The continued success of genome sequencing projects has resulted in a wealth of information, but 40-50% of identified genes correspond to hypothetical proteins or proteins of unknown function. The Functional Annotation Screening Technology by NMR (FAST-NMR) screen was developed to assign a biological function for these unannotated proteins with a structure solved by the Protein Structure Initiative. FAST-NMR is based on the premise that a biological function can be described by a similarity in binding sites and ligand interactions with proteins of known function. The resulting co-structure and functional assignment may provide a starting point for a drug discovery effort