Biochemical and Structural Insights into RNA Binding by Ssh10b, a Member of the Highly Conserved Sac10b Protein Family in Archaea*
Biochemical and Structural Insights into RNA Binding by Ssh10b, a Member of the Highly Conserved Sac10b Protein Family in Archaea*
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DOI：
10.1074/jbc.m113.521351
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发表时间：
2013-12
期刊：
影响因子：
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通讯作者：
Li Guo;Jingjin Ding;R. Guo;Yanjie Hou;Dacheng Wang;Li Huang
中科院分区：
文献类型：
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作者：
Li Guo;Jingjin Ding;R. Guo;Yanjie Hou;Dacheng Wang;Li Huang
背景：Sac10b家族蛋白在古生物中广泛存在。结果：柴胡Sac10b家族成员Ssh10b通过相邻结合蛋白二聚体之间的相互作用破坏结构RNA中的碱基配对。结论：Ssh10b结合破坏了RNA二级结构的稳定性。意义：Sac10b家族的蛋白质可能在需要RNA二级结构不稳定的RNA交易中发挥作用。Sac10b家族的蛋白在古生代中高度保守。Ssh10b是Sac10b家族中的一员，属于嗜热菌柴胡的Sac10b家族，在体内与RNA结合。在这里，我们证明了Ssh10b的结合破坏了RNA二级结构的稳定。对Ssh10b与含有局部扭曲的25个碱基的RNA双链形成的复合体的结构分析表明，Ssh10b以四聚体的形式对称地结合在两条RNA链上，每个二聚体不对称地结合到一条RNA链上。参与双链RNA结合的氨基酸残基与dsDNA结合的氨基酸残基相似，但不完全相同。由分子间β-Sheet介导的二聚体-二聚体相互作用似乎有助于RNA二级结构中碱基配对的不稳定。我们的结果表明，Sac10b家族的蛋白质可能在需要破坏Sulfolobus RNA二级结构不稳定的RNA交易中发挥重要作用。
Background: Proteins of the Sac10b family are widespread in Archaea. Results: Ssh10b, a member of the Sac10b family from Sulfolobus shibatae, disrupts base pairing in structured RNA through interactions between adjacently bound protein dimers. Conclusion: Binding by Ssh10b destabilizes RNA secondary structure. Significance: Proteins of the Sac10b family may play a role in RNA transactions requiring destabilization of RNA secondary structure. Proteins of the Sac10b family are highly conserved in Archaea. Ssh10b, a member of the Sac10b family from the hyperthermophilic crenarchaeon Sulfolobus shibatae, binds to RNA in vivo. Here we show that binding by Ssh10b destabilizes RNA secondary structure. Structural analysis of Ssh10b in complex with a 25-bp RNA duplex containing local distortions reveals that Ssh10b binds the two RNA strands symmetrically as a tetramer with each dimer bound asymmetrically to a single RNA strand. Amino acid residues involved in double-stranded RNA binding are similar, but non-identical, to those in dsDNA binding. The dimer-dimer interaction mediated by the intermolecular β-sheet appears to facilitate the destabilization of base pairing in the secondary structure of RNA. Our results suggest that proteins of the Sac10b family may play important roles in RNA transactions requiring destabilization of RNA secondary structure in Sulfolobus.