FIG 3.

Schematic representation of transcription plasmids carrying the full-length RRV VP4 gene. (A) Plasmid pBacT7-VP4(RRV) contains the authentic full-length VP4 gene cDNA of RRV, flanked by the T7 RNA polymerase promoter at the 5′ end and the HDV ribozyme at the 3′ end, followed by the T7 RNA polymerase terminator. Manipulation of the VP4 gene by means of silent mutations (positions are indicated by arrows below the sequences) was carried out in pBacT7-VP4(RRV): the mutant plasmids, pBacT7-VP4(RRV^XbaI) and pBacT7-VP4(RRV^R446G), contain a mutation creating a unique XbaI site and a mutation encoding an amino acid change from R to G, respectively. Numbers indicate the nucleotide positions in the RRV VP4 gene sequence. (B) Sequences at the 5′ and 3′ termini of the RRV VP4 gene in the transcription vectors. P_T7, ribozyme, T_T7, and UTR denote the T7 RNA polymerase promoter, HDV ribozyme, T7 RNA polymerase terminator, and untranslated region, respectively. ORF, open reading frame.