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1.
PLoS Comput Biol ; 17(12): e1009675, 2021 12.
Article in English | MEDLINE | ID: covidwho-1619980

ABSTRACT

Identifying the epitope of an antibody is a key step in understanding its function and its potential as a therapeutic. Sequence-based clonal clustering can identify antibodies with similar epitope complementarity, however, antibodies from markedly different lineages but with similar structures can engage the same epitope. We describe a novel computational method for epitope profiling based on structural modelling and clustering. Using the method, we demonstrate that sequence dissimilar but functionally similar antibodies can be found across the Coronavirus Antibody Database, with high accuracy (92% of antibodies in multiple-occupancy structural clusters bind to consistent domains). Our approach functionally links antibodies with distinct genetic lineages, species origins, and coronavirus specificities. This indicates greater convergence exists in the immune responses to coronaviruses than is suggested by sequence-based approaches. Our results show that applying structural analytics to large class-specific antibody databases will enable high confidence structure-function relationships to be drawn, yielding new opportunities to identify functional convergence hitherto missed by sequence-only analysis.


Subject(s)
Antigens, Viral/chemistry , COVID-19/immunology , COVID-19/virology , Epitopes, B-Lymphocyte/chemistry , SARS-CoV-2/chemistry , SARS-CoV-2/immunology , Amino Acid Sequence , Animals , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/genetics , Antibodies, Viral/chemistry , Antibodies, Viral/genetics , Antibodies, Viral/metabolism , Antibody Specificity , Antigen-Antibody Complex/chemistry , Antigen-Antibody Complex/genetics , Antigen-Antibody Reactions/genetics , Antigen-Antibody Reactions/immunology , Computational Biology , Coronavirus/chemistry , Coronavirus/genetics , Coronavirus/immunology , Databases, Chemical , Epitope Mapping , Epitopes, B-Lymphocyte/genetics , Humans , Mice , Models, Molecular , Pandemics , SARS-CoV-2/genetics , Single-Domain Antibodies/immunology
2.
Cell ; 184(1): 184-193.e10, 2021 01 07.
Article in English | MEDLINE | ID: covidwho-1385213

ABSTRACT

Transcription of SARS-CoV-2 mRNA requires sequential reactions facilitated by the replication and transcription complex (RTC). Here, we present a structural snapshot of SARS-CoV-2 RTC as it transitions toward cap structure synthesis. We determine the atomic cryo-EM structure of an extended RTC assembled by nsp7-nsp82-nsp12-nsp132-RNA and a single RNA-binding protein, nsp9. Nsp9 binds tightly to nsp12 (RdRp) NiRAN, allowing nsp9 N terminus inserting into the catalytic center of nsp12 NiRAN, which then inhibits activity. We also show that nsp12 NiRAN possesses guanylyltransferase activity, catalyzing the formation of cap core structure (GpppA). The orientation of nsp13 that anchors the 5' extension of template RNA shows a remarkable conformational shift, resulting in zinc finger 3 of its ZBD inserting into a minor groove of paired template-primer RNA. These results reason an intermediate state of RTC toward mRNA synthesis, pave a way to understand the RTC architecture, and provide a target for antiviral development.


Subject(s)
Coronavirus RNA-Dependent RNA Polymerase/chemistry , Cryoelectron Microscopy , RNA, Messenger/chemistry , RNA, Viral/chemistry , SARS-CoV-2/chemistry , Viral Replicase Complex Proteins/chemistry , Amino Acid Sequence , Coronavirus/chemistry , Coronavirus/classification , Coronavirus/enzymology , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Methyltransferases/metabolism , Models, Molecular , RNA Helicases/metabolism , RNA-Binding Proteins/chemistry , RNA-Binding Proteins/metabolism , SARS-CoV-2/enzymology , Sequence Alignment , Transcription, Genetic , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/metabolism , Virus Replication
4.
ACS Appl Mater Interfaces ; 13(26): 30295-30305, 2021 Jul 07.
Article in English | MEDLINE | ID: covidwho-1337092

