一种与 5S RNA 结合锌指蛋白 TFIIIA 和 p43 具有高亲和力和高特异性的 RNA 适体。

An RNA aptamer with high affinity and high specificity for the 5S RNA binding zinc finger proteins TFIIIA and p43.

机构信息

Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055, Victoria, British Columbia V8W 3P6, Canada.

出版信息

Biochemistry. 2010 Mar 2;49(8):1755-65. doi: 10.1021/bi901664h.

DOI:10.1021/bi901664h

PMID:20095591

Abstract

The Xenopus zinc finger proteins TFIIIA and p43 bind to 5S RNA in immature oocytes to form 7S and 42S ribonucleoprotein storage particles. To probe the similarities and differences in the RNA binding domains of these two proteins, a library of random RNA molecules was enriched using TFIIIA as the bait protein. One of the abundant aptamers isolated, RNA22, bound to both TFIIIA and p43 derived zinc finger peptides with high affinity and specificity even though the predicted secondary structure of the RNA was unrelated to that of 5S RNA. The interactions of TFIIIA and p43 peptides with RNA22 were compared to their interactions with 5S RNA by characterizing the effects of assay conditions, mutations in RNA22, and mutations in the zinc finger proteins. The similarities and differences in the mechanisms by which these two zinc finger proteins interact with 5S RNA compared to RNA22 suggest they share a common platform for RNA binding with enough flexibility to form specific interactions with both RNAs.

摘要

非洲爪蟾锌指蛋白 TFIIIA 和 p43 在未成熟卵母细胞中与 5S RNA 结合，形成 7S 和 42S 核糖核蛋白储存颗粒。为了探究这两种蛋白质的 RNA 结合域的相似性和差异性，我们使用 TFIIIA 作为诱饵蛋白，从文库中富集了随机 RNA 分子。其中一个丰富的适体 RNA22 与 TFIIIA 和 p43 衍生的锌指肽具有高亲和力和特异性结合，尽管 RNA 的预测二级结构与 5S RNA 无关。通过描述测定条件的影响、RNA22 中的突变以及锌指蛋白中的突变，比较了 TFIIIA 和 p43 肽与 RNA22 的相互作用与其与 5S RNA 的相互作用。这两种锌指蛋白与 5S RNA 相互作用的机制与 RNA22 的相似性和差异性表明，它们共享一个用于 RNA 结合的通用平台，具有足够的灵活性，可以与两种 RNA 形成特异性相互作用。