6MFN image
Entry Detail
PDB ID:
6MFN
Keywords:
Title:
Human Argonaute2-miR-27a bound to HSUR1 target RNA
Biological Source:
Host Organism:
PDB Version:
Deposition Date:
2018-09-11
Release Date:
2019-08-07
Method Details:
Experimental Method:
Resolution:
2.50 Å
R-Value Free:
0.24
R-Value Work:
0.20
R-Value Observed:
0.21
Space Group:
P 2 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Protein argonaute-2
Mutations:D669A, S387D, S824A, S828D, S831D, S834A
Chain IDs:A
Chain Length:859
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polyribonucleotide
Description:RNA (5'-R(P*UP*UP*CP*AP*CP*AP*GP*UP*G)-3')
Chain IDs:B (auth: C)
Chain Length:21
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polyribonucleotide
Description:RNA (5'-R(P*UP*CP*UP*GP*UP*GP*AP*UP*AP*A)-3')
Chain IDs:C (auth: E)
Chain Length:22
Number of Molecules:1
Biological Source:synthetic construct
Ligand Molecules
Primary Citation
Structural Basis for Target-Directed MicroRNA Degradation.
Mol.Cell 75 1243 ? (2019)
PMID: 31353209 DOI: 10.1016/j.molcel.2019.06.019

Abstact

MicroRNAs (miRNAs) broadly regulate gene expression through association with Argonaute (Ago), which also protects miRNAs from degradation. However, miRNA stability is known to vary and is regulated by poorly understood mechanisms. A major emerging process, termed target-directed miRNA degradation (TDMD), employs specialized target RNAs to selectively bind to miRNAs and induce their decay. Here, we report structures of human Ago2 (hAgo2) bound to miRNAs and TDMD-inducing targets. miRNA and target form a bipartite duplex with an unpaired flexible linker. hAgo2 cannot physically accommodate the RNA, causing the duplex to bend at the linker and display the miRNA 3' end for enzymatic attack. Altering 3' end display by changing linker flexibility, changing 3' end complementarity, or mutationally inducing 3' end release impacts TDMD efficiency, leading to production of distinct 3'-miRNA isoforms in cells. Our results uncover the mechanism driving TDMD and reveal 3' end display as a key determinant regulating miRNA activity via 3' remodeling and/or degradation.

Legend

Protein

Chemical

Disease

Primary Citation of related structures