Figure 1. Genomic organization of HCV and protein synthesis. The HCV genome contains
a single open reading frame flanked by 5 and 3 non-coding regions. The 5 NTR contains
an internal ribosome entry site (IRES). After its synthesis, the HCV polyprotein is cleaved
by host signal peptidase (red vertical arrows) and by viral encoded proteases (NS2 and
NS3/4A) as indicated by corresponding arrows. An additional cleavage removing the
carboxy-terminal region of the core protein is mediated by cellular signal peptide peptidase
(green vertical arrow). The functions of the individual proteins are indicated in the text.