5JJ3

Refined Structure of the Mature Virion Conformation of P22 Portal Protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 7.00 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.239 
  • R-Value Observed: 0.240 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Portal protein functions akin to a DNA-sensor that couples genome-packaging to icosahedral capsid maturation.

Lokareddy, R.K.Sankhala, R.S.Roy, A.Afonine, P.V.Motwani, T.Teschke, C.M.Parent, K.N.Cingolani, G.

(2017) Nat Commun 8: 14310-14310

  • DOI: 10.1038/ncomms14310
  • Primary Citation of Related Structures:  
    5JJ1, 5JJ3

  • PubMed Abstract: 
  • Tailed bacteriophages and herpesviruses assemble infectious particles via an empty precursor capsid (or 'procapsid') built by multiple copies of coat and scaffolding protein and by one dodecameric portal protein. Genome packaging triggers rearrangement of the coat protein and release of scaffolding protein, resulting in dramatic procapsid lattice expansion ...

    Tailed bacteriophages and herpesviruses assemble infectious particles via an empty precursor capsid (or 'procapsid') built by multiple copies of coat and scaffolding protein and by one dodecameric portal protein. Genome packaging triggers rearrangement of the coat protein and release of scaffolding protein, resulting in dramatic procapsid lattice expansion. Here, we provide structural evidence that the portal protein of the bacteriophage P22 exists in two distinct dodecameric conformations: an asymmetric assembly in the procapsid (PC-portal) that is competent for high affinity binding to the large terminase packaging protein, and a symmetric ring in the mature virion (MV-portal) that has negligible affinity for the packaging motor. Modelling studies indicate the structure of PC-portal is incompatible with DNA coaxially spooled around the portal vertex, suggesting that newly packaged DNA triggers the switch from PC- to MV-conformation. Thus, we propose the signal for termination of 'Headful Packaging' is a DNA-dependent symmetrization of portal protein.


    Organizational Affiliation

    Institute of Biomembranes and Bioenergetics, National Research Council, Via Amendola 165/A, 70126 Bari, Italy.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Portal proteinABCDEFGHABCDEFGHIJKL
725Salmonella virus P22Mutation(s): 0 
Gene Names: 1
Find proteins for P26744 (Salmonella phage P22)
Explore P26744 
Go to UniProtKB:  P26744
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 7.00 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.239 
  • R-Value Observed: 0.240 
  • Space Group: I 4
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 409.043α = 90
b = 409.043β = 90
c = 260γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
PHENIXphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM100888
National Institutes of Health/National Cancer Institute (NIH/NCI)United StatesP30CA56036

Revision History  (Full details and data files)

  • Version 1.0: 2017-02-08
    Type: Initial release
  • Version 1.1: 2017-02-15
    Changes: Database references
  • Version 1.2: 2017-09-27
    Changes: Author supporting evidence
  • Version 1.3: 2019-12-04
    Changes: Author supporting evidence