Mapping of domains on the human parainfluenza virus type 2 nucleocapsid protein (NP) required for NP-phosphoprotein or NP-NP interaction

The epitopes recognized by 41 monoclonal antibodies directed against the nu cleocapsid protein (NP) of human parainfluenza virus type 2 (hPIV-2) were m apped on the primary structure of the hPIV-2 NP protein by testing their re activities with deletion mutants, By Western immunoblotting using these mon oclonal antibodies, the analysis of deletion mutants of the hPIV-2 NP prote in was performed to identify the region essential for NP-NP interaction and phosphoprotein (P)-binding sites on the NP protein. The results indicate t hat the N-terminal 294 aa of the NP protein are all required for NP-NP self -assembly, and that two C-terminal parts of the NP protein are essential fo r NP-P binding: one region, aa 295-402, is required for binding to the C-te rminal part of the P protein and another region, aa 403-494, to the N-termi nal part of the P protein.