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John A. G. Briggs - One of the best experts on this subject based on the ideXlab platform.
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Structure and assembly of the Ebola virus nucleocapsid
Nature, 2017Co-Authors: William Wan, Larissa Kolesnikova, Stephan Becker, Takeshi Noda, Mairi Clarke, Alexander Koehler, John A. G. BriggsAbstract:Ebola and Marburg viruses are filoviruses: filamentous, enveloped viruses that cause haemorrhagic fever. Filoviruses are within the order Mononegavirales, which also includes rabies virus, measles virus, and respiratory syncytial virus. Mononegaviruses have non-segmented, single-stranded negative-sense RNA genomes that are encapsidated by Nucleoprotein and other viral proteins to form a helical nucleocapsid. The nucleocapsid acts as a scaffold for virus assembly and as a template for genome transcription and replication. Insights into Nucleoprotein-Nucleoprotein interactions have been derived from structural studies of oligomerized, RNA-encapsidating Nucleoprotein, and cryo-electron microscopy of nucleocapsid or nucleocapsid-like structures. There have been no high-resolution reconstructions of complete mononegavirus nucleocapsids. Here we apply cryo-electron tomography and subtomogram averaging to determine the structure of Ebola virus nucleocapsid within intact viruses and recombinant nucleocapsid-like assemblies. These structures reveal the identity and arrangement of the nucleocapsid components, and suggest that the formation of an extended α-helix from the disordered carboxy-terminal region of Nucleoprotein-core links Nucleoprotein oligomerization, nucleocapsid condensation, RNA encapsidation, and accessory protein recruitment.
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structural dissection of ebola virus and its assembly determinants using cryo electron tomography
Proceedings of the National Academy of Sciences of the United States of America, 2012Co-Authors: Tanmay A M Bharat, Larissa Kolesnikova, Stephan Becker, James D. Riches, Verena Kraehling, John A. G. BriggsAbstract:Ebola virus is a highly pathogenic filovirus causing severe hemorrhagic fever with high mortality rates. It assembles heterogenous, filamentous, enveloped virus particles containing a negative-sense, single-stranded RNA genome packaged within a helical nucleocapsid (NC). We have used cryo-electron microscopy and tomography to visualize Ebola virus particles, as well as Ebola virus-like particles, in three dimensions in a near-native state. The NC within the virion forms a left-handed helix with an inner Nucleoprotein layer decorated with protruding arms composed of VP24 and VP35. A comparison with the closely related Marburg virus shows that the N-terminal region of Nucleoprotein defines the inner diameter of the Ebola virus NC, whereas the RNA genome defines its length. Binding of the Nucleoprotein to RNA can assemble a loosely coiled NC-like structure; the loose coil can be condensed by binding of the viral matrix protein VP40 to the C terminus of the Nucleoprotein, and rigidified by binding of VP24 and VP35 to alternate copies of the Nucleoprotein. Four proteins (NP, VP24, VP35, and VP40) are necessary and sufficient to mediate assembly of an NC with structure, symmetry, variability, and flexibility indistinguishable from that in Ebola virus particles released from infected cells. Together these data provide a structural and architectural description of Ebola virus and define the roles of viral proteins in its structure and assembly.
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cryo electron tomography of marburg virus particles and their morphogenesis within infected cells
PLOS Biology, 2011Co-Authors: Tanmay A M Bharat, Larissa Kolesnikova, Stephan Becker, James D. Riches, Sonja Welsch, Verena Krahling, Norman E Davey, Marielaure Parsy, John A. G. BriggsAbstract:Several major human pathogens, including the filoviruses, paramyxoviruses, and rhabdoviruses, package their single-stranded RNA genomes within helical nucleocapsids, which bud through the plasma membrane of the infected cell to release enveloped virions. The virions are often heterogeneous in shape, which makes it difficult to study their structure and assembly mechanisms. We have applied cryo-electron tomography and sub-tomogram averaging methods to derive structures of Marburg virus, a highly pathogenic filovirus, both after release and during assembly within infected cells. The data demonstrate the potential of cryo-electron tomography methods to derive detailed structural information for intermediate steps in biological pathways within intact cells. We describe the location and arrangement of the viral proteins within the virion. We show that the N-terminal domain of the Nucleoprotein contains the minimal assembly determinants for a helical nucleocapsid with variable number of proteins per turn. Lobes protruding from alternate interfaces between each Nucleoprotein are formed by the C-terminal domain of the Nucleoprotein, together with viral proteins VP24 and VP35. Each Nucleoprotein packages six RNA bases. The nucleocapsid interacts in an unusual, flexible “Velcro-like” manner with the viral matrix protein VP40. Determination of the structures of assembly intermediates showed that the nucleocapsid has a defined orientation during transport and budding. Together the data show striking architectural homology between the nucleocapsid helix of rhabdoviruses and filoviruses, but unexpected, fundamental differences in the mechanisms by which the nucleocapsids are then assembled together with matrix proteins and initiate membrane envelopment to release infectious virions, suggesting that the viruses have evolved different solutions to these conserved assembly steps.
