catalytic core domain of RNA-dependent RNA polymerase (RdRp) in the family Endornaviridae of positive-sense single-stranded RNA [(+)ssRNA] viruses
This group contains the catalytic core domain of RdRp of RNA viruses belonging to the family Endornaviridae, order Martellivirales. The family Endornaviridae includes viruses with linear (+)ssRNA genomes that range from 9.7 to 17.6 kb. The family consists of two genera, Alphaendornavirus and Betaendornavirus. Alphaendornavirus includes species whose members infect plants, fungi and oomycetes, while the genus Betaendornavirus includes species whose members infect ascomycete fungi. Plant endornaviruses are transmitted only through the gametes. A conserved RNA-dependent RNA polymerase domain located in the C-terminal region of the polyprotein is a feature common to all endornaviruses. 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.
Jiyao W et al.(2023). "The conserved domain database in 2023.",