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3adi
From Proteopedia
Structure of Arabidopsis HYL1 and its molecular implications for miRNA processing
Structural highlights
Function[DRB1_ARATH] Double-stranded RNA-binding protein involved in RNA-mediated post-transcriptional gene silencing (PTGS). Functions in the microRNAs (miRNAs) biogenesis by assisting DICER-LIKE 1 (DCL1) in the accurate processing from primary miRNAs (pri-miRNAs) to miRNAs in the nucleus. Forms a complex with SERRATE (SE) and DCL1 to promote accurate processing of pri-miRNAs by DCL1. Binds and assist DCL1 for accurate processing of precursor miRNAs (pre-miRNA). Indirectly involved in the production of trans-acting small interfering RNAs (ta-siRNAs) derived from the TAS1, TAS2 or TAS3 endogenous transcripts by participating in the production of their initiating miRNAs. Involved with argonaute 1 (AGO1) in the guide strand selection from miRNA duplexes, presumably by directional loading of the miRNA duplex (guide stand and passenger strand) onto the RNA-induced silencing complex (RISC) for passenger strand degradation. Does not participate in sense transgene-induced post-transcriptional gene silencing (S-PTGS). Involved in several plant development aspects and response to hormones through its role in miRNAs processing.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] 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 PubMedThe Arabidopsis HYPONASTIC LEAVES1 (HYL1) is a double-stranded RNA-binding protein that forms a complex with DICER-LIKE1 (DCL1) and SERRATE to facilitate processing of primary miRNAs into microRNAs (miRNAs). However, the structural mechanisms of miRNA maturation by this complex are poorly understood. Here, we present the crystal structures of double-stranded RNA binding domains (dsRBD1 and dsRBD2) of HYL1 and HYL1 dsRBD1 (HR1)/dsRNA complex as well as human TRBP2 dsRBD2 (TR2)/dsRNA complex for comparison analysis. Structural and functional study demonstrates that both HR1 and TR2 are canonical dsRBDs for dsRNA binding, whereas HR2 of HYL1 is a non-canonical dsRBD harboring a putative dimerization interface. Domain swapping within the context of HYL1 demonstrates that TR2 can supplant the function of HR1 in vitro and in vivo. Further biochemical analyses suggest that HYL1 probably binds to the miRNA/miRNA( *) region of precursors as a dimer mediated by HR2. Structure of arabidopsis HYPONASTIC LEAVES1 and its molecular implications for miRNA processing.,Yang SW, Chen HY, Yang J, Machida S, Chua NH, Yuan YA Structure. 2010 May 12;18(5):594-605. PMID:20462493[13] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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