Interactions between small molecules and proteins mediate the biological processes of life. A knowledge of how proteins specifically interact with small molecules provides us with the tools to probe complex biology, but also allows us to develop potent and specific drugs to manipulate these processes to prevent, manage and cure disease.

In the first part of this thesis, the interactions between non-pheromone small molecules and the pheromone binding protein from Bombyx mori were explored by using X-ray crystallography to solve structures of these complexes. Pheromone signal transduction in moths provides a relatively simple model of the complex biology of neurological processing.

The second part of this thesis aimed to discover the functional form of a peptide substrate that interacts with biosynthetic enzymes to make pantocin A. This antibiotic is effective against Erwinia amylovora, the pathogen that causes fire blight disease. The functional form of the substrate was explored through genetic manipulation of the biosynthetic pathway that produces pantocin A.