ABSTRACT

As viruses have been threatening global public health, fast diagnosis has been critical to effective disease management and control. Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) is now widely used as the gold standard for detecting viruses. Although a multiplex assay is essential for identifying virus types and subtypes, the poor multiplicity of RT-qPCR makes it laborious and time-consuming. In this paper, we describe the development of a multiplex RT-qPCR platform with hydrogel microparticles acting as independent reactors in a single reaction. To build target-specific particles, target-specific primers and probes are integrated into the particles in the form of noncovalent composites with boron nitride nanotubes (BNNTs) and carbon nanotubes (CNTs). The thermal release characteristics of DNA, primer, and probe from the composites of primer-BNNT and probe-CNT allow primer and probe to be stored in particles during particle production and to be delivered into the reaction. In addition, BNNT did not absorb but preserved the fluorescent signal, while CNT protected the fluorophore of the probe from the free radicals present during particle production. Bicompartmental primer-incorporated network (bcPIN) particles were designed to harness the distinctive properties of two nanomaterials. The bcPIN particles showed a high RT-qPCR efficiency of over 90% and effective suppression of non-specific reactions. 16-plex RT-qPCR has been achieved simply by recruiting differently coded bcPIN particles for each target. As a proof of concept, multiplex one-step RT-qPCR was successfully demonstrated with a simple reaction protocol.


Subject(s)
Hydrogels/chemistry , Multiplex Polymerase Chain Reaction/methods , Nanotubes, Carbon/chemistry , RNA, Viral/analysis , Reverse Transcriptase Polymerase Chain Reaction/methods , Boron Compounds/chemistry , Coronavirus/chemistry , DNA Primers/chemistry , DNA, Single-Stranded/chemistry , Fluorescent Dyes/chemistry , Graphite/chemistry , Influenza A virus/chemistry , Newcastle disease virus/chemistry , Proof of Concept Study , RNA, Viral/chemistry , Virus Diseases/diagnosis
5.
Arch Virol ; 166(7): 1811-1817, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1155281

ABSTRACT

Coronaviruses are a large family of important pathogens that cause human and animal diseases. At the end of 2019, a pneumonia epidemic caused by a novel coronavirus brought attention to coronaviruses. Exploring the interaction between the virus and its receptor will be helpful in developing preventive vaccines and therapeutic drugs. The coronavirus spike protein (S) plays an important role in both binding to receptors on host cells and fusion of the viral membrane with the host cell membrane. This review introduces the structure and function of the S protein and its receptor, focusing on the binding mode and binding region of both.


Subject(s)
Coronavirus/metabolism , Receptors, Virus/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Binding Sites , COVID-19/metabolism , COVID-19/virology , Coronavirus/chemistry , Coronavirus/physiology , Humans , Protein Binding , Protein Conformation , Receptors, Virus/classification , SARS-CoV-2/chemistry , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/classification , Virus Internalization
6.
Nat Commun ; 12(1): 1607, 2021 03 11.
Article in English | MEDLINE | ID: covidwho-1132069

ABSTRACT

In recognizing the host cellular receptor and mediating fusion of virus and cell membranes, the spike (S) glycoprotein of coronaviruses is the most critical viral protein for cross-species transmission and infection. Here we determined the cryo-EM structures of the spikes from bat (RaTG13) and pangolin (PCoV_GX) coronaviruses, which are closely related to SARS-CoV-2. All three receptor-binding domains (RBDs) of these two spike trimers are in the "down" conformation, indicating they are more prone to adopt the receptor-binding inactive state. However, we found that the PCoV_GX, but not the RaTG13, spike is comparable to the SARS-CoV-2 spike in binding the human ACE2 receptor and supporting pseudovirus cell entry. We further identified critical residues in the RBD underlying different activities of the RaTG13 and PCoV_GX/SARS-CoV-2 spikes. These results collectively indicate that tight RBD-ACE2 binding and efficient RBD conformational sampling are required for the evolution of SARS-CoV-2 to gain highly efficient infection.


Subject(s)
COVID-19/virology , Chiroptera/virology , Coronavirus/chemistry , Coronavirus/genetics , Pangolins/virology , SARS-CoV-2/chemistry , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Amino Acid Sequence , Angiotensin-Converting Enzyme 2/chemistry , Animals , COVID-19/epidemiology , COVID-19/transmission , Cryoelectron Microscopy , Evolution, Molecular , Host Microbial Interactions , Humans , Models, Molecular , Pandemics , Protein Domains , Sequence Homology, Amino Acid , Species Specificity , Spike Glycoprotein, Coronavirus/ultrastructure
7.
Virus Res ; 297: 198382, 2021 05.
Article in English | MEDLINE | ID: covidwho-1118716

