Insects detect and discriminate a diverse array of chemicals using odorant receptors (ORs), which are ligand-gated ion channels comprising a divergent odorant-sensing OR and a conserved odorant receptor co-receptor (Orco). In this work, we report structures of the Ap OR5-Orco heterocomplex from the pea aphid Acyrthosiphon pisum alone and bound to its known activating ligand, geranyl acetate. In these structures, three Ap Orco subunits serve as scaffold components that cannot bind the ligand and remain relatively unchanged. Upon ligand binding, the pore-forming helix S7b of Ap OR5 shifts outward from the central pore axis, causing an asymmetrical pore opening for ion influx. Our study provides insights into odorant recognition and channel gating of the OR-Orco heterocomplex and offers structural resources to support development of innovative insecticides and repellents for pest control.

中文翻译：

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昆虫气味受体 OR-Orco 杂复合物气味识别的结构基础


昆虫使用气味受体 (OR) 来检测和区分多种化学物质，气味受体是配体门控离子通道，包含不同的气味感应 OR 和保守的气味受体辅助受体 (Orco)。在这项工作中，我们报告了来自豌豆蚜 Acyrthosiphon pisum 的 Ap OR5-Orco 杂复合物的结构，并与其已知的激活配体乙酸香叶酯结合。在这些结构中，三个 Ap Orco 亚基作为支架组件，不能与配体结合并保持相对不变。配体结合后，Ap OR5 的成孔螺旋 S7b 从中心孔轴向外移动，导致离子流入的不对称孔开口。我们的研究提供了对 OR-Orco 异质复合物的气味识别和通道门控的见解，并提供了结构资源来支持开发用于害虫控制的创新杀虫剂和驱避剂。