Laboratoire ARN-RNP Maturation-Structure-Fonction, Enzymologie Moléculaire et Structurale (AREMS), UMR 7214 CNRS-UHP Faculté des Sciences et Techniques, Université Henri Poincaré, Nancy 1, Bld des Aiguillettes, BP 70239, 54506 Vandoeuvre-les-Nancy, France.
Biochemistry. 2010 Jun 22;49(24):4934-44. doi: 10.1021/bi100408z.
Post-transcriptional ribonucleotide modification is a phenomenon best studied in tRNA, where it occurs most frequently and in great chemical diversity. This paper reviews the intrinsic network of modifications in the structural core of the tRNA, which governs structural flexibility and rigidity to fine-tune the molecule to peak performance and to regulate its steady-state level. Structural effects of RNA modifications range from nanometer-scale rearrangements to subtle restrictions of conformational space on the angstrom scale. Structural stabilization resulting from nucleotide modification results in increased thermal stability and translates into protection against unspecific degradation by bases and nucleases. Several mechanisms of specific degradation of hypomodified tRNA, which were only recently discovered, provide a link between structural and metabolic stability.
转录后核糖核苷酸修饰是在 tRNA 中研究得最好的现象，它在 tRNA 中发生得最频繁，化学多样性也最大。本文综述了 tRNA 结构核心中内在的修饰网络，该网络控制着结构的灵活性和刚性，以微调分子使其达到最佳性能，并调节其稳态水平。RNA 修饰的结构效应范围从纳米级别的重排到对构象空间的微妙限制在埃尺度上。核苷酸修饰导致的结构稳定性导致热稳定性增加，并转化为对碱基和核酸酶的非特异性降解的保护。最近才发现的几种修饰 tRNA 特异性降解的机制为结构和代谢稳定性之间提供了联系。
