Structural and functional analyses of archaeal sRNPs

古菌 sRNP 的结构和功能分析

• 批准号: 6968011
• 负责人: BERNARD ANDREW BROWN
• 金额: $ 22.6万
• 依托单位: WAKE FOREST UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6968011
• 关键词: Archaea; membrane biogenesis; methylation; molecular assembly /self assembly; protein binding; protein biosynthesis; protein structure function; ribosomal RNA; small nuclear ribonucleoproteins; structural biology

DESCRIPTION (provided by applicant): Ribosomal RNAs are covalently modified during biogenesis. Failure to properly modify rRNA can affect the efficiency of protein synthesis and may be involved in tumor-formation and disease pathogenesis. One of the most prevalent rRNA modification in both eukaryotes and archaea is the 2'-O-methylation of ribose 2'-hydroxyl groups. These modifications are directed by the conserved family of box C/D small nucleolar RNAs, which contain terminal box C/D and juxtaposed internal box C
O/D
O motifs. At present, archaeal box C'/D' small ribonucleoproteins (sRNPs) are the only RNA-guided nucleotide modification systems that can be reconstituted in vitro to obtain enzymatically active complexes. These systems are ripe for structural investigations that determine the mechanism of complex-assembly and its linkage to regulation, and assess how mutations affect methylation activity. The long-term goals of this research are to investigate the structural biology of the box C/D-guided 2'-O-methylation systems in archaeal organisms and compare them to eukaryotic counterparts. This investigation will specifically examine the structure <--> activity relationship of the Methanocaldococcus jannaschii and Aeropyrum pernix box C/D sRNPs. In these systems, the L7Ae core protein initiates sRNP assembly by binding box C/D RNAs and establishing interactions with the Nop56/58 and fibrillarin core proteins. The goals are to elucidate how protein-RNA and protein/protein interactions, binding, folding, and assembly regulate biological activity. The specific aims are: 1. To compare and contrast the structures of the individual and juxtaposed archaeal box C/D and C'/D' sRNA motifs to those in isolated and juxtaposed L7Ae-box C/D and L7Ae-C'/D' sRNP complexes; and 2. To examine the archaeal core protein L7Ae's role in initiating sRNP assembly and the putative function of zinc in these interactions. The rationale for this investigation is to add complementary biophysical and structural data to support the mounting biochemical studies on archaeal box C/D RNA modification systems. These studies will provide insight to the evolution and development of ribonucleoprotein enzyme complexes, and illuminate the similarities and difference between the archaeal and eukaryotic sRNP systems.

描述（由申请人提供）：核糖体RNA在生物发生过程中被共价修饰。 rRNA 修饰不当会影响蛋白质合成的效率，并可能参与肿瘤形成和疾病发病机制。真核生物和古细菌中最常见的 rRNA 修饰之一是核糖 2'-羟基的 2'-O-甲基化。这些修饰是由盒 C/D 小核仁 RNA 保守家族指导的，该家族包含末端盒 C/D 和并列的内部盒 C O/D O 基序。目前，古细菌盒C'/D'小核糖核蛋白（sRNP）是唯一可以在体外重构以获得酶活性复合物的RNA引导的核苷酸修饰系统。这些系统对于结构研究来说已经成熟，可以确定复杂组装的机制及其与调节的联系，并评估突变如何影响甲基化活性。 这项研究的长期目标是研究古细菌中盒 C/D 引导的 2'-O-甲基化系统的结构生物学，并将其与真核生物进行比较。本研究将专门检查 Methanocaldocococus jannaschii 和 Aeropyrum pernix box C/D sRNP 的结构 <--> 活性关系。在这些系统中，L7Ae 核心蛋白通过结合盒 C/D RNA 并与 Nop56/58 和纤维蛋白核心蛋白建立相互作用来启动 sRNP 组装。目标是阐明蛋白质-RNA 和蛋白质/蛋白质相互作用、结合、折叠和组装如何调节生物活性。 具体目标是： 1. 比较和对比单个和并置的古菌盒 C/D 和 C'/D' sRNA 基序与分离和并置的 L7Ae-box C/D 和 L7Ae-C'/D' sRNP 复合体中的结构；和 2. 检查古菌核心蛋白 L7Ae 在启动 sRNP 组装中的作用以及锌在这些相互作用中的推定功能。 这项研究的基本原理是添加补充的生物物理和结构数据，以支持对古细菌盒 C/D RNA 修饰系统进行的生化研究。这些研究将为核糖核蛋白酶复合物的进化和发展提供深入的了解，并阐明古菌和真核 sRNP 系统之间的异同。