This is a Presidential Young Investigator award to support Dr. Buchman's studies concerning the molecular mechanisms governing gene expression and chromosome organization in yeast. His experiments will help characterize classes of protein-protein and protein-DNA interactions generally employed to create compound regulatory elements. Results of those experiments will help answer questions such as: How do diverse genetic elements combine to create a completely different regulatory element? How do regional changes in chromatin structure affect gene expression? How are significance of this research is that it addresses fundamental questions of chromosome organization in a simple eukaryotic that should be applicable as well to higher eukaryotic systems.