FIG. 1.

Individual residues targeted by mutagenesis. (A) The NP regions responsible for binding to RNA (red), NP itself (orange), and PB2 (purple) are shown. (B) Amino acid sequence of WSN NP. Amino acids tested in this study are shaded. The unconventional NLS, the bipartite NLS, the cytoplasmic accumulation signal (CAS), and the NP tail loop, which mediates NP oligomerization, are shown in different colors. NP mutants flagged with an asterisk were further tested for intracellular localization and incorporation efficiency of a vRNA segment(s) into VLPs, in addition to replicative ability and polymerase activity.