2 RNA-BINDING MOTIFS IN THE DOUBLE-STRANDED RNA-ACTIVATED PROTEIN-KINASE, DAI
2 RNA-BINDING MOTIFS IN THE DOUBLE-STRANDED RNA-ACTIVATED PROTEIN-KINASE, DAI
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DOI：
10.1101/gad.6.12b.2478
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发表时间：
1992-12-01
影响因子：
10.5
通讯作者：
MATHEWS, MB
中科院分区：
文献类型：
--
作者：
GREEN, SR;MATHEWS, MB
蛋白激酶DAI是双链RNA激活的翻译抑制剂，是干扰素诱导的细胞抗病毒反应的重要组成部分。该酶受激活剂和抑制剂RNA的结合调节。我们在体外合成了DAI，并将其RNA结合结构域定位在氨基末端171个残基内。该结构域包含两个拷贝的RNA结合基序，其特征在于高密度的碱性氨基酸、保守残基的存在和可能的α-螺旋结构。两个基序中的任何一个的缺失都阻止了dsRNA的结合，但它们的相对位置可以交换，这表明它们合作与dsRNA相互作用。RNA结合基序内的重复点突变和单个基序的重复表明基序的第一个拷贝起着更重要的作用。削弱结合的突变对不同长度的双链RNA和腺病毒VA RNA（I）的结合具有相似的影响，这意味着激活和抑制RNA之间的区分发生在RNA结合之后。
The protein kinase DAI, the double-stranded RNA-activated inhibitor of translation, is an essential component of the interferon-induced cellular antiviral response. The enzyme is regulated by the binding of activator and inhibitor RNAs. We synthesized DAI in vitro and located its RNA-binding domain within the amino-terminal 171 residues. This domain contains two copies of an RNA-binding motif characterized by a high density of basic amino acids, by the presence of conserved residues, and by a probable alpha-helical structure. Deletion of either of the two motifs prevents the binding of dsRNA, but their relative positions can be exchanged, suggesting that they cooperate to interact with dsRNA. Clustered point mutations within the RNA-binding motifs and duplications of the individual motifs indicate that the first copy of the motif plays the more important role. Mutations that impair binding have similar effects on the binding of double-stranded RNAs of various lengths and of adenovirus VA RNA(I), implying that discrimination between activator and inhibitory RNAs takes place subsequent to RNA binding.