Curtis Edward A, Liu David R
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
Chem Biol. 2013 Apr 18;20(4):521-32. doi: 10.1016/j.chembiol.2013.02.015.
Biological RNAs that bind small molecules have been implicated in a variety of regulatory and catalytic processes. Inspired by these examples, we used in vitro selection to search a pool of genome-encoded RNA fragments for naturally occurring GTP aptamers. Several aptamer classes were identified, including one (the "G motif") with a G-quadruplex structure. Further analysis revealed that most RNA and DNA G-quadruplexes bind GTP. The G motif is abundant in eukaryotes, and the human genome contains 75,000 examples with dissociation constants comparable to the GTP concentration of a eukaryotic cell (300 μM). G-quadruplexes play roles in diverse cellular processes, and our findings raise the possibility that GTP may play a role in the function of these elements. Consistent with this possibility, the sequence requirements of several classes of regulatory G-quadruplexes parallel those of GTP binding.
与小分子结合的生物RNA参与了多种调控和催化过程。受这些实例启发，我们利用体外筛选技术，在一组基因组编码的RNA片段中寻找天然存在的GTP适配体。我们鉴定出了几类适配体，其中一类（“G基序”）具有G-四链体结构。进一步分析表明，大多数RNA和DNA G-四链体都能结合GTP。G基序在真核生物中很丰富，人类基因组中约有75,000个实例，其解离常数与真核细胞的GTP浓度（约300μM）相当。G-四链体在多种细胞过程中发挥作用，我们的研究结果增加了GTP可能在这些元件功能中发挥作用的可能性。与此可能性一致的是，几类调控性G-四链体的序列要求与GTP结合的序列要求相似。
