Figure 1

Representation of a genome scale network for E. coli K-12. The bipartite network contains genes (circles) connected to a set of nodes that include operons (squares), transcription factors (octagons), sigma factors (hexagons), metabolic pathways (diamonds) and cell functional categories (triangles). Edges connect gene nodes with the other node categories if associated. Arcs connect transcription and sigma factors with genes whose expression is regulated by them.