Tip49a/Tip49b及其相关复合物的冷冻电镜结构研究

项目名称： Tip49a/Tip49b及其相关复合物的冷冻电镜结构研究

项目编号： No.31500606

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 生物科学

项目作者： 宋峰

作者单位： 德州学院

项目金额： 20万元

中文摘要： Tip49a和Tip49b是AAA+超家族的两个蛋白，它们保守地存在于从酵母到人的多个物种中，在细胞内通常以复合物的形式存在。它们在DNA损伤修复、转录调控、snoRNP成熟、染色质重塑等生命活动中发挥重要的调控作用，但迄今为止仍然没有Tip49a/Tip49b全长蛋白相关复合物的结构报道。本研究拟主要应用冷冻电镜单颗粒三维重构技术解析人源Tip49a/Tip49b及其参与形成的两种高级复合物（R2TP、Tip49a/Tip49b-核小体）的高精度三维结构，并结合生化实验确定Tip49a/Tip49b在两种高级复合物中的作用。本项目的研究成果将为理解Tip49a/Tip49b在snoRNP组装（R2TP复合物）和ATP依赖的染色质重塑（Tip49a/Tip49b-核小体复合物）中的工作机制提供可靠的结构信息。

中文关键词： 冷冻电镜；单颗粒三维重构；蛋白复合物组装

英文摘要： Tip49a and Tip49b are two structurally and functionally highly related proteins that belong to the AAA+ (ATPase Associated with diverse cellular Activities) superfamily. They are existed in many species of which ranging from yeast to human. Both Tip49a and Tip49b are conserved components of various multi-subunit complexes, which are linked to a wide range of cellular processes, such as DNA damage response, transcription regulation, snoRNP biogenesis and ATP-dependent chromatin remodeling. Despite their diverse roles, there is no available high resolution structure of full-length Tip49a/Tip49b protein complex. The mainly purpose of our research is to reveal the high resolution structures of dodecameric Tip49a/Tip49b and determine their functions in two larger complexes which containing them, R2TP and Tip49a/Tip49b-nucleosome complex, by using cryo-EM single particle analysis combining with biochemical and biophysical techniques. Our research will provide insights into the structural basis of Tip49a/Tip49b in mediating snoRNP biogenesis(R2TP complex) and ATP-dependent chromatin remodeling(Tip49a/Tip49b-nucleosome complex).

英文关键词： cryo-EM;single particle reconstruction;protein complex assembly