Assembles with the minor capsid protein to form an icosahedral capsid with a T=7 symmetry, about 60 nm in diameter, and consisting of 415 capsid proteins. The major and minor capsid proteins are incorporated into the capsid in about a 90/10 ratio respectively. Once the capsid formed, encapsidates one single copy of the viral genome. Homohexamer. Interacts with the connector protein and the minor capsid protein. Interacts with the capsid assembly scaffolding protein; capsid proteins and scaffolding proteins form building blocks that assemble to form the procapsid, each hexamer of the major capsid protein interacting with 2 scaffolding proteins. The N-terminus interacts with an internal region of the major capsid protein subunit in an adjacent capsomere (intercapsomeric interactions) to stabilize the capsid. Produced by conventional translation. Belongs to the T7virus major capsid protein family.