FIG 1.

Schematic representation of the genomes of picornaviruses. (A) Genome of monocistronic (most prevalent) picornaviruses. The leader L and 2A proteins (shown in red and not to scale) are highly variable in structure and function and may be dispensable for viral viability. They may be represented by several distinct copies or be absent in a given genome. The various positions of the replicative cre (oriI) cis-element (hairpins) are indicated. The VPg protein covalently linked to the 5′ end of the viral RNA is shown as a red circle. (B) Genome of dicistronic picornaviruses. The position of cre is unknown.