In order to understand the role of nucleic acid conformation in genetic regulation, Dr. Feigon plans to: 1) continue studies of DNA oligomers containing potential B-Z junctions and triple stranded DNAs; 2) investigate echinomycin-DNA complexes; 3) examine how ECORI restriction enzyme and methylase bind specifically to the DNA sequence GAATTC; and 4) the study the interaction of the typtophan repressor with operator DNA. This project is concerned with the range of conformations that nucleic acids adopt, both free in solution and in complex with proteins and drugs, and in the specific factors that determine sequence specific binding of proteins and other ligands to nucleic acids. The primary research tool for this project is high field nuclear magnetic resonance spectroscopy, particulary two-dimensional, to elucidate structure and dynamics.