Guy Schoehn - One of the best experts on this subject based on the ideXlab platform.
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near atomic cryo em structure of the helical measles virus nucleocapsid
Science, 2015Co-Authors: Irina Gutsche, Ambroise Desfosses, Grégory Effantin, Wai-li Ling, Melina Haupt, Carsten Sachse, Guy SchoehnAbstract:Measles is a highly contagious human disease. We used cryo-electron microscopy and single particle-based helical image analysis to determine the structure of the helical nucleocapsid formed by the folded domain of the measles virus Nucleoprotein encapsidating an RNA at a resolution of 4.3 angstroms. The resulting pseudoatomic model of the measles virus nucleocapsid offers important insights into the mechanism of the helical polymerization of nucleocapsids of negative-strand RNA viruses, in particular via the exchange subdomains of the Nucleoprotein. The structure reveals the mode of the Nucleoprotein-RNA interaction and explains why each Nucleoprotein of measles virus binds six nucleotides, whereas the respiratory syncytial virus Nucleoprotein binds seven. It provides a rational basis for further analysis of measles virus replication and transcription, and reveals potential targets for drug design.
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crystal structure of the rabies virus Nucleoprotein rna complex
Science, 2006Co-Authors: Aurélie A V Albertini, Amy K Wernimont, Tadeusz Muziol, Raimond B G Ravelli, Cedric R Clapier, Guy SchoehnAbstract:Negative-strand RNA viruses condense their genome into a helical Nucleoprotein-RNA complex, the nucleocapsid, which is packed into virions and serves as a template for the RNA-dependent RNA polymerase complex. The crystal structure of a recombinant rabies virus Nucleoprotein-RNA complex, organized in an undecameric ring, has been determined at 3.5 angstrom resolution. Polymerization of the Nucleoprotein is achieved by domain exchange between protomers, with flexible hinges allowing nucleocapsid formation. The two core domains of the Nucleoprotein clamp around the RNA at their interface and shield it from the environment. RNA sequestering by Nucleoproteins is likely a common mechanism used by negative-strand RNA viruses to protect their genomes from the innate immune response directed against viral RNA in human host cells at certain stages of an infectious cycle.
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Morphology of Marburg Virus NP–RNA
Virology, 2002Co-Authors: Manos Mavrakis, Larissa Kolesnikova, Guy Schoehn, Stephan BeckerAbstract:Abstract When Marburg virus (MBGV) Nucleoprotein (NP) is expressed in insect cells, it binds to cellular RNA and forms NP–RNA complexes such as insect cell-expressed Nucleoproteins from other nonsegmented negative-strand RNA viruses. Recombinant MBGV NP–RNA forms loose coils that resemble rabies virus N–RNA. MBGV NP monomers are rods that are spaced along the coil similar to the Nucleoprotein monomers of the rabies virus N–RNA. High salt treatment induces tight coiling of the MBGV NP–RNA, again a characteristic observed for other nonsegmented negative-strand virus N–RNAs. Electron microscopy of fixed Marburg virus particles shows that the viral nucleocapsid has a smaller diameter than the free, recombinant NP–RNA. This difference in helical parameters could be caused by the interaction of other viral proteins with the NP–RNA. A similar but opposite phenomenon is observed for rhabdovirus nucleocapsids that are condensed by the viral matrix protein upon which they acquire a larger diameter. Finally, there appears to be an extensive and regular protein scaffold between the viral nucleocapsid and the membrane that seems not to exist in the other negative-strand RNA viruses.
