Crystal structure of Epiphyas postvittana pheromone binding protein 3

Abstract

The insect olfactory system operates as a well-choreographed ensemble of molecules which functions 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 to receptors present in olfactory sensory neurons. Though the exact mechanism through which these proteins operate is still under investigation, these carriers clearly play a critical role in determining what an insect can smell. Binding proteins that transport important sex pheromones are colloquially named pheromone binding proteins (PBPs). Here, we have produced a functional recombinant PBP from the horticultural pest, Epiphyas postvittana (EposPBP3), and experimentally solved its apo-structure through X-ray crystallography to a resolution of 2.60 Å. Structural comparisons with related lepidopteran PBPs further allowed us to propose models for the binding of pheromone components to EposPBP3. The data presented here represent the first structure of an olfactory-related protein from the tortricid family of moths, whose members cause 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.

Insights Into Chemosensory Proteins From Non-Model Insects: Advances and Perspectives in the Context of Pest Management

“…Thus, aphid Rhopalosiphum padi , for which OBP7 strongly bound ( E )-β-farnesene, a repellent for R. padi , was supported by the use of crystal structures of M. viciae and N. ribisnigri OBPs. More recently, the crystal structure for Epiphyas postvittana PBP3 was reported, representing the first 3D structure of an OBP for tortricid moths, which have an enormous economic impact for agriculture worldwide ( Hamiaux et al, 2020 ). This represents an important advance in the study of other tortricids of economic importance, such as Lobesia botrana , Grapholita molesta and Cydia pomonella , allowing a more precise construction of 3D models for OBPs.…”