Yamamoto R, Toyoda S, Viljanen P, Machida K, Nishikawa S, Murakami K, Taira K, Kumar P K
Institute of Applied Biochemistry, University of Tsukuba, Japan.
Nucleic Acids Symp Ser. 1995(34):145-6.
The Tat protein of human immunodeficiency virus interacts specifically with its target RNA sequence, TAR, and activates viral gene expression at the early stage of infection. Here, we have used in vitro genetic selection strategy to determine what sequence or structural motifs might exist between RNA's that interact specifically with the Tat protein. Starting from a RNA pool that has a 120 base random sequence core, aptamers that bind specifically to the Tat protein were selected by repeating 11 rounds of selection and amplification. A comparative analysis of 64 aptamers that were isolated from the 11th generation revealed two main sequence classes. Interestingly, one of these two classes of aptamers had minimum of one U residues in bulge loop and 2 specific adjacent base pairs. This region is very much homologous to the core sequence of TAR RNA that is essential for the specific Tat-TAR interactions. Further analyses of the sequences from the 11th generation should reveal what kind of RNA structures are required in order to show a high affinity for the Tat protein.
人类免疫缺陷病毒的反式激活因子（Tat）蛋白与它的靶RNA序列反式激活应答元件（TAR）特异性相互作用，并在感染早期激活病毒基因表达。在此，我们采用体外遗传筛选策略来确定与Tat蛋白特异性相互作用的RNA之间可能存在哪些序列或结构基序。从具有120个碱基随机序列核心的RNA库开始，通过重复11轮筛选和扩增，选择出与Tat蛋白特异性结合的适体。对从第11代分离出的64个适体进行的比较分析揭示了两个主要的序列类别。有趣的是，这两类适体中的一类在膨出环中至少有一个U残基和2个特定的相邻碱基对。该区域与TAR RNA的核心序列高度同源，而TAR RNA的核心序列对于Tat-TAR特异性相互作用至关重要。对第11代序列的进一步分析应能揭示为了对Tat蛋白表现出高亲和力需要何种RNA结构。
