Determinación estructural de virus con envuelta lipída mediante crio-microscopía electrónica

Résumé

Viruses are parasitic biological agents that in the virion state contain differentmorphologies and assembly organisations. In some virions, a lipid membrane of cellularorigin is a structural component of the infectious particle. This membrane can belocated as the outermost layer or internally depending on the species. Our work aims atunderstanding the mechanism of assembly and the viral proteins involved in cellularinfection, using for that Cryo-electron microscopy (Cryo-EM) and Cryo-electrontomography (Cryo-ET).In the first case, we present the 3D structures of the archaeal, halophilic, internalmembrane-containing Haloarcula californiae icosahedral virus 1 (HCIV-1) andHaloarcula hispanica icosahedral virus 2 (HHIV-2) at 3.7 and 3.8 Å resolution,respectively, using single-particle cryo-electron microscopy. These structures reveal theviral assembly mechanisms of the capsid shell over the internal membrane and themorphology of the viral receptors.In the second case (ongoing study), using Cryo-ET technique, we have morphologicallycharacterised pleomorphic Bovine Viral Diarrhea Virus 1 (BVDV), as very little isknown about the assembly, virus entry and antibody recognition. Thus, combining cryo-ET with sub-tomogram averaging, we present the preliminary cryo-ET average map ofthe BVDV type 1 bound to mAbs against the glycoproteins Erns.