21AL

Tetrameric complex of the Borna disease virus 1 nucleoprotein (mutant Arg341Ala)

Summary for 21AL

• Entry DOI: 10.2210/pdb21al/pdb
• EMDB information: 61914 67470
• Descriptor: Nucleoprotein (1 entity in total)
• Functional Keywords: nucleoprotein, complex, viral protein
• Biological source: Borna disease virus 1
• Total number of polymer chains: 1
• Total formula weight: 43490.71

Authors

Sugita, Y.,Goto, S.H.,Hirai, Y.,Horie, M. (deposition date: 2025-12-05, release date: 2026-03-11, Last modification date: 2026-04-29)

Primary citation

Sugita, Y.,Hirai, Y.,Goto, S.H.,Fujiwara, T.,Tomonaga, K.,Noda, T.,Horie, M.
Structure and assembly of Borna disease virus 1 nucleoprotein-RNA complexes.
Sci Adv, 12:eaeb0835-eaeb0835, 2026

PubMed Abstract: Structures of nucleoprotein (N)-RNA complexes of the , a virus family in the order , have not been reported. Here, using cryo-electron microscopy (cryo-EM), we report high-resolution structures of Borna disease virus 1 (BoDV-1) N-RNA complex assemblies, including a dominant hexameric ring-like complex and less populated heptameric and octameric forms, the first RNA-bound N structures reported from this family. These structures reveal key features of N-RNA engagement and a BoDV-1-specific stoichiometry of eight nucleotides per N, providing a framework for comparison with related negative-strand RNA viruses. In addition to these RNA-bound complexes, we identified multiple RNA-free oligomers, indicating substantial conformational flexibility of N. Mutational analyses identified residues essential for nucleocapsid formation and RNA synthesis. Cryo-EM of mutant complexes captured RNA-free assemblies, suggesting that initial N oligomerization precedes RNA binding. These findings clarify the structural organization of the N-RNA complex and suggest how oligomeric plasticity contributes to nucleocapsid assembly.

PubMed: 41961918
DOI: 10.1126/sciadv.aeb0835

Experimental method

ELECTRON MICROSCOPY (3.57 Å)