Assembles with the major capsid protein to form an icosahedral capsid with a T=7 symmetry, about 60 nm in diameter, and consisting of 415 capsid proteins (PubMed:20962334). 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. Interacts with the connector protein and the major capsid protein. The minor capsid protein is produced by a -1 ribosomal frameshift near the C-terminus of the ORF coding for the major capsid protein, producing a protein with a C-terminal extension compared to the major capsid protein. The major capsid protein is produced by conventional translation of the same ORF. Produced by -1 ribosomal frameshifting. Belongs to the T7virus minor capsid protein family.