Structural and functional insights into the fly microRNA biogenesis factor Loquacious.
Structural and functional insights into the fly microRNA biogenesis factor Loquacious.
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DOI：
10.1261/rna.055426.115
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发表时间：
2016-03
期刊：
影响因子：
--
通讯作者：
Meister G
中科院分区：
文献类型：
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作者：
Jakob L;Treiber T;Treiber N;Gust A;Kramm K;Hansen K;Stotz M;Wankerl L;Herzog F;Hannus S;Grohmann D;Meister G
在microRNA(MiRNA)途径中，Dier将前体加工成成熟的miRNAs。为了有效的加工，双链RNA结合蛋白支持DICER蛋白。在果蝇中，loqous(Loqs)与Dicer1(DmDcr1)相互作用，以促进miRNA的加工。在这里，我们已经解决了LOQS的第三个双链RNA结合域(DsRBD)的结构，并定义了与dmDcr1相互作用的特定结构元件。此外，我们还表明，dsRBD3之前的连接子对dmDcr1的结合有显著贡献。此外，我们的结构工作表明，Loqs的第三个dsRBD形成了同源二聚体。二聚化界面的突变消除了dmDcr1的相互作用。然而，LOQS使用确定的二聚化表面作为单体与dmDcr1结合，这表明在dmDcr1不存在或无法访问的条件下，LOQS可能形成二聚体。由于关键序列元件是保守的，我们认为二聚化可能是dsRBD蛋白在基因沉默中的一个普遍特征。
In the microRNA (miRNA) pathway, Dicer processes precursors to mature miRNAs. For efficient processing, double-stranded RNA-binding proteins support Dicer proteins. In flies, Loquacious (Loqs) interacts with Dicer1 (dmDcr1) to facilitate miRNA processing. Here, we have solved the structure of the third double-stranded RNA-binding domain (dsRBD) of Loqs and define specific structural elements that interact with dmDcr1. In addition, we show that the linker preceding dsRBD3 contributes significantly to dmDcr1 binding. Furthermore, our structural work demonstrates that the third dsRBD of Loqs forms homodimers. Mutations in the dimerization interface abrogate dmDcr1 interaction. Loqs, however, binds to dmDcr1 as a monomer using the identified dimerization surface, which suggests that Loqs might form dimers under conditions where dmDcr1 is absent or not accessible. Since critical sequence elements are conserved, we suggest that dimerization might be a general feature of dsRBD proteins in gene silencing.