FIG 1.

Schematic representation of the enterovirus genome. The 5′ NCR includes a small (<100 nucleotide) cloverleaf that serves as an RNA replication platform and a larger IRES region that controls translation of virus proteins. The single open reading frame (ORF) codes for a single polyprotein that is later separated into 11 proteins (1A through 3D) via the action of virus-encoded proteases. This review focuses upon structural studies of the 5′-cloverleaf (5′-CL) replication platform and the four replication-linked proteins found in region P3 of the polygene (3A, 3B, 3C, and 3D).