Quantitative analysis of high-order structures of non-coding DNA and non-coding RNA sequences

正如核酶和核开关等上编码rna所显示的那样，DNA序列涉及端粒DNA和不具有遗传信息的非翻译区域，在基因表达中应该具有调节作用。本文研究了这些非编码dna在分子拥挤条件下的结构和热力学。结果发现，源自端粒序列的富鸟嘌呤RNA序列仅能折叠成平行链g -四重体，且这种折叠几乎不受序列和周围因素的影响。相反，相应的dna根据序列和周围因素形成不同的g -四联体。这些结果表明非编码DNA序列的非规范结构可能参与各种生物过程的重要性。

As shown in the on-coding RNAs such as ribozymes and riboswitches, DNA sequences, involving telomeric DNA and untranslated regions which do not posses genetic information, should have regulatory roles in gene expression. Here we investigated structure and thermodynamics of such non-coding DNAs under molecular crowding conditions. It was found that the guanine-rich RNA sequences, derived from telomere sequences, were only able to fold into a parallel-stranded G-quadruplex, and this folding was almost independent of sequence and surrounding factors. In contrast, corresponding DNAs formed various G-quadruplexes depending on the sequence and surrounding factors. These results suggest importance of non-canonical structures of the non-coding DNA sequences which may participate various biological processes.