Fig. 2.

Schematic diagram of PRRSV N protein deletion mutants. Gray box indicates part of the viral genome, and dashed line represents the deleted residues. pAPRRS was the wild-type full-length clone. p7USC was a full-length infectious cDNA clone that contained an Asc I site after the stop codon of ORF7. (A) Schematic drawing of N-terminal deletion mutants; (B) graphic representation of C-terminal deletion mutants; (C) construction strategy of internal deletion mutants; (D) schematic drawing of double mutants containing the primary C-terminal engineered deletion together with a second-site mutation. The “C” underlined in pCΔ3/Y61C indicates the mutated residue.