Structural Motifs in RNA

9600971佩罗纳最近发现的核糖核酸的新催化功能极大地提高了人们对这种分子在生物体内的关键作用的认识。对RNA生物学功能的充分认识必须包括对其三维结构如何组织的全面描述，但到目前为止，对RNA分子的原子水平描述很少。我们以前在谷氨酰tRNA合成酶-tRNAGIn复合体的结晶和结构测定方面的工作为快速确定RNA新结构域的结构提供了一个独特的载体，这是拟议项目的重点。这种大型蛋白质-RNA复合体的现有晶格将被利用，方法是将新的RNA结构域插入tRNA的特定位置，以便新材料能够容纳在晶体的溶剂间隙中。体外筛选方法被用来获得折叠正确并保持生物活性的新型杂化RNA分子。这些新的RNA之所以被选中，是因为它们有潜力告诉我们三维折叠的基本规则，以及它们今天的生物学意义。新的RNA结构的快速增加将提供对基于RNA的细胞过程的基本洞察，并可能对定义基于结构的药物设计的新的靶点具有进一步的影响。建立一个从事大分子结晶学的实验室一直是南加州大学期待已久的发展。因此，未来五年的一项重要活动将是对相关领域的学生和其他教职员工进行教育。由于化学和跨部门生物化学和分子生物学计划(BMB)是联合任命的，因此相互作用的范围将特别广泛。将开发一门新的结晶学研究生课程，现有的一门物理生物化学课程已经进行了广泛的修订。最先进的数据收集和计算机图形设施通过提供最重要技术的实践经验，增加了教育机会。结晶学的到来也标志着UCSB生物化学和生物物理学长期发展阶段的开始。因此，将有大量学生参加与结构生物学相关的几个新的本科课程：由化学系授予的生物化学学士学位，以及药理学的跨学科课程。该大学还坚定地承诺支持本科生的研究机会，霍华德·休斯医学院和材料研究实验室资助的项目就是明证。在实验室直接指导本科生将是教育计划的一个重要方面。大学内部的合作项目以及与其他机构的资深科学家的合作项目增加了学生在实验室接受教育的机会。所有活细胞中的基本构件分子是DNA、RNA和蛋白质。DNA在其核苷酸序列中对遗传信息进行编码，但为了细胞发挥功能，这些信息必须首先复制到类似的分子RNA中，然后翻译成蛋白质。直到最近，人们还认为蛋白质是细胞中唯一能够执行必要的化学和机械生命过程的分子。然而，新的发现表明，RNA具有类似的能力。我们试图了解RNA如何执行复杂的功能，历史上仅归因于蛋白质。要做到这一点，需要对RNA的三维结构进行可视化，这一壮举是通过诱导非常纯的RNA样品形成有序的晶体来实现的，并通过X射线衍射进行分析。在我们的实验室里，我们正在开发一种新的实验系统，以生长与蛋白质结合的RNA分子晶体，而不是通常的非结合状态。这个系统有可能让我们快速确定许多新的RNA结构。我们希望这些结构将为我们提供对RNA在基本细胞过程中的功能作用的基本见解。***

9600971 Perona Recent discoveries of new catalytic functions of RNA have greatly heightened awareness of the pivotal role of this molecule in living organisms. A full appreciation of the biological function of RNA must include a thorough description of how its three-dimensional structure is organized, but to date very few atomic-level descriptions of RNA molecules are available. Our previous work on crystallization and structure determination of the glutaminyl-tRNA synthetase-tRNAGIn complex provides a unique vehicle to rapidly determine the structures of new domains of RNA, the focus of the proposed project. The pre-existing crystal lattice of this large protein-RNA complex will be exploited by inserting new domains of RNA into specific positions of the tRNA, so that the new material is accomodated in the solvent interstices of the crystal. In-vitro selection methods are employed to obtain novel hybrid RNA molecules which fold correctly and retain biological activity. These new RNAs are chosen for their potential to teach us the underlying rules of three-dimensional folding and for their present-day biological significance. A rapid increase in new RNA structures will provide fundamental insight into RNA-based cellular processes and may have further implications to defining a new class of targets for structure-based drug design. The establishment of a laboratory engaged in Macromolecular Crystallography has been a long-awaited development at UCSB. Consequently, a significant activity in the next five years will be the education of students as well as other faculty members in related fields. Because a joint appointment is held in Chemistry and in an Interdepartmental Biochemistry and Molecular Biology Program (BMB), the range of interactions will be especially broad. A new graduate course in crystallography will be developed, and an existing course in Physical Biochemistry has already been extensively revised. State of the art data collection and computer graphics facilities enhance the educat ional opportunities by providing hands-on experience in the most important techniques. The arrival of crystallography also marks the onset of a long-term growth phase in Biochemistry and Biophysics at UCSB. Thus, there will be substantial participation in several new undergraduate curricula related to Structural Biology: a new B.S. degree in Biochemistry to be awarded by the Chemistry department, and an interdisciplinary program in Pharmacological Sciences. The University also possesses strong commitments to supporting undergraduate research opportunities, as manifested by programs funded by the Howard Hughes Medical Institute and the Materials Research Laboratory. Direct mentoring of undergraduates in the laboratory will be an important aspect of the educational program. Collaborative projects inside the University, as well as with senior scientists at other institutions, enhance the educational opportunities for students in the laboratory. %%% The fundamental building-block molecules in all living cells are DNA, RNA and protein. DNA encodes the genetic information within its nucleotide sequence, but for the cell to function this information must first be copied into a similar molecule, RNA, and then translated into protein. Until recently it was thought that proteins were the only molecules in cells capable of carrying out the necessary chemical and mechanical life processes. However, new discoveries have shown that RNA has a similar capability. We seek to understand how RNA can perform complex functions historically attributed only to protein. To do this requires visualization of RNA structure in three dimensions, a feat accomplished by inducing very pure samples of RNA to form well-ordered crystals which are analyzed by Xray diffraction. In our laboratory we are developing a new experimental system to grow crystals of RNA molecules bound to protein rather than in the usual unbound state. This system has the potential to allow us to rapidly determine many new RNA structures. We expect that the structures will provide us with fundamental insight into the functional roles of RNA in essential cellular processes. ***