Structure and Physical Properties of RNA

描述(由申请人提供)：本申请寻求支持的主要活动是通过核磁共振和X射线结晶学确定生理上重要的RNA的结构。最终目标是从化学上了解所研究的RNA的生物学特性。由于RNA在基因表达中起着关键作用，所寻求的知识是我们理解对包括人类在内的所有生物体至关重要的过程的基础。有两个具体的问题需要研究：细菌中核糖体蛋白质合成的调节，以及真核生物中核糖体RNA转录物的假脱氧核糖核酸。在细菌中，核糖体蛋白的合成在翻译水平上受到反馈调节，其机制取决于特定的核糖体蛋白与编码它们的mRNAs之间的相互作用，其中许多是多顺反子的。直接关注的两个这样的系统是SPC操纵子/S8系统和L10操纵子/L10系统，但如果时间允许，将调查其他系统；例如阿尔法操纵子/L4系统。对每个核糖体蛋白操纵子的调控至关重要的mRNA序列将被尽可能精确地确定。将获得这些RNA序列和与其结合的核糖体蛋白之间形成的复合体的结构。在这些结构的基础上形成的关于翻译抑制机制的假说，随后将进行生化测试。由于细菌调节核糖体蛋白质合成的机制与真核生物不同，因此可以想象，特异性抑制细菌生长的新方法将被揭示。第二个要研究的问题是由boxH/ACA snoRNP系统提出的，该系统负责在高等生物体中假游走rRNA转录本。这些SnRNPs的RNA成分被认为以一种在文献中没有先例的方式与rRNA转录本中的序列相互作用。将进行生化实验，以确定是否可能存在假设类型的RNA/RNA相互作用，并将获得snoRNA的结构，结合和不结合适当的rRNA序列。

DESCRIPTION (provided by applicant): The principle activity for which this application seeks support is determination of the structures of physiologically important RNAs by NMR and X-ray crystallography. The ultimate objective is a chemical understanding of the biological properties of the RNAs studied. Since RNAs play critical roles in gene expression, the knowledge sought is fundamental to our understanding of processes vital to all organisms, including humans. Two specific problems are to be investigated: the regulation of ribosomal protein synthesis in bacteria, and the pseudouridylation of ribosomal RNA transcripts in eukaryotes. In bacteria, ribosomal protein synthesis is feed-back regulated at the translational level by mechanisms that depend on interactions between specific ribosomal proteins and sequences within the mRNAs that encode them, many of which are polycistronic. The two such systems of immediate concern are the spc operon/S8 system, and L10 operon./L10 system, but time permitting, others will be investigates; e.g. the alpha operon/L4 system. The mRNA sequence critical for the regulation of each ribosomal protein operon will be determined as precisely as possible. Structures will be obtained of the complexes that form between these RNA sequences and the ribosomal proteins that bind to them. Hypotheses about the mechanism of translational repression, formulated on the basis of those structures, will then be tested biochemically. Since bacteria regulate ribosomal protein synthesis by mechanisms unlike those used by eukaryotes, it is conceivable that new ways of specifically inhibiting bacterial growth will be revealed. The second problem to be investigated is posed by the boxH/ACA snoRNP system responsible for pseudouridylating rRNA transcripts in higher organisms. The RNA components of these snRNPs are postulated to interact with sequences in rRNA transcripts in a way that has no precedent in the literature. Biochemical experiments will be done to determine whether RNA/RNA interactions of the sort hypothesized are possible, and structures will be obtained for a snoRNA, with and without an appropriate rRNA sequence bound.