Homomultimeric structure by assembly of sirv2 p98 proteins or p98 variants, conjugate and uses thereof

The present invention relates to a homomultimeric protein structure constituted by assembled monomers of the P98 protein of Sulfolobus islandicus rod-shaped virus 2 (SIRV2) or assembled monomer variants of said P98 protein. In a particular embodiment, this homomultimeric protein structure has a seven-fold rotational symmetry, and is found in an open conformation or closed conformation. A particular structure has the form of baseless 7-face pyramid. The invention also relates to a conjugate comprising or consisting of a homomultimeric protein structure of the invention to which one or more heterologous molecule(s) is attached. Furthermore, the invention also concerns a homomultimeric protein structure or a conjugate of the invention, inserted into or exposed at the surface of a lipid layer or bilayer, of a vesicle or of a cell, and their uses thereof.