Unraveling the complexities of the Borna disease virus 1

Cases of Borna disease virus 1 (BoDV-1) are extremely rare in humans, but in those who develop disease, the outcome is severe, almost always resulting in fatal encephalitis or inflammation in the brain. This zoonotic virus ...

Filling a key structural gap After their previous structural work on Ebola virus nucleoprotein-RNA complexes, a team of researchers from Kyoto University, Osaka Dental University, and Osaka Metropolitan University recognized this key unresolved question and collaborated to address it. Their study is published in the journal Science Advances . "Bornaviruses are less well known than many other human RNA viruses, yet they represent the last major unresolved case for nucleoprotein-RNA structural analysis among human-infecting mononegaviruses," says first author Yukihiko Sugita. "Closing this long-standing gap and connecting structural biology with virological function were major motivations for our team."

Imaging BoDV-1 in fine detail Using cryo-electron microscopy , the researchers obtained high-resolution images of BoDV-1 nucleoprotein-RNA complexes and performed computational classification to separate and reconstruct the distinct assembly states of each complex in the sample. They then used mutational and functional assays to test nucleoprotein-RNA residues and evaluate their roles in viral RNA synthesis and assembly.

The structure of the nucleoprotein-RNA complex was identified from multiple complex states. Credit: KyotoU / Yukihiko Sugita Read more

Phylogenetic tree showing the relationships, evolutionary relatedness, among viruses in the order Mononegavirales. A phylogenetic tree is a diagram that represents the evolutionary relationships among organisms in a tree-like form. This tree was constructed based on the similarity of amino acid sequences of RNA polymerase, a protein required for viral replication. Credit: Masayuki Horie / Osaka Metropolitan University; Yukihiko Sugita / Kyoto University Read more

Overview of this study. Credit: Yukihiko Sugita / KyotoU Read more