4P9A: X-ray Crystal Structure of PA protein from Influenza strain H7N9

Influenza A viruses cause the respiratory illness influenza, which can be mild to fatal depending on the strain and host immune response. The flu polymerase acidic (PA), polymerase basic 1 (PB1), and polymerase basic 2 (PB2) proteins comprise the RNA-dependent RNA polymerase complex responsible for viral genome replication. The first crystal structures of the C-terminal domain of PA (PA-CTD) in the absence of PB1-derived peptides show a number of structural changes relative to the previously reported PB1-peptide bound structures. The human A/WSN/1933 (H1N1) and avian A/Anhui1/2013 (H7N9) strain PA-CTD proteins exhibit the same global topology as other strains in the absence of PB1, but differ extensively in the PB1 binding pocket including a widening of the binding groove and the unfolding of a beta-turn. Both PA-CTD proteins exhibited a significant increase in thermal stability in the presence of either a PB1-derived peptide or a previously reported inhibitor in differential scanning fluorimetry assays. These structural changes demonstrate plasticity in the PA-PB1 binding interface which may be exploited in the development of novel therapeutics.
PDB ID: 4P9ADownload
MMDB ID: 121936
PDB Deposition Date: 2014/4/2
Updated in MMDB: 2017/12
Experimental Method:
x-ray diffraction
Resolution: 2.1999  Å
Source Organism:
Similar Structures:
Biological Unit for 4P9A: monomeric; determined by software (PISA)
Molecular Components in 4P9A
Label Count Molecule
Protein (1 molecule)
Polymerase PA
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB