title: A Second RNA-Binding Site in the NS1 Protein of Influenza B Virus.
abstract: Influenza viruses cause a highly contagious respiratory disease in humans. The NS1 proteins of influenza A and B viruses (NS1A and NS1B proteins, respectively) are composed of two domains, a dimeric N-terminal domain and a C-terminal domain, connected by a flexible polypeptide linker. Here we report the 2.0-Å X-ray crystal structure and nuclear magnetic resonance studies of the NS1B C-terminal domain, which reveal a novel and unexpected basic RNA-binding site that is not present in the NS1A protein. We demonstrate that single-site alanine replacements of basic residues in this site lead to reduced RNA-binding activity, and that recombinant influenza B viruses expressing these mutant NS1B proteins are severely attenuated in replication. This novel RNA-binding site of NS1B is required for optimal influenza B virus replication. Most importantly, this study reveals an unexpected RNA-binding function in the C-terminal domain of NS1B, a novel function that distinguishes influenza B viruses from influenza A viruses.
authors.affiliation: Department of Molecular Biology and Biochemistry, Center for Advanced Biotechnology and Medicine, Rutgers, The State University of New Jersey, Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA.
authors.forename: Li-Chung
authors.initials: LC
authors.lastname: Ma
authors.affiliation: Department of Molecular Biology and Biochemistry, Center for Advanced Biotechnology and Medicine, Rutgers, The State University of New Jersey, Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA.
authors.forename: Rongjin
authors.initials: R
authors.lastname: Guan
authors.affiliation: Department of Molecular Biology and Biochemistry, Center for Advanced Biotechnology and Medicine, Rutgers, The State University of New Jersey, Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA.
authors.forename: Keith
authors.initials: K
authors.lastname: Hamilton
authors.affiliation: Department of Molecular Biology and Biochemistry, Center for Advanced Biotechnology and Medicine, Rutgers, The State University of New Jersey, Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Aramini
authors.affiliation: Department of Molecular Biology and Biochemistry, Center for Advanced Biotechnology and Medicine, Rutgers, The State University of New Jersey, Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Mao
authors.affiliation: Department of Molecular Biosciences, Center for Infectious Disease, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Molecular Biosciences, Center for Infectious Disease, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA. Electronic address: rkrug@austin.utexas.edu.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Krug
authors.affiliation: Department of Molecular Biology and Biochemistry, Center for Advanced Biotechnology and Medicine, Rutgers, The State University of New Jersey, Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA; Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA. Electronic address: gtm@rutgers.edu.
authors.forename: Gaetano T
authors.initials: GT
authors.lastname: Montelione
mesh_terms: D000072283:A549 Cells; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001665:Binding Sites; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D015870:Gene Expression; D006801:Humans; D009980:Influenza A virus / Q000235:genetics* / Q000378:metabolism; D009981:Influenza B virus / Q000235:genetics* / Q000378:metabolism; D007700:Kinetics; D008958:Models, Molecular; D009154:Mutation; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D017433:Protein Structure, Secondary; D012367:RNA, Viral / Q000737:chemistry* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013379:Substrate Specificity; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014779:Virus Replication
chemical_list: C085820:INS1 protein, influenza virus; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D017361:Viral Nonstructural Proteins