RNA-dependent RNA polymerase (RdRp) in the family Gammaflexiviridae of positive-sense single-stranded RNA [(+)ssRNA] viruses, in the order Tymovirales
This group contains the RdRp of RNA viruses belonging to the family Gammaflexiviridae, order Tymovirales. Virions within the Gammaflexiviridae family are flexuous filaments of 720 nm modal length and about 13 nm in diameter. Members of the Tymovirales order are mainly plant pathogens that are characterized by similarities in their replication-associated polyproteins, which account for the majority of their genomic coding capacity. They are considered to form a group, phylogenetically, referred to as flexiviruses, with filamentous virions. 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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