+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-31431 | |||||||||
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Title | Cyanophage A-1(L) capsid asymmetric unit | |||||||||
Map data | The whole capsid structure of cyanophage A-1(L) | |||||||||
Sample |
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Keywords | Major capsid proteins / VIRUS | |||||||||
Function / homology | Putative major capsid protein Function and homology information | |||||||||
Biological species | Nostoc phage A1 (virus) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 3.35 Å | |||||||||
Authors | Cui N / Li Q | |||||||||
Funding support | China, 1 items
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Citation | Journal: J Virol / Year: 2021 Title: Capsid Structure of Cyanophage A-1(L). Authors: Ning Cui / Feng Yang / Jun-Tao Zhang / Hui Sun / Yu Chen / Rong-Cheng Yu / Zhi-Peng Chen / Yong-Liang Jiang / Shu-Jing Han / Xudong Xu / Qiong Li / Cong-Zhao Zhou / Abstract: A-1(L) is a freshwater cyanophage with a contractile tail that specifically infects sp. PCC 7120, one of the model strains for molecular studies of cyanobacteria. Although isolated for half a ...A-1(L) is a freshwater cyanophage with a contractile tail that specifically infects sp. PCC 7120, one of the model strains for molecular studies of cyanobacteria. Although isolated for half a century, its structure remains unknown, which limits our understanding on the interplay between A-1(L) and its host. Here we report the 3.35 Å cryo-EM structure of A-1(L) capsid, representing the first near-atomic resolution structure of a phage capsid with a T number of 9. The major capsid gp4 proteins assemble into 91 capsomers, including 80 hexons: 20 at the center of the facet and 60 at the facet edge, in addition to 11 identical pentons. These capsomers further assemble into the icosahedral capsid, via gradually increasing curvatures. Different from the previously reported capsids of known-structure, A-1(L) adopts a noncovalent chainmail structure of capsid stabilized by two kinds of mortise-and-tenon inter-capsomer interactions: a three-layered interface at the pseudo 3-fold axis combined with the complementarity in shape and electrostatic potential around the 2-fold axis. This unique capsomer construction enables A-1(L) to possess a rigid capsid, which is solely composed of the major capsid proteins with an HK97 fold. Cyanobacteria are the most abundant photosynthetic bacteria, contributing significantly to the biomass production, O generation, and CO consumption on our planet. Their community structure and homeostasis in natural aquatic ecosystems are largely regulated by the corresponding cyanophages. In this study, we solved the structure of cyanophage A-1(L) capsid at near-atomic resolution and revealed a unique capsid construction. This capsid structure provides the molecular details for better understanding the assembly of A-1(L), and a structural platform for future investigation and application of A-1(L) in combination with its host sp. PCC 7120. As the first isolated freshwater cyanophage that infects the genetically tractable model cyanobacterium, A-1(L) should become an ideal template for the genetic engineering and synthetic biology studies. | |||||||||
History |
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-Structure visualization
Movie |
Movie viewer |
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Structure viewer | EM map: SurfViewMolmilJmol/JSmol |
Supplemental images |
-Downloads & links
-EMDB archive
Map data | emd_31431.map.gz | 1.8 GB | EMDB map data format | |
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Header (meta data) | emd-31431-v30.xml emd-31431.xml | 9.6 KB 9.6 KB | Display Display | EMDB header |
Images | emd_31431.png | 52.4 KB | ||
Filedesc metadata | emd-31431.cif.gz | 5 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-31431 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-31431 | HTTPS FTP |
-Validation report
Summary document | emd_31431_validation.pdf.gz | 746.9 KB | Display | EMDB validaton report |
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Full document | emd_31431_full_validation.pdf.gz | 746.5 KB | Display | |
Data in XML | emd_31431_validation.xml.gz | 9.6 KB | Display | |
Data in CIF | emd_31431_validation.cif.gz | 11.1 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-31431 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-31431 | HTTPS FTP |
-Related structure data
Related structure data | 7f38MC M: atomic model generated by this map C: citing same article (ref.) |
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Similar structure data |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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-Map
File | Download / File: emd_31431.map.gz / Format: CCP4 / Size: 1.9 GB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Annotation | The whole capsid structure of cyanophage A-1(L) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 1.22 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
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-Supplemental data
-Sample components
-Entire : Nostoc phage A1
Entire | Name: Nostoc phage A1 (virus) |
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Components |
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-Supramolecule #1: Nostoc phage A1
Supramolecule | Name: Nostoc phage A1 / type: virus / ID: 1 / Parent: 0 / Macromolecule list: all / NCBI-ID: 1775256 / Sci species name: Nostoc phage A1 / Virus type: VIRION / Virus isolate: OTHER / Virus enveloped: No / Virus empty: No |
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Host (natural) | Organism: Nostoc sp. PCC 7120 = FACHB-418 (bacteria) |
-Macromolecule #1: Putative major capsid protein
Macromolecule | Name: Putative major capsid protein / type: protein_or_peptide / ID: 1 / Number of copies: 9 / Enantiomer: LEVO |
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Source (natural) | Organism: Nostoc phage A1 (virus) |
Molecular weight | Theoretical: 39.524617 KDa |
Recombinant expression | Organism: Nostoc phage A1 (virus) |
Sequence | String: MPLTNLTPTE LLANKAVDYL ANSFLVETPM LGLLANRVIN QKQKAIEWGA KVAQGVVGGR TRTGALANDT QGTIKGASLS VPDYYIKHQ FDVGKDEIVN SDATGKISAV RDPVGTAIAD AFDVLSKKIN SVLYTASGVA DATNYGIFGL DAAAGTTVAN S ATGTYAGI ...String: MPLTNLTPTE LLANKAVDYL ANSFLVETPM LGLLANRVIN QKQKAIEWGA KVAQGVVGGR TRTGALANDT QGTIKGASLS VPDYYIKHQ FDVGKDEIVN SDATGKISAV RDPVGTAIAD AFDVLSKKIN SVLYTASGVA DATNYGIFGL DAAAGTTVAN S ATGTYAGI SKVTFPRWRS IIQGGAVPGT NEALTIARMT AMLRARRTAG VTYKGNQNQR LVILTSDNIE NDVLRPLYGT VV DNQNVDF TRLDKDLLPY VNYMVKGIPV VSDIDCPANK MYLLNLDKLA IYSFDQSDAD QSNGKITYIP LRYVDETGDT PSE STLWVR LADVSDEHPD LLKFELSVAL QLVAFDLIDS ISVIRDITQ UniProtKB: Putative major capsid protein |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Buffer | pH: 7.5 |
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Vitrification | Cryogen name: ETHANE |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Image recording | Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Average electron dose: 50.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: SPOT SCAN / Imaging mode: BRIGHT FIELD |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
-Image processing
Startup model | Type of model: INSILICO MODEL |
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Final reconstruction | Resolution.type: BY AUTHOR / Resolution: 3.35 Å / Resolution method: FSC 0.143 CUT-OFF / Number images used: 32687 |
Initial angle assignment | Type: RANDOM ASSIGNMENT |
Final angle assignment | Type: RANDOM ASSIGNMENT |