2W69

Influenza polymerase fragment


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.220 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

The CAP-Snatching Endonuclease of Influenza Virus Polymerase Resides in the Pa Subunit

Dias, A.Bouvier, D.Crepin, T.Mccarthy, A.A.Hart, D.J.Baudin, F.Cusack, S.Ruigrok, R.W.H.

(2009) Nature 458: 914

  • DOI: 10.1038/nature07745
  • Primary Citation of Related Structures:  
    2W69

  • PubMed Abstract: 
  • The influenza virus polymerase, a heterotrimer composed of three subunits, PA, PB1 and PB2, is responsible for replication and transcription of the eight separate segments of the viral RNA genome in the nuclei of infected cells. The polymerase synthe ...

    The influenza virus polymerase, a heterotrimer composed of three subunits, PA, PB1 and PB2, is responsible for replication and transcription of the eight separate segments of the viral RNA genome in the nuclei of infected cells. The polymerase synthesizes viral messenger RNAs using short capped primers derived from cellular transcripts by a unique 'cap-snatching' mechanism. The PB2 subunit binds the 5' cap of host pre-mRNAs, which are subsequently cleaved after 10-13 nucleotides by the viral endonuclease, hitherto thought to reside in the PB2 (ref. 5) or PB1 (ref. 2) subunits. Here we describe biochemical and structural studies showing that the amino-terminal 209 residues of the PA subunit contain the endonuclease active site. We show that this domain has intrinsic RNA and DNA endonuclease activity that is strongly activated by manganese ions, matching observations reported for the endonuclease activity of the intact trimeric polymerase. Furthermore, this activity is inhibited by 2,4-dioxo-4-phenylbutanoic acid, a known inhibitor of the influenza endonuclease. The crystal structure of the domain reveals a structural core closely resembling resolvases and type II restriction endonucleases. The active site comprises a histidine and a cluster of three acidic residues, conserved in all influenza viruses, which bind two manganese ions in a configuration similar to other two-metal-dependent endonucleases. Two active site residues have previously been shown to specifically eliminate the polymerase endonuclease activity when mutated. These results will facilitate the optimisation of endonuclease inhibitors as potential new anti-influenza drugs.


    Organizational Affiliation

    Unit of Virus Host-Cell Interactions, UJF-EMBL-CNRS, UMR 5233, 6 rue Jules Horowitz, BP181, 38042 Grenoble Cedex 9, France.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
POLYMERASE ACIDIC PROTEINABD216Influenza A virusMutation(s): 0 
EC: 3.1
Find proteins for P31343 (Influenza A virus (strain A/Victoria/3/1975 H3N2))
Explore P31343 
Go to UniProtKB:  P31343
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download CCD File 
A, B, D
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
MN
Query on MN

Download CCD File 
A, B, D
MANGANESE (II) ION
Mn
WAEMQWOKJMHJLA-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.220 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 67.13α = 90
b = 67.13β = 90
c = 302.95γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling
SHELXDphasing
SHARPphasing
REFMACrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-02-03
    Type: Initial release
  • Version 1.1: 2011-06-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance