Together with the penton and the other minor capsid proteins (M1249L, p17), forms a complicated network immediately below the outer capsid shell, stabilizing the whole capsid (By similarity). Plays an essential role in the formation of infectious virus particles. Especially required for the formation of the capsid vertices (By similarity). During virion assembly, associates with the membrane and probably mediates the docking of the penton complex to the inner membrane, where it recruits the capsomers to form the penton core (By similarity). Localizes in close proximity to the capsid vertices. Expressed in the late phase of the viral replicative cycle. Belongs to the asfivirus p49 structural protein family.