Self-capping of nucleoprotein filaments protects Newcastle Disease Virus genome

Non-segmented negative-strand RNA viruses, such as Measles, Ebola and Newcastle disease viruses (NDV), encapsidate viral genomic RNAs into helical nucleocapsids which serve as the template for viral replication and transcription. Here, the clam-shaped nucleocapsid structure, where the NDV viral genome is sequestered, was determined at 4.8 Å resolution by cryo-electron microscopy. The clam-shaped structure is composed of two single-turn spirals packed in a back-to-back mode, and the tightly packed structure functions as a seed for nucleocapsid to assemble from both directions and grows into double-headed filaments with two separate R NA strings inside. Disruption of this structure by mutations on its loop interface yielded a single-headed unfunctional filament.
Source: eLife - Category: Biomedical Science Tags: Microbiology and Infectious Disease Structural Biology and Molecular Biophysics Source Type: research