The 'Graphing' function of the Proteome Navigator displays the network of interactions satisfying the input search criterion. (a) Nodes are colored by functional categories explained in the right-hand border. Edges connecting proteins are colored by the method predicting the interaction, also described in the figure border. Associations predicted by multiple methods are shown in black. The double box around fliG indicates that this was the input protein used to generate this network. Clicking on a node brings the user to a protein-annotation page, and the search can be continued using the new protein to generate a new network search. (b) An example of functional discovery using Prolinks. Using kdtA as the initial seed, we speculate that GutQ, an uncharacterized E. coli protein, may be associated with lipopolysaccharide and cell-wall synthesis. Confirmation of these predictions awaits further scientific inquiry.