Worldwide, plant pests and pathogens cause 40% yield losses annually. Among plant pathogens, viruses account for nearly half of the plant endemics. Potyviruses (genus Potyvirus, family Potyviridae) form the largest group of known plant-infecting RNA viruses. The type species, potato virus Y (PVY), is the most economically important virus, severely affecting production of potato and other solanaceous crops worldwide. Potyviral virions are flexuous filamentous particles with a 10 kb positive-sense single-stranded RNA genome. As is typical for RNA viruses, genome size limitation leads to an economic distribution of functions within a small number of multitasking proteins with multidomain structure and regions of intrinsic disorder to allow binding promiscuity and functional diversity.
In 2019, we determined a high-resolution structure of PVY and its virus-like particles (VLPs) (Kežar et al., 2019). These were also the first structures of large biological complexes determined by cryo-electron microscopy in Slovenia. The structures of PVY and VLP represent an important contribution to the understanding of the PVY assembly mechanism as well as the different steps of the infection cycle. Results pave the way for our further studies of the interactions of the viral proteins with other plant or vector ( aphid ) molecules at high resolution.
We are also exploring the potential of potyviral VLPs as nanoscale molecular platforms for various applications in medicine, drug delivery, vaccine development, or synthesis of hybrid (nano)materials using synthetic biology approaches.