Glucose transport through N-acetylgalactosamine phosphotransferase system in Escherichia coli C strain

Abstract

When ptsG, a glucose-specific phototransferase system (PTS) component, is deleted in Escherichia coli, growth can be severely poor because of the lack of efficient glucose transport. We discovered a new PTS transport system that could transport glucose through the growth-coupled experimental evolution of ptsG-deficient E. coli C strain under anaerobic conditions. Genome sequencing revealed mutations in agaR, which encodes a regulator of N-acetylgalactosamine (Aga) PTS expression in evolved progeny strains. RT-qPCR analysis showed that the expression of Aga PTS gene increased because of the loss-of-function of agaR (encoding an AgaR transcriptional repressor). We confirmed the efficient Aga PTS-mediated glucose uptake by genetic complementation and anaerobic fermentation. We discussed the new glucose transporter in terms of different genetic backgrounds of E. coli strains.