RNAs that Bind Small Substrates and Cofactors

能够结合特定配体的罕见RNA序列可以从大量随机序列分子中分离出来。这种配体结合序列，称为适体，可以通过亲和层析富集，并通过重复的富集和扩增循环分离。P.I.将描述几个最近分离的适体，对常见的代谢底物和辅助因子具有特异性。他还将分离新的适配体到其他底物和辅因子上，以探索化学上不同的配体与RNA结构结合的亲和力和特异性。他将研究结合位点的性质以及通过化学和分子生物学手段结合的重要相互作用类型。结构研究将与核磁共振和x射线晶体学实验室合作进行。随着功能性RNA序列的分离，P.I.将在序列数据库中搜索这些结构的出现，以寻找这些结构在生物学中使用的可能示例；任何此类事件的重要性都将进行基因测试。这项工作将对许多研究领域产生重大影响。能够结合所有主要种类的生物底物和辅助因子的RNA结构的分离增加了中间代谢进化发生在RNA世界时代的模型的合理性。研究RNA结构从一种结合特异性到另一种结合特异性的定向进化将提高我们对RNA进化灵活性的理解，并最终允许比较核酸和蛋白质进化新功能的能力，包括开发新的催化剂。新RNA结构的解决将有助于更好地理解核酸折叠的原理。最后，在这项工作过程中开发的技术可能在分子识别、诊断、生物传感器和制药领域有应用。许多科学家现在相信RNA酶在生命的起源和早期进化中起了重要作用。如果这是真的，RNA分子必须能够加速各种不同的化学反应；这反过来意味着RNA分子必须能够与各种不同的小分子紧密结合。这个实验室最近已经能够证明RNA实际上可以形成非常特定的小分子结合位点。他们从大量随机RNA序列开始，然后使用实验室版本的达尔文进化来选择能够结合特定目标分子的罕见RNA序列。我们将对其中的几种RNA进行表征，试图了解它们是如何识别它们的靶标的。该实验室还计划尝试了解它们是如何识别目标的。该实验室还计划寻找在生物学中使用这种RNA结构的可能例子。这项工作将提高我们对RNA如何在生物学中发挥其各种结构和催化作用的理解，并可能导致在分子识别，诊断，生物传感器和制药领域的应用。

Rare RNA sequences capable of binding specific ligands can be isolated from large pools of random sequence molecules. Such ligand binding sequences, known as aptamers, may be enriched by affinity chromatography, and isolated by repeated cycles of enrichment and amplification. The P.I. will characterize several recently isolated aptamers with specificity for common metabolic substrates and cofactors. He will also isolate new aptamers to additional substrates and cofactors in order to explore the affinity and specificity with which chemically diverse ligands can be bound by RNA structures. He will study the nature of the binding sites and the types of interactions that are important for binding by chemical and molecular biological means. Structural studies will be pursued in collaboration with NMR and X-ray crystallography labs. As functional RNA sequences are isolated, the P.I. will search for occurrences of these structures in the sequence databases for possible examples of the use of these structures in biology; the significance of any such occurrences will be tested genetically. This work will have significant implications for a number of areas of research. The isolation of RNA structures capable of binding all major classes of biological substrates and cofactors increases the plausibility of models in which the evolution of intermediary metabolism occurred at the time of the RNA world. Studies of the directed evolution of RNA structures from one binding specificity to another will improve our understanding of the evolutionary flexibility of RNA, and will eventually allow a comparison of the abilities of nucleic acids and proteins to evolve new functions, including the development of new catalysts. The solution of new RNA structures should lead to a better understanding of the principles of nucleic acid folding. Finally, the technology developed in the course of this work may have applications in the areas of molecular recognition, diagnostics, biosensors, and pharmaceuticals. %%% Many scientists now believe that RNA enzymes played an important role in the origin and early evolution of life. For this to be true, RNA molecules would have to be able to speed up a wide range of different chemical reactions; this in turn implies that RNA molecules would have to be able to bind tightly to a variety of different small molecules. This lab has recently been able to show that RNA's can in fact form very specific small molecule binding sites. They started with a large pool of random RNA sequences, and then used a laboratory version of Darwinian evolution to select for the rare RNA sequences capable of binding specific target molecules. Several o of these RNA's will be characterized to try to understand how they recognize their targets. The lab also plans to try to understand how they recognize their targets. The lab also plans to search for possible examples of the use of such RNA structures in biology. This work will improve our understanding of how RNA carries out its varied structural and catalytic roles in biology, and may lead to applications in the areas of molecular recognition, diagnostics, biosensors, and pharmaceuticals.