Regulation of GlcNAc synthesis and catabolic genes in E. coli. The upper image illustrates the regulation of the GlcNAc catabolic genes and the lower panel shows the GlcNAc synthesis genes. Note that the NagC transcriptional regulator acts as a repressor of the nagABCDE operon but is an activator of the glmUS operon. Binding of GlcNAc-6-PO4 alters NagC so that the expression of the GlcNAc catabolic genes (nagABCDE) is increased and the expression of the synthesis genes (glmUS) is decreased. (Note: gene sizes are not drawn to scale in order to present NagC regulation more clearly.)