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structure of recombinant rabies virus Nucleoprotein rna complex and identification of the phosphoprotein binding site
Journal of Virology, 2001Co-Authors: Guy Schoehn, Manos Mavrakis, Danielle Blondel, Frédéric Iseni, Rob W H RuigrokAbstract:Rabies virus Nucleoprotein (N) was produced in insect cells, in which it forms Nucleoprotein-RNA (N-RNA) complexes that are biochemically and biophysically indistinguishable from rabies virus N-RNA. We selected recombinant N-RNA complexes that were bound to short insect cellular RNAs which formed small rings containing 9 to 11 N monomers. We also produced recombinant N-RNA rings and viral N-RNA that were treated with trypsin and that had lost the C-terminal quarter of the Nucleoprotein. Trypsin-treated N-RNA no longer bound to recombinant rabies virus phosphoprotein (the viral polymerase cofactor), so the presence of the C-terminal part of N is needed for binding of the phosphoprotein. Both intact and trypsin-treated recombinant N-RNA rings were analyzed with cryoelectron microscopy, and three-dimensional models were calculated from single-particle image analysis combined with back projection. Nucleoprotein has a bilobed shape, and each monomer has two sites of interaction with each neighbor. Trypsin treatment cuts off part of one of the lobes without shortening the protein or changing other structural parameters. Using negative-stain electron microscopy, we visualized phosphoprotein bound to the tips of the N-RNA rings, most likely at the site that can be removed by trypsin. Based on the shape of N determined here and on structural parameters derived from electron microscopy on free rabies virus N-RNA and from nucleocapsid in virus, we propose a low-resolution model for rabies virus N-RNA in the virus.
Stephan Becker - One of the best experts on this subject based on the ideXlab platform.
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Structure and assembly of the Ebola virus nucleocapsid
Nature, 2017Co-Authors: William Wan, Larissa Kolesnikova, Stephan Becker, Takeshi Noda, Mairi Clarke, Alexander Koehler, John A. G. BriggsAbstract:Ebola and Marburg viruses are filoviruses: filamentous, enveloped viruses that cause haemorrhagic fever. Filoviruses are within the order Mononegavirales, which also includes rabies virus, measles virus, and respiratory syncytial virus. Mononegaviruses have non-segmented, single-stranded negative-sense RNA genomes that are encapsidated by Nucleoprotein and other viral proteins to form a helical nucleocapsid. The nucleocapsid acts as a scaffold for virus assembly and as a template for genome transcription and replication. Insights into Nucleoprotein-Nucleoprotein interactions have been derived from structural studies of oligomerized, RNA-encapsidating Nucleoprotein, and cryo-electron microscopy of nucleocapsid or nucleocapsid-like structures. There have been no high-resolution reconstructions of complete mononegavirus nucleocapsids. Here we apply cryo-electron tomography and subtomogram averaging to determine the structure of Ebola virus nucleocapsid within intact viruses and recombinant nucleocapsid-like assemblies. These structures reveal the identity and arrangement of the nucleocapsid components, and suggest that the formation of an extended α-helix from the disordered carboxy-terminal region of Nucleoprotein-core links Nucleoprotein oligomerization, nucleocapsid condensation, RNA encapsidation, and accessory protein recruitment.
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structural dissection of ebola virus and its assembly determinants using cryo electron tomography
Proceedings of the National Academy of Sciences of the United States of America, 2012Co-Authors: Tanmay A M Bharat, Larissa Kolesnikova, Stephan Becker, James D. Riches, Verena Kraehling, John A. G. BriggsAbstract:Ebola virus is a highly pathogenic filovirus causing severe hemorrhagic fever with high mortality rates. It assembles heterogenous, filamentous, enveloped virus particles containing a negative-sense, single-stranded RNA genome packaged within a helical nucleocapsid (NC). We have used cryo-electron microscopy and tomography to visualize Ebola virus particles, as well as Ebola virus-like particles, in three dimensions in a near-native state. The NC within the virion forms a left-handed helix with an inner Nucleoprotein layer decorated with protruding arms composed of VP24 and VP35. A comparison with the closely related Marburg virus shows that the N-terminal region of Nucleoprotein defines the inner diameter of the Ebola virus NC, whereas the RNA genome defines its length. Binding of the Nucleoprotein to RNA can assemble a loosely coiled NC-like structure; the loose coil can be condensed by binding of the viral matrix protein VP40 to the C terminus of the Nucleoprotein, and rigidified by binding of VP24 and VP35 to alternate copies of the Nucleoprotein. Four proteins (NP, VP24, VP35, and VP40) are necessary and sufficient to mediate assembly of an NC with structure, symmetry, variability, and flexibility indistinguishable from that in Ebola virus particles released from infected cells. Together these data provide a structural and architectural description of Ebola virus and define the roles of viral proteins in its structure and assembly.
