Journal: J Mol Biol / Year: 2010 Title: Mutually-induced conformational switching of RNA and coat protein underpins efficient assembly of a viral capsid. Authors: Óttar Rolfsson / Katerina Toropova / Neil A Ranson / Peter G Stockley / Abstract: Single-stranded RNA viruses package their genomes into capsids enclosing fixed volumes. We assayed the ability of bacteriophage MS2 coat protein to package large, defined fragments of its genomic, ...Single-stranded RNA viruses package their genomes into capsids enclosing fixed volumes. We assayed the ability of bacteriophage MS2 coat protein to package large, defined fragments of its genomic, single-stranded RNA. We show that the efficiency of packaging into a T=3 capsid in vitro is inversely proportional to RNA length, implying that there is a free-energy barrier to be overcome during assembly. All the RNAs examined have greater solution persistence lengths than the internal diameter of the capsid into which they become packaged, suggesting that protein-mediated RNA compaction must occur during assembly. Binding ethidium bromide to one of these RNA fragments, which would be expected to reduce its flexibility, severely inhibited packaging, consistent with this idea. Cryo-EM structures of the capsids assembled in these experiments with the sub-genomic RNAs show a layer of RNA density beneath the coat protein shell but lack density for the inner RNA shell seen in the wild-type virion. The inner layer is restored when full-length virion RNA is used in the assembly reaction, implying that it becomes ordered only when the capsid is filled, presumably because of the effects of steric and/or electrostatic repulsions. The cryo-EM results explain the length dependence of packaging. In addition, they show that for the sub-genomic fragments the strongest ordered RNA density occurs below the coat protein dimers forming the icosahedral 5-fold axes of the capsid. There is little such density beneath the proteins at the 2-fold axes, consistent with our model in which coat protein dimers binding to RNA stem-loops located at sites throughout the genome leads to switching of their preferred conformations, thus regulating the placement of the quasi-conformers needed to build the T=3 capsid. The data are consistent with mutual chaperoning of both RNA and coat protein conformations, partially explaining the ability of such viruses to assemble so rapidly and accurately.
History
Deposition
Feb 21, 2011
-
Header (metadata) release
May 13, 2011
-
Map release
May 13, 2011
-
Update
Sep 26, 2012
-
Current status
Sep 26, 2012
Processing site: PDBe / Status: Released
-
Structure visualization
Movie
Surface view with section colored by density value
Entire : Bacteriophage MS2 virus-like particles assembled in vitro from pu...
Entire
Name: Bacteriophage MS2 virus-like particles assembled in vitro from purified MS2 coat protein and 3' genomic RNA fragments (nts 992-3569).
Components
Sample: Bacteriophage MS2 virus-like particles assembled in vitro from purified MS2 coat protein and 3' genomic RNA fragments (nts 992-3569).
Virus: Enterobacterio phage MS2 (virus)
RNA: Single stranded MS2 RNA
-
Supramolecule #1000: Bacteriophage MS2 virus-like particles assembled in vitro from pu...
Supramolecule
Name: Bacteriophage MS2 virus-like particles assembled in vitro from purified MS2 coat protein and 3' genomic RNA fragments (nts 992-3569). type: sample / ID: 1000 / Oligomeric state: One capsid to one RNA / Number unique components: 2
-
Supramolecule #1: Enterobacterio phage MS2
Supramolecule
Name: Enterobacterio phage MS2 / type: virus / ID: 1 / Name.synonym: MS2 / NCBI-ID: 12022 / Sci species name: Enterobacterio phage MS2 / Virus type: VIRUS-LIKE PARTICLE / Virus isolate: STRAIN / Virus enveloped: No / Virus empty: No / Syn species name: MS2
Host (natural)
Organism: Escherichia coli (E. coli) / synonym: BACTERIA(EUBACTERIA)
Virus shell
Shell ID: 1 / Diameter: 280 Å / T number (triangulation number): 3
-
Macromolecule #1: Single stranded MS2 RNA
Macromolecule
Name: Single stranded MS2 RNA / type: rna / ID: 1 / Name.synonym: Single stranded MS2 RNA Details: nucleotides 991-3569 was made by in vitro transcription from a cDNA template of the MS2 genome. Classification: OTHER / Structure: SINGLE STRANDED / Synthetic?: No
Category: FILM / Film or detector model: KODAK SO-163 FILM / Digitization - Scanner: OTHER / Digitization - Sampling interval: 9.88 µm / Average electron dose: 18 e/Å2
Electron beam
Acceleration voltage: 200 kV / Electron source: FIELD EMISSION GUN
In the structure databanks used in Yorodumi, some data are registered as the other names, "COVID-19 virus" and "2019-nCoV". Here are the details of the virus and the list of structure data.
Jan 31, 2019. EMDB accession codes are about to change! (news from PDBe EMDB page)
EMDB accession codes are about to change! (news from PDBe EMDB page)
The allocation of 4 digits for EMDB accession codes will soon come to an end. Whilst these codes will remain in use, new EMDB accession codes will include an additional digit and will expand incrementally as the available range of codes is exhausted. The current 4-digit format prefixed with “EMD-” (i.e. EMD-XXXX) will advance to a 5-digit format (i.e. EMD-XXXXX), and so on. It is currently estimated that the 4-digit codes will be depleted around Spring 2019, at which point the 5-digit format will come into force.
The EM Navigator/Yorodumi systems omit the EMD- prefix.
Related info.:Q: What is EMD? / ID/Accession-code notation in Yorodumi/EM Navigator
Yorodumi is a browser for structure data from EMDB, PDB, SASBDB, etc.
This page is also the successor to EM Navigator detail page, and also detail information page/front-end page for Omokage search.
The word "yorodu" (or yorozu) is an old Japanese word meaning "ten thousand". "mi" (miru) is to see.
Related info.:EMDB / PDB / SASBDB / Comparison of 3 databanks / Yorodumi Search / Aug 31, 2016. New EM Navigator & Yorodumi / Yorodumi Papers / Jmol/JSmol / Function and homology information / Changes in new EM Navigator and Yorodumi