STRUCTURAL STUDIES OF EXORIBONUCLEASES AND PSEUDOURIDINE SYNTHASES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 核糖核酸酶：核糖核酸酶(RNase)在许多RNA细胞过程中起着核心作用。这些过程包括mRNA的降解、成熟和稳定RNA的周转，这对所有细胞的正常运作都是至关重要的。我们的实验室正在专注于外切核糖核酸酶的结构研究，它在末端水解RNA。在大肠杆菌中有八种外切核糖核酸酶，我们最初的重点是这些酶中三个DEDD家族成员的结构。这项研究的长期目标是了解单个有机体(大肠杆菌)中所有外切核糖核酸酶的结构和作用机制；这些研究补充了一项平行研究，以完全确定和表征大肠杆菌中所有外切核酸酶的生理作用，该研究目前正在迈阿密大学医学院的Deutscher实验室进行。 假尿苷合成酶：与James Ofengand的实验室合作，我们正在进行细菌假尿苷合成酶的结构研究。这些普遍存在的酶负责在结构RNA(如tRNAs、核糖体和剪接体RNAs)中将特定的尿氨酸异构化为假尿苷，并分为五个蛋白质家族。我们已经获得了大肠杆菌中十个假尿苷合成酶中的两个的结构，进一步的研究正在进行中，以更好地了解这些酶是如何识别其RNA靶标和进行尿苷异构化的。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Exoribonucleases: Ribonucleases (RNases) play a central role in a number of RNA cellular processes. These processes include mRNA degradation, maturation, and turnover of stable RNAs, which are vital for the proper functioning of all cells. Our laboratory is focusing on structural studies of exoribonucleases, which hydrolyse RNA at their ends. There are eight exoribonucleases in E. coli, and our initial emphasis is on the structures of the three DEDD family members in these enzymes. The long term goals of this research are to understand the structures and mechanisms of action of all the exoribonucleases in a single organism (E. coli); these studies complement a parallel study to completely determine and characterize the physiological role of all the exoribonucleases in E. coli, now underway in the Deutscher laboratory at the University of Miami School of Medicine. Pseudouridine Synthases: In collaboration with the laboratory of James Ofengand, we are carrying out structural studies of bacterial pseudouridine synthases. These ubiquitous enzymes are responsible for isomerization of specific uridines to pseudouridines in structured RNAs such as tRNAs, ribosomal and splicosomal RNAs, and fall into five protein families. We have obtained structures of two of the ten pseudouridine synthases in E. coli and further studies are in progress to better understand how these enzymes recognize their RNA targets and carry out uridine isomerization.