Analysis of the N-terminus of nucleocapsid protein of Mason-Pfizer monkey virus: its role in the particle assembly.

摘要

Assembly of immature retroviral particles is mediated mainly by mutual interactions of capsid (CA) and nucleocapsid (NC) domains of Gag polyproteins and viral genomic RNA. We identified a "basic domain" (NC16-23) at the N-terminus of Mason-Pfizer monkey virus (M-PMV) NC that contributes to the oligomerization of CA leading to the assembly of virus-like particles (VLP). Within the basic domain we identified a stretch of the three lysine residues K16, K18, and K20 crucial for the assembly. The basic region can be substituted by non-specific positively charged peptide. In summary, we report here the importance of basic residues at the N-terminus of M-PMV NC for the assembly of immature-like particles.