These genome sequences represent a wealth of data, but researchers are presently struggling to interpret their meaning and full utility. Genome sequences instruct cells how and when to make proteins. The proteins in turn are the active players in the cell. Proteins form the machinery of cells, allow cells to communicate, and can control the growth or death of an organism. Because of their role in cells, almost all drug targets are proteins.
Drugs work by binding specifically to a protein, thus changing the protein's function.
Extensive knowledge about the function of a protein can guide the selection of targets for pharmaceutical chemists. Protein Pathways provides a whole new way of discovering protein function. Previously, the only way to determine a protein function was by sequence similarity to another protein of known function. This boot-strapping approach left many gaps in our understanding. The analysis of genomes by the methods of Protein Pathways fills in these gaps by creating extensive networks of interactions between proteins.