RNA: Structure, Biophysics and Physiology

RNA：结构、生物物理学和生理学

• 批准号: 9572298
• 负责人: Adrian Ferre-D'Amare
• 金额: $ 85.62万
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/9572298
• 关键词: Alternative Splicing; Anti-Bacterial Agents; Binding Sites; Biochemical; Biological Models; Biophysics; Calcium; Calcium ion; Catalytic RNA; Catheters; Cations; Cell Aging; Cells; Chemicals; Clinical; Coenzymes; Complex; Disease; Evolution; Future; Gene Expression; Genetic Transcription; Health; Implant; In Vitro; Messenger RNA; Microbial Biofilms; Molecular; Morbidity - disease rate; Nutritional; Physiological; Physiology; Point Mutation; Procedures; Proteins; RNA; Regulator Genes; Ribonucleoproteins; Site; Structure; Study Subject; Telomerase; Time; Tissues; Translations; Variant; Vascular Endothelial Growth Factors; Work; interest; mRNA Decay; magnesium ion; metalloenzyme; mortality; mutant; nutrition; response; small molecule; tumor growth

In the past year, we have made progress in the subject of RNA-cation interactions and how RNA can employ cation selectivity. Our previous in vitro selection, biochemical and structural studies of the bacterial glmS ribozyme-riboswitch had demonstrated that a point mutation can convert the coenzyme-dependent wild-type RNA into a metalloenzyme. In new work, we have subjected the metalloenzyme variant to further in vitro evolution, obtaining a ribozyme with exquisite selectivity for calcium ion over magnesium ion. This RNA is over 10,000 times more active in the former than the latter. Biochemical probing suggests that calcium selectivity was acquired by a pre-existing, formerly non-specific cation binding site which functions primarily in structural stabilization in the wild-typre ribozyme. In the mutant, this site has been co-opted to participate in the transition state when bound to calcium. This is thus a clear case of molecular exaptation.

在过去的一年里，我们在 RNA-阳离子相互作用以及 RNA 如何利用阳离子选择性方面取得了进展。 我们之前对细菌glmS核酶-核糖开关的体外选择、生化和结构研究表明，点突变可以将辅酶依赖性野生型RNA转化为金属酶。 在新的工作中，我们对金属酶变体进行了进一步的体外进化，获得了对钙离子比镁离子具有精细选择性的核酶。 前者的 RNA 活性比后者高 10,000 倍以上。 生化探测表明，钙选择性是通过预先存在的、以前的非特异性阳离子结合位点获得的，该结合位点主要在野生型核酶中的结构稳定中发挥作用。 在突变体中，当与钙结合时，该位点被选择参与过渡态。 因此，这是分子外适应的一个明显例子。