C-terminal domain of Measles virus phosphoprotein and related proteins
This family includes the C-terminal domain of the P protein of plant viruses belonging to the Paramyxoviridae family such as measles virus and mumps virus. The family Paramyxoviridae belongs to the order Mononegavirales which are nonsegmented negative-stranded RNA viruses (NNVs). The genomes of NNVs are encapsidated by their nucleocapsid (N) proteins to form N-RNA complexes which serves as a template for transaction and replication. The C-terminus of P protein binds nucleocapsid. P protein plays multiple roles in transcription and translation, which include acting as a chaperone of nascent nucleoprotein (N), and as a cofactor of the viral polymerase (L) where P forms a two-subunit polymerase with a large catalytic subunit (L) and stabilizes the polymerase on its template of N-RNA. Paramyxoviruses have a polycistronic phosphoprotein (P) gene which encodes for proteins in addition to P protein; for example the measles virus P gene encodes for P protein and virulence factor V (MV-V). This domain family includes the unshared C-terminal domain of P protein not present in MV-V.