Structure and its transformation of elliptical nege- like virus Tanay virus

Negeviruses that infect insects are recently identified virus species that are phylogenetically related to several plant viruses. They exhibit a unique virion structure, an elliptical core with a short projection. Negeviruses encode two structural proteins, a glycoprotein that forms a short projection, and an envelope protein that forms an elliptical core. The glycoprotein has been reported only in the negeviruses' genes, and not in phylogenetically related plant viruses' genes. In this report, we first describe the three- dimensional electron cryo- microscopy (cryo- EM) structure of Tanay virus (TANAV), one of the nege- like viruses. TANAV particle demonstrates a periodical envelope structure consisting of three layers surrounding the centred viral RNA. The elliptical core dynamically changes its shape under acidic and even low detergent conditions to form bullet- like or tubular shapes. The further cryo- EM studies on these transformed TANAV particles reveal their overall structural rearrangement. These findings suggest putative geometries of TANAV and its transformation in the life cycle, and the potential importance of the short projection for enabling cell entry to the insect hosts.

Automated summary

This study describes the three-dimensional electron cryo- microscopy (cryo- EM) structure of Tanay virus (TANAV), a recently identified insect-infecting virus. The TANAV particle has a unique core and envelope structure, and can change its shape under certain conditions. These findings provide insights into the cell entry mechanism and structural changes during the lifecycle of TANAV.