THE STRUCTURE OF THE HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 TAR RNA REVEALS PRINCIPLES OF RNA RECOGNITION BY TAT PROTEIN
THE STRUCTURE OF THE HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 TAR RNA REVEALS PRINCIPLES OF RNA RECOGNITION BY TAT PROTEIN
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DOI：
10.1006/jmbi.1995.0555
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发表时间：
1995-10-20
影响因子：
5.6
通讯作者：
VARANI, G
中科院分区：
文献类型：
--
作者：
ABOULELA, F;KARN, J;VARANI, G
人类免疫缺陷病毒1型（HIV-1）达特蛋白刺激转录延伸。达特通过与所有HIV-1 mRNA上发现的5'前导序列编码的反式激活反应区（TAR）RNA茎环结合而被引入转录机制。我们已经使用多维异源NMR来确定在ADP-1多肽存在下TAR RNA的结构，ADP-1多肽是一种37聚体，其携带达特蛋白的最小RNA识别区域，并且紧密模拟达特结合特异性。在多种配体（包括ADP-1、相关碱性肽和氨基酸衍生物N-异丁酰胺）存在下，TAR的凸起区域经历局部构象重排并形成更稳定的结构。在绑定形式的TAR的结构已被确定从超过1000 NMR衍生的约束。凸起5'端的U23残基位于大沟中的G26和A27附近，而不是像游离TAR中那样堆叠在A22上。U23和G26通过与共同精氨酸残基的胍基和侧链酰胺基接触而紧密接近。然而，这种胍基与TAR的相互作用不是结合特异性的唯一来源。除了参与构象变化的精氨酸残基的NOE之外，ADP-1还显示了TAR的分子间NOE，这表明TAR RNA与来自达特的基本和核心区域的残基之间存在多个接触点。这些结构的结果提供了重要的线索，对识别小分子量和/或肽模拟抑制剂的基本Tat-TAR相互作用。(C)1995年学术出版社
The human immunodeficiency virus type-1 (HIV-1) Tat protein stimulates transcriptional elongation. Tat is introduced to the transcription machinery by binding to the transactivation response region (TAR) RNA stem-loop encoded by the 5' leader sequence found on all HIV-1 mRNAs. We have used multidimensional heteronuclear NMR to determine the structure of the TAR RNA in the presence of the ADP-1 polypeptide, a 37-mer that carries the minimal RNA recognition region of the Tat protein and closely mimics Tat binding specificity In the presence of a variety of ligands, including ADP-1, related basic peptides and the amino acid derivative argininamide, the bulge region of TAR undergoes a local conformational rearrangement and forms a more stable structure. The structure of TAR in the bound form has been determined from over 1000 NMR-derived constraints. The U23 residue at the 5' end of the bulge is positioned near G26 and A27 in the major groove, rather than stacked on A22 as in the free TAR. U23 and G26 are brought into close proximity by contacts to the guanidinium group and side-chain amide group of a common arginine residue. However, the interaction of this guanidinium group with TAR is not the only source of binding specificity Besides NOEs to the arginine residue participating in the conformational change, ADP-1 shows additional intermolecular NOEs to TAR, suggesting that there are multiple points of contacts between TAR RNA and residues from the basic and core regions of Tat. These structural results provide important clues towards the identification of small molecular mass and/or peptidomimetic inhibitors of the essential Tat-TAR interaction. (C) 1995 Academic Press Limited