Examination of protein-DNA interactions involved in regulating gene expression is the major focus of research efforts in this laboratory. Genetic regulation is an essential function in all organisms and provides the ability to respond to signals that reflect environmental conditions, determine developmental processes, and communicate other information within an organism. The lactose repressor (LacI) controls expression of the enzymes that metabolize lactose in E. coli. Our long-term goal is detailed insight into mechanisms by which both LacI recognition and regulation occur, and experiments with collaborators extend the applications of this protein. The Ultrabithorax gene encodes a member of the homeodomain family of proteins (Hox proteins) that participate in specifying segmental identity in the Drosophila embryo during development. Experiments are underway with collaborators to explore regulation of DNA recognition and transcriptional regulation and to understand the interesting materials properties of this protein.