FIGURE 7.

Model for long-distance interactions required for PVX replication. (A) Relative locations of all conserved octanucleotide elements in the PVX genome are illustrated as hatched boxes. The direction of hatch marks in terminal elements are opposite to internal elements to denote complementarity for pairing. The 5′ m7GpppG cap structure and poly(A) tail mark the termini by a black dot and asterisk, respectively. Although not to scale, the three stem–loop structures (SL1, SL2, and SL3) are illustrated in the 3′ NTR, with the hexanucleotide element located in the loop of SL3. (B) One possible paired configuration. Other combinations of both terminal elements pairing with different internal elements are also possible and may be dynamic during replication.