Proof of Concept of the Yadokari Nature: a Capsidless Replicase-Encoding but Replication-Dependent Positive-Sense Single-Stranded RNA Virus Hosted by an Unrelated Double-Stranded RNA Virus
Subha Das, Md. Mahfuz Alam, Rui Zhang, Sakae Hisano, Nobuhiro Suzuki
Abstract
-encapsidation of its own RNA and RdRp. YkV1 was hypothesized to divert the heterocapsid as the replication site, as is commonly observed for dsRNA viruses. Herein, mutational analyses showed that the RdRp and 2A-like domains of the YkV1 polyprotein are important for its replication. The active RdRp must be cleaved by a 2A-like peptide from the C-proximal protein. Cesium chloride equilibrium density gradient centrifugation allowed for the separation of particles, with YnV1 capsids solely packaging YkV1 dsRNA and RdRp. This study provides proof of concept of a virus neo-lifestyle where a (+)ssRNA virus snatches capsids from an unrelated dsRNA virus to replicate with its own RdRp, thereby mimicking the typical dsRNA virus lifestyle.