Figure 1. Diagram of a MeV particle (top) and of the viral RNA genome (bottom).

The particle is drawn with its six main components: the nucleocapsid (N) that covers the genomic RNA and interacts with the phosphoprotein (P), and polymerase (large, L), forming the ribonucleocapsid complex; the fusion (F) and hemagglutinin (H) proteins forming the membrane fusion apparatus; and the matrix (M) protein controlling particle assembly as well as transcription and membrane fusion. Particles contain multiple encapsidated genomes, of which three are drawn schematically. On the genome (shown here as positive strand, bottom), the coding regions of the proteins are color-coded, non-coding regions are black. The P gene codes also for the V and C proteins (see Fig. 3 for details).