Abstract:
RNA\'s diversity of structures and functions impacts all life forms since primordia. We use calorimetric force spectroscopy to investigate RNA folding landscapes in previously unexplored low-temperature conditions. We find that Watson-Crick RNA hairpins, the most basic secondary structure elements, undergo a glass-like transition below [Formula: see text]C where the heat capacity abruptly changes and the RNA folds into a diversity of misfolded structures. We hypothesize that an altered RNA biochemistry, determined by sequence-independent ribose-water interactions, outweighs sequence-dependent base pairing. The ubiquitous ribose-water interactions lead to universal RNA phase transitions below TG, such as maximum stability at [Formula: see text]C where water density is maximum, and cold denaturation at [Formula: see text]C. RNA cold biochemistry may have a profound impact on RNA function and evolution.
摘要:
RNA结构和功能的多样性影响自原基以来的所有生命形式。我们使用比色力光谱法来研究以前未开发的低温条件下的RNA折叠景观。我们发现沃森-克里克RNA发夹,最基本的二级结构要素,经历低于[公式:参见文字]C的玻璃状转变,其中热容量突然变化,RNA折叠成各种错误折叠的结构。我们假设RNA生物化学改变,由序列独立的核糖-水相互作用决定,超过序列依赖性碱基配对。无处不在的核糖-水相互作用导致TG以下的通用RNA相变,例如在[公式:参见文本]C处的最大稳定性,其中水密度最大,和冷变性在[公式:见文本]C。RNA冷生物化学可能对RNA的功能和进化产生深远的影响。