A postdoctoral research scientist position is available at Columbia University Medical Center. We study the structure and function of cell surface receptors using a combination of x-ray crystallography, cryo-EM and biochemical methods. The successful candidate will focus on the _expression_ and purification of several receptors using recombinant systems, and structure determination by crystallography or EM. The candidate should have a strong background in molecular biology and protein biochemistry. Extensive research experience in large-scale protein production is required. Prior experience with membrane protein and cell-based functional analysis is preferred.