生命体中的蛋白质往往需要形成大的复合物以完成复杂的生物学功能。对蛋白质复合体结构与功能的研究是当今生物学研究的热点和前沿。迅速发展的冷冻电子显微学已经成为公认的研究蛋白质复合体的重要方法。本项目旨在运用冷冻电子显微学，并结合生物化学、生物物理学和分子生物学的方法，研究生命过程中重要的蛋白质复合体的结构与功能。研究内容包括两个方面：一，通过研究囊泡转运系统中重要的蛋白质机器20S复合体的结构，揭示AAA型ATPase酶家族蛋白成员NSF解开SNARE复合体的分子机制。二，通过研究HtrA蛋白酶家族成员DegP和DegQ与其底物结合的复合体的结构，揭示其行使蛋白酶和分子伴侣功能的结构基础及调节机制。

Proteins often need to form large complexes to accomplish the complicated biological functions. The structural and functional studies of protein complexes are at the forefront of current biology. As a fast-developing technology, cryo-electron microscopy has become acknowledged to be an indispensable tool in the study of protein complexes. In this project, we are aiming to elucidate the structures and functions of the most important protein complexes in cellular events by using cryo-electron microscopy in combination with techniques in biochemistry, biophysics and molecular biology. The specific aims are: 1) study the structure of 20S particle, which has an essential role in intracellular vesicle fusion events, in order to elucidate the molecular mechanism underlying disassembly of the SNARE complex by NSF, a member of AAA+ ATPase family; 2) study the structures of two bacterial HtrA proteases, DegP and DegQ, in complex with their substrates, in order to elucidate the structural basis and regulation mechanism underlying the proteolytic function and chaperone activity of HtrA proteins.