ABSTRACT

Coronaviruses are a large group of RNA viruses that infect a wide range of animal species. The replication strategy of coronaviruses involves recombination and mutation events that lead to the possibility of cross-species transmission. The high plasticity of the viral receptor due to a continuous modification of the host species habitat may be the cause of cross-species transmission that can turn into a threat to other species including the human population. The successive emergence of highly pathogenic coronaviruses such as the Severe Acute Respiratory Syndrome (SARS) in 2003, the Middle East Respiratory Syndrome Coronavirus in 2012, and the recent SARS-CoV-2 has incentivized a number of studies on the molecular basis of the coronavirus and its pathogenesis. The high degree of interrelatedness between humans and wild and domestic animals and the modification of animal habitats by human urbanization, has favored new viral spreads. Hence, knowledge on the main clinical signs of coronavirus infection in the different hosts and the distinctive molecular characteristics of each coronavirus is essential to prevent the emergence of new coronavirus diseases. The coronavirus infections routinely studied in veterinary medicine must be properly recognized and diagnosed not only to prevent animal disease but also to promote public health.


Subject(s)
Coronavirus Infections , Coronavirus , Host Specificity , Viral Zoonoses , Animals , Coronavirus/chemistry , Coronavirus/genetics , Coronavirus/physiology , Coronavirus Infections/transmission , Coronavirus Infections/veterinary , Coronavirus Infections/virology , Genome, Viral , Humans , Open Reading Frames , RNA, Viral , Viral Proteins , Viral Structures , Viral Transcription , Viral Zoonoses/transmission , Viral Zoonoses/virology , Virus Assembly , Virus Replication
8.
J Virol ; 95(3)2021 01 13.
Article in English | MEDLINE | ID: covidwho-1039853

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other SARS-related CoVs encode 3 tandem macrodomains within nonstructural protein 3 (nsp3). The first macrodomain, Mac1, is conserved throughout CoVs and binds to and hydrolyzes mono-ADP-ribose (MAR) from target proteins. Mac1 likely counters host-mediated antiviral ADP-ribosylation, a posttranslational modification that is part of the host response to viral infections. Mac1 is essential for pathogenesis in multiple animal models of CoV infection, implicating it as a virulence factor and potential therapeutic target. Here, we report the crystal structure of SARS-CoV-2 Mac1 in complex with ADP-ribose. SARS-CoV-2, SARS-CoV, and Middle East respiratory syndrome coronavirus (MERS-CoV) Mac1 domains exhibit similar structural folds, and all 3 proteins bound to ADP-ribose with affinities in the low micromolar range. Importantly, using ADP-ribose-detecting binding reagents in both a gel-based assay and novel enzyme-linked immunosorbent assays (ELISAs), we demonstrated de-MARylating activity for all 3 CoV Mac1 proteins, with the SARS-CoV-2 Mac1 protein leading to a more rapid loss of substrate than the others. In addition, none of these enzymes could hydrolyze poly-ADP-ribose. We conclude that the SARS-CoV-2 and other CoV Mac1 proteins are MAR-hydrolases with similar functions, indicating that compounds targeting CoV Mac1 proteins may have broad anti-CoV activity.IMPORTANCE SARS-CoV-2 has recently emerged into the human population and has led to a worldwide pandemic of COVID-19 that has caused more than 1.2 million deaths worldwide. With no currently approved treatments, novel therapeutic strategies are desperately needed. All coronaviruses encode a highly conserved macrodomain (Mac1) that binds to and removes ADP-ribose adducts from proteins in a dynamic posttranslational process that is increasingly being recognized as an important factor that regulates viral infection. The macrodomain is essential for CoV pathogenesis and may be a novel therapeutic target. Thus, understanding its biochemistry and enzyme activity are critical first steps for these efforts. Here, we report the crystal structure of SARS-CoV-2 Mac1 in complex with ADP-ribose and describe its ADP-ribose binding and hydrolysis activities in direct comparison to those of SARS-CoV and MERS-CoV Mac1 proteins. These results are an important first step for the design and testing of potential therapies targeting this unique protein domain.


Subject(s)
N-Glycosyl Hydrolases/metabolism , SARS-CoV-2/enzymology , Viral Nonstructural Proteins/metabolism , Adenosine Diphosphate Ribose/chemistry , Adenosine Diphosphate Ribose/metabolism , Amino Acid Sequence , Coronavirus/chemistry , Coronavirus/enzymology , Coronavirus/metabolism , Crystallography, X-Ray , Humans , Hydrolysis , Kinetics , N-Glycosyl Hydrolases/chemistry , Protein Binding , Protein Domains , SARS-CoV-2/chemistry , SARS-CoV-2/metabolism , Viral Nonstructural Proteins/chemistry
9.
J Virol ; 95(3)2021 01 13.
Article in English | MEDLINE | ID: covidwho-1027782