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cryo electron tomography of marburg virus particles and their morphogenesis within infected cells
PLOS Biology, 2011Co-Authors: Tanmay A M Bharat, Larissa Kolesnikova, Stephan Becker, James D. Riches, Sonja Welsch, Verena Krahling, Norman E Davey, Marielaure Parsy, John A. G. BriggsAbstract:Several major human pathogens, including the filoviruses, paramyxoviruses, and rhabdoviruses, package their single-stranded RNA genomes within helical nucleocapsids, which bud through the plasma membrane of the infected cell to release enveloped virions. The virions are often heterogeneous in shape, which makes it difficult to study their structure and assembly mechanisms. We have applied cryo-electron tomography and sub-tomogram averaging methods to derive structures of Marburg virus, a highly pathogenic filovirus, both after release and during assembly within infected cells. The data demonstrate the potential of cryo-electron tomography methods to derive detailed structural information for intermediate steps in biological pathways within intact cells. We describe the location and arrangement of the viral proteins within the virion. We show that the N-terminal domain of the Nucleoprotein contains the minimal assembly determinants for a helical nucleocapsid with variable number of proteins per turn. Lobes protruding from alternate interfaces between each Nucleoprotein are formed by the C-terminal domain of the Nucleoprotein, together with viral proteins VP24 and VP35. Each Nucleoprotein packages six RNA bases. The nucleocapsid interacts in an unusual, flexible “Velcro-like” manner with the viral matrix protein VP40. Determination of the structures of assembly intermediates showed that the nucleocapsid has a defined orientation during transport and budding. Together the data show striking architectural homology between the nucleocapsid helix of rhabdoviruses and filoviruses, but unexpected, fundamental differences in the mechanisms by which the nucleocapsids are then assembled together with matrix proteins and initiate membrane envelopment to release infectious virions, suggesting that the viruses have evolved different solutions to these conserved assembly steps.
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Morphology of Marburg Virus NP–RNA
Virology, 2002Co-Authors: Manos Mavrakis, Larissa Kolesnikova, Guy Schoehn, Stephan BeckerAbstract:Abstract When Marburg virus (MBGV) Nucleoprotein (NP) is expressed in insect cells, it binds to cellular RNA and forms NP–RNA complexes such as insect cell-expressed Nucleoproteins from other nonsegmented negative-strand RNA viruses. Recombinant MBGV NP–RNA forms loose coils that resemble rabies virus N–RNA. MBGV NP monomers are rods that are spaced along the coil similar to the Nucleoprotein monomers of the rabies virus N–RNA. High salt treatment induces tight coiling of the MBGV NP–RNA, again a characteristic observed for other nonsegmented negative-strand virus N–RNAs. Electron microscopy of fixed Marburg virus particles shows that the viral nucleocapsid has a smaller diameter than the free, recombinant NP–RNA. This difference in helical parameters could be caused by the interaction of other viral proteins with the NP–RNA. A similar but opposite phenomenon is observed for rhabdovirus nucleocapsids that are condensed by the viral matrix protein upon which they acquire a larger diameter. Finally, there appears to be an extensive and regular protein scaffold between the viral nucleocapsid and the membrane that seems not to exist in the other negative-strand RNA viruses.
Rob W H Ruigrok - One of the best experts on this subject based on the ideXlab platform.
