RNA-dependent RNA polymerase (RdRp) in the genus Hepacivirus, within the family Flaviviridae of positive-sense single-stranded RNA (+ssRNA) viruses
This group contains the RdRp of RNA viruses belonging to the Hepacivirus genus within the family Flaviviridae, order Amarillovirales. The genus Hepacivirus includes hepatitis C virus, a major human pathogen causing progressive liver disease, and several other viruses of unknown pathogenicity that infect horses, rodents, bats, cows and primates. Infections are typically persistent and target the liver. Virions of Hepacivirus have a single, small, basic capsid (C) protein and two envelope proteins. They contain a single, long ORF flanked by 5'- and 3'-terminal non-coding regions, which form specific secondary structures required for genome replication and translation. The RdRp domain displays a right hand with three functional subdomains, called fingers, palm, and thumb. All RdRps contain conserved polymerase motifs (A-G), located in the palm (A-E motifs) and finger (F-G) subdomains. All these motifs have been implicated in RdRp fidelity such as processes of correct incorporation and reorganization of nucleotides.