Cell Adhesion Laboratory, Department of Cancer Biology, The Scripps Research Institute, Jupiter, Florida 33458, USA.
Protein Sci. 2011 Aug;20(8):1464-70. doi: 10.1002/pro.664. Epub 2011 Jun 17.
Raver1 is a multifunctional protein that modulates both alternative splicing and focal adhesion assembly by binding to the nucleoplasmic splicing repressor polypyrimidine tract protein (PTB) or to the cytoskeletal proteins vinculin and α-actinin. The amino-terminal region of raver1 has three RNA recognition motif (RRM1, RRM2, and RRM3) domains, and RRM1 interacts with the vinculin tail (Vt) domain and vinculin mRNA. We previously determined the crystal structure of the raver1 RRM1-3 domains in complex with Vt at 2.75 Å resolution. Here, we report crystal structure of the unbound raver1 RRM1-3 domains at 2 Å resolution. The apo structure reveals that a bound sulfate ion disrupts an electrostatic interaction between the RRM1 and RRM2 domains, triggering a large relative domain movement of over 30°. Superposition with other RNA-bound RRM structures places the sulfate ion near the superposed RNA phosphate group suggesting that this is the raver1 RNA binding site. While several single and some tandem RRM domain structures have been described, to the best of our knowledge, this is the second report of a three-tandem RRM domain structure.
Raver1 是一种多功能蛋白，通过与核质剪接抑制蛋白多嘧啶 tract 蛋白 (PTB) 或细胞骨架蛋白 vinculin 和 α-actinin 结合，调节选择性剪接和黏着斑组装。Raver1 的氨基末端区域有三个 RNA 识别模体（RRM1、RRM2 和 RRM3）结构域，RRM1 与 vinculin 尾（Vt）结构域和 vinculin mRNA 相互作用。我们之前已确定了 Rav-er1 RRM1-3 结构域与 Vt 在 2.75 Å 分辨率下复合物的晶体结构。在这里，我们报告了 Rav-er1 RRM1-3 结构域在 2 Å 分辨率下的未结合晶体结构。无配体结构显示，结合的硫酸盐离子破坏了 RRM1 和 RRM2 结构域之间的静电相互作用，导致超过 30°的相对较大的结构域运动。与其他 RNA 结合的 RRM 结构的叠加将硫酸盐离子置于重叠的 RNA 磷酸基团附近，表明这是 Rav-er1 的 RNA 结合位点。虽然已经描述了几个单和一些串联 RRM 结构域结构，但据我们所知，这是第二个报道的三串联 RRM 结构域结构。