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other SARS-related CoVs encode 3 tandem macrodomains within nonstructural protein 3 (nsp3). The first macrodomain, Mac1, is conserved throughout CoVs and binds to and hydrolyzes mono-ADP-ribose (MAR) from target proteins. Mac1 likely counters host-mediated antiviral ADP-ribosylation, a posttranslational modification that is part of the host response to viral infections. Mac1 is essential for pathogenesis in multiple animal models of CoV infection, implicating it as a virulence factor and potential therapeutic target. Here, we report the crystal structure of SARS-CoV-2 Mac1 in complex with ADP-ribose. SARS-CoV-2, SARS-CoV, and Middle East respiratory syndrome coronavirus (MERS-CoV) Mac1 domains exhibit similar structural folds, and all 3 proteins bound to ADP-ribose with affinities in the low micromolar range. Importantly, using ADP-ribose-detecting binding reagents in both a gel-based assay and novel enzyme-linked immunosorbent assays (ELISAs), we demonstrated de-MARylating activity for all 3 CoV Mac1 proteins, with the SARS-CoV-2 Mac1 protein leading to a more rapid loss of substrate than the others. In addition, none of these enzymes could hydrolyze poly-ADP-ribose. We conclude that the SARS-CoV-2 and other CoV Mac1 proteins are MAR-hydrolases with similar functions, indicating that compounds targeting CoV Mac1 proteins may have broad anti-CoV activity.IMPORTANCE SARS-CoV-2 has recently emerged into the human population and has led to a worldwide pandemic of COVID-19 that has caused more than 1.2 million deaths worldwide. With no currently approved treatments, novel therapeutic strategies are desperately needed. All coronaviruses encode a highly conserved macrodomain (Mac1) that binds to and removes ADP-ribose adducts from proteins in a dynamic posttranslational process that is increasingly being recognized as an important factor that regulates viral infection. The macrodomain is essential for CoV pathogenesis and may be a novel therapeutic target. Thus, understanding its biochemistry and enzyme activity are critical first steps for these efforts. Here, we report the crystal structure of SARS-CoV-2 Mac1 in complex with ADP-ribose and describe its ADP-ribose binding and hydrolysis activities in direct comparison to those of SARS-CoV and MERS-CoV Mac1 proteins. These results are an important first step for the design and testing of potential therapies targeting this unique protein domain.


Subject(s)
N-Glycosyl Hydrolases/metabolism , SARS-CoV-2/enzymology , Viral Nonstructural Proteins/metabolism , Adenosine Diphosphate Ribose/chemistry , Adenosine Diphosphate Ribose/metabolism , Amino Acid Sequence , Coronavirus/chemistry , Coronavirus/enzymology , Coronavirus/metabolism , Crystallography, X-Ray , Humans , Hydrolysis , Kinetics , N-Glycosyl Hydrolases/chemistry , Protein Binding , Protein Domains , SARS-CoV-2/chemistry , SARS-CoV-2/metabolism , Viral Nonstructural Proteins/chemistry
10.
Int J Mol Sci ; 22(1)2020 Dec 23.
Article in English | MEDLINE | ID: covidwho-1011558

ABSTRACT

Our evolutionary and structural analyses revealed that the severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) spike gene is a complex mosaic resulting from several recombination events. Additionally, the fixation of variants has mainly been driven by purifying selection, suggesting the presence of conserved structural features. Our dynamic simulations identified two main long-range covariant dynamic movements of the novel glycoprotein, and showed that, as a result of the evolutionary duality, they are preserved. The first movement involves the receptor binding domain with the N-terminal domain and the C-terminal domain 2 and is maintained across human, bat and pangolin coronaviruses. The second is a complex network of long-range dynamics specific to SARS-CoV-2 involving the novel PRRA and the conserved KR*SF cleavage sites, as well as conserved segments in C-terminal domain 3. These movements, essential for host cell binding, are maintained by hinges conserved across human, bat, and pangolin coronaviruses glycoproteins. The hinges, located around Threonine 333 and Proline 527 within the N-terminal domain and C-terminal domain 2, represent candidate targets for the future development of novel pan-coronavirus inhibitors. In summary, we show that while recombination created a new configuration that increased the covariant dynamic movements of the SARS-CoV-2 glycoprotein, negative selection preserved its inter-domain structure throughout evolution in different hosts and inter-species transmissions.


