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. The nuclear pore complex (NPC) is the largest protein assembly in eukaryotic cell, which mediate transport between nucleus and cytoplasm. NPC have approximately 30 unique proteins (known as nucleoporins), clustered together to form approximately 125 MDa protein complex in vertebrates. Based on biochemical purification and in vitro binding experiments, all nucleoporins have been grouped into several subcomplexes. One of these subcomplex, named as Nup93 subcomplex contribute to correct assembly of NPC at nuclear membrane and also maintains its size exclusion limit. Nup93 subcomplex located in the core region of NPC has Nup93, Nup205, Nup188, Nup35 and Nup155 members, which interact with each other. Our lab is trying to reconstitute this subcomplex and then determine its 3D structure by crystallographic methods. The long term goal of our lab is to determine the 3D structure of individual nucleoporins or complex of nucleoporins.The structural information of these proteins will be like snapshots of nuclear trafficking via NPC. Currently we have crystals of Nup93 and Nup35 which are diffracting poorly.The goal is to collect good data set and determine its 3D structure using MAD/MIR methods The 3D structure of nucleoporins would demonstrate how the largest protein assembly of the cell is organized and what are structural features of the proteins which regulate the fundamental process of nuclear transport.Eventually this information will led us to understand the complex organization of life at cellular level.