Crystal structure of Epiphyas postvittana pheromone binding protein 3

Authors: HAMIAUX, CYRIL - New Zealand Institute Of Plant & Food Research; CARRAHER, COLM - New Zealand Institute Of Plant & Food Research; LÖFSTEDT, CHRISTER - Lund University; Corcoran, Jacob

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/9/2020
Publication Date: 10/1/2020
Citation: Hamiaux, C., Carraher, C., Löfstedt, C., Corcoran, J. 2020. Crystal structure of Epiphyas postvittana pheromone binding protein 3. Scientific Reports. 10, 16366. https://doi.org/10.1038/s41598-020-73294-8.
DOI: https://doi.org/10.1038/s41598-020-73294-8

Interpretive Summary: Horticultural crops in the United States sustain tremendous losses each year due to invasive pest insects. In their native environment, populations of these pests are kept under control by natural enemies. When these pest insects migrate to new areas their natural enemies are often not present, which allows populations to flourish and wreak havoc on agricultural crops. New predator-prey relationships may eventually evolve, however, in the interim alternative control measures must be implemented to help prevent crop losses. The use of broad-spectrum insecticides, while effective, is not ideal due to the off-target effects on beneficial insects present in the environment. Technological advances now allow for the development of highly specific insecticides that target molecules that are unique to a given insect, thus significantly reducing or eliminating off-target effects. In this study we have determined the three-dimensional structure of one such molecule, a protein that has a critical role in reproduction in an invasive, horticultural pest moth. The results presented here will serve as a foundation for scientists to develop species-specific, next-generation insecticides based on this structural information. Ultimately, this research will benefit agricultural producers through reduced crop losses to invasive insects, as well as the environment through reduced use of broad-spectrum insecticides that negatively impact beneficial insects.

Technical Abstract: The insect olfactory system operates as a well-choreographed ensemble of molecular entities whose function is to selectively translate volatile chemical messages present in the environment into neuronal impulses that guide insect behaviour. Of these molecules, binding proteins are believed to transport hydrophobic odorant molecules across the aqueous lymph present in antennal sensilla, the main insect olfactory organ, to olfactory receptors present in olfactory sensory neurons. Though the exact mechanism through which these proteins operate is still under investigation, it is clear that these carriers play a critical role in determining what an insect can smell. Binding proteins that transport the extremely important sex pheromones that allow an insect to find conspecifics for mating purposes are colloquially named pheromone binding proteins. Here, we have produced a functional recombinant pheromone binding protein from the horticultural pest, Epiphyas postvittana, and experimentally solved its structure through X-ray crystallography to a resolution of 2.6 Å. The data presented here represent the first structure of an olfactory-related protein from the tortricid family of moths, whose members are responsible for causing billions of dollars in losses to agricultural producers each year. Knowledge of the structure of these important proteins will allow for subsequent studies in which novel, olfactory molecule-specific insecticides can be developed.