Transmembrane signaling is critical to the initiation of many crucial cellular processes. This project aims to gain insight into the structural mechanisms for signal transduction by transmembrane receptors. This will be accomplished using the solid state nuclear magnetic resonance technique, REDOR, to measure internuclear distances in the serine receptor of the bacteria, E. coli. This distances will be measured in the presence and absence of serine and then used to model the conformation change occurring in this receptor protein upon serine binding.