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structure of recombinant rabies virus Nucleoprotein rna complex and identification of the phosphoprotein binding site
Journal of Virology, 2001Co-Authors: Guy Schoehn, Manos Mavrakis, Danielle Blondel, Frédéric Iseni, Rob W H RuigrokAbstract:Rabies virus Nucleoprotein (N) was produced in insect cells, in which it forms Nucleoprotein-RNA (N-RNA) complexes that are biochemically and biophysically indistinguishable from rabies virus N-RNA. We selected recombinant N-RNA complexes that were bound to short insect cellular RNAs which formed small rings containing 9 to 11 N monomers. We also produced recombinant N-RNA rings and viral N-RNA that were treated with trypsin and that had lost the C-terminal quarter of the Nucleoprotein. Trypsin-treated N-RNA no longer bound to recombinant rabies virus phosphoprotein (the viral polymerase cofactor), so the presence of the C-terminal part of N is needed for binding of the phosphoprotein. Both intact and trypsin-treated recombinant N-RNA rings were analyzed with cryoelectron microscopy, and three-dimensional models were calculated from single-particle image analysis combined with back projection. Nucleoprotein has a bilobed shape, and each monomer has two sites of interaction with each neighbor. Trypsin treatment cuts off part of one of the lobes without shortening the protein or changing other structural parameters. Using negative-stain electron microscopy, we visualized phosphoprotein bound to the tips of the N-RNA rings, most likely at the site that can be removed by trypsin. Based on the shape of N determined here and on structural parameters derived from electron microscopy on free rabies virus N-RNA and from nucleocapsid in virus, we propose a low-resolution model for rabies virus N-RNA in the virus.
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structure of influenza virus rnp i influenza virus Nucleoprotein melts secondary structure in panhandle rna and exposes the bases to the solvent
The EMBO Journal, 1994Co-Authors: Florence Baudin, Stephen Cusack, C Bach, Rob W H RuigrokAbstract:The influenza virus genome consists of eight segments of negative-sense RNA, i.e. the viral (v) RNA forms the template for the mRNA. Each segment is encapsidated by the viral Nucleoprotein to form a riboNucleoprotein (RNP) particle and each RNP carries its own polymerase complex. We studied the interaction of purified Nucleoprotein with RNA in vitro, by using a variety of enzymatic and chemical probes for RNA conformation. Our results suggest that the Nucleoprotein binds to the vRNA backbone without apparent sequence specificity, exposing the bases to the outside and melting all secondary structure. In this way, the viral polymerase may transcribe the RNA without the need for dissociating the Nucleoprotein and without being stopped by RNA secondary structure, and the viral RNPs are ready to start transcription as soon as they enter the host cell.
Larissa Kolesnikova - One of the best experts on this subject based on the ideXlab platform.
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Structure and assembly of the Ebola virus nucleocapsid
Nature, 2017Co-Authors: William Wan, Larissa Kolesnikova, Stephan Becker, Takeshi Noda, Mairi Clarke, Alexander Koehler, John A. G. BriggsAbstract:Ebola and Marburg viruses are filoviruses: filamentous, enveloped viruses that cause haemorrhagic fever. Filoviruses are within the order Mononegavirales, which also includes rabies virus, measles virus, and respiratory syncytial virus. Mononegaviruses have non-segmented, single-stranded negative-sense RNA genomes that are encapsidated by Nucleoprotein and other viral proteins to form a helical nucleocapsid. The nucleocapsid acts as a scaffold for virus assembly and as a template for genome transcription and replication. Insights into Nucleoprotein-Nucleoprotein interactions have been derived from structural studies of oligomerized, RNA-encapsidating Nucleoprotein, and cryo-electron microscopy of nucleocapsid or nucleocapsid-like structures. There have been no high-resolution reconstructions of complete mononegavirus nucleocapsids. Here we apply cryo-electron tomography and subtomogram averaging to determine the structure of Ebola virus nucleocapsid within intact viruses and recombinant nucleocapsid-like assemblies. These structures reveal the identity and arrangement of the nucleocapsid components, and suggest that the formation of an extended α-helix from the disordered carboxy-terminal region of Nucleoprotein-core links Nucleoprotein oligomerization, nucleocapsid condensation, RNA encapsidation, and accessory protein recruitment.
