GraphVis Java applet showing the reconstruction of the SOS and stress response module of C. glutamicum. The graph was generated by means of the yFiles JAVA graph library using the hierarchical layout mode. Nodes represent genes included in this functional module. Color code: red node and line, repressor and repressing regulatory interaction; green node and line, activator and activating regulatory interaction; green node and blue line, sigma factor and sigma factor interaction; gray node, regulated target gene preceded by a transcription factor binding site; gray box, regulated target gene that is part of an operon and not preceded by a transcription factor binding site. The top level regulation of gene expression is indicated by the green node of the rel gene that is responsible for the cellular amount of ppGpp.