Major capsid protein that self-assembles to form an icosahedral capsid with a T=3 symmetry, about 23 nm in diameter, and consisting of 180 capsid proteins monomers (PubMed:31611039, PubMed:34813955). Most of the 180 monomers are the major capsid protein, but a small percentage contain the minor capsid protein, which has a long C-terminal extension (PubMed:31611039). The N-terminus like those of many plant virus capsid proteins is highly basic. These regions may be involved in protein-RNA interaction. Belongs to the luteoviruses capsid protein family.