4EQK

Crystal structure of the cap-binding domain of polymerase basic protein 2 from influenza virus A/Hong Kong/1/68 (h3n2) with bound m7GTP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.183 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural and functional characterization of K339T substitution identified in the PB2 subunit cap-binding pocket of influenza A virus

Liu, Y.Qin, K.Meng, G.Zhang, J.Zhou, J.Zhao, G.Luo, M.Zheng, X.

(2013) J.Biol.Chem. 288: 11013-11023

  • DOI: 10.1074/jbc.M112.392878
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Influenza virus RNA-dependent RNA polymerase is a heterotrimer composed of PA, PB1, and PB2 subunits. RNA-dependent RNA polymerase is required for both transcription and replication of influenza viral RNA taking place in the nucleus of infected cells ...

    Influenza virus RNA-dependent RNA polymerase is a heterotrimer composed of PA, PB1, and PB2 subunits. RNA-dependent RNA polymerase is required for both transcription and replication of influenza viral RNA taking place in the nucleus of infected cells. A "cap-snatching" mechanism is used to generate a 5'-capped primer for transcription in which the cap-binding domain of PB2 (PB2cap) captures the 5' cap of the host pre-mRNA. Our statistical analysis of PB2 sequences showed that residue Lys(339) located in the cap-binding pocket of H5N1 PB2cap was gradually replaced by Thr(339) over the past decade. To understand the role of this amino acid polymorphism, we solved the crystal structures of PB2cap with or without a pre-mRNA cap analog, m(7)GTP, in the presence of Lys(339) or Thr(339). The structures showed that Lys(339) contributes to binding the γ-phosphate group of m(7)GTP, and the replacement of Lys(339) by Thr eliminates this interaction. Isothermal titration calorimetry analysis showed that Thr(339) attenuated the PB2cap cap binding activity in vitro compared with Lys(339). Further functional studies confirmed that Thr(339)-PB2-containing ribonucleoprotein complex has a reduced influenza polymerase activity and RNA synthesis activity, and a reconstituted H5N1 virus containing the Thr(339) substitution exhibited a lower virulence to mice but more active replication in Madin-Darby canine kidney cells. The K339T substitution in the cap-binding pocket of PB2 modulates the polymerase activity and virulence by regulating the cap binding activity. It is informative to track variations in the cap-binding pocket of PB2 in surveillance of the evolution and spread of influenza virus.


    Organizational Affiliation

    State Key Lab of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Polymerase basic protein 2
A
170Influenza A virus (strain A/Hong Kong/1/1968 H3N2)Mutation(s): 0 
Gene Names: PB2
Find proteins for Q91MB1 (Influenza A virus (strain A/Hong Kong/1/1968 H3N2))
Go to UniProtKB:  Q91MB1
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MGT
Query on MGT

Download SDF File 
Download CCD File 
A
7N-METHYL-8-HYDROGUANOSINE-5'-TRIPHOSPHATE
C11 H20 N5 O14 P3
BUJQMJUTTBGELS-KQYNXXCUSA-N
 Ligand Interaction
NO3
Query on NO3

Download SDF File 
Download CCD File 
A
NITRATE ION
N O3
NHNBFGGVMKEFGY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.183 
  • Space Group: I 2 2 2
Unit Cell:
Length (Å)Angle (°)
a = 55.379α = 90.00
b = 70.151β = 90.00
c = 93.941γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data collection
MOLREPphasing
REFMACrefinement
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-03-06
    Type: Initial release
  • Version 1.1: 2014-03-12
    Type: Database references