title: Identification of a major intermediate along the self-assembly pathway of an icosahedral viral capsid by using an analytical model of a spherical patch.
abstract: Viruses are astonishing edifices in which hundreds of molecular building blocks fit into the final structure with pinpoint accuracy. We established a robust kinetic model accounting for the in vitro self-assembly of a capsid shell derived from an icosahedral plant virus by using time-resolved small-angle X-ray scattering (TR-SAXS) data at high spatiotemporal resolution. By implementing an analytical model of a spherical patch into a global fitting algorithm, we managed to identify a major intermediate species along the self-assembly pathway. With a series of data collected at different protein concentrations, we showed that free dimers self-assembled into a capsid through an intermediate resembling a half-capsid. The typical lifetime of the intermediate was a few seconds and yet the presence of so large an oligomer was not reported before. The progress in instrumental detection along with the development of powerful algorithms for data processing contribute to shedding light on nonequilibrium processes in highly complex systems such as viruses.
authors.affiliation: Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France. doru.constantin@u-psud.fr guillaume.tresset@u-psud.fr.
authors.forename: Didier
authors.initials: D
authors.lastname: Law-Hine
authors.affiliation: Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France. doru.constantin@u-psud.fr guillaume.tresset@u-psud.fr.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Zeghal
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bressanelli
authors.affiliation: Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France. doru.constantin@u-psud.fr guillaume.tresset@u-psud.fr.
authors.forename: Doru
authors.initials: D
authors.lastname: Constantin
authors.affiliation: Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France. doru.constantin@u-psud.fr guillaume.tresset@u-psud.fr.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Tresset
mesh_terms: D002213:Capsid / Q000737:chemistry*; D036022:Capsid Proteins / Q000737:chemistry*; D053838:Scattering, Small Angle; D014771:Virion / Q000502:physiology*; D019065:Virus Assembly; D014961:X-Ray Diffraction
chemical_list: D036022:Capsid Proteins