English: Chrysoviridae. Genome organization of Penicillium chrysogenum virus (PcV). The genomes consist of four dsRNA segments; each is monocistronic. The proteins encoded are represented by rectangular boxes. The light coloured box in dsRNA 1 represents the RdRP_4 motif (PF00680); the dark coloured box in dsRNA 1 represents an independent P-loop NTPase domain. Although the functions of P3 and P4 are unknown (see below) for both viruses, the N-terminal region of alphachryso-P3 shares high sequence similarity with the corresponding N-terminal region of the RdRP (P7/P-loop domain; possibly a nucleotide triphosphate hydrase [NTPase] domain), as indicated by the blue boxes above the ORFs. Alphachryso-P4 is a putative cysteine protease.