Proteins found mainly in icosahedral DNA and RNA viruses. They consist of proteins directly associated with the nucleic acid inside the NUCLEOCAPSID.

Synonyms: Protein P19, Viral, Core Proteins, Virus, Core Protein, Major, Virus Core Proteins, Major Core Protein, Influenza Virus Core Proteins, Protein, Major Core, Major Core Protein lambda 1, Viral Protein P19, Major Core Proteins, Viral, Adenovirus Core Protein VII, Proteins, P30 Core, Proteins, Virus Core, Major Core Protein sigma-2, Protein P19, Oncornaviral, P30 Core Proteins, Viral Core Proteins, 0, OVP 19, Major Core Protein sigma 2, Major Core Protein lambda-1, Proteins, Viral Core, Oncornaviral Protein P19, Core Protein lambda 2, Core Protein V, Core Proteins, P30, Core Proteins, Viral