Molecular Basis for the Single-Nucleotide Precision of Primary microRNA Processing

S. Chul Kwon, S. Chan Baek, Yeon Gil Choi, Jihye Yang, Young suk Lee, Jae Sung Woo, V. Narry Kim

Research output: Contribution to journalArticlepeer-review

43 Citations (Scopus)


Microprocessor, composed of DROSHA and its cofactor DGCR8, initiates microRNA (miRNA) biogenesis by processing the primary transcripts of miRNA (pri-miRNAs). Here we investigate the mechanism by which Microprocessor selects the cleavage site with single-nucleotide precision, which is crucial for the specificity and functionality of miRNAs. By testing ∼40,000 pri-miRNA variants, we find that for some pri-miRNAs the cleavage site is dictated mainly by the mGHG motif embedded in the lower stem region of pri-miRNA. Structural modeling and deep-sequencing-based complementation experiments show that the double-stranded RNA-binding domain (dsRBD) of DROSHA recognizes mGHG to place the catalytic center in the appropriate position. The mGHG motif as well as the mGHG-recognizing residues in DROSHA dsRBD are conserved across eumetazoans, suggesting that this mechanism emerged in an early ancestor of the animal lineage. Our findings provide a basis for the understanding of miRNA biogenesis and rational design of accurate small-RNA-based gene silencing.

Original languageEnglish
Pages (from-to)505-518.e5
JournalMolecular Cell
Issue number3
Publication statusPublished - 2019 Feb 7


  • DGCR8
  • RNase III
  • miRNA
  • microRNA

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology


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