Geminiviridae are ssDNA plant viruses whose control has both economical and agricultural importance. Their capsids assemble into two distinct architectural forms: (i) a T = 1 icosahedral and (ii) a unique twinned quasi-isometric capsid. Described here are the high-resolution structures of both forms of the maize streak virus using cryo-EM. A comparison of these two forms provides details of the coat protein (CP) and CP-CP and CP-genome interactions that govern the assembly of the architecture of the capsids. Comparative analysis of other representative members of Geminiviridae reveals structural conservation of 60-95% compared to a sequence similarity of 21-30%. This study provides a structural atlas of these plant pathogens and suggests possible antiviral-targetable regions of these capsids.
Keywords: capsid; cryo-EM; geminivirus; icosahedral; pathogen; plant.