title: (19)F NMR reveals multiple conformations at the dimer interface of the nonstructural protein 1 effector domain from influenza A virus.
abstract: Nonstructural protein 1 of influenza A virus (NS1A) is a conserved virulence factor comprised of an N-terminal double-stranded RNA (dsRNA)-binding domain and a multifunctional C-terminal effector domain (ED), each of which can independently form symmetric homodimers. Here we apply (19)F NMR to NS1A from influenza A/Udorn/307/1972 virus (H3N2) labeled with 5-fluorotryptophan, and we demonstrate that the (19)F signal of Trp187 is a sensitive, direct monitor of the ED helix:helix dimer interface. (19)F relaxation dispersion data reveal the presence of conformational dynamics within this functionally important protein:protein interface, whose rate is more than three orders of magnitude faster than the kinetics of ED dimerization. (19)F NMR also affords direct spectroscopic evidence that Trp187, which mediates intermolecular ED:ED interactions required for cooperative dsRNA binding, is solvent exposed in full-length NS1A at concentrations below aggregation. These results have important implications for the diverse roles of this NS1A epitope during influenza virus infection.
authors.affiliation: Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, and Northeast Structural Genomics Consortium, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, U.S.A.
authors.forename: James M
authors.initials: JM
authors.lastname: Aramini
authors.affiliation: Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, and Northeast Structural Genomics Consortium, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, U.S.A.
authors.forename: Keith
authors.initials: K
authors.lastname: Hamilton
authors.affiliation: Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, and Northeast Structural Genomics Consortium, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, U.S.A.
authors.forename: Li-Chung
authors.initials: LC
authors.lastname: Ma
authors.affiliation: Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, and Northeast Structural Genomics Consortium, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, U.S.A.
authors.forename: G V T
authors.initials: GVT
authors.lastname: Swapna
authors.affiliation: Department of Biochemistry and Molecular Biology and Center for Biomolecular Structure and Function, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, U.S.A.
authors.forename: Paul G
authors.initials: PG
authors.lastname: Leonard
authors.affiliation: Department of Biochemistry and Molecular Biology and Center for Biomolecular Structure and Function, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, U.S.A.
authors.forename: John E
authors.initials: JE
authors.lastname: Ladbury
authors.affiliation: Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, Center for Infectious Disease, University of Texas, Austin, Texas 78712, U.S.A.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Krug
authors.affiliation: Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, and Northeast Structural Genomics Consortium, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, U.S.A.|Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey 08854, U.S.A.
authors.forename: Gaetano T
authors.initials: GT
authors.lastname: Montelione
mesh_terms: D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D066235:Fluorine-19 Magnetic Resonance Imaging; D015870:Gene Expression; D053122:Influenza A Virus, H3N2 Subtype / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012330:RNA, Double-Stranded / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D014364:Tryptophan / Q000031:analogs & derivatives* / Q000737:chemistry; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000235:genetics
chemical_list: D012330:RNA, Double-Stranded; D011994:Recombinant Proteins; D017361:Viral Nonstructural Proteins; C026927:5-fluorotryptophan; D014364:Tryptophan