catalytic core domain of RNA-dependent RNA polymerase (RdRp) in the genus Alphanecrovirus of positive-sense single-stranded RNA [(+)ssRNA] viruses, within the Procedovirinae subfamily
This group contains the catalytic core domain of RdRp of RNA viruses belonging to the Alphanecrovirus genus within the subfamily Procedovirinae, family Tombusviridae, order Tolivirales. Alphanecroviruses are non-enveloped, with icosahedral and spherical geometries, and T=3 symmetry, and a diameter of around 28 nm. Their genomes are linear, around 4 kb in length. In the Alphanecrovirus genus plants serve as natural hosts. There are 4 species in this genus: Olive latent virus 1, Olive mild mosaic virus, Potato necrosis virus, and Tobacco necrosis virus A. 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.",