title: Structural intermediates in the fusion-associated transition of vesiculovirus glycoprotein.
abstract: Vesiculoviruses enter cells by membrane fusion, driven by a large, low-pH-induced, conformational change in the fusion glycoprotein G that involves transition from a trimeric pre-fusion toward a trimeric post-fusion state via monomeric intermediates. Here, we present the structure of the G fusion protein at intermediate pH for two vesiculoviruses, vesicular stomatitis virus (VSV) and Chandipura virus (CHAV), which is responsible for deadly encephalopathies. First, a CHAV G crystal structure shows two intermediate conformations forming a flat dimer of heterodimers. On virions, electron microscopy (EM) and tomography reveal monomeric spikes similar to one of the crystal conformations. In solution, mass spectrometry shows dimers of G. Finally, mutations at a dimer interface, involving fusion domains associated in an antiparallel manner to form an intermolecular β-sheet, affect G fusion properties. The location of the compensatory mutations restoring fusion activity strongly suggests that this interface is functionally relevant. This work reveals the range of G structural changes and suggests that G monomers can re-associate, through antiparallel interactions between fusion domains, into dimers that play a role at some early stage of the fusion process.
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France.
authors.forename: Eduard
authors.initials: E
authors.lastname: Baquero
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France.
authors.forename: Aurélie A
authors.initials: AA
authors.lastname: Albertini
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Raux
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France.
authors.forename: Abbas
authors.initials: A
authors.lastname: Abou-Hamdan
authors.affiliation: CNRS, CEA, Institut de Biologie Structurale (IBS), Université Grenoble Alpes, Grenoble, France.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Boeri-Erba
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France.
authors.forename: Malika
authors.initials: M
authors.lastname: Ouldali
authors.affiliation: Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Linda
authors.initials: L
authors.lastname: Buonocore
authors.affiliation: Yale University School of Medicine, New Haven, CT, USA.
authors.forename: John K
authors.initials: JK
authors.lastname: Rose
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France jean.lepault@i2bc.paris-saclay.fr stephane.bressanelli@i2bc.paris-saclay.fr yves.gaudin@i2bc.paris-saclay.fr.
authors.forename: Jean
authors.initials: J
authors.lastname: Lepault
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France jean.lepault@i2bc.paris-saclay.fr stephane.bressanelli@i2bc.paris-saclay.fr yves.gaudin@i2bc.paris-saclay.fr.
authors.forename: Stéphane
authors.identifier: 0000-0002-0921-6727
authors.initials: S
authors.lastname: Bressanelli
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France jean.lepault@i2bc.paris-saclay.fr stephane.bressanelli@i2bc.paris-saclay.fr yves.gaudin@i2bc.paris-saclay.fr.
authors.forename: Yves
authors.identifier: 0000-0002-0122-2954
authors.initials: Y
authors.lastname: Gaudin
mesh_terms: D018360:Crystallography, X-Ray; D006023:Glycoproteins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D008854:Microscopy, Electron; D008954:Models, Biological; D008958:Models, Molecular; D011487:Protein Conformation; D055503:Protein Multimerization; D014054:Tomography; D018116:Vesiculovirus / Q000502:physiology*; D014759:Viral Envelope Proteins / Q000378:metabolism*; D053586:Virus Internalization
chemical_list: D006023:Glycoproteins; D014759:Viral Envelope Proteins
keywords: conformational change; glycoprotein; intermediate structures; membrane fusion; vesiculovirus