This proposal requests funds for the purchase of a high performance, high field, instrument (500 MHz for proton observation) that will be dedicated to macromolecular structure determination. It will serve a small group of investigators in the chemistry department of Yale University who have ongoing projects directed at structure elucidation of biological macromolecules. These projects span a range of subjects that include DNA and RNA binding proteins, proteins and nucleic acids important in ribosome function, proteins important in lipid biosynthesis, and molecules important to cell surface recognition.