The nonstructural protein NS1A from influenza virus is a multifunctional
virulence factor and a potent inhibitor of host immunity. It has two functional
domains: an N-terminal 73-amino-acid RNA-binding domain and a C-terminal
effector domain. Here, the crystallographic structure of the NS1A effector
domain of influenza A/Udorn/72 virus is presented. Structure comparison with the
NS1 effector domain from mouse-adapted influenza A/Puerto Rico/8/34 (PR8) virus
strain reveals a similar monomer conformation but a different dimer interface.
Further analysis and evaluation shows that the dimer interface observed in the
structure of the PR8 NS1 effector domain is likely to be a crystallographic
packing effect. A hypothetical model of the intact NS1 dimer is presented.
Figure 1.
Electron density for the influenza A/Udorn/72 NS1A effector
domain. This is a section of a 2F [o] [minus sign] F [c] map
contoured at 1[sigma] to show the interface of the
effector-domain dimer. Acta Crystallogr D Biol Crystallogr. 2009
January 1; 65(Pt 1): 11–17. Published online 2008 December 19.
doi: 10.1107/S0907444908032186. Copyright [copyright]
International Union of Crystallography 2009
Figure 4.
The dimer interface for the influenza A/Udorn/72 NS1A
effector domain. (a) A space-filling model of monomer subunit A
reveals a distinct largely hydrophobic pocket that has evolved
to bind aromatic residues from the F2F3 domain of CPSF30. Here,
Trp187 from effector domain monomer subunit B (shown in blue)
binds in that pocket. (b) A detailed view of the interactions of
Trp187 with monomer subunit A binding-cleft residues (shown in
green). Acta Crystallogr D Biol Crystallogr. 2009 January 1;
65(Pt 1): 11–17. Published online 2008 December 19. doi:
10.1107/S0907444908032186. Copyright [copyright] International
Union of Crystallography 2009
The above figures are
reprinted
from an Open Access publication published by the IUCr:
Acta Crystallogr D Biol Crystallogr
(2009,
65,
11-17)
copyright 2009.
