Cryo-EM near-atomic structure of a dsRNA fungal virus shows ancient structural motifs preserved in the dsRNA viral lineage.

ABSTRACT: Viruses evolve so rapidly that sequence-based comparison is not suitable for detecting relatedness among distant viruses. Structure-based comparisons suggest that evolution led to a small number of viral classes or lineages that can be grouped by capsid protein (CP) folds. Here, we report that the CP structure of the fungal dsRNA Penicillium chrysogenum virus (PcV) shows the progenitor fold of the dsRNA virus lineage and suggests a relationship between lineages. Cryo-EM structure at near-atomic resolution showed that the 982-aa PcV CP is formed by a repeated α-helical core, indicative of gene duplication despite lack of sequence similarity between the two halves. Superimposition of secondary structure elements identified a single "hotspot" at which variation is introduced by insertion of p

SUBMITTER: Luque D 

PROVIDER: S-EPMC4040568 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature