2yt4
From Proteopedia
Crystal structure of human DGCR8 core
Structural highlights
Function[DGCR8_HUMAN] Component of the microprocessor complex that acts as a RNA- and heme-binding protein that is involved in the initial step of microRNA (miRNA) biogenesis. Component of the microprocessor complex that is required to process primary miRNA transcripts (pri-miRNAs) to release precursor miRNA (pre-miRNA) in the nucleus. Within the microprocessor complex, DGCR8 function as a molecular anchor necessary for the recognition of pri-miRNA at dsRNA-ssRNA junction and directs DROSHA to cleave 11 bp away form the junction to release hairpin-shaped pre-miRNAs that are subsequently cut by the cytoplasmic DICER to generate mature miRNAs. The heme-bound DGCR8 dimer binds pri-miRNAs as a cooperative trimer (of dimers) and is active in triggering pri-miRNA cleavage, whereas the heme-free DGCR8 monomer binds pri-miRNAs as a dimer and is much less active. Both double-stranded and single-stranded regions of a pri-miRNA are required for its binding. Involved in the silencing of embryonic stem cells self-renewal.[1] [2] [3] [4] [5] [6] [7] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedA 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. Crystal structure of human DGCR8 core.,Sohn SY, Bae WJ, Kim JJ, Yeom KH, Kim VN, Cho Y Nat Struct Mol Biol. 2007 Sep;14(9):847-53. Epub 2007 Aug 19. PMID:17704815[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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