Subject(s)
Recombination, Genetic , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Amino Acid Sequence , Animals , Chiroptera/virology , Coronavirus/chemistry , Coronavirus/genetics , Evolution, Molecular , Host Specificity , Humans , Molecular Dynamics Simulation , Pangolins/virology , Phylogeny , Protein Binding , Protein Domains , SARS-CoV-2/genetics
11.
Eur J Pharmacol ; 892: 173751, 2021 Feb 05.
Article in English | MEDLINE | ID: covidwho-996863

ABSTRACT

Coronavirus Disease 2019 named as COVID-19 imposing a huge burden on public health as well as global economies, is caused by a new strain of betacoronavirus named as SARS-CoV-2. The high transmission rate of the virus has resulted in current havoc which highlights the need for a fast and effective approach either to prevent or treat the deadly infection. Development of vaccines can be the most prominent approach to prevent the virus to cause COVID-19 and hence will play a vital role in controlling the spread of the virus and reducing mortality. The virus uses its spike proteins for entering into the host by interacting with a specific receptor called angiotensin converting enzyme-2 (ACE2) present on the surface of alveolar cells in the lungs. Researchers all over the world are targeting the spike protein for the development of potential vaccines. Here, we discuss the immunopathological basis of vaccine designing that can be approached for vaccine development against SARS-CoV-2 infection and different platforms that are being used for vaccine development. We believe this review will increase our understanding of the vaccine designing against SARS-CoV-2 and subsequently contribute to the control of SARS-CoV-2 infections. Also, it gives an insight into the current status of vaccine development and associated outcomes reported at different phases of trial.


Subject(s)
COVID-19 Vaccines , Animals , Biological Products/therapeutic use , COVID-19/immunology , COVID-19/prevention & control , Coronavirus/chemistry , Coronavirus/genetics , Drug Design , Drug Development , Humans , Immunologic Factors/therapeutic use , Viral Structures
12.
Microbiol Immunol ; 65(4): 154-160, 2021 Apr.
Article in English | MEDLINE | ID: covidwho-965526

ABSTRACT

Currently, the whole world is facing the coronavirus disease-19 pandemic. As of now, approximately 0.15 million people around the globe are infected with the novel coronavirus. In the last decade, two strains of the coronavirus family, severe acute respiratory syndrome-related coronavirus and Middle East respiratory syndrome coronavirus, also resulted in epidemics in south Asian and the Middle Eastern countries with high mortality rate. This scenario demands the development of a putative vaccine which may provide immunity against all current and new evolving coronavirus strains. In this study, we designed an epitope-based vaccine using an immunoinformatic approach. This vaccine may protect against all coronavirus strains. The vaccine is developed by considering the geographical distribution of coronavirus strains and host genetics (Chinese population). Nine experimentally validated epitopes sequences from coronavirus strains were used to derive the variants considering the conservancy in all strains. Further, the binding affinities of all derived variants were checked with most abundant human leukocyte antigen alleles in the Chinese population. Three major histocompatibility complex (MHC) Class I epitopes from spike glycoprotein and nucleoprotein showed sufficient binding while one MHC Class II epitope from spike glycoprotein was found to be an effective binder. A cocktail of these epitopes gave more than 95% population coverage in the Chinese population. Moreover, molecular dynamics simulation supported the aforementioned predictions. Further, in vivo studies are needed to confirm the immunogenic potential of these vaccines.


Subject(s)
Coronavirus Infections/prevention & control , Coronavirus/immunology , Viral Vaccines/immunology , Alleles , Amino Acid Sequence , China , Coronavirus/chemistry , Coronavirus/genetics , Coronavirus Infections/genetics , Coronavirus Infections/immunology , Coronavirus Infections/virology , Epitopes/chemistry , Epitopes/genetics , Epitopes/immunology , HLA Antigens/genetics , HLA Antigens/immunology , Humans , Molecular Docking Simulation , Molecular Dynamics Simulation , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Viral Vaccines/chemistry , Viral Vaccines/genetics
13.
Microb Pathog ; 150: 104641, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-939160

