Faculty of Science, Department of Chemistry, Shizuoka University , 836 Ohya, Suruga, Shizuoka 422-8529, Japan.
Biochemistry. 2011 Jun 14;50(23):5369-78. doi: 10.1021/bi2003857. Epub 2011 May 18.
The G-quadruplex nucleic acid structural motif is a target for designing molecules with potential anticancer properties. To achieve therapeutic selectivity by targeting the G-quadruplex, the molecules must be able to differentiate between the DNA of different G-quadruplexes. We recently reported that the Arg-Gly-Gly repeat (RGG) of the C-terminus in Ewing's sarcoma protein (EWS), which is a group of dominant oncogenes that arise due to chromosomal translocations, is capable of binding to G-quadruplex telomere DNA and RNA via arginine residues and stabilize the G-quadruplex DNA form in vitro. Here, we show that the RGG of EWS binds preferentially to G-quadruplexes with longer loops, which is not related to the topology of the G-quadruplex structure. Moreover, the G-quadruplex DNA binding of the RGG in EWS depends on the phosphate backbone of the loops in the G-quadruplex DNA. We also investigated the G-quadruplex DNA binding activity of the N- and C-terminally truncated RGG to assess the role of the regions in the RGG in G-quadruplex DNA binding. Our findings indicate that the RGG and the other arginine-rich motif of residues 617-656 of the RGG in EWS are important for the specific binding to G-quadruplex DNA. These findings will contribute to the development of molecules that selectively target different G-quadruplex DNA.
G-四链体核酸结构基序是设计具有潜在抗癌特性的分子的目标。为了通过靶向 G-四链体实现治疗选择性，这些分子必须能够区分不同 G-四链体的 DNA。我们最近报道，尤文肉瘤蛋白（EWS）的 C 末端的精氨酸-甘氨酸-甘氨酸重复序列（RGG）是一组由于染色体易位而产生的优势致癌基因，能够通过精氨酸残基结合到端粒 G-四链体 DNA 和 RNA，并在体外稳定 G-四链体 DNA 形式。在这里，我们表明 EWS 的 RGG 优先结合具有更长环的 G-四链体，这与 G-四链体结构的拓扑结构无关。此外，EWS 中 RGG 的 G-四链体 DNA 结合取决于 G-四链体 DNA 中环的磷酸骨架。我们还研究了 N-和 C-末端截断的 RGG 的 G-四链体 DNA 结合活性，以评估 RGG 中该区域在 G-四链体 DNA 结合中的作用。我们的研究结果表明，RGG 和 EWS 中 RGG 的 617-656 位残基的其他精氨酸丰富基序对于与 G-四链体 DNA 的特异性结合很重要。这些发现将有助于开发选择性靶向不同 G-四链体 DNA 的分子。
