Probing the structure of influenza B hemagglutinin using site-directed mutagenesis.
The crystal structure of the hemagglutinin (HA) of influenza virus A/Aichi/68 (H3N2) from the X-31 reassortant virus was reported in 1981, but as yet there are no X-ray diffraction structures for hemagglutinins of other types or even subtypes of influenza virus. We have used site-directed mutagenesis to probe the structure of the hemagglutinin of influenza B/Hong Kong/8/73. We investigated a region in the globular head domain that is helical in the influenza A HA structure, targeting sidechains that in the H3 HA point toward solvent (Thr196) or into the receptor-binding pocket (Gln197). None of the mutations affected hemagglutination activity, but mutations T196P or Q1971 eliminated binding of a monoclonal antibody. The data suggest that this region of the influenza B HA forms a surface structure different from the alpha-helix of the influenza A HA structure and that it accounts for much of the antigenic activity of influenza B HA.
Department of Microbiology, University of Alabama at Birmingham 35294.
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Rivera
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Thomas
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Zhang
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Bossart-Whitaker
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Wei
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D006224:Cricetinae; D004912:Erythrocytes / Q000502:physiology / Q000821:virology; D004926:Escherichia coli; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D009980:Influenza A virus / Q000737:chemistry; D009981:Influenza B virus / Q000737:chemistry*; D007668:Kidney; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides; D017433:Protein Structure, Secondary; D011991:Receptors, Virus / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014759:Viral Envelope Proteins / Q000737:chemistry; D014961:X-Ray Diffraction
D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral; D009838:Oligodeoxyribonucleotides; D011991:Receptors, Virus; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins