Structural basis for paramyxovirus-mediated membrane fusion.
Paramyxoviruses are responsible for significant human mortality and disease worldwide, but the molecular mechanisms underlying their entry into host cells remain poorly understood. We have solved the crystal structure of a fragment of the simian parainfluenza virus 5 fusion protein (SV5 F), revealing a 96 A long coiled coil surrounded by three antiparallel helices. This structure places the fusion and transmembrane anchor of SV5 F in close proximity with a large intervening domain at the opposite end of the coiled coil. Six amino acids, potentially part of the fusion peptide, form a segment of the central coiled coil, suggesting that this structure extends into the membrane. Deletion mutants of SV5 F indicate that putative flexible tethers between the coiled coil and the viral membrane are dispensable for fusion. The lack of flexible tethers may couple a final conformational change in the F protein directly to the fusion of two bilayers.
Baker
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Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston, Illinois 60208-3500, USA.
Dutch
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Lamb
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Jardetzky
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D000595:Amino Acid Sequence; D017124:Conserved Sequence; D003460:Crystallization; D019281:Dimerization; D004583:Electrons; D006860:Hydrogen Bonding; D007477:Ions; D008561:Membrane Fusion; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D018108:Respirovirus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion; D014760:Viral Fusion Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D007477:Ions; D010446:Peptide Fragments; D014760:Viral Fusion Proteins