Viral protein

The genetic material of a virus is stored within a viral protein structure called the capsid.

The capsid is a "shield" that protects the viral nucleic acids from getting degraded by host enzymes or other types of pesticides or pestilences.

[2] Three asymmetric and nonidentical viral protein units make up each of the twenty identical triangular faces in the icosahedral capsid.

Viral membrane fusion proteins act as catalysts to overcome this high energy barrier.

[1] Viral nonstructural 4b (NS4B) protein alters the host cell's membrane and starts the formation process of the replication complex.

[1][7] The immune response of a host to an infected cell can be adjusted through the immunomodulatory properties of viral nonstructural proteins.

[1] Viral regulatory and accessory proteins also influence and adjust cellular functions of the host cell, such as the regulation of genes, and apoptosis.

[12] However, in some instances, maintaining the replication of viruses would require the help (and function) of viral accessory proteins.

[12] Syncytin is an endogenous retrovirus protein that has been captured in the mammalian genome to allow membrane fusion in placental morphogenesis.