Structural rearrangements of HIV-1 Tat-responsive RNA upon binding of neomycin B
Structural rearrangements of HIV-1 Tat-responsive RNA upon binding of neomycin B
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DOI：
10.1074/jbc.m000920200
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发表时间：
2000-07-07
影响因子：
4.8
通讯作者：
Rösch, P
中科院分区：
文献类型：
--
作者：
Faber, C;Sticht, H;Rösch, P
人类免疫缺陷病毒1型（HIV-1）反式激活因子（达特）蛋白对Tat应答RNA（TAR）的发现对于病毒复制是必需的，并且被认为是设计抗HIV药物的有希望的起点。NMR光谱表明氨基糖苷类新霉素B和核糖霉素与TAR结合，新霉素能够抑制达特与TAR结合。新霉素结合的TAR的溶液结构已通过NMR光谱测定。化学位移图和分子间核Overhauser效应确定了氨基糖苷类在TAR上的结合区域，并为小沟结合提供了强有力的证据。基于15个核Overhauser效应衍生的分子间距离限制，计算了TAR-新霉素复合物的模型结构。新霉素结合在由下茎的小沟和TAR的富含尿苷的凸起形成的结合口袋中，其采用不同于已知的构象。氨基糖苷类的新霉胺核心（环I和环II）被凸起覆盖，解释了通过变构机制抑制达特。新霉素减少了结合达特的大沟的体积，从而阻碍了必需的蛋白质-RNA接触。
finding of human immunodeficiency virus type 1 (HIV-I) transactivator (Tat) protein to Tat-responsive RNA (TAR) is essential for viral replication and is considered a promising starting point for the design of anti-HIV drugs. NMR spectroscopy indicated that the aminoglycosides neomycin B and ribostamycin bind to TAR and that neomycin is able to inhibit Tat binding to TAR. The solution structure of the neomycin-bound TAR has been determined by NMR spectroscopy. Chemical shift mapping and intermolecular nuclear Overhauser effects define the binding region of the aminoglycosides on TAR and give strong evidence for minor groove binding. Based on 15 nuclear Overhauser effect-derived intermolecular distance restraints, a model structure of the TAR-neomycin complex was calculated. Neomycin is bound in a binding pocket formed by the minor groove of the lower stem and the uridine-rich bulge of TAR, which adopts a conformation different from those known. The neamine core of the aminoglycoside (rings I and II) is covered with the bulge, explaining the inhibition of Tat by an allosteric mechanism. Neomycin reduces the volume of the major groove in which Tat is bound and thus impedes essential protein-RNA contacts.