechanism of resistance of a poxvirus to the antiviral drug rifampin. In addition, it affirms the importance of the interaction between the D13 scaffold protein and the A17 membrane protein for assembly of virus particles. Resistance to rifampin was linked to a partial duplication of the gene encoding the A17 protein, similar to the resistance to hydroxyurea enabled by duplication of the gene encoding the small subunit of ribonucleotide reductase and of the K3L gene to allow adaptation to the antiviral action of protein kinase R. Gene duplication may provide a way for poxviruses and other DNA viruses with high-fidelity DNA polymerases to adjust rapidly to changes in the environment.
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Structure analysis of the major capsid proteins of human polyomaviruses 6 and 7 reveals an obstructed sialic acid binding site. J Virol 2014; 88:10831-9. [PMID: 25008942 DOI: 10.1128/jvi.01084-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED Human polyomavirus 6 (HPyV6) and HPyV7 are commonly found on human skin. We have determined the X-ray structures of their major capsid protein, VP1, at resolutions of 1.8 and 1.7 Å, respectively. In polyomaviruses, VP1 commonly determines antigenicity as well as cell-surface receptor specificity, and the protein is therefore linked to attachment, tropism, and ultimately, viral pathogenicity. The structures of HPyV6 and HPyV7 VP1 reveal uniquely elongated loops that cover the bulk of the outer virion surfaces, obstructing a groove that binds sialylated glycan receptors in many other polyomaviruses. In support of this structural observation, interactions of VP1 with α2,3- and α2,6-linked sialic acids could not be detected in solution by nuclear magnetic resonance spectroscopy. Single-cell binding studies indicate that sialylated glycans are likely not required for initial attachment to cultured human cells. Our findings establish distinct antigenic properties of HPyV6 and HPyV7 capsids and indicate that these two viruses engage nonsialylated receptors. IMPORTANCE Eleven new human polyomaviruses, including the skin viruses HPyV6 and HPyV7, have been identified during the last decade. In contrast to better-studied polyomaviruses, the routes of infection, cell tropism, and entry pathways of many of these new viruses remain largely mysterious. Our high-resolution X-ray structures of major capsid proteins VP1 from HPyV6 and from HPyV7 reveal critical differences in surface morphology from those of all other known polyomavirus structures. A groove that engages specific sialic acid-containing glycan receptors in related polyomaviruses is obstructed, and VP1 of HPyV6 and HPyV7 does not interact with sialylated compounds in solution or on cultured human cells. A comprehensive comparison with other structurally characterized polyomavirus VP1 proteins enhances our understanding of molecular determinants that underlie receptor specificity, antigenicity, and, ultimately, pathogenicity within the polyomavirus family and highlight the need for structure-based analysis to better define phylogenetic relationships within the growing polyomavirus family and perhaps also for other viruses.
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Abstract
Nucleocytoplasmic large dsDNA viruses (NCLDVs) encompass an ever-increasing group of large eukaryotic viruses, infecting a wide variety of organisms. The set of core genes shared by all these viruses includes a major capsid protein with a double jelly-roll fold forming an icosahedral capsid, which surrounds a double layer membrane that contains the viral genome. Furthermore, some of these viruses, such as the members of the Mimiviridae and Phycodnaviridae have a unique vertex that is used during infection to transport DNA into the host.
