Honey Bee Deformed Wing Virus Structures Reveal that Conformational Changes Accompany Genome Release
The picornavirus-like deformed wing virus (DWV) has been directly linked to colony collapse; however, little is known about the mechanisms of host attachment or entry for DWV or its molecular and structural details. Here we report the three-dimensional (3-D) structures of DWV capsids isolated from infected honey bees, including the immature procapsid, the genome-filled virion, the putative entry intermediate (A-particle), and the empty capsid that remains after genome release. The capsids are decorated by large spikes around the 5-fold vertices. The 5-fold spikes had an open flower-like conformation for the procapsid and genome-filled capsids, whereas the putative A-particle and empty capsids that had released the genome had a closed tube-like spike conformation. Between the two conformations, the spikes undergo a significant hinge-like movement that we predicted using a Robetta model of the structure comprising the spike. We conclude that the spike structures likely serve a function during host entry, changing conformation to release the genome, and that the genome may escape from a 5-fold vertex to initiate infection. Finally, the structures illustrate that, similarly to picornaviruses, DWV forms alternate particle conformations implicated in assembly, host attachment, and RNA release.
Journal of Virology
Organtini LJ, Shingler KL, Ashley RE, Capaldi EA, Durrani K, Dryden KA, Makhov AM, Conway JF, Pizzorno MC, Hafenstein S. 2017. Honey bee deformed wing virus structures reveal that conformational changes accompany genome release. J Virol 91:e01795-16. https://doi.org/10.1128/JVI.01795-16.