Biological Assembly 1  

 3D View: Structure

Global Symmetry: Icosahedral - I  (3D View)
Global Stoichiometry: Homo 180-mer - A180 

Biological assembly 1 assigned by authors and generated by (software)

Macromolecule Content

• Total Structure Weight: 41.22 kDa 
• Atom Count: 3065 
• Residue Count: 387 
• Unique protein chains: 1

2MS2

THE REFINED STRUCTURE OF BACTERIOPHAGE MS2 AT 2.8 ANGSTROMS RESOLUTION

• DOI: 10.2210/pdb2MS2/pdb
• Entry: 2MS2 supersedes: 1MS2

• Classification: VIRUS
• Organism(s): Enterobacteria phage MS2
• Mutation(s): No 


• Deposited: 1994-08-23 Released: 1995-01-26 
• Deposition Author(s): Valegard, K., Liljas, L.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Work: 0.189 
• R-Value Observed: 0.189 

Literature

The refined structure of bacteriophage MS2 at 2.8 A resolution.

Golmohammadi, R., Valegard, K., Fridborg, K., Liljas, L.

(1993) J Mol Biol 234: 620-639

• PubMed: 8254664 
• DOI: 10.1006/jmbi.1993.1616
• Structures With Same Primary Citation


• PubMed Abstract: 
  

Bacteriophage MS2 is an icosahedral virus with 180 copies of a coat protein forming a shell around a single-stranded RNA molecule. The coat protein subunits form a lattice with the triangulation number T = 3. The coat protein has a fold which is different from the fold of all other viral coat proteins so far known. It consists of a five-stranded beta sheet facing the inside of the particle, and a hairpin and two helices on the outside. The crystal structure has been refined at 2.8 A resolution. The final R-factor was 0.189 for reflections with F > 2 sigma, and the root-mean-square deviation from idealized bond lengths and bond angles was 0.015 A and 2.9 degrees, respectively. The three chemically identical conformers A, B and C are largely similar. The B conformer has a unique conformation in one loop, which is involved in 5-fold interactions, while the A and C conformers, which are involved in the quasi-6-fold contacts, are similar throughout the structure. One cis-proline has been identified in the B conformer but the corresponding prolines in A and C are of the trans isomer. This residue is conserved within small RNA coliphages and it is proposed that this isomerization enables a less elongated loop (FG) around the 5-fold axis, thus creating a channel. The extensive dimer contact supports the idea of dimers as initial building blocks. An assembly pathway is proposed where five dimers converge into a pentamer and 12 pentamers are linked together with free dimers creating a complete particle.

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Related Citations: 

• Structure Determination of the Bacteriophage MS2
  Valegard, K., Liljas, L., Fridborg, K., Unge, T.
  (1991) Acta Crystallogr B 47: 949

• The Three-Dimensional Structure of the Bacterial Virus MS2
  Valegard, K., Liljas, L., Fridborg, K., Unge, T.
  (1990) Nature 345: 36

• The Structure of Bacteriophage MS2
  Liljas, L., Valegard, K.
  (1990) Semin Virol 1: 467

• Purification, Crystallization and Preliminary X-Ray Data of the Bacteriophage MS2
  Valegard, K., Unge, T., Montelius, I., Strandberg, B., Fiers, W.
  (1986) J Mol Biol 190: 587

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Organizational Affiliation: 

Department of Molecular Biology, Uppsala University Uppsala Biomedical Centre, Sweden.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
BACTERIOPHAGE MS2 COAT PROTEIN	A, B, C	129	Enterobacteria phage MS2	Mutation(s): 0
Find proteins for P03612 (Escherichia phage MS2) Go to UniProtKB:  P03612

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Work: 0.189 
• R-Value Observed: 0.189 
• Space Group: H 3 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 288	α = 90
b = 288	β = 90
c = 653	γ = 120

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1994-08-23 
• Released Date: 1995-01-26 
Deposition Author(s): Valegard, K., Liljas, L.
• This entry supersedes: 1MS2

Revision History 

• Version 1.0: 1995-01-26
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance