Figure 3From: Effect of iclR and arcA knockouts on biomass formation and metabolic fluxes in Escherichia coli K12 and its implications on understanding the metabolism of Escherichia coliBL21 (DE3)Transcriptional regulation of the aceBAK and the glc operon. (A): the aceBAK operon. Genes encode for the following enzymes; aceB: malate synthase A, aceA: isocitrate lyase, aceK: isocitrate dehydrogenase kinase/phosphatase. IclR and ArcA are repressors, FruR and IHF activate transcription [57]. The role of Crp is somewhat unclear. It has been reported as a repressor [25, 39], but metabolic flux analysis and enzyme activity measurements show its role as an activator [23, 83]. (B): the glc operons. Genes encode for the following enzymes; glcC: glycolate DNA binding regulator, glcDEF: glycolate oxidase subunits, glcG: conserved protein with unknown function, glcB: malate synthase G, glcA: glycolate transporter. ArcA and Fis are transcriptional repressors, Crp and IHF are activators. GlgC (glucose-1-phosphate adenylyltransferase, active in glycogen biosynthesis) activates the glcD operon and represses the glcC operon [57].Back to article page