Figure 1
From: Metabolic engineering of probiotic Escherichia coli for cytolytic therapy of tumors
Schematic illustration of the strategy applied to rewire EcN metabolism. Shown were metabolic pathways involved in this study. Pathways of blockage and genes of deletion were marked with “X”. Through the PEP:carbohydrate phosphotransferase system (PTS), EIIAGlc receives the phosphoryl group from phosphoenolpyruvate (PEP) and becomes phosphorylated (P-EIIAGlc) associated with the production of pyruvate (PYR). During translocation via PTS, glucose (Glc) is phosphorylated to glucose 6-phosphate (G6P) by P-EIIAGlc. The araBAD operon which consists of araB (encoding L-ribulokinase), araA (encoding L-arabinose isomerase), and araD (encoding L-ribulose-5-phosphate 4-epimerase) mediates conversion of L-arabinose (L-Ara) to D-xylulose 5-phosphate (X5P). PBAD is activated (“+”) by regulator proteins involving AraC and CRP which complex with L-Ara and cAMP, respectively. Refer to text for more details. Notes: AraC, arabinose regulator; AraE, arabinose-proton symporter (encoded by araE); AraFGH, arabinose ABC transporter (encoded by araFGH operon); CRP, cAMP receptor protein; CyaA, adenylate cyclase; PtsG, glucose transporter (encoded by ptsG), PFGH, endogenous promoter of araFGH operon.