ABSTRACT

Coronaviruses (CoVs) are causing a number of human and animal diseases because of their zoonotic nature such as Middle East respiratory syndrome (MERS), severe acute respiratory syndrome (SARS) and coronavirus disease 2019 (COVID-19). These viruses can infect respiratory, gastrointestinal, hepatic and central nervous systems of human, livestock, birds, bat, mouse, and many wild animals. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a newly emerging respiratory virus and is causing CoVID-19 with high morbidity and considerable mortality. All CoVs belong to the order Nidovirales, family Coronaviridae, are enveloped positive-sense RNA viruses, characterised by club-like spikes on their surfaces and large RNA genome with a distinctive replication strategy. Coronavirus have the largest RNA genomes (~26-32 kilobases) and their expansion was likely enabled by acquiring enzyme functions that counter the commonly high error frequency of viral RNA polymerases. Non-structural proteins (nsp) 7-16 are cleaved from two large replicase polyproteins and guide the replication and processing of coronavirus RNA. Coronavirus replicase has more or less universal activities, such as RNA polymerase (nsp 12) and helicase (nsp 13), as well as a variety of unusual or even special mRNA capping (nsp 14, nsp 16) and fidelity regulation (nsp 14) domains. Besides that, several smaller subunits (nsp 7- nsp 10) serve as essential cofactors for these enzymes and contribute to the emerging "nsp interactome." In spite of the significant progress in studying coronaviruses structural and functional properties, there is an urgent need to understand the coronaviruses evolutionary success that will be helpful to develop enhanced control strategies. Therefore, it is crucial to understand the structure, function, and interactions of coronaviruses RNA synthesizing machinery and their replication strategies.


Subject(s)
Coronavirus/physiology , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/metabolism , Animals , COVID-19/virology , Coronavirus/chemistry , Coronavirus/genetics , Coronavirus/metabolism , Genome, Viral , Humans , Structure-Activity Relationship , Viral Nonstructural Proteins/genetics , Virus Replication
14.
Biomed Res Int ; 2020: 7234961, 2020.
Article in English | MEDLINE | ID: covidwho-889954

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has a single-stranded RNA genome that encodes 14 open reading frames (ORFs), eight of which encode accessory proteins that allow the virus to infect the host and promote virulence. The genome expresses around 29 structural and nonstructural protein products. The accessory proteins of SARS-CoV-2 are not essential for virus replication but do affect viral release, stability, and pathogenesis and finally contribute to virulence. This paper has attempted the structure prediction and functional analysis of two such accessory proteins, 9b and ORF14, in the absence of experimental structures. Sequence analysis, structure prediction, functional characterization, and evolutionary analysis based on the UniProtKB reviewed the amino acid sequences of SARS-CoV-2 9b (P0DTD2) and ORF14 (P0DTD3) proteins. Modeling has been presented with the introduction of hybrid comparative and ab initio modeling. QMEANDisCo 4.0.0 and ProQ3 for global and local (per residue) quality estimates verified the structures as high quality, which may be attributed to structure-based drug design targets. Tunnel analysis revealed the presence of 1-2 highly active tunneling sites, perhaps which will able to provide certain inputs for advanced structure-based drug design or to formulate potential vaccines in the absence of a complete experimental structure. The evolutionary analysis of both proteins of human SARS-CoV-2 indicates close relatedness to the bat coronavirus. The whole-genome phylogeny indicates that only the new bat coronavirus followed by pangolin coronaviruses has a close evolutionary relationship with the novel SARS-CoV-2.


Subject(s)
COVID-19/virology , Chiroptera/virology , Coronavirus/genetics , Open Reading Frames , SARS-CoV-2/genetics , Viral Proteins/chemistry , Viral Proteins/genetics , Amino Acid Sequence , Animals , Coronavirus/chemistry , Coronavirus/metabolism , Evolution, Molecular , Genome, Viral , Humans , Models, Molecular , Phylogeny , Protein Conformation , SARS-CoV-2/chemistry , SARS-CoV-2/metabolism , Sequence Analysis , Virus Replication
15.
Cell Syst ; 12(1): 82-91.e3, 2021 01 20.
Article in English | MEDLINE | ID: covidwho-856528

ABSTRACT

Viruses deploy genetically encoded strategies to coopt host machinery and support viral replicative cycles. Here, we use protein structure similarity to scan for molecular mimicry, manifested by structural similarity between viral and endogenous host proteins, across thousands of cataloged viruses and hosts spanning broad ecological niches and taxonomic range, including bacteria, plants and fungi, invertebrates, and vertebrates. This survey identified over 6,000,000 instances of structural mimicry; more than 70% of viral mimics cannot be discerned through protein sequence alone. We demonstrate that the manner and degree to which viruses exploit molecular mimicry varies by genome size and nucleic acid type and identify 158 human proteins that are mimicked by coronaviruses, providing clues about cellular processes driving pathogenesis. Our observations point to molecular mimicry as a pervasive strategy employed by viruses and indicate that the protein structure space used by a given virus is dictated by the host proteome. A record of this paper's transparent peer review process is included in the Supplemental Information.