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structural dissection of ebola virus and its assembly determinants using cryo electron tomography
Proceedings of the National Academy of Sciences of the United States of America, 2012Co-Authors: Tanmay A M Bharat, Larissa Kolesnikova, Stephan Becker, James D. Riches, Verena Kraehling, John A. G. BriggsAbstract:Ebola virus is a highly pathogenic filovirus causing severe hemorrhagic fever with high mortality rates. It assembles heterogenous, filamentous, enveloped virus particles containing a negative-sense, single-stranded RNA genome packaged within a helical nucleocapsid (NC). We have used cryo-electron microscopy and tomography to visualize Ebola virus particles, as well as Ebola virus-like particles, in three dimensions in a near-native state. The NC within the virion forms a left-handed helix with an inner Nucleoprotein layer decorated with protruding arms composed of VP24 and VP35. A comparison with the closely related Marburg virus shows that the N-terminal region of Nucleoprotein defines the inner diameter of the Ebola virus NC, whereas the RNA genome defines its length. Binding of the Nucleoprotein to RNA can assemble a loosely coiled NC-like structure; the loose coil can be condensed by binding of the viral matrix protein VP40 to the C terminus of the Nucleoprotein, and rigidified by binding of VP24 and VP35 to alternate copies of the Nucleoprotein. Four proteins (NP, VP24, VP35, and VP40) are necessary and sufficient to mediate assembly of an NC with structure, symmetry, variability, and flexibility indistinguishable from that in Ebola virus particles released from infected cells. Together these data provide a structural and architectural description of Ebola virus and define the roles of viral proteins in its structure and assembly.
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cryo electron tomography of marburg virus particles and their morphogenesis within infected cells
PLOS Biology, 2011Co-Authors: Tanmay A M Bharat, Larissa Kolesnikova, Stephan Becker, James D. Riches, Sonja Welsch, Verena Krahling, Norman E Davey, Marielaure Parsy, John A. G. BriggsAbstract:Several major human pathogens, including the filoviruses, paramyxoviruses, and rhabdoviruses, package their single-stranded RNA genomes within helical nucleocapsids, which bud through the plasma membrane of the infected cell to release enveloped virions. The virions are often heterogeneous in shape, which makes it difficult to study their structure and assembly mechanisms. We have applied cryo-electron tomography and sub-tomogram averaging methods to derive structures of Marburg virus, a highly pathogenic filovirus, both after release and during assembly within infected cells. The data demonstrate the potential of cryo-electron tomography methods to derive detailed structural information for intermediate steps in biological pathways within intact cells. We describe the location and arrangement of the viral proteins within the virion. We show that the N-terminal domain of the Nucleoprotein contains the minimal assembly determinants for a helical nucleocapsid with variable number of proteins per turn. Lobes protruding from alternate interfaces between each Nucleoprotein are formed by the C-terminal domain of the Nucleoprotein, together with viral proteins VP24 and VP35. Each Nucleoprotein packages six RNA bases. The nucleocapsid interacts in an unusual, flexible “Velcro-like” manner with the viral matrix protein VP40. Determination of the structures of assembly intermediates showed that the nucleocapsid has a defined orientation during transport and budding. Together the data show striking architectural homology between the nucleocapsid helix of rhabdoviruses and filoviruses, but unexpected, fundamental differences in the mechanisms by which the nucleocapsids are then assembled together with matrix proteins and initiate membrane envelopment to release infectious virions, suggesting that the viruses have evolved different solutions to these conserved assembly steps.
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Morphology of Marburg Virus NP–RNA
Virology, 2002Co-Authors: Manos Mavrakis, Larissa Kolesnikova, Guy Schoehn, Stephan BeckerAbstract:Abstract When Marburg virus (MBGV) Nucleoprotein (NP) is expressed in insect cells, it binds to cellular RNA and forms NP–RNA complexes such as insect cell-expressed Nucleoproteins from other nonsegmented negative-strand RNA viruses. Recombinant MBGV NP–RNA forms loose coils that resemble rabies virus N–RNA. MBGV NP monomers are rods that are spaced along the coil similar to the Nucleoprotein monomers of the rabies virus N–RNA. High salt treatment induces tight coiling of the MBGV NP–RNA, again a characteristic observed for other nonsegmented negative-strand virus N–RNAs. Electron microscopy of fixed Marburg virus particles shows that the viral nucleocapsid has a smaller diameter than the free, recombinant NP–RNA. This difference in helical parameters could be caused by the interaction of other viral proteins with the NP–RNA. A similar but opposite phenomenon is observed for rhabdovirus nucleocapsids that are condensed by the viral matrix protein upon which they acquire a larger diameter. Finally, there appears to be an extensive and regular protein scaffold between the viral nucleocapsid and the membrane that seems not to exist in the other negative-strand RNA viruses.
