N
Domain
Ncore is globular and carries regions required for N self-assembly and RNA-binding. Ntail is an intrinsically disordered monomeric domain in the C-terminus.
Function
Forms the helical nucleocapsid (NC) in a ratio of 1 N per 6 ribonucleotides, protecting the genome from nucleases (By similarity). The nucleocapsid (NC) has a helical structure with either 12.35 or 11.64 N per turn, approximately 20 nm in diameter, with a hollow central cavity approximately 5 nm in diameter (By similarity). The encapsidated genomic RNA serves as template for transcription and replication; encapsidation by N is coupled to RNA synthesis (By similarity). Forms the encapsidation complex with the phosphoprotein protein P (By similarity). Before encapsidation, the newly synthesized free N protein, so-called N0, is chaperoned by P (By similarity). Participates, together with P, in the formation of viral factories (viroplasms), which are large inclusions in the host cytoplasm where replication takes place (By similarity). N is released in the blood following lysis of measles infected cells, it interacts then with human FCGR2B on immune cells, inducing apoptosis and blocking inflammatory immune response (By similarity).
Post-translational modifications
Phosphorylation at Thr-279 is required for the formation of the nucleocapsid.
Sequence Similarities
Belongs to the paramyxoviruses nucleocapsid family.
Cellular localization
- Virion
- Host cytoplasm
- Host nucleus
Alternative names
NP, N, Nucleoprotein, Nucleocapsid protein, Protein N