MEMBRANE PROTEINS THAT MEDIATE ION TRANSPORT

点击翻译按钮获取中文摘要

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. Our aim is to determine the structures of two membrane proteins involved on ion transport, a Na/K symporter and a potassium channel. The Na/K symporter is expected to have the same architecture observed in the KcsA potassium channel structure solved by the Mackinnon group. However the symporter works as an ion pump that transports K+ into the cell using the Na+ gradient as energy source. Its mechanism of transport is still unclear and a three-dimensional structure will be essential for a complete understanding of its function. The potassium channel we are working on is regulated by cAMP and is part of a large family of ion channels gated by cyclic-nucleotides that play important roles in sensory systems like vision. With the structure of this bacterial potassium channel we are hoping to understand the mechanism of gating by these nucleotides. Both of these projects are still at a stage of screening for crystallization conditions. My group is fairly experienced on all macromolecular diffraction experiments and between us we have solved more than 10 different protein structures.