Capsid protein self assembles to form an icosahedral capsid with a T=3 symmetry, about 38 nm in diameter, and consisting of 180 capsid proteins. A smaller form of capsid with a diameter of 23 nm might be capsid proteins assembled as icosahedron with T=1 symmetry. The capsid encapsulate the genomic RNA and VP2 proteins. Attaches virion to target cells by binding to feline junctional adhesion molecule A (F11R) and/or to alpha-2,6-linked sialic acid. Once attached, the virion is endocytosed. Acidification of the endosome induces conformational change of capsid protein thereby injecting virus genomic RNA into host cytoplasm (By similarity). Homodimerizes, then multimerizes. May bind to VP3 and Vpg proteins. Binds to alpha-2,6-linked sialic acid at surface of target cells. Interacts with host F11R (By similarity). Cleaved by virus calcivirin to produce mature capsid protein. Cleaved by host caspase-2 and caspase-6 to generate protein p40. Belongs to the caliciviridae capsid protein family.