Moss Walter N
Roy J. Carver Department of Biophysics, Biochemistry and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
Noncoding RNA Res. 2018 May 24;3(3):100-107. doi: 10.1016/j.ncrna.2018.04.005. eCollection 2018 Sep.
In addition to energetically optimal structures, RNAs can fold into near energy suboptimal conformations that may be populated and play functional roles. The diversity of this structural ensemble can be estimated using a metric derived from the calculated RNA partition function: the . In this report, 10 classes of functional RNAs were analyzed: the 5.8S and 5S rRNAs, ribozyme, RNase P, snoRNA, snRNA, SRP RNA, tmRNA, Vault RNA and Y RNA. Representative sequences from each class were mutagenized in two ways: firstly, all possible point mutations were generated and secondly, wild type sequences were randomized to generate multiple scrambled mutants. Compared to the mutants, the native RNA ensemble diversity was predicted to be lower. This finding held true when all available sequences (378,455 sequences) for each RNA class (archived in the RNAcentral database) were analyzed. This suggests that a compact structural ensemble is an evolved characteristic of functional RNAs.
除了能量最优结构外，RNA还能折叠成接近能量次优的构象，这些构象可能存在并发挥功能作用。这种结构集合的多样性可以使用从计算出的RNA分配函数导出的一个指标来估计：即 。在本报告中，分析了10类功能性RNA：5.8S和5S rRNA、核酶、RNase P、snoRNA、snRNA、SRP RNA、tmRNA、穹窿体RNA和Y RNA。每类的代表性序列通过两种方式进行诱变：首先，产生所有可能的点突变；其次，将野生型序列随机化以产生多个乱序突变体。与突变体相比，天然RNA集合的多样性预计较低。当分析每个RNA类别的所有可用序列（378,455个序列，存档于RNAcentral数据库）时，这一发现依然成立。这表明紧凑的结构集合是功能性RNA的一种进化特征。
