catalytic core domain of RNA-dependent RNA polymerase (RdRp) in the order Tymovirales of positive-sense single-stranded RNA [(+)ssRNA] viruses
This group contains the catalytic core domain of RdRp of RNA viruses belonging to the order Tymovirales. The Tymovirales order contains viruses that mostly infect plants, have a single molecule of (+)ssRNA, and which are united by the similarities in their replication-associated polyproteins. Tymovirales contains five families (Alpha-, Beta-, Delta- and Gammaflexiviridae and Tymoviridae) and groups mostly plant-infecting agents, although a few Tymovirales members have either fungal or insect hosts. Botrytis virus F (BVF), isolated from the fungus Botrytis cinerea, is a flexuous mycovirus that is typical of members of the genus Mycoflexivirus (family Gammaflexiviridae). 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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