title: Structural insights into the membrane fusion mechanism mediated by influenza virus hemagglutinin.
abstract: Membrane fusion is involved in many fundamental cellular processes and entry of enveloped viruses into host cells. Influenza type A virus HA has long served as a paradigm for mechanistic studies of protein-mediated membrane fusion via large-scale structural rearrangements induced by acidic pH. Here we report the newly determined crystal structure of influenza B virus HA2 in the postfusion state. Together with a large number of previously determined prefusion structures of influenza A and B virus HA and a postfusion structure of influenza A/H3N2 HA2, we identified conserved features that are shared between influenza A and B virus HA in the conformational transition and documented substantial differences that likely influence the detailed mechanisms of this process. Further studies are needed to dissect the effects of these and other structural differences in HA conformational changes and influenza pathogenicity and transmission, which may ultimately expedite the discovery of novel anti-influenza fusion inhibitors.
authors.affiliation: Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine , One Baylor Plaza, Houston, Texas 77030, United States.
authors.forename: Fengyun
authors.initials: F
authors.lastname: Ni
authors.forename: Xiaorui
authors.initials: X
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Shen
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Wang
mesh_terms: D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry*; D053122:Influenza A Virus, H3N2 Subtype / Q000378:metabolism; D009981:Influenza B virus / Q000378:metabolism*; D008561:Membrane Fusion; D008958:Models, Molecular; D011487:Protein Conformation
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus