Cryo-EM Structure of a Begomovirus Geminate Particle

Tobacco curly shoot virus, a monopartite begomovirus associated with betasatellite, causes serious leaf curl diseases on tomato and tobacco in China. Using single-particle cryo-electron microscopy, we determined the structure of tobacco curly shoot virus (TbCSV) particle at 3.57 Å resolution and confirmed the characteristic geminate architecture with single-strand DNA bound to each coat protein (CP). The CP–CP and DNA–CP interactions, arranged in a CP–DNA–CP pattern at the interface, were partially observed. This suggests the genomic DNA plays an important role in forming a stable interface during assembly of the geminate particle.