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Open data
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Basic information
Entry | Database: EMDB / ID: EMD-4421 | |||||||||
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Title | Representative tomogram of immature M-PMV particles | |||||||||
![]() | Representative tomogram of immature M-PMV particles for subtomogram averaging | |||||||||
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Biological species | ![]() | |||||||||
Method | electron tomography / cryo EM | |||||||||
![]() | Qu K / Glass B / Dolezal M / Schur FKM / Rein A / Rumlova M / Ruml T / Kraeusslich HG / Briggs JAG | |||||||||
![]() | ![]() Title: Structure and architecture of immature and mature murine leukemia virus capsids. Authors: Kun Qu / Bärbel Glass / Michal Doležal / Florian K M Schur / Brice Murciano / Alan Rein / Michaela Rumlová / Tomáš Ruml / Hans-Georg Kräusslich / John A G Briggs / ![]() ![]() ![]() ![]() ![]() Abstract: Retroviruses assemble and bud from infected cells in an immature form and require proteolytic maturation for infectivity. The CA (capsid) domains of the Gag polyproteins assemble a protein lattice as ...Retroviruses assemble and bud from infected cells in an immature form and require proteolytic maturation for infectivity. The CA (capsid) domains of the Gag polyproteins assemble a protein lattice as a truncated sphere in the immature virion. Proteolytic cleavage of Gag induces dramatic structural rearrangements; a subset of cleaved CA subsequently assembles into the mature core, whose architecture varies among retroviruses. Murine leukemia virus (MLV) is the prototypical γ-retrovirus and serves as the basis of retroviral vectors, but the structure of the MLV CA layer is unknown. Here we have combined X-ray crystallography with cryoelectron tomography to determine the structures of immature and mature MLV CA layers within authentic viral particles. This reveals the structural changes associated with maturation, and, by comparison with HIV-1, uncovers conserved and variable features. In contrast to HIV-1, most MLV CA is used for assembly of the mature core, which adopts variable, multilayered morphologies and does not form a closed structure. Unlike in HIV-1, there is similarity between protein-protein interfaces in the immature MLV CA layer and those in the mature CA layer, and structural maturation of MLV could be achieved through domain rotations that largely maintain hexameric interactions. Nevertheless, the dramatic architectural change on maturation indicates that extensive disassembly and reassembly are required for mature core growth. The core morphology suggests that wrapping of the genome in CA sheets may be sufficient to protect the MLV ribonucleoprotein during cell entry. | |||||||||
History |
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Structure visualization
Movie |
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Supplemental images |
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Downloads & links
-EMDB archive
Map data | ![]() | 3.7 GB | ![]() | |
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Header (meta data) | ![]() ![]() | 11.9 KB 11.9 KB | Display Display | ![]() |
Images | ![]() | 140.9 KB | ||
Archive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 0290C ![]() 0291C ![]() 0292C ![]() 0293C ![]() 4419C ![]() 4422C ![]() 6gzaC ![]() 6hwiC ![]() 6hwwC ![]() 6hwxC ![]() 6hwyC C: citing same article ( |
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Links
EMDB pages | ![]() ![]() |
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Map
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Annotation | Representative tomogram of immature M-PMV particles for subtomogram averaging | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 2.7 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
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-Supplemental data
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Sample components
-Entire : Mason-Pfizer monkey virus
Entire | Name: ![]() |
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Components |
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-Supramolecule #1: Mason-Pfizer monkey virus
Supramolecule | Name: Mason-Pfizer monkey virus / type: virus / ID: 1 / Parent: 0 / Macromolecule list: #1 / NCBI-ID: 11855 / Sci species name: Mason-Pfizer monkey virus / Virus type: VIRION / Virus isolate: STRAIN / Virus enveloped: Yes / Virus empty: No |
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Host system | Organism: ![]() |
-Experimental details
-Structure determination
Method | cryo EM |
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![]() | electron tomography |
Aggregation state | particle |
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Sample preparation
Buffer | pH: 6 |
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Grid | Model: C-flat-2/1 / Material: COPPER / Mesh: 300 / Support film - Material: CARBON / Support film - topology: HOLEY / Pretreatment - Type: GLOW DISCHARGE |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 95 % / Chamber temperature: 288 K / Instrument: FEI VITROBOT MARK II |
Details | Purified virus solution was inactivated and diluted 1:1 with PBS containing 10 nm colloidal gold. |
Sectioning | Other: NO SECTIONING |
Fiducial marker | Manufacturer: UMC Utrecht / Diameter: 10 nm |
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Electron microscopy
Microscope | FEI TITAN KRIOS |
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Specialist optics | Energy filter - Name: GIF Quantum LS / Energy filter - Slit width: 20 eV |
Image recording | Film or detector model: GATAN K2 QUANTUM (4k x 4k) / Detector mode: SUPER-RESOLUTION / Digitization - Dimensions - Width: 3710 pixel / Digitization - Dimensions - Height: 3838 pixel / Digitization - Sampling interval: 5.0 µm / Digitization - Frames/image: 1-6 / Number grids imaged: 1 / Average exposure time: 0.6 sec. / Average electron dose: 2.0 e/Å2 Details: Dose fluctuation was caused by the ring collapse of FEG during data collection. |
Electron beam | Acceleration voltage: 300 kV / Electron source: ![]() |
Electron optics | C2 aperture diameter: 50.0 µm / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.7 mm / Nominal defocus max: 4.5 µm / Nominal defocus min: 2.0 µm / Nominal magnification: 105000 |
Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN |
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Image processing
Final reconstruction | Software - Name: eTomo / Number images used: 41 | ||||||
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CTF correction | Software:
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