Dicer-TRBP complex formation ensures accurate mammalian microRNA biogenesis

Mol Cell. 2015 Feb 5;57(3):397-407. doi: 10.1016/j.molcel.2014.11.030. Epub 2014 Dec 31.


RNA-mediated gene silencing in human cells requires the accurate generation of ∼22 nt microRNAs (miRNAs) from double-stranded RNA substrates by the endonuclease Dicer. Although the phylogenetically conserved RNA-binding proteins TRBP and PACT are known to contribute to this process, their mode of Dicer binding and their genome-wide effects on miRNA processing have not been determined. We solved the crystal structure of the human Dicer-TRBP interface, revealing the structural basis of the interaction. Interface residues conserved between TRBP and PACT show that the proteins bind to Dicer in a similar manner and by mutual exclusion. Based on the structure, a catalytically active Dicer that cannot bind TRBP or PACT was designed and introduced into Dicer-deficient mammalian cells, revealing selective defects in guide strand selection. These results demonstrate the role of Dicer-associated RNA binding proteins in maintenance of gene silencing fidelity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Argonaute Proteins / metabolism
  • Catalytic Domain
  • Cells, Cultured
  • Crystallography, X-Ray
  • DEAD-box RNA Helicases / chemistry*
  • DEAD-box RNA Helicases / genetics
  • DEAD-box RNA Helicases / metabolism*
  • Gene Silencing
  • Humans
  • Mice
  • MicroRNAs / metabolism*
  • Molecular Sequence Data
  • Protein Conformation
  • RNA-Binding Proteins / chemistry*
  • RNA-Binding Proteins / metabolism*
  • Ribonuclease III / chemistry
  • Ribonuclease III / metabolism*
  • Sequence Alignment


  • Argonaute Proteins
  • MicroRNAs
  • PRKRA protein, human
  • RNA-Binding Proteins
  • trans-activation responsive RNA-binding protein
  • DICER1 protein, human
  • Dicer1 protein, mouse
  • Ribonuclease III
  • DEAD-box RNA Helicases

Associated data

  • BioProject/PRJNA267577
  • PDB/4WYQ