Structure of the dimerization domain of DiGeorge critical region 8
- UCLA
Maturation of microRNAs (miRNAs, {approx}22nt) from long primary transcripts [primary miRNAs (pri-miRNAs)] is regulated during development and is altered in diseases such as cancer. The first processing step is a cleavage mediated by the Microprocessor complex containing the Drosha nuclease and the RNA-binding protein DiGeorge critical region 8 (DGCR8). We previously reported that dimeric DGCR8 binds heme and that the heme-bound DGCR8 is more active than the heme-free form. Here, we identified a conserved dimerization domain in DGCR8. Our crystal structure of this domain (residues 298-352) at 1.7 {angstrom} resolution demonstrates a previously unknown use of a WW motif as a platform for extensive dimerization interactions. The dimerization domain of DGCR8 is embedded in an independently folded heme-binding domain and directly contributes to association with heme. Heme-binding-deficient DGCR8 mutants have reduced pri-miRNA processing activity in vitro. Our study provides structural and biochemical bases for understanding how dimerization and heme binding of DGCR8 may contribute to regulation of miRNA biogenesis.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 1002656
- Journal Information:
- Protein Sci., Vol. 19, Issue (7) ; 07, 2010
- Country of Publication:
- United States
- Language:
- ENGLISH
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