catalytic core domain of RNA-dependent RNA polymerase (RdRp) in the family Hypoviridae of positive-sense single-stranded RNA [(+)ssRNA] viruses
This group contains the catalytic core domain of RdRp of RNA viruses belonging to the family Hypoviridae. The Hypoviridae, comprising one genus, Hypovirus, is a family of capsidless viruses with (+)ssRNA genomes of 9.1-12.7 kb that possess either a single large ORF or two ORFs. Hypoviruses have been detected in ascomycetous or basidiomycetous filamentous fungi, and are considered to be replicated in host Golgi-derived, lipid vesicles that contain their double-stranded RNA (dsRNA) as a replicative form. Some hypoviruses induce hypovirulence to host fungi, while others do not. 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.
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