Subject(s)
Coronavirus/genetics , Host-Pathogen Interactions/genetics , Molecular Mimicry/genetics , Viral Proteins/genetics , Virome/genetics , Virus Diseases/genetics , Animals , Coronavirus/chemistry , Culicidae , Databases, Genetic , Humans , Protein Structure, Secondary , Viral Proteins/chemistry , Virus Diseases/epidemiology , Viruses/chemistry , Viruses/genetics
16.
Epidemiol Infect ; 148: e229, 2020 09 29.
Article in English | MEDLINE | ID: covidwho-851179

ABSTRACT

The pandemic due to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has emerged as a serious global public health issue. Since the start of the outbreak, the importance of hand-hygiene and respiratory protection to prevent the spread of the virus has been the prime focus for infection control. Health regulatory organisations have produced guidelines for the formulation of hand sanitisers to the manufacturing industries. This review summarises the studies on alcohol-based hand sanitisers and their disinfectant activity against SARS-CoV-2 and related viruses. The literature shows that the type and concentration of alcohol, formulation and nature of product, presence of excipients, applied volume, contact time and viral contamination load are critical factors that determine the effectiveness of hand sanitisers.


Subject(s)
Alcohols/chemistry , Betacoronavirus/drug effects , Hand Sanitizers/chemistry , Hand Sanitizers/standards , Alcohols/pharmacology , Betacoronavirus/chemistry , COVID-19 , Coronavirus/chemistry , Coronavirus/drug effects , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Drug Contamination , Hand Sanitizers/pharmacology , Humans , Pandemics/prevention & control , Pneumonia, Viral/epidemiology , Pneumonia, Viral/prevention & control , SARS-CoV-2
17.
Vet Microbiol ; 250: 108853, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-779738

ABSTRACT

Coronaviruses (CoVs) is showing obvious interspecies transmission, such as the SARS-CoV, MERS-CoV and SARS-CoV-2. Here, the emerging porcine deltacoronavirus (PDCoV) strain, isolated from Shanghai, China, broadly infects porcine, human and chicken cells in vitro. Previously studies by our group and others have confirmed that PDCoV nucleocapsid (N) protein performs an important role in antagonizing retinoic acid-induced gene I-like receptor (RLR) activation. However, the mechanism of PDCoV N protein suppressing porcine type I IFN production remains unclear, especially the downstream of porcine RLR signaling pathway. In the present study, porcine IRF7 (poIRF7) was identified as the interaction protein of PDCoV N protein through LC-MS/MS. The poIRF7 (268-487aa) was the key region of binding PDCoV N protein. Although IRF7 is a conserved functional protein in species, the PDCoV N protein has been confirmed to interact with only poIRF7 and significantly decrease poIRF7-induced type I IFN production, but not human or chicken IRF7. Furthermore, PDCoV N protein can promote poIRF7 degradation via the ubiquitin-proteasome pathway, which directly increased the K6, K11, and K29-linked polyubiquitination of poIRF7. Lysine 359 of poIRF7 was a key site in PDCoV N protein inducing poIRF7 degradation. Taken together, our results reveal a novel mechanism that PDCoV N protein could species-specifically interact with poIRF7 and then promote its degradation to suppress porcine type I IFN production. The novel findings provide a new insight into PDCoV and other zoonotic coronavirus evading the innate immune response of different species.


Subject(s)
Coronavirus/chemistry , Interferon Regulatory Factor-7/immunology , Interferons/metabolism , Nucleocapsid Proteins/immunology , Animals , Blotting, Western , Cell Line , Chickens , China , Chromatography, Liquid , Coronavirus/classification , Fluorescent Antibody Technique, Indirect , HEK293 Cells , Humans , Immunoprecipitation , Interferons/immunology , LLC-PK1 Cells , Phylogeny , Plasmids , Proteasome Endopeptidase Complex/metabolism , Species Specificity , Swine , Tandem Mass Spectrometry , Ubiquitin/metabolism , Whole Genome Sequencing/veterinary
18.
Biomed Pharmacother ; 130: 110559, 2020 Oct.
Article in English | MEDLINE | ID: covidwho-702922

