Crystal structure of human DGCR8 core.
A complex of Drosha with DGCR8 (or its homolog Pasha) cleaves primary microRNA (pri-miRNA) substrates into precursor miRNA and initiates the microRNA maturation process. Drosha provides the catalytic site for this cleavage, whereas DGCR8 or Pasha provides a frame for anchoring substrate pri-miRNAs. To clarify the molecular basis underlying recognition of pri-miRNA by DGCR8 and Pasha, we determined the crystal structure of the human DGCR8 core (DGCR8S, residues 493-720). In the structure, the two double-stranded RNA-binding domains (dsRBDs) are arranged with pseudo two-fold symmetry and are tightly packed against the C-terminal helix. The H2 helix in each dsRBD is important for recognition of pri-miRNA substrates. This structure, together with fluorescent resonance energy transfer and mutational analyses, suggests that the DGCR8 core recognizes pri-miRNA in two possible orientations. We propose a model for DGCR8's recognition of pri-miRNA.
Sohn
Sun Young
SY
National Creative Research Center for Structural Biology and Department of Life Science, Pohang University of Science and Technology, Hyo-ja dong, San31, Pohang, KyungBook 790-784, South Korea.
Bae
Won Jin
WJ
Kim
Jeong Joo
JJ
Yeom
Kyu-Hyeon
KH
Kim
V Narry
VN
Cho
Yunje
Y
D018360:Crystallography, X-Ray; D024202:Electrophoretic Mobility Shift Assay; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins
C474043:DGCR8 protein, human; D035683:MicroRNAs; D011506:Proteins; D016601:RNA-Binding Proteins