National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R35 GM136275
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R35 GM127094
米国
National Institutes of Health/National Institute of Environmental Health Sciences (NIH/NIEHS)
1ZIA50165
米国
引用
ジャーナル: Mol Cell / 年: 2022 タイトル: Structural basis of microRNA biogenesis by Dicer-1 and its partner protein Loqs-PB. 著者: Karina Jouravleva / Dmitrij Golovenko / Gabriel Demo / Robert C Dutcher / Traci M Tanaka Hall / Phillip D Zamore / Andrei A Korostelev / 要旨: In animals and plants, Dicer enzymes collaborate with double-stranded RNA-binding domain (dsRBD) proteins to convert precursor-microRNAs (pre-miRNAs) into miRNA duplexes. We report six cryo-EM ...In animals and plants, Dicer enzymes collaborate with double-stranded RNA-binding domain (dsRBD) proteins to convert precursor-microRNAs (pre-miRNAs) into miRNA duplexes. We report six cryo-EM structures of Drosophila Dicer-1 that show how Dicer-1 and its partner Loqs‑PB cooperate (1) before binding pre-miRNA, (2) after binding and in a catalytically competent state, (3) after nicking one arm of the pre-miRNA, and (4) following complete dicing and initial product release. Our reconstructions suggest that pre-miRNA binds a rare, open conformation of the Dicer‑1⋅Loqs‑PB heterodimer. The Dicer-1 dsRBD and three Loqs‑PB dsRBDs form a tight belt around the pre-miRNA, distorting the RNA helix to place the scissile phosphodiester bonds in the RNase III active sites. Pre-miRNA cleavage shifts the dsRBDs and partially closes Dicer-1, which may promote product release. Our data suggest a model for how the Dicer‑1⋅Loqs‑PB complex affects a complete cycle of pre-miRNA recognition, stepwise endonuclease cleavage, and product release.