CRYSTALLOGRAPHIC STUDIES OF EXORIBONUCLEASES AND PSEUDOURIDINE SYNTHASES

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。外核糖核酸酶：核糖核酸酶（RNases）在许多RNA细胞过程中起核心作用。这些过程包括mRNA的降解、成熟和稳定rna的转换，这对所有细胞的正常功能至关重要。我们的实验室专注于外核糖核酸酶的结构研究，它在末端水解RNA。大肠杆菌中有八种外核糖核酸酶，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一生物（大肠杆菌）中所有外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核糖核酸酶的生理作用，该研究目前正在迈阿密大学医学院的Deutscher实验室进行。假尿嘧啶合成酶：与James Ofengand实验室合作，我们正在进行细菌假尿嘧啶合成酶的结构研究。这些普遍存在的酶负责在结构rna（如trna，核糖体和剪接体rna）中将特定尿苷异构化为假尿苷，并分为五个蛋白质家族。我们已经获得了大肠杆菌中10种假尿嘧啶合成酶中的2种的结构，进一步的研究正在进行中，以更好地了解这些酶如何识别其RNA靶标并进行尿嘧啶异构化。

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.