Nucleocapsid protein of severe acute respiratory syndrome coronavirus 2 (N protein)

The nucleocapsid protein of severe acute respiratory syndrome coronavirus 2 (N protein or Nucleocapsid (N) protein) is a highly expressed, multifunctional viral structural protein essential for the coronavirus life cycle[2][8][5]. Structurally, it contains two major domains: an N-terminal RNA-binding domain and a C-terminal oligomerization/dimerization domain, connected by a disordered linker region with post-translational modifications including phosphorylation and methylation[5][3]. Its key biological role is to bind and compress the ~30 kb positive-sense viral RNA genome for packaging into new virions, a process facilitated by the protein’s propensity for oligomerization and phase separation with RNA[3][6]. The N protein also participates in viral replication and assembly, modulates immune responses, and is the most abundantly produced viral antigen during infection, making it a prominent target for diagnostic assays and a potential target for antiviral drug development[2][8][5]. Unlike most approved COVID-19 therapies which target the spike protein, the N protein’s high conservation offers potential for pan-coronavirus therapeutic strategies but also presents challenges owing to its intrinsic disorder and dynamic interactions[8][4][6]. Currently, no clinically approved drugs directly target the N protein, though candidate inhibitors that disrupt RNA binding or protein oligomerization are under investigation[2][6][8].

Other names

SARS-CoV-2 nucleocapsid proteinN proteinCoronavirus nucleocapsid proteinNucleocapsid (N) protein

Inhibition of RNA binding by N protein (prevents genome encapsidation)[2][6]. Inhibition of oligomerization or phase separation (disrupts genome packaging and virion assembly)[2][6][4].