FIG. 7.

Comparison of the protein domains involved in interactions between replication proteins of different members of the alphavirus-like supergroup. Schematic representation of the protein fragments involved in the interactions of the TYMV 140K and 66K and the BMV 1a and 2a replication proteins. Protein domains are indicated (MT, methyltransferase; PRR, proline-rich region; PRO, proteinase; HEL, helicase; POL, polymerase). The limits of the interaction domains characterized with the two-hybrid system (43; this study) are indicated. The locations of the eight conserved sequence motifs in RdRp of positive-strand RNA viruses (31) are indicated by filled squares.