Summary information and primary citation
- PDB-id
- 8dga; DSSR-derived features in text and JSON formats
- Class
- RNA binding protein-RNA
- Method
- cryo-EM (3.73 Å)
- Summary
- Structural basis of microrna biogenesis by dicer-1 and its partner protein loqs-pb - complex iv
- Reference
- Jouravleva K, Golovenko D, Demo G, Dutcher RC, Hall TMT, Zamore PD, Korostelev AA (2022): "Structural basis of microRNA biogenesis by Dicer-1 and its partner protein Loqs-PB." Mol.Cell, 82, 4049-4063.e6. doi: 10.1016/j.molcel.2022.09.002.
- Abstract
- 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.