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Affiliation(s)
- Thomas Klose
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Michael G. Rossmann
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
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Cryo-EM near-atomic structure of a dsRNA fungal virus shows ancient structural motifs preserved in the dsRNA viral lineage. Proc Natl Acad Sci U S A 2014; 111:7641-6. [PMID: 24821769 DOI: 10.1073/pnas.1404330111] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Viruses evolve so rapidly that sequence-based comparison is not suitable for detecting relatedness among distant viruses. Structure-based comparisons suggest that evolution led to a small number of viral classes or lineages that can be grouped by capsid protein (CP) folds. Here, we report that the CP structure of the fungal dsRNA Penicillium chrysogenum virus (PcV) shows the progenitor fold of the dsRNA virus lineage and suggests a relationship between lineages. Cryo-EM structure at near-atomic resolution showed that the 982-aa PcV CP is formed by a repeated α-helical core, indicative of gene duplication despite lack of sequence similarity between the two halves. Superimposition of secondary structure elements identified a single "hotspot" at which variation is introduced by insertion of peptide segments. Structural comparison of PcV and other distantly related dsRNA viruses detected preferential insertion sites at which the complexity of the conserved α-helical core, made up of ancestral structural motifs that have acted as a skeleton, might have increased, leading to evolution of the highly varied current structures. Analyses of structural motifs only apparent after systematic structural comparisons indicated that the hallmark fold preserved in the dsRNA virus lineage shares a long (spinal) α-helix tangential to the capsid surface with the head-tailed phage and herpesvirus viral lineage.
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Pietilä MK, Demina TA, Atanasova NS, Oksanen HM, Bamford DH. Archaeal viruses and bacteriophages: comparisons and contrasts. Trends Microbiol 2014; 22:334-44. [PMID: 24647075 DOI: 10.1016/j.tim.2014.02.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/14/2014] [Accepted: 02/20/2014] [Indexed: 10/25/2022]
Abstract
Isolated archaeal viruses comprise only a few percent of all known prokaryotic viruses. Thus, the study of viruses infecting archaea is still in its early stages. Here we summarize the most recent discoveries of archaeal viruses utilizing a virion-centered view. We describe the known archaeal virion morphotypes and compare them to the bacterial counterparts, if such exist. Viruses infecting archaea are morphologically diverse and present some unique morphotypes. Although limited in isolate number, archaeal viruses reveal new insights into the viral world, such as deep evolutionary relationships between viruses that infect hosts from all three domains of life.
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Affiliation(s)
- Maija K Pietilä
- Institute of Biotechnology and Department of Biosciences, P.O. Box 56, Viikinkaari 5, 00014 University of Helsinki, Helsinki, Finland
| | - Tatiana A Demina
- Institute of Biotechnology and Department of Biosciences, P.O. Box 56, Viikinkaari 5, 00014 University of Helsinki, Helsinki, Finland
| | - Nina S Atanasova
- Institute of Biotechnology and Department of Biosciences, P.O. Box 56, Viikinkaari 5, 00014 University of Helsinki, Helsinki, Finland
| | - Hanna M Oksanen
- Institute of Biotechnology and Department of Biosciences, P.O. Box 56, Viikinkaari 5, 00014 University of Helsinki, Helsinki, Finland
| | - Dennis H Bamford
- Institute of Biotechnology and Department of Biosciences, P.O. Box 56, Viikinkaari 5, 00014 University of Helsinki, Helsinki, Finland.
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Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology. Proc Natl Acad Sci U S A 2014; 111:4274-9. [PMID: 24591590 DOI: 10.1073/pnas.1320670111] [Citation(s) in RCA: 316] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The largest known DNA viruses infect Acanthamoeba and belong to two markedly different families. The Megaviridae exhibit pseudo-icosahedral virions up to 0.7 μm in diameter and adenine-thymine (AT)-rich genomes of up to 1.25 Mb encoding a thousand proteins. Like their Mimivirus prototype discovered 10 y ago, they entirely replicate within cytoplasmic virion factories. In contrast, the recently discovered Pandoraviruses exhibit larger amphora-shaped virions 1 μm in length and guanine-cytosine-rich genomes up to 2.8 Mb long encoding up to 2,500 proteins. Their replication involves the host nucleus. Whereas the Megaviridae share some general features with the previously described icosahedral large DNA viruses, the Pandoraviruses appear unrelated to them. Here we report the discovery of a third type of giant virus combining an even larger pandoravirus-like particle 1.5 μm in length with a surprisingly smaller 600 kb AT-rich genome, a gene content more similar to Iridoviruses and Marseillevirus, and a fully cytoplasmic replication reminiscent of the Megaviridae. This suggests that pandoravirus-like particles may be associated with a variety of virus families more diverse than previously envisioned. This giant virus, named Pithovirus sibericum, was isolated from a >30,000-y-old radiocarbon-dated sample when we initiated a survey of the virome of Siberian permafrost. The revival of such an ancestral amoeba-infecting virus used as a safe indicator of the possible presence of pathogenic DNA viruses, suggests that the thawing of permafrost either from global warming or industrial exploitation of circumpolar regions might not be exempt from future threats to human or animal health.
