The Structure of the RNA-Dependent RNA Polymerase of a Permutotetravirus Suggests a Link between Primer-Dependent and Primer-Independent Polymerases.

ABSTRACT: Thosea asigna virus (TaV), an insect virus belonging to the Permutatetraviridae family, has a positive-sense single-stranded RNA (ssRNA) genome with two overlapping open reading frames, encoding for the replicase and capsid proteins. The particular TaV replicase includes a structurally unique RNA-dependent RNA polymerase (RdRP) with a sequence permutation in the palm sub-domain, where the active site is anchored. This non-canonical arrangement of the RdRP palm is also found in double-stranded RNA viruses of the Birnaviridae family. Both virus families also share a conserved VPg sequence motif at the polymerase N-terminus which in birnaviruses appears to be used to covalently link a fraction of the replicase molecules to the 5'-end of the genomic segments. Birnavirus VPgs are presumed to be

SUBMITTER: Ferrero DS 

PROVIDER: S-EPMC4666646 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature