A 1.3-Å resolution crystal structure of the HIV-1 trans-activation response region RNA stem reveals a metal ion-dependent bulge conformation
A 1.3-Å resolution crystal structure of the HIV-1 trans-activation response region RNA stem reveals a metal ion-dependent bulge conformation
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DOI：
10.1073/pnas.95.17.9819
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发表时间：
1998-08-18
影响因子：
11.1
通讯作者：
Steitz, TA
中科院分区：
文献类型：
--
作者：
Ippolito, JA;Steitz, TA
含有反式激活蛋白 Tat 结合位点的 HIV-1 反式激活响应区 (TAR) RNA 片段的晶体结构已确定为 1.3 埃分辨率。在该晶体结构中，TAR 的特征性 UCU 凸起采用由三个二价钙离子稳定的构象，与之前通过溶液 NMR 测定的构象不同。对环构象至关重要的一种金属离子直接与环区域中的三个磷酸盐结合。该结构强调了金属离子结合对RNA结构的影响，并且考虑到细胞中二价金属离子的丰富性，提出了金属离子是否在TAR RNA的构象以及体内TAR与Tat和细胞周期蛋白T的相互作用中发挥作用的问题。
The crystal structure of an HIV-1 transactivation response region (TAR) RNA fragment containing the binding site for the trans-activation protein Tat has been determined to 1.3-Angstrom resolution. In this crystal structure, the characteristic UCU bulge of TAR adopts a conformation that is stabilized by three divalent calcium ions and differs from those determined previously by solution NMR. One metal ion, crucial to the loop conformation, binds directly to three phosphates in the loop region. The structure emphasizes the influence of metal ion binding on RNA structure and, given the abundance of divalent metal ion in the cell, raises the question of whether metal ions play a role in the conformation of TAR RNA and the interaction of TAR with Tat and cyclin T in vivo.