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Jagodzinski F, Clark P, Grant J, Liu T, Monastra S, Streinu I. Rigidity analysis of protein biological assemblies and periodic crystal structures. BMC Bioinformatics 2013; 14 Suppl 18:S2. [PMID: 24564201 PMCID: PMC3817814 DOI: 10.1186/1471-2105-14-s18-s2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background We initiate in silico rigidity-theoretical studies of biological assemblies and small crystals for protein structures. The goal is to determine if, and how, the interactions among neighboring cells and subchains affect the flexibility of a molecule in its crystallized state. We use experimental X-ray crystallography data from the Protein Data Bank (PDB). The analysis relies on an effcient graph-based algorithm. Computational experiments were performed using new protein rigidity analysis tools available in the new release of our KINARI-Web server http://kinari.cs.umass.edu. Results We provide two types of results: on biological assemblies and on crystals. We found that when only isolated subchains are considered, structural and functional information may be missed. Indeed, the rigidity of biological assemblies is sometimes dependent on the count and placement of hydrogen bonds and other interactions among the individual subchains of the biological unit. Similarly, the rigidity of small crystals may be affected by the interactions between atoms belonging to different unit cells. We have analyzed a dataset of approximately 300 proteins, from which we generated 982 crystals (some of which are biological assemblies). We identified two types of behaviors. (a) Some crystals and/or biological assemblies will aggregate into rigid bodies that span multiple unit cells/asymmetric units. Some of them create substantially larger rigid cluster in the crystal/biological assembly form, while in other cases, the aggregation has a smaller effect just at the interface between the units. (b) In other cases, the rigidity properties of the asymmetric units are retained, because the rigid bodies did not combine. We also identified two interesting cases where rigidity analysis may be correlated with the functional behavior of the protein. This type of information, identified here for the first time, depends critically on the ability to create crystals and biological assemblies, and would not have been observed only from the asymmetric unit. For the Ribonuclease A protein (PDB file 5RSA), which is functionally active in the crystallized form, we found that the individual protein and its crystal form retain the flexibility parameters between the two states. In contrast, a derivative of Ribonuclease A (PDB file 9RSA), has no functional activity, and the protein in both the asymmetric and crystalline forms, is very rigid. For the vaccinia virus D13 scaffolding protein (PDB file 3SAQ), which has two biological assemblies, we observed a striking asymmetry in the rigidity cluster decomposition of one of them, which seems implausible, given its symmetry. Upon careful investigation, we tracked the cause to a placement decision by the Reduce software concerning the hydrogen atoms, thus affecting the distribution of certain hydrogen bonds. The surprising result is that the presence or lack of a very few, but critical, hydrogen bonds, can drastically affect the rigid cluster decomposition of the biological assembly. Conclusion The rigidity analysis of a single asymmetric unit may not accurately reflect the protein's behavior in the tightly packed crystal environment. Using our KINARI software, we demonstrated that additional functional and rigidity information can be gained by analyzing a protein's biological assembly and/or crystal structure. However, performing a larger scale study would be computationally expensive (due to the size of the molecules involved). Overcoming this limitation will require novel mathematical and computational extensions to our software.
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