ABSTRACT

As the number of people infected with the newly identified 2019 novel coronavirus (SARS-CoV2) is continuously increasing every day, development of potential therapeutic platforms is vital. Based on the comparatively high similarity of receptor-binding domain (RBD) in SARS-CoV2 and SARS-CoV, it seems crucial to assay the cross-reactivity of anti-SARS-CoV monoclonal antibodies (mAbs) with SARS-CoV2 spike (S)-protein. Indeed, developing mAbs targeting SARS-CoV2 S-protein RBD could show novel applications for rapid and sensitive development of potential epitope-specific vaccines (ESV). Herein, we present an overview on the discovery of new CoV followed by some explanation on the SARS-CoV2 S-protein RBD site. Furthermore, we surveyed the novel therapeutic mAbs for targeting S-protein RBD such as S230, 80R, F26G18, F26G19, CR3014, CR3022, M396, and S230.15. Afterwards, the mechanism of interaction of RBD and different mAbs were explained and it was suggested that one of the SARS-CoV-specific human mAbs, namely CR3022, could show the highest binding affinity with SARS-CoV2 S-protein RBD. Finally, some ongoing challenges and future prospects for rapid and sensitive advancement of therapeutic mAbs targeting S-protein RBD were discussed. In conclusion, it may be proposed that this review may pave the way for recognition of RBD and different mAbs to develop potential therapeutic ESV.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antigens, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/immunology , Pandemics , Pneumonia, Viral/immunology , Spike Glycoprotein, Coronavirus/immunology , Amino Acid Sequence , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/metabolism , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/metabolism , Antibodies, Viral/chemistry , Antibodies, Viral/metabolism , Antibody Affinity , Antigen-Antibody Reactions , Antigens, Viral/metabolism , Binding Sites, Antibody , COVID-19 , COVID-19 Vaccines , Coronavirus/chemistry , Coronavirus/immunology , Coronavirus Infections/prevention & control , Epitopes/immunology , Humans , Models, Molecular , Phylogeny , Protein Binding , Protein Conformation , Protein Domains , SARS-CoV-2 , Sequence Alignment , Sequence Homology, Amino Acid , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Viral Vaccines/immunology
19.
Nat Commun ; 11(1): 3618, 2020 07 17.
Article in English | MEDLINE | ID: covidwho-651635

ABSTRACT

Global emergencies caused by the severe acute respiratory syndrome coronavirus (SARS-CoV), Middle-East respiratory syndrome coronavirus (MERS-CoV) and SARS-CoV-2 significantly endanger human health. The spike (S) glycoprotein is the key antigen and its conserved S2 subunit contributes to viral entry by mediating host-viral membrane fusion. However, structural information of the post-fusion S2 from these highly pathogenic human-infecting coronaviruses is still lacking. We used single-particle cryo-electron microscopy to show that the post-fusion SARS-CoV S2 forms a further rotated HR1-HR2 six-helix bundle and a tightly bound linker region upstream of the HR2 motif. The structures of pre- and post-fusion SARS-CoV S glycoprotein dramatically differ, resembling that of the Mouse hepatitis virus (MHV) and other class I viral fusion proteins. This structure suggests potential targets for the development of vaccines and therapies against a wide range of SARS-like coronaviruses.


Subject(s)
Betacoronavirus/chemistry , Betacoronavirus/physiology , Spike Glycoprotein, Coronavirus/chemistry , Amino Acid Motifs , COVID-19 , Coronavirus/chemistry , Coronavirus/classification , Coronavirus Infections/virology , Cryoelectron Microscopy , Humans , Membrane Fusion , Models, Molecular , Pandemics , Pneumonia, Viral/virology , Protein Conformation , Protein Multimerization , SARS-CoV-2 , Virus Internalization
20.
Biochemistry ; 59(28): 2608-2615, 2020 07 21.
Article in English | MEDLINE | ID: covidwho-612794

ABSTRACT

The virus that causes COVID-19, SARS-CoV-2, has a large RNA genome that encodes numerous proteins that might be targets for antiviral drugs. Some of these proteins, such as the RNA-dependent RNA polymerase, helicase, and main protease, are well conserved between SARS-CoV-2 and the original SARS virus, but several others are not. This study examines one of the proteins encoded by SARS-CoV-2 that is most different, a macrodomain of nonstructural protein 3 (nsp3). Although 26% of the amino acids in this SARS-CoV-2 macrodomain differ from those observed in other coronaviruses, biochemical and structural data reveal that the protein retains the ability to bind ADP-ribose, which is an important characteristic of beta coronaviruses and a potential therapeutic target.


Subject(s)
Betacoronavirus/chemistry , Viral Nonstructural Proteins/chemistry , Adenosine Diphosphate Ribose/metabolism , COVID-19 , Coronavirus/chemistry , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Coronavirus Papain-Like Proteases , Crystallography, X-Ray , Drug Delivery Systems , Humans , Models, Molecular , Pandemics , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , Protein Domains , SARS-CoV-2 , Thermodynamics , Viral Nonstructural Proteins/metabolism
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