title: X-ray structures of NS1 effector domain mutants.
abstract: The influenza A virus nonstructural protein NS1 is a multifunctional dimeric protein that acts as a potent inhibitor of the host cellular antiviral state. The C-terminal effector domain of NS1 binds host proteins, including CPSF30, and is a target for the development of new antiviral drugs. Here we present crystallographic structures of two mutant effector domains, W187Y and W187A, of influenza A/Udorn/72 virus. Unlike wild-type, the mutants behave exclusively as monomers in solution based on gel filtration data and light scattering. The W187Y mutant is able to bind CPSF30 with a binding affinity close to the wild-type protein; that is, it retains a receptor site for aromatic ligands nearly identical to the wild-type. Therefore, this monomeric mutant protein could serve as a drug target for a high throughput inhibitor screening assays, since its binding pocket is unoccupied in solution and potentially more accessible to small molecule ligands.
authors.affiliation: Institute for Cellular and Molecular Biology, Department of Chemistry and Biochemistry, University of Texas, 1 University Station A5300, Austin, TX 78712, USA.
authors.forename: Shuangluo
authors.initials: S
authors.lastname: Xia
authors.forename: Jon D
authors.initials: JD
authors.lastname: Robertus
mesh_terms: D000818:Animals; D039223:Cleavage And Polyadenylation Specificity Factor / Q000378:metabolism; D018360:Crystallography, X-Ray; D004353:Drug Evaluation, Preclinical; D053122:Influenza A Virus, H3N2 Subtype; D008958:Models, Molecular; D050505:Mutant Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D017434:Protein Structure, Tertiary / Q000235:genetics; D012996:Solutions; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism
chemical_list: D039223:Cleavage And Polyadenylation Specificity Factor; C085820:INS1 protein, influenza virus; D050505:Mutant Proteins; D012996:Solutions; D017361:Viral Nonstructural Proteins