FIG. 7.

Summary of intramolecular interactions within the M protein and intermolecular interactions between the M and N proteins suggested by this study. The schematic at the top shows the relative topologies and interfaces of the M, N, and E proteins at or within the virion envelope. The linear representation of the M and N proteins depicts the genetic interactions revealed by the MΔ2 revertant analysis. Solid rectangles indicate the three transmembrane domains of the M protein (39); the hatched rectangle indicates the RNA-binding domain of the N protein (20, 27). The carboxy-terminal truncations of the M and N proteins introduced, respectively, by the MΔ2 mutation and the Q437MMA mutation are also indicated by solid rectangles. gRNA, genomic RNA.