Plant Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
Graduate School of Life Sciences, Tōhoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577, Japan.
Cell Rep. 2019 Jan 22;26(4):855-865.e5. doi: 10.1016/j.celrep.2019.01.003.
In plants, strigolactones are perceived by the dual receptor-hydrolase DWARF14 (D14). D14 belongs to the superfamily of α/β hydrolases and is structurally similar to the karrikin receptor KARRIKIN INSENSITIVE 2 (KAI2). The moss Physcomitrella patens is an ideal model system for studying this receptor family, because it includes 11 highly related family members with unknown ligand specificity. We present the crystal structures of three Physcomitrella D14/KAI2-like proteins and describe a loop-based mechanism that leads to a permanent widening of the hydrophobic substrate gorge. We have identified protein clades that specifically perceive the karrikin KAR and the non-natural strigolactone isomer (-)-5-deoxystrigol in a highly stereoselective manner.
在植物中，独脚金内酯被双受体水解酶 DWARF14（D14）所感知。D14 属于 α/β 水解酶超家族，与卡列金受体 KARRIKIN INSENSITIVE 2（KAI2）在结构上相似。苔藓植物拟南芥是研究该受体家族的理想模型系统，因为它包含 11 个具有未知配体特异性的高度相关的家族成员。我们呈现了三种拟南芥 D14/KAI2 样蛋白的晶体结构，并描述了一个基于环的机制，该机制导致疏水性底物峡谷的永久性变宽。我们已经鉴定出了特定感知卡列金 KAR 和非天然独脚金内酯异构体（-）-5-去氧独脚金内酯的蛋白进化枝，具有高度立体选择性。
