GROUP I RIBOZYME P4-P6 DOMAIN FROM TETRAHYMENA

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。 I组内含子或核酶是独立折叠的RNA分子，可以在翻译前从信使RNA(MRNA)中自我剪接。自25年前发现I类内含子以来，已鉴定出2000多个序列。根据序列和二级结构保守性，将这些核酶分为不同的亚群。嗜热四膜虫核酶的第一个结构域(160个核苷酸，非催化)是在1996年获得的。2001年，一个含有单核苷酸变化的突变体获得了更高的分辨率。 在这个项目中，我们首先获得了P4-P6结构域和特定结合配体之间的络合物的晶体。我们希望，该复合体的高分辨率结构将有助于我们理解小分子与其RNA靶标之间的分子识别。 其次，为了进一步提高分辨率，我们对原有的RNA结构进行了进一步的突变。目前正在对这些结构进行结晶筛选。这一方法可以为未来结晶学用RNA结构的设计提供一般指导。

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. Group I introns ¿¿¿¿¿"or ribozymes¿¿¿¿¿" are independently folded RNA molecules that can self-splice from a messenger RNA (mRNA) prior to translation. More than 2000 sequences of group I introns have been identified since their discovery ~25 years ago. These ribozymes were classified into different subgroups based on sequence and secondary structure conservation. The first crystal structure of a domain (160 nucleotides; non-catalytic) from a group I ribozyme from the ciliate Tetrahymena thermophila was obtained in 1996. Improved resolutions were obtained in 2001 for a mutant containing a single nucleotide change. In this project, we first obtained crystals of a complex between the P4-P6 domain and a specifically bound ligand. Our hope is that a structure of that complex at high resolution would facilitate our understanding of the molecular recognition between a small molecule and its RNA target. Second, we further mutated the original RNA construct in order to seek for further improvement of resolution. These constructs are being currently screened for crystallization. This approach could offer general guidelines for the future design of RNA constructs for crystallography.